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rosco01

Lc Lj Torana Scratch Builds

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Thanks Shaynus - agreed, except for double listing of "I wanted to".

 

Before I go any further - apologies to the forum for this thread becoming a "machining" thread... but, it's part and parcel of this build and as I come up to each process - I'll punch it out and post... rather than opening a number of different posts under different headings... I hope this meets the guidelines for this forum, Mods...?

 

Slo - yes, the hub or boss is 6.35 mm in diameter. The step diameter is 14.34 mm.... divided by two is 7.17 mm to axial centre line.

Diameter of axle hole is 2.38, divided by two is 1.19... 7.17 minus 1.19 equals 5.98 mm.... I can easily pre drill a 1.5 mm tapping hole down to 5.0 mm from the outer diameter of the step....

The diameter of the hub (boss) is 6.35, divided by two is 3.175.... 7.17 minus 3.175 (not that I'm that good with drilling in thousandths of a mm) equals 3.995.. the outer edge of the hub...

I can pre drill the blank using a 2,0 mm or even a 2.5 mm drill down to 3.995 from the top of the step.....

When both the rim and hub of the wheel is turned down, there will be a half hole in the side of the rim to allow clearance for the 1.5 mm tapping hole to be drilled into the hub.....

I think this is what Slot-It do... if you look at a Slot-It wheel, you'll notice the relief of the half hole is of a larger diameter than that of the grub hole..

 

Off to the workshop shortly - another day, more possibilities - and hope...

 

thank you again for you very helpful reply... I'll get there, every day is bringing me closer..

 

And again, apologies to the forum if I have stepped (excuse pun) outside the guidelines for this forum.

 

As a final question - I have found pix on the internet of PB's Bathurst Torana in action.. in some of them, there is no credit to the photographer or any watermark/copyright... can I post these into my thread?... I understand that I must give credit to any who publish their name to a pic, and cannot post anything with a watermark or copyright tag...

I could post the internet link... as I have seen done on occasion...

 

Happy to obey and conform to forum guidelines..

 

frats,

Rosco

Edited by rosco01

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Hi folk, no report from yesterday - because there were so many interruptions to the day that I didn't get to drill the axle hole... today - fingers crossed on all fronts.

 

I have managed to track down the suggested #42 Suttons drill for this, and now have two of them.

 

I have come up with a new plan for the front wheel axle arrangement.

I fitted "rolling" wheels to the little Cooper.. which made them independent from each other... a suggestion from my mentor in the build, and who has offered to help again with the Torana builds.

 

This involved fitting axles with holes in the ends of them... can't remember the stock item number, but they are Slot-It.

They come with eyelets which insert into the end holes. This allows for the fitting of thin spacers each side of the wheel as plain side bearings.

 

The issue arises when replacement tyres are needed.... easy for the rear as the wheels are mounted using grub screws.

 

But, for the front - the wheel inserts need to be removed so that access can be gained to remove the eyelets.... I am not prepared to risk damage to the inserts.

 

My cunning plan (Baldrick) is to fit stub axles to the front... they will have to be made from these axles with holes in the end of them... for eyelets... I do like the free running independent concept for front wheels.... we can't do anything (as yet) for the rear, because it involves a differential drive.. which I am not prepared to either purchase (if one such thing is available) or make (getting into enough strife with wheels)..

 

I will cut stub axles from the supplied Slot It axle... and mount these into a common tube. I will drill and tap this tube on both sides to locate and secure the stub axle.... this will also afford adjustment to both wheel track and also clearance for the wheels to rotate within.

 

The main aim for all of this - is so that I can simply remove the stub axles at a later date - and fit new tyres to be trued.... I am stuck for ideas on how best to do this with the front wheels of the little Cooper. In one of the proxy series that that little car ran in - something was used (maybe WD40) to clean the tyres... they have gone "red" and soft... splitting in places.... the set need replacing before I can run this model again.

 

This is my "plan" at this stage...

 

As stated, these two Torana's will not be performance models... but, they will run and I will build into them a bit beyond what commercially produced and retailed models are supplied as...

 

Will be back later with a report on today's work...

 

frats,

Rosco

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Thanks Shaynus - sort of what I have in mind, but not quite.

My plan is to have "stub" axles which are secured in a common sleeve by the use of a grub screw locking each stub axle...

I can then release the grub and the entire wheel/stub will come out as a unit... no "C" circlips to go flying off into pile carpet for me any more.

 

I can make up a carrier to drive the wheel for renewing tyres and truing them down on my tyre truer... this will all pan out as I get to it... and in this thread.

 

Still waiting for my scratchbuilder to arrive - and we can start work on the chassis...

 

Today's wheel report next....

 

Thanks for posting the above - if I wasn't so determined to do things myself, I'd probably opt for your suggestion.. but - I'm going the long way, not the quick/easy one...

 

frats,

Rosco

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Hi folk,

11 days.... and the 10th wheel..... I'm there.

Success!..... finally....

 

With this tenth wheel, I started out with the blank end of the stock 16 mm rod and literally "started again"... determined to find out if it was that dastardly grub screw hole or something out of whack with part of my lathe setup/equipment...

 

I pre-drilled the grub hole - but left 1.5 mm uncut to where the bore of the axle would be. Further, because it would be nigh on impossible to commence drilling with 1/2 step and 1/2 hub smack bang in the centre of the grub hole - I over drilled this hole with a 3/32" bit.. as far as the top of the hub would end up.... for access to the grub hole post lathe..... this worked - and I am now firmly of the belief this is what Slot-It did when machining the wheels I have....

 

Turning as before... step, outer rim, inner rim, hub, inner insert recess and finally setting up the drill chuck to "again" attempt to bore the axle hole without the drill bit deflecting and ruining the wheel.....

 

This pic shows the final turning of the hub... the last machining before the axle hole was to be drilled...

You can see in this pic, the twice that I drilled the grub hole - first with the 1.5 mm tapping drill and then with the 3/32" (I hate mixing units).. you can see that the point of the tapping drill has left a definite centre point for later drilling after the axle hole is done...

 

 

01-10-turned-mail.jpg

 

 

 

I centre drilled again as before - using 1.0 mm centre bit and then 1.5 mm centre bit...

 

I set a 2.0 mm Sutton drill bit into the drill chuck and tested it for being absolutely centre in the chuck.... then span up the lathe to 100 rpms....

 

I watched like a hawk - almost every micro-millimetre of the bit as it went in...using a large magnifying glass.... if it was going to deflect - I was going to be right on top of it and immediately stop drilling....

 

With the insert recess at 3.0 mm from the outer rim edge, I calculated that I'd be bang on the area I struggled with two days back.. where the drill bit began to deflect.... this was going to come up at 4.0 mm in from the start of the insert recess....... that being, the outer rim at 2.0 mm width, step at 4.0 mm width and half of the inner rim which is 1.0 mm... 7.0 mm minus the 3.0 mm for the recess.... bang on 4.0 mm before the grub hole...

I further calculated that if I reached 6.6 mm without deflection - I'd be through for the full drilling to the outer face of the hub....

 

I watched... again, withdrawing very often to clear the swarf..... in it went, time and time again.....

 

It did not deflect one jot... and when I had reached 7.0 mm - I breathed a huge sigh of relief....

Withdrew the 2.0 mm and fitted the #42 and bored again... and, watched intently with the magnifying glass.... all good.

 

I tried to fit the 3/32 mm axle - without success... it did go as far as the beveled centering drill had cut, but no further... I didn't panic and decided to part off the wheel from the stock and take a closer look away from the lathe...

 

Having the wheel parted gave me this and I made up a reaming tool from a 3/32" Slot-It hardened steel axle (as suggested by Slo and Phil).

I used this tool very carefully and removed a miniscule number of dust particles in the process... it was enough!... after the reamer went through, I blew the hole through and tried the axle... it is an amazing fit (thanks Slo - that #42 is exactly perfect)... there is not one jot of lateral movement of the wheel on the axle and it is a "sliding" fit... perfect.... just like the Slot-It ones are.....

 

Now, for the acid test..... I fitted the wheel up to a home made axle stand with bronze bearings in it... and span the wheel..... absolutely perfect - not one sign of run-out or wobble.. this wheel runs so well, that unless you look at the grub screw hole - it seems stationary whilst spinning... I am just so happy with this...

 

So - now the grub hole and tapping it.... this time, I did it by hand - using a micro drill chuck (like a pin vice, but with a three jaw chuck)... the tapping drill went through with some effort.. and also the tapping drill.. but neither were any issue at all... the 3/32" drill bit I had used to give clearance in the rim worked perfectly.

In future, I will use a 2.0 mm drill for this... there is no point in going beyond the 2.0 mm grub screw diameter.. and in fact, it will help to align the tapping tool as it uses the half hole as a guide down into the hub.....

 

So - 11 days, 9 wasted wheels... and I'm there..

 

Well, not quite - I will use this wheel.... but, for the next 7 - I will take a bit more care with finish.. there is some galling on the inside of the rim and hub of this wheel... I should have set the home made left hand knife tool a little further angled inwards to the cut... the side of it has galled the wall in the process of turning.... I also "rushed" the insert recess........ I was more focused on this blasted axle hole today... and this was "only" going to be a test wheel - to determine if I had a lathe or drill chuck issue....

 

Pix all self-explanatory now after the reams and reams of pages in this thread already... It would appear, I have a tyre repair to do.. there is a slight tear in the outer wall of this MJK tyre....

 

Pix....

 

02-10-polished-mail.jpg

 

 

03-10-grub-relief-mail.jpg

 

 

04-10-inner-tyre-mail.jpg

 

 

05-10-outer-tyre-mail.jpg

 

 

So, Mother's Day tomorrow..... might sneak off into the garage and make a start on #11.... Mrs. Rosco can only drink so much tea..... I'll fill 'er up and beg my leave....

 

'til tomorrow....

 

frats,

Rosco

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Ok..... #11 wheel - landed with a "thud"..... drill bit took the detour again...

#11 is one of the remaining three which I had pre-drilled and tapped the grub hole in.. and tried to avoid the detour by drilling though on both sides of the hub....

Drill bit began to "wander" exactly on reaching the grub hole again... so - lesson to all - do not pre-drill grub holes unless you are going to stop well short of where the axle will be drilled ....

 

I have made a start on #12... pre-drilled the grub as for #10, which was a succes.

I stopped drilling at 5.5 mm from the outer diameter of the 16 mm rod... it leaves me with 1.3 mm of "meat" still in the hub for the axle hole to pass through.

Further, I drilled a clearance hole for the grub using a 2.0 mm drill this time and stopped drilling at 4.8 mm from the 16 mm rod...

 

Tomorrow is another day - I now have 10 wheels almost perfectly turned that have a very slight "wobble" on the axle.. it's only about 0.5 mm of a wobble and could easily be corrected if a tyre was fitted and trued up on a tyre truer.. I may yet do this - and use them on some "Scalextric" models that still have plastic wheels... I can "offset" the insert at a very slight angle so that they will run true... and probably no one will be the wiser... but, for these Torana's - I want "true" wheels... I have done it, and I know I will be able to produce them... I have around 3.2 m of 16 mm rod left... might just get another 7 turned out of all that....

 

Until tomorrow...

 

frats,

Rosco

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It is very bad practice to drill the grub screw hole first, this should only be drilled once the axle hole is drilled and reamed.

The rear of the wheel should be left larger until the grub screw hole is drilled and then the almost complete wheel put back into the chuck and the rear hub turned to size.

If you want to turn the hub and wheel all in one go then I suggest you make a small jig to allow the grub screw hole to be angled to avoid the step in the wheel.

BWA wheels were all made with the grub screw hole drilled and tapped after the wheel was completed.


Phil

 

Hobart Miniature Car Club

 

Tassie Resins

 

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Thanks Phil,

yes - this is now my practice.... had to learn it my way - "don't know what you can do, until you find out what you can't".

 

I have decided not to use the remaining three blanks with pre-drilled grub holes....

Today, we go back to pre-drilling the grub holes without going as far as the intended axle hole - leaving a clearance of some 1.2 mm... it worked with wheel #10.... let's see how it goes with #12....

 

Report later.

 

Thanks for your reply and suggestions -

 

frats,

Rosco

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Update... day 13 - successive...... #12 and #13 wheel crashed and burned.....

#12 - I failed...... didn't leave enough room on the rod for the hub (boss).... duh!... head is full of numbers - eventually had to take its toll.

But I pushed on to drill the axle hole - not quite as good as #10 (my best thus far)... there is just the slightest amount of clearance in this one... but, it's useless without a hub and the grub hole is against the rim.... scrap box..

 

#13.. all went perfectly well... until drilling the axle.... this was going to be the partner for #10... a matched set for the rear axle...

 

Set it up - 1.0 mm centreing drill... and increased chuck speed to 400 rpms instead of the 100 used previously.... pushed too hard, the ali got hot and swelled onto the tiny pilot of the centering drill... sheared it off...... duh!.... absolutely no chance of getting the HSS out of ali... each attempt sent the drill bit off centre and wandered way out of centre....... 2 wheels in the scrap bin tonight....

 

Lessons learned - hope not to repeat either of those, now that I have practiced my belief in that you don't know what you can do - until you find out what you can't...

 

Tomorrow is another day - if this scratchbuilding jig takes two weeks to get here... I might just have 4 wheels ready for the first build.....

 

frats,

Rosco

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Are you confusing a centering hole with a pilot hole Rosco. A centre hole is drilled with a centre drill. A smaller drill bit is not a centre drill.


"Me Auntie's a Jack !!!"

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Interesting wheel build roscoe think i might pass and carry on buying mine chuckle looks easier , but good luck

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Nah - it's a centering drill bit.... has a very fine point which is elongated then tapers out to a bevel...

 

Not sure of all these terms... but I purchased a set of "centering drill bits"... and that's what I have been using prior to going in with an ordinary drill bit.....

I'm using a 2.0 mm bit, then the #42 (0.0935") bit to finish off the hole....

 

I broke off the fine point of the centering bit in #13 wheel..... no chance of drilling it after that - tried and failed to push through then next size up centering drill... and even worse - the 2.0.. it went haywire altogether.

 

Thought I might try drilling in from the rear - but setting the wheel up in the mill accurately is not yet within my ability.... I can get close, but doubt that I would get it exact....

 

Thanks for your thoughts..

 

Peter - I'm determined to get this.... it's just "little" things which are tripping me up for the time being.. I'll get there - no way I'm going to give up..... I've done one - I can do more...

 

frats,

Rosco

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Hi folk,

After 14 days - I now have two perfect wheels..... thanks to Slo for his advice on correcting my issues.

 

Hope to have at least one more done by this time tomorrow night - maybe, just maybe... will have four wheels for the first of these two Torana builds.... and then, we can finally get into some modeling...

 

frats,

Rosco

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Bump.... builds have stalled... waiting for scratch builder jig to arrive, but mainly due to correcting issues with the lathe... spent nearly three weeks on the tailstock alone.. it's so darned close to concentric now that I can't see anything to suggest it is at all off centre to the headstock chuck centre.

Now that this has been corrected and is accurate, other issues have shown up .. both the cross-slide and compound slide have issues... backlash and out of centering gib strips.

I did the compound today - I had to re-drill the gib adjusting screw holes in the gib strips.. the "dimples" ex factory were poorly done... I have now ground them out so that the gibs sit full face on to the dovetail faces... this has made a huge difference to the stability of it when under load.

I did the cross-slide last week... have modified the slide nut and mounts.. drilled out the little M4 threads and fitted larger M5 cap screws which seat very nicely in the M4 recess... this modification now locks the slide nut in position... operation of the cross slide is now smooth and virtually backlash free.

Next issue has been poor cutting... now that the offending tail-stock and both slides have been corrected... I believe I have headstock bearing issues.

These little lathes come from the factory with simple ball bearings in them.... this type of bearing may be fine for something which is entirely loaded radially.... but, in a lathe - there is probably more load exerted laterally as the cutter is wound in or out against the workpiece... and this is where I am now at... I am about to replace both ball bearings in the headstock with tapered roller ones... waiting for more parts on order to turn up .. the 10 tonne shop press arrived today... I have the bearings... 

 

Anyone with one of these little SC-3 or even C-3 lathes are more than welcome to PM me for full details of what I have both found - and done to rectify these little issues.

It should be a darned good lathe by the time I'm finished with it (if that ever happens).

 

Update on wheels.... we now have wheel #21 in the chuck of the lathe.... of all of them, there are perhaps three which I will use... they are "almost" perfect for use... the others, are either slightly out of spec (100ths of on mm) or there was a batch in the middle when the tail-stock was causing off centre drilling of the axle hole. It's not much, but I can see it using a magnifying glass.. and I won't use them. From wheel #3 to # 7, I had issues with the drill bit going wayward when it reached the pre-drilled grub screw hole.... these wheels are the worst of all of them... four light weight paper weights if anyone wants them... 

 

So folk, we are almost back in business with turning wheels which we be usable.... I only need 8.. I have three, they now take me about 3 hours to turn ..... but work on correcting this lathe has put the build way back.. 

I have  question for anyone who has stayed reading this post..... tyres...... now that I can pretty  much turn out any wheel I want... I am after some "scale" sized tyres for these Torries... I need tyres equivalent to 195 75 R 13.... that is roughly a rolling diameter of 24".. divided by 32 = 19.05 mm... but, we need them to only be 6" wide.... that is approximately 5.78 mm wide...I'm happy to go to 6 mm.... so, MJK tyres that are 19.0 mm in diameter (or can be turned down to) and just 6 mm wide... I will turn wheels to suit if I can source these sized tyres for both Torana's... the MJK's I have purchased are far too wide.... they are 9.0 mm..... 

 

I have tried to gain access to the MJK tyre chart that was created in Excel.. but cannot get any results for what I need..... I would like to know if anyone has a full list of available MJK tyres that I can work through and find the most suited for my requirements.... 

If so, I will then turn up wheels to suit.... making the 10.8 mm x 3.0 recess for the amazing centres that Munter has provided me with in the kits.... they are indeed "the" wheel for these XU-1 models.... Globe "Sprintmaster" wheels - as fitted to the XU-1's ex factory - and which were required to be used under the terms of "series production" circuit racing back in the day.... 

 

fingers crossed, I'll get there - but I now need these tyres so that I can determine the dimensions of the wheels which need to be turned... 

 

Just for some eye candy, pic below shows the previous wheel having been parted from the remaining 20 mm 6262 aluminium stock in the chuck.... you can see that the 2.35 mm drill bit through the cut off wheel was centred exactly in the middle of the stock... it took three weeks to get the tail-stock to do this - final shimming was one sheet of kitchen Alfoil each side of the tail-stock mating faces to get final height... I must have had that tailstock apart 200 or more times... blocking down the faces a few microns at a time, then re-fitting and testing the quill of the tail stock for both parallel and correct height to dead centre of the headstock chuck..... sure hope I never have to go through that again.... pic.... 

 

 

001-lathe-chuck-fitting-mail.jpg

frats,

Rosco

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Ok folk..... suppose this is more related to the model build and less of the lathe to "some" extent... turning #23 wheel - finally, I have one that I am happy with - 6 hours later only stopping for lunch.

First up, because it is nearly impossible to drill these holes once the step and rim have been turned in the lathe, we drill a 1.5 mm hole 7.8 mm down into the stock, then follow up with a 2.0 mm hole only 6.8 mm into it...... the first hole stops short of where the later axle hole will be drilled through - we've been down that track a number of times when the drill bit followed the easier path where the grub hole was and sent the hole off centre. The following 2.0 mm hole allows entrance of the later tapping tools to tap out a 2.0 mm M2 thread.... 

This is all the work the Mill does for this wheel.... it's really an over engineered and over priced drill press here... 

 

001-grub-holes-milled-mail.jpg

 

Next, we see the 20 mm 6262 aluminium stock bar in the chuck of the lathe - I am taking the first cut here, right to left .. somewhere, under all this metal - is a hiding wheel... here we go to "find" it.... 

 

002-turning-20-mm-stock-mail.jpg

 

In the next pic, we have made quite a number of passes along the rod - taking cuts of about 0.5 mm each pass. We can see here that I stop at 12 mm from the end of the bar.. this is enough for the 10 mm wide wheel and 2 mm for the parting tool to go through and separate the finished wheel from the stock.

 

003-12-mm-length-turned-mail.jpg

 

In the next pic, I have stopped exactly at 14.33 mm.. the chosen maximum diameter of the wheel.. this will later become the "step" - a section of the wheel on which both sides the tyre is fitted... 

Working with fine tolerances, it is perhaps timely to mention that I use a precision measuring tool called a "micronometer"... they take a bit of getting used to - modern ones are digital, but I don't mind working with the two scales... if you look closely at the barrel, you can see that the body of the moving part has stopped next to the "14th" line.. and that we add another 33 from the rolling scale to bring us to 14.33 mm

 

004-14-33-mm-step-turned-mail.jpg

 

Next, we start work on the right hand side end of the wheel... we now want to turn down 2.0 mm in from the end for the "rim"... this is the part of the wheel on which the outer edge of the tyre sits against.... there are two "rims"... one each side of the step.

Here we can see that the micronometer shows I have reached my desired 12.50 mm.... see if you can work out the scales.

 

005-12-50-rim-turned-mail.jpg

 

Having turned the outer rim, we now change tools and position - and fit a "boring" tool.. I made this one up from some unused carbide tools which came with my lathe.. it works really well.

You can see in this pic, that we are now looking "along" the lathe bed, back towards the chuck... the line circles of the end of the stock show where I had previously turned down the length of the stock rod.. it is rough, but there was no need for anything special.. most of this is about to be bored out for the "recess".... into which a caste resin outer body of a scale wheel will be inserted.

 

006-turning-recess-mail.jpg

 

In this pic, we can see the 10.50 mm recess for the wheel insert has been bored. I bore this to a depth of 3.0 mm... it leaves a nice little "end" of the ali wheel showing beyond the insert

What we can also see in this pic, is another form of micronometer... this time, it's an "inside" micronometer.. it measures from the inside going outwards.

When reading the scales - they actually work in "reverse".. as you wind the thimble forwards... the scale moves to the left... as opposed to that of the outside mic - on which the scale moves to the right as the reading increases... it's all a bit confusing near the end of the day - when you have been "adding" and reading forwards.. then have to start subtracting and reading backwards... but, here we have reached our 12.50 mm..... oh, and I forgot to mention. The Thimble only registers 1/2 of one mm per revolution on both mics... you can see in this pic, that the body of the thimble has stopped on a second row of lines below the larger ones on top of the numbered scale... these "half" lines show 1/2 mm's... that is - where the thimble has stopped in this pic, it is half way between the 10 (hidden) and the 11.. but, on the scale below - it is exactly on the "half" line... so, we read the thimble as 10 + 1/2.... and this is shown on the thimble as 10.50...... 

 

007-10-80-recess-bored-mail.jpg

 

Ok, we're done with the right hand end of the wheel for some time now.. so, we need to start work on the left end.... the inner wheel side.

To gain access using a knife tool on the left side of the wheel (some call it left hand, others call it right hand - but it is easier to explain that this tool cuts from left to right - opposite to that we used above to cut from right to left) we need to open up a gap for the tool to start cutting from and we do this with a tool called a "parting" tool... it's a nightmare of a thing to use and any novice dreads the need to use this tool.... in fact, some don't use it at all.. and simply use a hacksaw..... it causes the lathe to shudder and shake as the front edge of it starts "digging" into the solid wall of metal in front of it.... it's a bit of a trick to get this tool to work... it has to be given some "stick" and forced into the metal until a "ribbon" strip starts coming off... looks like a stream of water curling away in a long strip when it's working correctly.. it can't me molly-coddled.. if you release pressure too much - the lathe goes back into convulsions of shaking.. so too, does it do the same if you advance the cut to deeply.. it's a balance of speed, feed and cut.... I'm getting there, no longer afraid of it on aluminium... not so sure on steel though... 

Here, we can see that I've used this parting tool to create a wide gap into which I can begin to start taking cuts from the left..

 

008-parting-tool-for-left-end-opening-ma

 

Ok, we have now turned down the inside "rim" to the same 12.50 mm as the outer rim... 

 

009-left-rim-turned-mail.jpg

 

Now we need to turn down the "hub"... that part of the wheel which sits up against a bush in the chassis..... the diameter of the hub for this wheel is 6.37 mm

 

010-hub-turned-mail.jpg

 

Ok, we're done with the cross slide and top (or compound) slide for now... we turn our attention back to the outer end of the wheel - and bring into play another part of the lathe... the "tail stock"... which has taken me the best part of the last three weeks to get it to my satisfaction... hence my absence from the forum.... I must have had this tailstock off and on and apart at least 200 times in the three weeks... getting the inside sliding tube part (called the quill) to point directly  dead centre to the dead centre of the other end of the lathe - called the "headstock".... my final adjustment to get the correct height, was the use of one thickness of a piece of kitchen aluminium foil.. 0.03 mm..... and the two faces needed to be honed on a stone to get the "quill" to point parallel as it was wound in and out..... 

Without this accuracy, any hole drilled into a wheel (or any other work) would either be too high or not exactly "through" the work, but off to one side... in any one of the 360 degree directions around the face of the work..... 

For many of us who run slot cars - we have all seen "wobbly" wheels.... trust me, it doesn't take much for a wheel to wobble.... even as little as 0.05 mm can easily be seen by the naked eye... much less, if any close up inspection is used..... 

In this pic, we can see I have opted not to use a drill chuck mounted in the tailstock.. but am using a "collet" chuck.... these are extremely accurate - whereas even one of the best (I have a German engineered one) drill chucks are often a "fraction" off centre using the three jaws to centre a drill bit... collets, use some 20 or more of these jaws to secure a drill bit exactly in teh centre...... and of course, this is of no use if the tailstock into which the collet chuck is fitted - is not accurate..... that's why it took me three weeks - I wanted "accurate".. and eventually got it.... 

011-ER-25-collet-in-tailstock-mail.jpg

 

Ok, we fit what is called a "centre" bit to the collet.... this will drill a small pilot hole with a tapered outer edge.... in preparation for a following drill bit.... 

Here we have drilled out centering hole - you can clearly see that the tapered entrance is a welcoming sight to the later drill bit... this hole is exactly dead centre in the wheel.. 

 

012-centre-drilled-mail.jpg

 

And now, it's time to draw in breath... up until now, everything achieved so far can be totally wasted if the next step goes wayward...... I have seen this many times whilst turning the previous 22 wheels.. some of them taking me an entire day to get to this point, and the next 10 seconds sends it into the scap box..... drilling the axle hole..... grit your teeth and triple check everything... if there's one mistake I have made turning wheels - it's about to repeat itself in the next 10 seconds... 

 

013-2-35-mm-drill-bit-mail.jpg

 

A number of "cut and retrieve" and enter again.. each time removing the swarf from the cut with a small stiff brush..... until I reach a depth of 10 mm.... it's way beyond that of the remainder of the wheel body, but I've stuffed up one wheel by not drilling deep enough... the remaining stock ali on the bar is cheap compared to a day's work gone to waste for the sake of 1 mm of it.... so, I drill to 10 mm..... 3 more than I need to...

Here we have drilled our hole... and breathed a huge sigh of relief. I use a 2.35 mm drill bit... the axle is 2.38 mm... I know almost immediately if the hole is good... if the axle will not go in - I stand a pretty good chance that the hole has not drilled out of round.... in this case - the axle did not fit, but it's only 0.03 mm to large.. which is a fairly big ask... considering that we must multiply any error by 2... due to the nature of a rotating wheel in a chuck.... you cut "both" sides... so, even an error of 0.01 mm. shows up as 0.02 mm... takes a bit of getting your head around it when you first start to turn on a lathe... taking cuts "across" the lathe are double that of cutting along the length of it...... hope that makes sense?

 

014-axle-hole-drilled-mail.jpg

 

Ok... so, we have started to breath again... but, now we're back to the other end of the wheel.... it's almost finished in the lathe now.... but, we have to separate it from the stock.... and yes, this means bringing out our dreaded friend again from the tool chest.... the "parting" tool.... 

I use a tooth pick through the axle hole when parting off...... it avoids me having to pull the entire garage apart looking for the wheel when it separates and goes spinning off into parts unknown..... once bitten....... 

 

015-parting-off-mail.jpg

 

Just out of interest...... for that 12 mm length that we used of the 20 mm ali rod.... "this" is what came out of it that is now not part of the wheel... it amazes me how much ends up from just one wheel... 

 

016-chips-mail.jpg

 

Ok - we're done with the lathe for this wheel... clean it down, oil it up and put the canvas cover back over out little friend until tomorrow's wheel (#24)... work to be done inside my little "den"... where it's a bit warmer and cups of tea are more readily accessible.. 

What we now need to do, is to tap the threads into that grub screw hole.. but, the hole has to be drilled through into the axle hole first... the last 1.0 mm of it... this is done using a "pin vice"... and the hole finished off by hand.

Next, we use M2 taps.... they cut the thread into the 1.5 mm hole previously made... you will now appreciate why we drilled that additional 2.0 mm hole at the start of this wheel in the Mill... it would have been impossible to get the M2 tap to start the thread on the shelf of the rim and hub... so, by having a 2 mm hole already drilled as far down as the start of the hub - the tap slides down and guides it towards the smaller 1.5 mm hole for the thread to be cut...

I use a three tap system for making my threads.. shown in the pic below - the first is a "rough" tap, then an "intermediate" and finally the finishing tap... they make for an excellent thread and are almost impossible to stuff up making a thread into the prescribed hole size.... again, this is done using the little hand pin vice... 

017-grub-tapping-mail.jpg

 

You can see in the pic below - the mentioned outer 2.0 mm hole and the now tapped M2 threaded one in the hub... the grub screw runs very smoothly into this thread.

 

018-thread-mail.jpg

 

And finally, we fit the wheel to an axle, nip up the grub and fit the axle to my little Dremel machine... turn it on  - and presto!.. the wheel runs true!... yippee... one more "good" one...

I now use the Dremel to turn the wheel on some polishing fibre pads with some polishing compound... working the wheel this way, and not using the pads in the Dremel avoids risking the wheel getting more rubbing in "spots" - and wasting much of the effort to have it perfectly round... 

I also use the Dremel with a small diamond engraver to number the wheel.. this one being "23"... 

In the pic below, you can see the finished product.. not as good as a Slot-It wheel, but I'm getting closer.... the axle and wheel are fitted into a little invention frame here that I used to use to determine if wheels were true... this unit also used to help me centre tyres wheels whilst the glue was setting... inverting it with two wheels fitted and gently rolling it over a flat surface.... 

 

So folk - that's one wheel... one full day.. but - one wheel I didn't have before today....  

Next time you look at the wheels on a slot car - spare me a little thought.... 

And now, that the work is done - don't sit down - there's time to "turn" another one... (where did that similar line come from - clue.... they are "Pink")..

 

019-finished-mail.jpg

 

frats,

Rosco

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So thorough Rosco

It is great to follow the process, gives a better understanding of what the robots in the factories have to do, wonder if they are programmed to get frustrated too. :D

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Cheers Grant

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Grant, they would knock these out in their dozens in just minutes using CNC robotics.. and the finish, as we already know - is simply outstanding.

i am still in awe at Slot-It wheels...everything about them is just so "perfect".... the only skillset required by human intervention is the programming... it's the robot which actually materialises (excuse pun) the end result...... 

Yes, it's a long drawn procedure to turn one yourself... and failure is at the cusp of every step..... one false move in direction with a wheel or knob..... doomed instantly as a cigarette paper - paper-weight...... 

I don't believe there is a mistake in turning these wheels that I haven't made..... most of them occur when my "eyechronometer" (as Munter puts it) assumes that there is plenty of cutting to go before we get close to size... and this, for some strange paradox - is always when turning down the inside rim... I don't know how many times I've put the "mic" onto that rim and found that I'm already undersize...even though the "eye-mic" tells me I have oodles to take off...... I now measure after every 10 lines from the step height.... and then every single one.

Incidentally, for those interested..... with my lathe, each little line on the slide wheel equals 0.049 mm cut - this results from the tool cutting "both" sides of the work... which is double that shown by the register on the wheels..... 10 lines = 0.49 mm.... one full revolution of the slide wheel (40 lines from "0" around to  "0") results in 1.96 mm reduction in diameter of the work... 

 

When working the compound slide for boring or against the "face" of the chuck.... this is halved.. because it is only making one cut on the face...... 

 

Thanks for your comments... hope this is of some use to anyone considering using a lathe for this work...

 

frats,

Rosco

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Ok folk,

getting closer to actually doing something about modeling these Torana's..... 

Today, I started work on the motor mount/gearbox/axle frame..... 

i decided some time ago to build my own from 1.0 mm brass strip... how I was going to do it was an ongoing thought process, but came to the conclusion that I could make up a "jig" to punch out my own.... it needed to be "generic" - so that I could use it in other models.

Munter put me onto some thoughts to consider and I set these in to motion yesterday.... purchasing some blocks of high tensile aluminium from which to make both the base and the insertion block, which together should allow me to press a 12 mm wide strip of 1.0 mm brass down using a 10 tonne bearing press (purchased to replace those pesky bearings in the lathe)... 

I have decided to follow Munter's suggestion to make the frame wide... and also to match the width of the intended motor.. both of them being Slot-It "flat 6's"... which, the motor body width is 20.5 mm.... so, my frame outside diameter (O.D.) will be 20.5 mm... the lines were scribed in a this through the ink... the depth I did not yet know, but I understood it may not have been possible to get the full depth of the gearbox... at least 10 mm should be enough to set both legs exactly at right angles to the motor mount holes.... and parallel to each other.

 

I have done zip all work with the Mill, other than a fair bit of dilling and one little practice session of how the collet and cutting bit worked... along with how the various wheels and dials on the machine allowed such fine control over machining a surface... etc....

 

So, today - we set off into the machine shop (very jumbled and confined space in a 2 car garage)... 

I faced one block and found that it does not come supplied in a true measurement.. it was miles out from one end to the other - at first believing that my Mill was well out of adjustment... but, with the dial gauge - it soon revealed the material... so, we put that to rest and I surfaced the block - and then painted on some "engineer's blue ink" and scribed out my work.... 

Before I got very far into the work, the machine started to protest.. it was making strange sounds and I shuddered at the thought of spending all weekend putting this one right as well... it took me nearly a month to get the lathe to where i wanted it.... I was really not too happy to find that this may be the case with the Mill as well..... 

Out with the manual - written in "Chinglish".... and interpreted enough to work out how to pull it apart... took off the cover - and presto!... the timing belt was almost loose.... four cap head screws later - and the noise is gone... decided to have a bit of a look around whilst I was in there.. lubed up some of the places that need a bit of undoing to get to and put it all back together..... much better... 

 

Set the block down and firmly secured it to a mounted vice on the lathe bed.. checked it for true and fitted a 2 flute 10 mm cutter to the collet... 

Set up the height and forward travel and took my "witness" cut... it ran beautifully... so much so, that I didn't want to stop...

 

Pic  below shows the first of these cuts... taking them at a depth of 0.5 mm per pass.... 

 

001-motor-axle-gearbox-frame-mail.jpg

 

I took the first cut right on the right hand line of the 20.5 mm..... in hindsight, I should have come back inside a bit - so that I could run a finishing "face" cut when the full depth was made.. but I didn't... neither did I for the left side cut either... note to self... Rem this... 

Left cuts....

 

002-motor-gearbox-axle-frame-mail.jpg

 

We're starting to get down towards the body of the vice now... and I realise that I will get my 10 mm depth... perhaps a smidge more...

Pretty happy with this first attempt so far.... I am gaining a lot of respect for this machine - it is doing everything that I could wish of it... the cuts are precise and exact... the finish is quite impressive considering I'm using a 2 flute cutter... 

You can see in the pix... the 10 mm cutter leaves a 0.5 mm centre section.. our width being 20.5 mm..... the cutter being 10.0 mm.... let's see what happens to the 0.5 mm piece in the middle... if the machine is accurate - it should leave it there.... but, the chips of metal blasting out from the cutter are certainly hitting it hard.... 

 

003-motor-gearbox-axle-frame-mail.jpg

 

So, here we are... we managed to get down to 11.0 mm depth on both sides..... this being exactly 10.0 mm from the surface when the 1.0 mm brass strip is fitted... I'm now pretty happy with this..... 

And.. that centre "wall".. it remained intact.. all 0.5 mm of it... you can see that my final cut was on the right side trench.. the chips deflecting the wall over to the left...

 

003-5-0-5-mm-centre-mail.jpg

 

It didn't take much to run the cutter down the centre and fling off that tiny piece.. here is the finished base of the jig... for a first attempt, I'm really happy with how it went.... 

There is so much aluminium laying around the mill and on the floor - I'm considering vacuuming it all up and taking it to a scrap metal cash point.. there is a time when I'd have stopped a train to pick this much up.... 

 

004-motor-gearbox-axle-frame-mail.jpg

 

And finally, we bring the jig inside and do a test fit of the flat six motor.. it is a "snug" fit... again, pretty chuffed with this ..... 

 

005-flat-6-motor-in-jig-mail.jpg

 

Next, we need to mark up, cut and mill the insertion block... 

 

I will machine it to size first, then drill the motor mount, axle bush and motor bearing holes... the brass strip can then be firmly screwed into place... and the insertion pressed into this bottom part of the jig to align it square and parallel... this is the plan - whether it works.... we'll see a bit later in this thread... 

 

frats,

Rosco

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Ok folk, 

bit more done... number 1 motor/gearbox/axle frame has now been completed.... pretty much as I expected, but this one won't be used for one of the builds... it was always going to be a prototype test piece... I could use it, it will work fine - but I have now revised my measurements knowing exactly where the axle holes will end up once the frame is bent to shape.

My calculations were a fair bit out... my spacing from motor face to centre line of axle bush is 3.5 mm out.... I added the 1.0 mm thickness of the frame and should have subtracted it... and I have now removed a further 1.5 mm of "fat" which I added in ...... "just in case"... 

I now know the measurement and will mark out number 2 frame shortly...

 

So, from the previous post... we made up our insertion block of the jig... and, during the thought processes - decided I'd also incorporate a rebate for the motor face as well as both sides.... this would ensure that the face stayed absolutely flat when pressed .... which it did.

 

So - here we go.... 

First up, the 12 mm x 1.0 mm brass strip has been marked out, drilled and cut to length..... it is sitting near the insertion block. You can see the 1.0 mm rebate I milled out for the brass strip to fit into when pressed into the "home" block.....

 

 001-holes-drilled-mail.jpg

 

Next, the frame plate has now been screwed down into the insertion block and is now ready to be placed in position over the block for pressing...

 

002-mounted-on-jig-block-mail.jpg

 

We are now pressing the insertion block into the home block, the brass has been deflected upwards whilst being held captive in the rebates as the plug travels down into the base....  - we are about half way down here... everything is going according to plan....

 

003-pressing-mail.jpg

 

We have now pressed it down for the first pressing..... it was removed after this and the cap screws removed... then pressed again so that the brass face plate for the motor would be absolutely flat.. and the corners "squared" up ..... I didn't take a pic of the second pressing...

 

004-pressed-mail.jpg

 

 

And here is our motor/gearbox/axle frame... all done - ready to be fitted out with axle bushes and motor... 

 

005-frame-mail.jpg

 

I fitted the motor, axle bushes, axle and crown wheel... plus some faulty turned wheels.... everything is square and parallel here.. I'm pretty happy with the end result.. but, the axle is 3.5 mm too far from the motor.... revision 1 will be marked out, drilled and pressed tomorrow... 

 

006-trial-fit-mail.jpg

 

You can see in this final pic, looking from the rear - everything is in alignment.. it is square on to the motor face and the width of the frame is exactly that of the width of the motor.... 

 

007-alignment-mail.jpg

 

When we come to build the chassis, the piano wire will be soldered under the side legs of this frame.... 

We also need to mill out another one of these for the front axle and guide frame..... I'm not certain which way I'm going with this yet... just to get this rear one worked out and done took a fair bit of headwork... 

 

Ok, back with revision 1 frame tomorrow night.... I should be able to punch these out fairly quickly now.

It will be a "universal" frame for many sedan type models I intend to build...... there is an EH Holden in the short term wings.... 

 

frats,

Rosco

Edited by rosco01
typo
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Hi Rosco, If you are planning on moving the axle forward (3.5mm) in order to have the motor shaft control the lateral movement of the Crown, you may want to consider the following.........in right hand corners the lateral movement of the axle lets the motor shaft rub on the left hand side of the Crown slot....in this instance the motor shaft is spinning in the opposite direction to the Crown, causing friction, and is the main reason you frequently see bronze/brass particles in this area. While lubricating the crown slot/motor shaft helps, it does not eliminate the fact that the motor shaft/crown are rotating in different direction, when they touch in right hand corners.

It is best to control lateral axle movement/mesh with axle spacers,.....and,.....although it is a pain, it is best to use these spacers on either side of the Crown, inboard of the rear bushings..........this eliminates any mesh issues should the wheels move  (in or out) on the axle, which invariably happens.

Stay Safe

Chris Walker

I have used a mix of different thickness spacers (you can't see the .005 ones) to control mesh/lash in both directions,....the mesh stays constant, and eliminates any motor shaft interference......more consistent, smoother (faster)  performance, and, your gears will last forever :D

DSCN4226-copy-2.jpg

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Good, no, great job there rosco. I can't imagine for the life of me taking such care to make a motor bracket. If it were me it'd be a bench vice a cordless drill and a ball pein hammer and wouldn't look half as good. It won't be long before people will be lining up to get your brackets


bram1_zpsfkhrhndv.jpg

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Thanks Chris... I drool over you chassis work each time I see a pic of one... the detail, and engineering astound me....

Yes, this is the plan - I did this with the little Cooper and it works perfectly... there isn't any slot in the RD gears that were made for me... and using shims both side of the crown was necessary to get the mesh... they have not worn one bit, as you suggest..... the crown and pinion are very small in that model, and it does not roll freely with them.... I don't know why, the mesh is good... maybe, it's to do with the size of the crown - I don't know. Everything else in that little car is free running - including the independent free spinning wheels on the front axle... which is also free to spin inside a brass tube.... Number two Cooper using the same gear set is exactly the same.. the motor is free spinning by hand - but in mesh, although there is no binding - it simply doesn't "roll" freely on the track.... it's a fairly fast car... but it simply doesn't roll - might be one of the reasons it is fast... braking wise... 

I intend to shim both sides of the crown on these models as well..... it's a much better arrangement than relying on the slot in the hub to centre the mesh... Slot-It crowns are simply superb, as is all their other gear.... but taking control of mesh and axle movement is far better by the shim method. I have accumulated a small container of MB shims... and the little shim feeler gauge that comes with the sheet.... I can turn out the larger spacers and add shims as needed for correct clearance and alignment.

 

I'm not too sure how to go with the front bracket yet... I'll try to get the guide as far forward as the model will allow... it has been suggested to me to do this for a circuit model... and to fit the guide post closer to the axle for a rally model.... I'm a bit a sea with the physics of this... 

 

Further, I'm not too sure how wide to make the front bracket.... the ones which I had made up for me to build the little Cooper were a different width to the rear frame.. I had some issues with fitting piano wire to both brackets and keeping them parallel to the centre-line of the mode... 

 

My current intention is to make both brackets the same width.. so that they can be soldered to the wire parallel... 

I intend to have two body posts for this model.. one screwed to the front bracket and one at the rear on a soldered plate behind the crown. I believe this will afford the greatest purchase on the chassis by the body, but it will be free floating..... I don't believe I need any side rails on the body.. perhaps a tab each side to relieve stress on the posts during a roll-over.. but this would be the only time the body would be likely to make contact with these two small arresting tabs.... 

 

Out to drill and punch out another frame shortly (when the frost melts... it's 1 deg C in the garage at present... I'm in no rush to go out yet.... 

 

Bram - thanks.... I do like to do my best. but there are quite a few "whoopsies" in the first bracket.. you can see "stray" drill marks in a few places.. and also grinding marks from the little Dremel.... I should do better with the result in being so fortunate to have these great machines... but, this project is not only adding to my slot building education... it is also educating me on how to use both machines... 

I don't know about anyone wanting to line up for these brackets... a much easier and simpler method as you suggest would avoid the 6 or so hours it takes me to mark up and punch one of these out.... I'm running out of years, my family would like to see some of me in the time I have remaining... I've got 20 wheels or so that are "surplus"... all of them could be used and most would be acceptable..... but, they are not going onto my models.... and will live in the "surplus" box until they find residency or purpose some place else... 

Of those, only 4 have "wobble" issues.. the rest of the "wronguns" are simply out of the very close spec I attempted.... mistakes in setting up the machines mostly the cause... but some were badly laid out in marking up.... I only need 8 good ones... I have 5 more yet to turn... 

 

Ok, thanks heaps for your info, Chris (again)... my scratchbuilder jig has not turned up yet... I've been tracking it and it seems to have found a blockage point someplace over the Pacific.... I believe US Post has now delivered its responsibility.... probably stuck in the "inbox" of AusPost at present.... goodness only knows how long it will gather dust there.... 

 

Back later with number two bracket...

Oh, forgot to mention... there has to be a revision made to the jig... I will drill and tap two holes under the base part... so that two screws can be used to push the upper part out of the base... it's an awful tight fit with the brass formed to shape under the 10 tonne press... it must "squeeze" everything into shape..... it took quite a bit of "encouraging" to separate the two after pressing them both times..... a simple cap screw each side will apply positive pressure to drive up the insertion block and bracket... I'm pretty happy with how the first bracket formed.... they will probably get a little less exacting when a number of them have been pressed and they make their own clearance in both parts of the jig... 

frats,

Rosco

Edited by rosco01

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Hi folk,

another day, more done...

I marked up, drilled and tapped two M4 threads into the base of the lower jig... so that screws could be wound in to press out the upper half with the brass frame "squashed" to shape.... 

I had a lot of trouble doing this last night with frame #1... this upgrade has made work a lot easier......

 

000-M4-extraction-screw-threads-mail.jpg

 

Ok, we have shortened the "revision 1" frame by 3.5 mm..... here it is after being marked out and drilled accurately using the Mill. You can see the motor shaft and bush plus the two axle bushes look a lot better than the first attempt. I spent a bit of time in the Suttons drill catalogue and found two drill bits which "almost" perfectly suit the motor bush and another one for the axle bushes.... if anyone is following this.. the motor bush drill bit is 6.2 mm and is a "stock" item for a rivet gun..... the axle bush one is not, but Suttons do make a bright steel one in 4.8 mm and a black bit in 4.9... I took two of the 4.8 and the bushes fit it with just enough clearance so that they can be fitted up with the axle in them and soldered into position... I wouldn't want them to be any closer a fit... they would then be a press fit and adjustment would be zilch.

Here are the holes drilled without filing with the motor and axle bushes in position... 

 

001-rev-1-frame-mail.jpg

 

Ok, we have pressed out frame to shape, twice - as before... and removed it from the jig... now we test to see how the reduction in length results.. and I am pretty happy with this.

In the pic below, you can see there is very little clearance left from the crown to one of the motor mount screws... this red Slot It crown is the largest in a set of 5.. I'll probably play around with all five to determine which of them best suits the Flat 6 motor.. I have two different pinions to play with as well..... it will be fun to determine how the model best runs on differing ratios.

I am now firmly of the belief that the length of this frame will now be my "go to" for future Flat 6 powered models....  I will detail specs a bit later in this post if anyone would like to squirrel them away for future reference..... never say never.. you never know... 

 

002-large-crown-mail.jpg

 

And here we have the green crown fitted.. the smallest of them. Note that the end of the motor shaft sits exactly in the same position in each of the differing crown hubs.... it is "just" inside the slot by the thickness of the shaft... 

As Chris W has suggested, I won't be using this slot for my axle position.. but to shim each side of the crown between the axle bushes on each side.

 

003-small-crown-mail.jpg

 

In this pic, you can see the two revised frames... and the original.... the revised have been shortened 3.5 mm.

 

004-frames-mail.jpg

 

And just to polish of tonight's edition... I gave one of the revised a bit of a scrub up... no point in going too far with it yet... it has to be soldered to the top of the chassis rails... whenever I get this scratchbuilder's jig and can finally sit down to work out the chassis layout.. 

 

005-frame-polished-mail.jpg

 

Ok..... scribble this down if you want the dimensions I have now "inked" in.... 

Material - K&H 1.0 mm x 12.0 mm brass strip - #9844... 3 pcs.

Length of frame plate...... 48.0 mm - centred at 24.0 mm

Motor bush hole - centre, lateral and vertical - size - 6.2 mm (Suttons drill bit).

Motor mount holes - 12.50 mm apart... 6.25 mm from centre line - M2 clearance holes.... 2 mm drill bit

Flat 6 mount face plate - 20.5 mm -  folds @ 10. 25 mm each side of centre line.

Axle bush holes - 20.25 mm from centre line..... 4.8 mm holes - Suttons drill bit - bush clearance fit

 

Happy to answer any further questions (relating to this post, for those with wit)... 

 

frats,

Rosco

 

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Ok folk,

bit of an update to keep this thread alive.

My scratchbuilder's jig and wire bender from Pro-Slot arrived yesterday - it will be a while now before I can make a start on the chassis - I will be "distancing" myself from this build for a bit of a spell and will report back in when I resume.

This is where it's at... I started work on the great Munter body.

First up - the original front door - I'm not in love with the quarter vent window and will remove it and make up a brass one - fitting it further to the rear,  just in front of the curve at the top - this is where I see it on the proto-type.

I drilled and slit the three vents in the fender quarter - I believe vents should not be "faux" if there is opportunity to open them... 

I have done quite a bit of work on door and window gaps.... original pic and revised... there is still work to be done in here to get some of the lines sharper - but I'm getting there.

 

2001-front-left-orig-mail.jpg

 

2002-primer-mail.jpg

 

Next up, the rear - I don't like the spoiler that the model was cast from.. it is way too big, has too much rearward rake and does not have the lovely little upward curve - I spent quite some time modifying this and believe I'm very close.... I have also trenched out around the tail-lights, bumper, window and all panels........

The body casting was very thin on the right rear corner - I broke through a few times and had to re-fill. The gaps will be filled almost flush with Aquadhere after I profile the lenses and the edge of the light surrounds will be brush painted in chrome - which I am yet to experiment with..... end result should be close to proto-type.....

before/after pix

 

2003-rear-orig-mail.jpg

 

2004-rear-primer-mail.jpg

 

 

And finally for this post - we come to the plenum vents in front of the window - there was some work in this.

I used a #80 drill in a pin vice to drill out top and bottom of each vent then hand made a scalpel blade with a very thin body. I sharpened the cutting edge and ground flat the back of the blade.

It took nearly two weeks of evenings, but all these slots are now open. I added some filler under the vents to create the plenum panel. Again, there is work to do to finish this off - but it is only touch up work. There were many break throughs and broken strips.... I believe the end effect will add some reality to the model.

 

 

2005-plenum-orig-mail.jpg

 

 

2006-plenum-mail.jpg

 

 

I don't like the front grille - it has a Chev bowtie badge in it.. and will mean an awful lot of work to open the holes in it. I have decided to make my own grille from brass strip.. 

The vents beneath the bumper can simply be ground out. I may re-inforce the rear of the bumper with a sort length of brass wire - I believe this will be necessary when the body casting material is removed from that area..... this model will have frontal collisions with barriers and other obstacles.. it will need a bit of beefing up at the front when I have done my work.

 

Ok - so, that's it for a spell now... 

 

frats,

Rosco

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