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rosco01

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Glazing.....

 

 

013-glazing-mail.jpg

 

 

Ok - that's it for tonight.....

I hope to chuck up some aluminium rod tomorrow and attempt a wheel... will take the camera out into the workshop and try to get some pix of the ordeal..

 

fingers crossed, I hope to have something by the end of the day - even if it is just a roughie... and might be reading some metalworking books as a follow up afterwards...

 

frats,

Rosco

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Thanks for your help, Shaynus... worked a treat.

 

Wheels - yes, issues..... I ran a set of digital calipers over the Slot-It wheels, then used the MJK tyre selector to find something which would fit... no joy, I'm afraid.

I am now of the opinion that I should make up four special wheels for the rears of both cars.. to fit a ready made MJK tyre..

The tyre will need sanding down to get a closer diameter... but by making up the wheels, it is easier than working the inner parts of tyres each time I need to replace them...

 

My measurements for the wheels needed for this model and the 4263 tyre are as follows.

 

Rim diameter - 12.0 mm

Rim width - 7.95 mm... although I'll probably go out to 8.0 mm

Step diameter - 14.3 mm

Step width - 4.0 mm

Hub diameter - 6.35 mm

Hub width - 1.55 mm

Internal rim diameter - 10.75 mm

Internal rim depth - yet to be determined.

 

I have not yet calculated scale dimension from the prototype... or track and wheelbase.

 

frats,

Rosco

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Ok folk,

update.... no further action on machining wheels..... intervention by my GP that my arm was needed to make a small hole into and subsequently a fluvax vaccine injected.... all done.

 

But - I did find some ali rod in my stock - 20 mm diameter.. and was about to uncover the machine and chuck it up.... GP call ended up being a lifeline for the 20 mm stock....

 

I dropped into my aluminium supplier on the return and purchased a 1.6 m length of 17 mm rod... equates to 100's of future wheels if my machining skills can be developed.. watch this space.

 

I now fully intend to set up the machine tomorrow.. and further hope to have a report up on proceedings by tomorrow night.

 

sorry to disappoint those who were keen on progress today...

 

frats,

Rosco

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You'll see it on the wheels if it does, Shaynus..... fingers crossed, I get some useful work done tomorrow on these..

Will include pix during the turning process...

Setting it up takes me most of my time (and effort) head will be sore tomorrow night - rest assured (in both terms).

 

frats,

Rosco

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I dropped into my aluminium supplier on the return and purchased a 1.6 m length of 17 mm rod... equates to 100's of future wheels if my machining skills can be developed.. watch this space.

 

 

Alright, throw a curveball why don't you, my interest has just perked up 10 fold.

 

..... watching this space .....

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banana.gifdribble.gifbanana.gif

 

Not getting excited.

 

(emoji's stolen from SFI)

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Ok, just in for a late lunch... little bit of work done, so far - so good.

 

For those who work a lathe, this might be a bit of a yawn - for others, a little bit informative about the process...

 

First up, we have the Slot-It wheel which I cannot fit the MJK tyre to... and a 200 mm length of the 17 mm ali stock purchased yesterday - cut using a humble hacksaw.

 

01-ali-stock-mail.jpg

 

 

Secondly, the ali has been chucked and shimmed to get the absolute most out of it... it has now been "centred" using shims - the "test dial indicator" reveals that it has no run-out as the work is rotated in the chuck of the lathe...

 

 

02-chuck-centred-mail.jpg

 

 

Next up, we "end dress" using a cutting tool angled at around 45 degrees and work the tool outwards from the centre - until it has a neat, flat surface...

 

 

03-face-dressed-mail.jpg

 

 

After doing this, I fitted a centre drill in a drill chuck at the other end of the lathe (tail-stock) and drilled a small hole into the end - absolutely dead centre.

 

 

04-centre-drilled-mail.jpg

 

 

Then a "live centre" was fitted into the tailstock to secure the work between it and the chuck...

We can now set up the cutting tool so that it will cut along the length of the work... I take my cuts at around 0.5 mm per run and for finishing, at about 0.05 mm cuts.. this seems to give me good results...

Here we are taking down the first cut along the work...

 

 

05-turning-down-mail.jpg

 

 

In this pic, you can see that I have a lot of turning to do until I get the work down to the desired 14.33 mm - which is the "step" height.. the maximum diameter that the wheel will be...

 

 

06-lots-to-go-mail.jpg

 

 

 

And finally, it is now down to 14.34 mm.... just 1/100th too large - I'm more than happy with this.. I was aiming to stop at 14.35 mm.... but a final finishing cut took 0.01 mm more than I had expected it to...

 

 

07-step-sized-mail.jpg

 

 

For all intents and purposes - I could be anywhere up to 0.5 mm out in this.. the glue which will hold the tyre to the rim will more than likely run out the tyre by way more than this.... truing down the tyres after fitting will resolve all this.

 

Next stage, is to turn down the rim diameter....

 

I should probably extended the work just a little bit more than I did... hindsight - wonderful thing....... I can easily get three wheels out of this piece of exposed work... it would have been more practical to have poked out enough for 4.... but, the two which will be made first will be exactly the same size... I'll use the third one still attached to the stock as a reference.

 

Ok, back later... no guarantee yet that this is going to work... haven't sorted out what I do after cutting the rim heights and width of step yet...

 

frats,

Rosco

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Ok, just learned something - if you bulk upload pix.. for some strange reason, they only come up in the post as thumbs....

 

I'll just upload one on its own now.. and see if it comes up as a full pic as previous...

 

07-step-sized-mail.jpg

 

frats,

Rosco

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Hi folk,

first time at doing this - and so far, so good... pretty happy tonight.

 

I turned down the outer rim to 12.0 mm diameter and set it in 2.0 mm..... I was going to set it in slightly narrower, then it dawned on me.... there is a 4.0 mm step and the width of the tyre is 8.0 mm... so, 4 + 2 + 2 = 8.... hence the 2.0 mm rim width each side.

 

I had a lot of trouble with turning down the rim on the blank side of the wheel... I only have one left hand turning tool and it couldn't be used to either make a start - or go in close enough without taking out a lot of metal from the next wheel to be turned up...

I ended up pulling out a parting tool, made a groove at the point where I will eventually part this wheel of and then cut left to right in small increments back to the start of the 4.0 mm step... that worked.

I also used the compound slide to make the traverse cut... it gave me exacting readings on its scale as to when I reached the start of the step.. just had to ensure I set it up exactly parallel to the lathe bed...

 

Pic of both rim faces turned down - the inner one will have to be turned down further yet to make the hub, but I'll bore out the open end first.

 

Apologies for the crap pix... daylight had gone and I was left with just the shadow light from two LED lamps I use for both the lathe and Mill at night.. I need better lighting out there... this is going to take some time to do...

 

PIc..

 

 

08-both-steps-mail.jpg

 

 

And to be certain my work is correct - at close of business tonight, I fitted the MJK tyre.. it's a great fit, doesn't slip and doesn't bulge... pretty happy.

 

Pic...

 

 

09-tyre-test-mail.jpg

 

 

Rain tomorrow - should be on the lathe all day.. hope to have two wheels finished by tomorrow night.

 

I'll more than likely drill the 3/32" axle hole before boring the open end tomorrow.. and drill through into wheel #2 as well.... negates the need to centre drill the next one..

 

In hindsight - anyone wanting to turn wheels - I might suggest drilling and tapping the grub screw holes first... before chucking up the metal.. it's going to be a big issue to drill the hole in this wheel now that it's been turned down.... hope I don't destroy it in the mill.

 

Until tomorrow..

 

frats,

Rosco

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Rosco's Race Rims is off to a strong start!

Can go belly up with one simple wrong turn of a knob, Shaynus...... will probably have nightmares about turning the bathroom tap on the wrong way tonight....

 

Out with the boring tool tomorrow - that's going to be fun ... not....

 

frats,

Rosco

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I'll more than likely drill the 3/32" axle hole before boring the open end tomorrow.. and drill through into wheel #2 as well.... negates the need to centre drill the next one..

 

Don't forget to drill slightly bigger than 3/32 (2.4mm maybe) for axle to fit.

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Thanks Grant,

I was actually going to hone down a 3/32" drill... a tad.... I really don't like wobbly wheels....

I will use a cutting paste to drill with - and take successive short cuts and withdraw/clean/re-insert... aluminium is soft, and the swarf tends to clog up clearance ways....

Let's see how I go.... I'll add some more pix when this is done.. and then we get to the scary bit.... boring... wow! - that's going to be an adventure - first timer at this.

 

Thanks for your help and advice - it is much appreciated.

 

I'm leaning towards a brass and piano wire chassis at this point.. short pieces of piano wire to join brass plates.

I now also intend to make up a jig for the motor/gearbox/rear axle bush mount..... probably spend a day or more on that alone.... I can precision drill with the Mill..

My intention is to accurately mark out and drill a brass plate, then mount it on a jig and bend it to shape using another over-lapping jig.... it's all in my head at present.

If I do this right, I can probably make a "universal" one which can be used time and time again for other models.

 

So much to do, only so many years left to get it done....

 

frats,

Rosco

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Better go well, I have gotten a bit of interest going now, if you don't lose and eye or hand I am thinking of a lathe as well, never had one before and you description or how to is great, keep it up Rosco.

 

Going to have a crack at resin casting too.

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Always wanted a lathe, Grant..... but a lot of other "wants" always seemed to get in the way.

At age 63, I finally got one... and about 6 months later, a Mill.... we'll see some of that later when I come to drill and tap these wheels.

 

PM me if you want my suggestions for lathe - I can give you prices and what extra you'll need.

When it comes to costing for one - allow twice as much for a reasonable set of tools - they don't come with the lathe.... that is a bit of a trap for a lot of people, they see a great price on a lathe which will suit their purposes - and find out that there isn't much they can do with it without forking out heavily for tools so that it can be used.

 

Same with the Mill... which for almost of my use thus far - is a very over-priced and over-engineered drill press. But, when it comes to getting precision and being able to rout away metal... nothing can do it like a Mill......

 

back later.... setting it up to do some boring at present - got a case of the "nervous Nellies"...

 

frats,

Rosco

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Ok - we're in trouble.... boring.

I have reached a point with boring out the inner wheel and can go no further with the tools I have - this will take a while.... I'm now making my own special tool for this work... report later.

 

To make a start for today, I am going to add a few little bits about the lathe - and working it, what it can do and the results which can be attained.

I most certainly am not a metalworker nor a machinist, but I seem to get by when push comes to shove and I don't have alternatives.

 

We'll start with the next step of making this wheel..... drilling the axle hole.

I am using a 3/32" (2.38 mm) drill bit... not used for anything else but slot car axle holes thus far. It's a "Suttons" tool, which a toolmaker in another hobby told me are right up amongst the best of them.

 

In the next pic, you can see the parts I added to my lathe tools for drilling using very small drill bits....

They are - the MT-2 (morse taper #2) adapter to fit the large drill chuck into the tailstock, the B13 drill chuck, which will hold a drill bit from about 1 mm up to 13 mm, another morse taper adapter (size 0) which is inserted into the larger drill chuck and onto which the small JT-0 miniature drill chuck is mounted.

 

01-JT-0-drill-chuck-mail.jpg

 

 

In the next pix, we see the entire assembly fitted to the tail-stock of the lathe.. with my 3/32" drill bit ready to be put to work.

 

02-drill-chuck-tailstock-mounted-mail.jpg

 

The greatest advantage of using the tail stock to drill into work, is that it drills perfectly straight and parallel to the work - exactly at right angles to the face of the work.... and, probably more important to the work we are doing with this wheel - absolutely dead centre of it.

 

If you think about it - it has to...... the work has been turned down in an exact parallel and square on plane to the cutting tools - and the turned down work is exactly centred by the cutting around a held centre in the tail-stock..... it is only logical that anything which is inserted into it whilst the work is spinning true - simply has to go in parallel and square...and dead centre.

 

 

Next, we see how this little micro-drill chuck works... a control wheel allows the ability to hand feed the drill bit into the work...... it is a sliding fit inside the adapter, and is a perfect sliding fit without any lateral movement.

It's a bit of an overkill for a large drill bit of this size - but when using bits down to just 0.3 mm.... it allows total control of the feed rate.... and drill bit breakage rests entirely on the operator...

 

 

03-JT-0-hand-control-wheel-mail.jpg

 

 

I drilled out the wheel using the 3/32".... in successive cuts... using a special wax lubricant to prevent galling in the bore.

The drill bit I used was a perfect sliding fit into the Slot-It wheel... but I have managed to incorporate some lateral movement (I can "feel" it, but I cannot "see" it.... ).

It will be fine, as the wheels I received for the little T-53 Cooper had more lateral movement in them and that car runs sweetly...

However, I will hone down the drill diameter.... using a diamond stone... it will only be a pass in the lathe (drill bit in chuck) and measure with a digital caliper.

I'm aiming to reduce the diameter by only 0.1 mm, at a guess, this is the movement I have with the axle in the bore of the wheel... I am aiming for a smooth sliding fit - as Slot-It have produced....

 

Pic -

 

04-axle-hole-drilled-mail.jpg

 

 

Next up - what I have been dreading for days.... boring out the inner rim diameter.

I went through my entire collection of boring tools and the best I could come up with was this one....

 

05-boring-tool-set-up-mail.jpg

 

 

The tool mounts into a tool holder. I recently changed my tool holding equipment for a "quick change" system.... it allows me to simply fit tools to a holder that can be very quickly fitted and removed from the main tool-post ..... and each time a tool is re-fitted - it is exactly in the same position when previously used...

I have about 6 of the tool holders... and can quickly change from one tool to another with the confidence that they will make cuts exactly as previously used...

 

 

Ok - so, this is where we are now at.. in trouble...

The boring tool has only allowed me to go in so far.... the body of the tool is now rubbing on the outer diameter of the wheel.

The cutting piece cannot be moved within the tool itself... it is locked into position.

The tool cannot be angled any better to gain access into the wheel without fouling on the rim....

 

In this pic, you can see that I am working my way out with cutting from the centre to the edge of the rim..... my final wall thickness is only going to be 0.65 mm - that's a big ask for a first timer... this is the diameter that Munter's magnificent wheel inserts will fit into the wheel - and I don't want to compromise those...

 

 

06-boring-cuts-mail.jpg

 

 

I have stopped for lunch - I have found another boring tool which i am about to grind down..... necessity is the Mother of invention.

It is a tungsten boring tool mounted on a steel holder. I'm hoping it has been brazed to the holder and not glued - I will have to grind away a lot of the meat of the holder to achieve the cutting tool I want... and more than likely "strike" the cutting edge... I expect this will take care of the afternoon.... grinding and honing up the edge to suit the inner boring of these wheels.....

 

Crazy? - definitely, but it's "what" I do... and enjoy doing it...

 

frats,

Rosco

Edited by rosco01
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Shaynus,

I went through every boring cutter that I have... Mill included - I am either yet to get some dedicated for purpose, or have not had sufficient experience (yet) to determine if there is more than one way to mount a tool.

 

Short answer - yes, you can...... but my Mill and Lathe use different Morse tapers.. the Lathe being MT-2 and the Mill an MT-3... I have the complete set of MT-3 collets for mill cutting....and boring, but the collett chuck that I have is MT-3..... and I much prefer to bore using the lathe, for reasons above.... my control of the X and Y direction in the Mill are not yet that good...... and to bore down into the wheel with a plunge cutter exactly the size needed is probably beyond my capability as well for now....

I know I can get an adapter so that the collett chuck can be used in the MT-2 tailstock of the lathe.... but, as you will read later - I have managed to overcome all issue with this now.. and have, in fact - bored out the internal of the wheel......

 

Thanks for you suggestion, I am a learning novice with the lathe... and even more so with the Mill.... I have not yet had enough experience in either to appreciate yet what can be done...... or can't be done...

 

frats,

Rosco

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A quick and simple way of getting flat bottomed holes of standard diameters in small jobs like this, is to use Slot Drills.

Google or look on ebay to see what they're like.

 

They are essentially centre cutting, 2 fluted, flat bottomed milling cutters that can bore straight into a work without a pilot drill

 

Check them out after you've done this job with your 'special tool'

 

Your lathe looks a bit lightweight, so start out with smallish dia bits (maybe 8mm to 13mm) to try if the lathe can handle them, but check what shank sizes are to see if they will fit in your chuck.

 

I'd just get a couple of the cheapest HSS ones to try first.

Steve K.

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Thanks Steve,

Yes - I have quite a few slot drills... and 3 fluted ones plus the finishing 4 fluted ones. I use these in the Mill.. not the lathe.

I suppose, I could try and fit one to the drill chuck in the tail-stock - held stationary... but I'd have to get one exactly the correct size of the inner diameter to be turned.

If I were to go this way, I'd probably bore out the inner diameter before turning down the rim.... that would make sense.

 

The lathe is not as small as it looks in the pix... the drill chuck in the tail-stock can handle up to 13 mm ..... the motor is more than powerful enough to handle 13 mm.

It is a medium sized hobby lathe - with a 400 mm centre. It has a brushless DC motor and I have only ever stalled it once.. when parting off (usual deal for novices).

I have also broken two belts.. when the motor did not stall.... and had numerous overloads which required a reset.. these were all in my very early days when my head had convinced me I knew what I was doing... and obviously didn't...

 

As you will read in the next post, I have overcome my issue and now have a tool which will be used for much of my boring work in aluminium... it works a treat.

 

Thanks for your suggestion - much appreciated.

 

frats,

Rosco

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Ok folk,

happy to report - that all ended well after stalling at lunch time today.

I overcome my issue with boring out the inner wheel... and expect that the following three wheels will go a lot smoother and with an improved result.

 

I found a boring tool from a set which came with the lathe - I have upgraded my cutting tools and this lot were using up drawer space...

I used a bench grinder to grind down as much of the tool as I could without compromising tool strength.. and yes, the tungsten bit was brazed onto the steel post.. phew!

 

Couple of pix.. you can see in these that this tool gives me ample clearance to go deep into a small recess. I honed up the cutting edge on a diamond stone... it worked perfectly.

 

01-modified-boring-tool-mail.jpg

 

 

Unfortunately, the damage to the inside of the rim was already done by the previous tool... the body of which was eating out what had already been bored before it...

But, this tool began to take fresh cuts from about half way into the amount I decided I was going to remove... just enough for Munter's insert to sit inside snugly with some of the exposed rim showing beyond the insert....

 

02-boring-out-wheel-mail.jpg

 

 

You can see in the pic below that I have ground down the body of this tool to give me ample clearance .... you can also clearly see the damage the body of the previous tool caused... and just how thin the very edge of the rim ended up being...

 

 

03-boring-tool-clearance-mail.jpg

 

 

 

With the inside of the rim now bored out, I took the rod out of the lathe and set it up into the vice of the mill... I will mark out and drill then tap these grub screw holes before turning the wheels down in the lathe in future.... it was very difficult to set up the turned wheel in the vice..

In this pic, you can see that I have centre punched where the hole is to be drilled.

I set the drill bit up and positioned it accurately by the use of a "centre finder".... this amazing little trick tool "snaps" into position when the point of the little tool is brought into line with the centre of the drill chuck... in this pic, you can see that this "snapping" has taken place and the mill is now positioned to accurately drill the hole for the grub screw... and subsequent tapping of the M2 thread...

 

04-mill-centre-finder-mail.jpg

 

 

Ok, bit of a jump ahead here.. I had a rush of blood in excitement once the grub hole was tapped..... and forgot to take pix.

I had re-chucked the rod into the lathe and turned down the inside of the wheel to get the hub diameter... which I set at 6.5 mm.

 

I then fitted the parting off tool (nightmare for beginners) and parted off the wheel from the rod.... fitting a wooden toothpick into the axle hole prevented the wheel from finding a secure place to hide... or get tangled up with the spinning chuck.

 

In the pic below, we can see the wheel fitted on the axle, the bronze bush fitted up against the hub of the wheel... and the grub screw inserted...

 

05-grub-screw-fitted-mail.jpg

 

 

So, for a comparison - I fitted the Slot-It wheel and my wheel on the axle... you can see the difference in the width of the step between the two.. mine having the narrower step.... I was pretty happy with this result. I did not get the amazing finish that Slot-It do with their wheels - but I do not have a CNC machine either.

I'm pretty happy for a first attempt at a wheel...

 

07-Slot-It-vs-mine-mail.jpg

 

 

And so - we test fit the tyre..... it sits very nicely on the wheel... it runs true along a flat surface and I'm again pretty happy with the result.

 

08-tyre-fitted-mail.jpg

 

 

And here we see the outside of the tyre on the wheel.... there is ever a slight gap between the rim edge and the inside diameter of the tyre... this will undoubtedly be filled with glue when the tyre is glued to the wheel.....

 

 

09-tyre-fitted-mail.jpg

 

 

And, to close this session...... here is the Munter insert partially fitted into the bored out recess we made.. the insert is yet to be sanded down for it to be pressed in further... but I believe it will look amazing when finished...

 

10-insert-fitted-mail.jpg

 

 

So, that's one down - 3 more to go.... maybe 7 more... I have another iron in the fire at present which may avoid having to make more than four of these.. but, I've enjoyed it - and will probably make all 8 for the exercise regardless...

 

Back tomorrow with only a short report on how the next wheels are going.... no great novel this time, it's just now repetitive work... unless I find something which makes it easier or produces a better result.....

 

frats,

Rosco

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