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Thanks again, Wobble - I'll chase those motor screws up..... although, I have some M2 x 10 mm which fit.... but they of course are grubs... the ones you refer to are probably flat headed and will hold down the motor to the pod.... the grubs, which I would use a small dab of loctite on - will only prevent the motor body turning.

 

I guess your Alan Mann #24 has "over-drive"... does it seem to lose torque coming out of corners or R1 chicanes?

 

thanks again,

 

frats,

Rosco

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I guess your Alan Mann #24 has "over-drive"... does it seem to lose torque coming out of corners or R1 chicanes?

 

thanks again,

 

frats,

Rosco

 

the 34 tooth is actually gearing it lower rather than 'overdrive'. Even on a 6m straight with this ratio the motor doesn't peak out before I have to button off and good brakes are even better but they need to be. A cobber has the black Mk2 and I used to think his was quick until I changed the gears. Mine bolts away from his now.


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Wobble, thanks - yes - I must have got my "teeth" mumbled.... of course, you've dropped two down - not up....

 

So, this gear reduction.... is it a crown-wheel change only - or does it require the matched set..?

 

I do appreciate that our Alan Mann CA18A models employ an 0.5mm offset match.... and expect that changing to the gearing you have employed must also be within the confines of that offset.... I have found hours and hours of reading new age advancement beyond my age-old understanding fascinating....

 

I ordered those engine screws this morning - along with enough MJK tyres to shoe up all my GT40's....

I also ordered a Slot-It pinion remover/installer ($65 - ouch).

 

I have the Tyre Razor coming in a week or so.. it's currently making its way across the equator... whether it's north or south of it by now.... only USPS knows....

 

I believe the extra grip attained through the tyres, perhaps some more torque from the wash and Zippo treatment - might befit dropping a gear down to benefit a little more "lift"... and brake... but, I run analogue - and actually re-wound my own Scaley controllers... I did incorporate a "dynamic" brake option to the control box I built... it won't afford me the brakes you folk are running - but at least I can bridge both track rails and destroy the EMF in my motors to gain something....

 

I've got the last of my CA18's chassis in the hot tub at present... the motor pod will go in tomorrow - then I can assemble the last of these six - with only three of them yet to be run.....

 

Thanks, Wobble - it certainly is fun working on the bench with these cars.... I'm still hoping to set up a track tomorrow during the "big race" and do some laps...

 

 

@Camber - thank you for the link to the post - I'll get to that in the next hour..... I've got to attend to another thread before I get a chance to take a peek.....

 

frats,

Rosco

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Hi Rosco, changing gear ratios in these is straight forward. The sidewinder pinions are 6.5mm regardless of the amount of teeth and likewise the spur gears in these are 18mm regardless of the amount of teeth. In this case to change the gear ratio to 34:11, it's simply a matter of changing the spur gear and leaving the pinion standard. By far the easiest option. If you try it just be sure you order 18mm spurs as 19mm are available also.


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Thanks,Wobble....... won't be until my next order.. might get a couple - I note there is a new to me material used in crown wheels... has three spokes from hub to teeth... not delrin... something else... think they might be made of some sort of metal... can't remember what it's called...

 

@ Camber - I can see why you directed me to that post - particularly the bit about washing out oil on the end bell bearing.... I may have done this to some extent with the first one I treated... but can adamantly state the remainder got enough oil to keep them quiet during the prolonged running periods...

 

Interesting also to note that the "water" run in - is projected to quicken the run-in period.... simply by the load water places on the spinning armature.... good reading - thanks.

 

As to whether there is any merit of using a water bath to run a motor in... I still don't know... but I'll continue to do so.... just will be very much more careful with the Zippo treatment that I ensure the end-bell bearing is kept oiled..... these sealed motors are not easy to look into... I am using a magnifying light AND an LED pencil torch... and I can just see the commutator...

 

Ok - one more - soldering the lead terminals... would never have thought of it....... heating up that common brush-holder/wire lead.... might anneal it - and lose brush tension to some extent... again, thanks..... guess if I have to solder again - it will be as suggested in a water bath.... with the tab "just" clear of the water... might take a bit of heating up the tab, though.... my soldering iron is not that hot....

I only use a 15W iron..... tin the lead - bring it to the tab and run the heat from the lead to the tab until they both fuse.... then immediately withdraw the iron.... and hopefully - the joint stays "shiny"... that's my method...... seems to work for me....

 

thanks folk - learned much more tonight...

 

And - that "NIfty" trick for cleaning up a dirty commutator..... AND the way it is abrasive.... would never have reached that conclusion.... been using it to wipe down highly polished paintwork on r/c aircraft for yonks.....

 

Guess who's going looking for a "dirty" Scaley motor to try it on...... no prizes for correct replies....

 

frats,

Rosco

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@Wobble... this one...? just added two to my cart - can change if incorrect.....

Oh - and the material is "Ergal".... no idea what it is - but it states "lightweight"... I expect it's one of these new wonder metals.......

 

I further suspect that it is harder than brass.... the pinion... so, does the brass color from your pinion end up on the Ergal spur gear?

 

http://www.armchairracer.com.au/workshop/gears/slot-it-gears-gs1834-34t-ultralight-ergal-sidewinder-spur-18mm

 

frats,

Rosco

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  • Yep, that's the one. Don't know what Ergal means but it doesn't sound like something you'd want to catch. Also, never noticed any brass build up on spur gears but I always put a dob of Vaseline on them anyway. There's probably better stuff that you could use but it works for me. Also, sometimes I use chainsaw bar oil for bushes but that's just 'cos I have a bottle of it for the saw anyway and it doesn't seem to fling off although it's a minimal amount.

Edited by Wobble

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Thanks Wobble.... just did a "wiki" search.. and post the following quote from wiki..

 

 

Trade names

 

7075 has been sold under various trade names including Zicral, Ergal and Fortal Constructal.

Some 7000 series alloys sold under brand names for making moulds include Alumec 79, Alumec 89, Contal, Certal, Alumould, and Hokotol.

 

7075 aluminium alloy

 

From Wikipedia, the free encyclopedia

Aluminium alloy 7075 is an aluminium alloy, with zinc as the primary alloying element. It is strong, with a strength comparable to many steels, and has good fatigue strength and average machinability, but has less resistance to corrosion than many other Al alloys. Its relatively high cost limits its use to applications where cheaper alloys are not suitable.

7075 aluminum alloy's composition roughly includes 5.6–6.1% zinc, 2.1–2.5% magnesium, 1.2–1.6% copper, and less than half a percent of silicon, iron, manganese, titanium, chromium, and other metals. It is produced in many tempers, some of which are 7075-0, 7075-T6, 7075-T651.

Uses

 

7000 series alloys such as 7075 are often used in transport applications, including marine, automotive and aviation, due to their high strength-to-density ratio.[2][9] Their strength and light weight is also desirable in other fields. Rock climbing equipment, bicycle components, inlineskating-frames and hang glider airframes are commonly made from 7075 aluminium alloy. Hobby grade RC models commonly use 7075 and 6061 for chassis plates. One interesting use for 7075 is in the manufacture of M16 rifles for the American military. In particular high quality M16 rifle lower and upper receivers as well as extension tubes are typically made from 7075-T6 alloy. Desert Tactical Arms and French armament company PGM use it for their precision rifles. It is also commonly used in shafts for lacrosse sticks, such as the STX sabre, and camping knife and fork sets.

Due to its strength, high density, thermal properties and its ability to be highly polished, 7075 is widely used in mold tool manufacture. This alloy has been further refined into other 7000 series alloys for this application, namely 7050 and 7020.

 

 

For my current lubrication, I use the Parma lube for cogs and MB slot for motors.

I'm now using Inox for axle bushes.

 

I lube up the cogs, run them free air at mid speed for 15 seconds or so at mid power, then swipe all excess away....

 

Thanks or the Ergal 34 tooth confirmation - I'll go ahead with an order - might pick up a 18mm 36 tooth as well......

 

frats,

Rosco

Edited by rosco01

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  • Don't know what Ergal means but it doesn't sound like something you'd want to catch.

 

A friend just returned from a trip to West Africa and now he can't stop buying raffle tickets...

 

...we are concerned that he may have contracted Tombola.


Outside the box looking in.

------------------------------------

You don't own stuff: Stuff owns you!

------------------------------------

Having a cold drink on hot day with a few friends is nice, but having a hot friend on a cold night after a few drinks - PRICELESS.

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  • Don't know what Ergal means but it doesn't sound like something you'd want to catch.

 

A friend just returned from a trip to West Africa and now he can't stop buying raffle tickets...

 

...we are concerned that he may have contracted Tombola.

 

 

Watch his arms as well. if one of them keeps moving towards and away from his mouth and he's not eating or drinking he might have a case of Trombosis.


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You Jazz players - words fail me...... sounds like it's all wind to me.....

 

Ok - time to pick people's knowledge again.... motor bearings.

I'm about to break in my final Slot-It orange bell 21,500 motor (water method) - but before I do, I found something that I'm not very happy about - and seek suggestion to correct before I run the motor......

 

I note there is slight play in the shaft/bearing at the bell end... it is lateral.... I can't detect whether if the play is between the shaft and the bearing or the bearing and the end-bell...... any suggestions?

 

I read somewhere (can't remember) about using oil and cyano-acrylate to correct this play... might have been applicable to axles/bearings... but I do know there's too much play for my liking in the end-bell/bearing/shaft... and don't want to destroy a new motor if I can do something prior to running it.

 

I don't know if the bearing can be replaced - if they are available.

 

I stripped one of these Mabuchi can motors in a Carrera due to some crap shorting out the armature/commutator - bits of solder - and know that the bearing in the end-bell is retained by those plastic "fingers" - it's also a spherical bearing... not fixed... so, there's every chance that the actual bearing has play in the endbell....

 

Hoping someone has corrected this.... it's the first one of these motors I've come across with this issue.

 

All of them are set up with the armature assembly drawn to the end-bell by the magnets.... none of them "float" in between the magnetic force - which I have read to be desirable for peak rpms.... the magnets are captive by the "U" shaped retainer - and they cannot be forced back into the can because of those two punched tabs in the can body.... I could flatten them - and glue the magnet further down the can.... anyone done that - just in case I do have to open this motor up.... if it's going to be a "dog" motor - I could play around with it if I open it up.....

 

All of them have huge amounts of play longitudinally as well.... if I were to open one up - and centre the magnetic force on the armature - I'd also pack the shaft with washers ...... that's what my head is tossing around at present...but, if there is remedy for this lateral play without opening the can - I'm hesitant to do anything inside the motor if I don't have to open it....

 

frats,

Rosco

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My Orange motor seemed to have a little play but that maybe psychosomatic as I was looking for it following the above. I re-lubed the motor and it has all gone. I can however make the shaft move at the endbell end if i apply a lot of force. I suspect I am applying enough pressure to deform the little plastic "fingers. But it is not "play"

 

Shaft end float on mine is 0.36mm. I assume that the shaft is going to rub on plastic washers at one end or another of the motor so irrelevant whether float is 0.36 or 0.1mm. How much drag would the oil between the washers cause if the tolerance is too small?

 

From a circuit racing perspective, correct tire choice or correct body float or car height or quiet gear mesh will account for more performance gain that reducing motor shaft float?


Outside the box looking in.

------------------------------------

You don't own stuff: Stuff owns you!

------------------------------------

Having a cold drink on hot day with a few friends is nice, but having a hot friend on a cold night after a few drinks - PRICELESS.

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Thanks,FITW - my end floats on all motors far exceed yours.... I'd be really happy with only endfloats of that magnitude.... mine up up in the 2+mm.... on every one of them....

I did pull that troublesome motor apart today - and found that the "play" was in the six fingered bearing retainer - I prised these closer together with a pair of pointy nosed pliers.... all noticeable "play" has now gone.... and the motor now runs sweetly.

 

I did the "water, isoprol, and zippo" treatment - and a lot of running at low volts (around 1.5 - 3, varying at intervals of about 20 minutes) - the motor is really now quite lovely....

 

Just in case you might like to know folk - the motor shaft shown by my digital vernier - 1.98 mm, the endbell bush O.D. 4mm, the I.D 2.0 mm and the wall thickness 2.2 mm...... I am told that this size is pretty much standard for the most popular of these types of motors.... except that one manufacturer does not employ the fingers... just a straight bush receiver.

 

When I pulled this motor apart (and I expect all of these end bell Slot-It motors will be the same - there is only one tiny little teflon washer insulating the commutator from the bronze bearing..... when that wears through - it will short the segments across each other....

I am seriously considering the fitting of an extra one of these washers.... of course, this will result in all that bedding in I've done - will cause the brushes/commutator to unseat ...... might leave that one until I have to go back into one of them.... and progressively upgrade them on that basis....

 

What I can also tell you - is that there is heaps of meat in those commutator segments..... I was quite amazed.. there would almost be a 1 mm depth in them....

 

The brush arrangement is very flimsy.... easily disturbed and the insulator/mount they slide into is not what I would call a positive way to hold them captive.

 

I have taken note that due to these being so flimsy - I will be extremely careful should I need to re-solder the leads from the guide..... I have read that over-heating the tab (which is also the flimsy piece of copper which holds the brush) can weaken the spring tension on the brush against the commutator.....

 

Matt - yes, I did do quite some work with testing results... and to be perfectly honest - I didn't get a consistent result to determine if there is any benefit in a water dunked, isoprol and Zippo treatment... some did - some didn't...

 

It was pointed out to me that the big gain in bedding in using water - is for those motors which get hot.... none of mine have done this..... well, the ones I did a traditional running in on the track with..... they have all run very cool - even when given quite a few consistent bursts around the track for many laps... but, I only run mostly at around 11v.... when I run one in - I drop it to 10v.... just in case I get a rush of blood........

 

So, in answer to your question - the jury is still out.... and, as for the Zippo treatment... yes, there is merit in this - it certainly free's up the motor for quite a while... and certainly makes the comm/brushes run much quieter.... until it evaporates...

 

Word of warning - no, big word of warning - that zippo will blow out/dissolve oil on the end bell bush... so, if you do this - be mindful to only give it 30 seconds or so after flushing... then re-oil (lightly) with a fine needle.... I noted some strange little squeaks in a couple of mine whilst running the zippo conditioning.... and both of them shut up immediately when the end bell bush was very lightly oiled.....

 

These motors are particularly difficult to look into up at that end.... yes, you can easily over-oil.... and yes, that flimsy little tiny teflon washer wont stop the zippo from washing out the oil on that bush... you can actually see it seep out through the shaft/endbell hole...... so, if you run this stuff - oil - but lightly.

 

Hope some of this helps - it's what I've found and read over the past week of breaking half of my motors in.....

 

Time will tell which ones last the longest.... but you'll grow old waiting here for my reply....

 

frats,

Rosco

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Cheers Rosco,

 

There is a great instructional video on the Slot.it Mclaren BMW F1 Gulf on the Austin Slot Car Club in Texas (USA).

 

He shows the how to's from start to finish on how to set up a car (albeit inline, not sidewinder like the GT40's) but you get the gist.

 

Nothing wrong with keeping an open mind on how slot cars can be tuned.

 

Not eveyone does the same thing but the results can speak for themselves.

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Thanks, Matt - will chase that one up.... always in the market for finding out something new.... whether I choose to follow each suggestion is always my choice...

 

I do not belong to a club yet, Matt - don't even know where the nearest one is around here.... and as such, probably don't need to bring these models up to state of the art ability... but, it's part of a passion - and I am certainly keen to learn more on how to make them faster.... in both power and handling....

 

We have a couple of old faithful dinosaurs which I really enjoy running around the track - by golly, they've done some miles... but they run very sweetly - even with a bit of engine noise when given a bucketful.... it is most likely the bearings... but they still run smoothly... and I won't make any more changes..... it will defeat the purpose of having kept them....

 

I did fit MJK tyres to the rear and axle bearings to front and back.... along with fabricating a guide holder (necessity).... other than that... they are pretty much as they came OTB..... it really is a pleasure to pound around the track with them....

 

We have a couple of dogs.... over the years, I've tried and tried to get them to behave.... both Scaley - the Mk2 black/yellow Escort and the Yellow TR-7... they are still boxed in their white/green boxes... which the celllophane has broken in a few places.....

 

I pulled both apart completely on a number of occasions to remedy - but they are both just lame ducks... flop all over the place and only get up to speed at full power....

They are pretty much on a level field... one goes faster than the other - but handles less well... and the other - the opposite....... we don't use them much - they are hard work..... don't know why we ever bought them... rush of blood perhaps...

 

Ok - getting right off topic here - apologies to the forum..

 

Hope to have some track up and get to enjoy the fruits of may labors this weekend...... will post after/if the event....

 

frats,

Rosco

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One trick I used on rebuildable motors in the 70's was to polish the comm with Brasso, then clean it off with shellite etc.

 

We used to balance our hand wound arms on razor blades which increased performance, no dynamic balancers in those days.

 

I use my Guitar Tuner to check and compare motor revs at certain voltages.

Edited by Rhythm Willie

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Watched and saved that vid on tweaking rpms using magnets....

I guess this is a common practice... is it a permanent tweak? - or does the effect wear off... and - what's the detrimental side of doing this...

 

I read somewhere that heating magnets reduces their draw... and am careful when working with a soldering iron...

 

frats,

Rosco

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