# Bearings in a T-jet



## Hornet (Dec 1, 2005)

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## Boosted-Z71 (Nov 26, 2007)

I have repaired some arm and axle holes with some brass tubing, like a bushing, but as far as bearings I have not seen that. Just as a side note never been able to get the brass on steel to be less friction than the stock steel to plastic setup, YRMV.

Boosted


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## Dyno Dom (May 26, 2007)

I remember an article about an HO "land speed race" in one of the 60's slot magazines. 
The winning car was a highly modified Lola GT that featured axle bearings.


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## slotking (May 27, 2008)

some of the local old timer here did have arm bearings in some of the unlimited t-jets (i think)


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## Hornet (Dec 1, 2005)

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## dtomol (Mar 30, 2005)

Hornet said:


> I've been kicking around HO on and off for close to 35 years,and i'd never seen anybody really mention anything about bearings in a T-jet,so that's why i was curious about using them in a pancake chassis.
> Boosted,did you use just straight brass tubing.
> Anybody ever try using an oilite style bushing,in any part of a pancake build-up.
> These are just curiousity questions to satisify my own curiousity,and thanks for the replies guys
> Rick


The Bauer Tjets resin cast cars from Germany come with Aramature bushing installed very smooth.


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## Boosted-Z71 (Nov 26, 2007)

I have tried both oilite & normal brass tubing, Oilite seems to release the encapsulted oil onto the motor brushes quite easily, I now only use mainly brass.

Boosted


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## Hornet (Dec 1, 2005)

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## Ralphthe3rd (Feb 24, 2011)

Hornet, I always thought that annealing was to heat up( & expand) the metal and let it cool naturally ? When you heat up and quench metal in either oil or water, that is more of a heat treating/hardening process- isn't it ?


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## Hornet (Dec 1, 2005)

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## Ralphthe3rd (Feb 24, 2011)

PS- Hornet, did you want to harden or soften the bushing ? As True Annealing(slow cooling) is how you soften and expand the metal. While Heat treating (thru rapid quenching) hardens the metal.


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## Ralphthe3rd (Feb 24, 2011)

PPS- when I used to race MX/Flattrack motorcycles(waaay back in the day). And when we tore down two strokes, which used Flat copper rings as head gaskets, we used to anneal those copper gaskets by heating them up and letting them cool naturally, which is the definition of annealing. And then we'd get a thicker softer gasket which extended it's (re)usage and lifespan....and I was just thinking that Heating Brass would have a simular effect ?


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## Hornet (Dec 1, 2005)

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## Ralphthe3rd (Feb 24, 2011)

Hornet, thats what I just said basically. So you are softening the brass then, as only Pounding it(sorta like Forging) will harden it.
But whats funny is, aluminum WILL Harden by heat treating it, and I believe copper will too....which is a major part off the alloy of Brass.
Interesting tangent/discussion


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## Hornet (Dec 1, 2005)

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## partspig (Mar 12, 2003)

Hi Guys, gotta chime in here and give ya some "old fart" wisdom. Take it or leave it, it is what I know, brass does not a good bushing make, why?? It is too soft! On the other hand, bronze is an ideal material for bushings. Something I learned from working at the plant for 35+ years, 30+ years ago my T-jets were bushed with bronze and they ran like greased pigs!!! No pun intended!!  :thumbsup:


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## Hornet (Dec 1, 2005)

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## partspig (Mar 12, 2003)

Bearings were just to expensive! You would, I think need at least eight for a T-jet chassis. JMOFHO (Just My Old Farts Honest Opinion)


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## Bill Hall (Jan 6, 2007)

Some time back I put brass bushings into an A-dub...I fergit which release it was. The rattling ones with the gigundous arm slop and axle holes all akimbo.

I did the upper and lower armature bores, the cluster shaft bore on the gear plate, and four axle holes. There really isnt room to squeeze one into the chassis for the lower cluster shaft bore, so I relieved the hole and tried to square it up best as possible. The pinion was swapped to a nine tooth, and a t-jet crown and axles were used.

What a great ride! Very smooth, and muuuuch more quiet! The added zip from the AW arm translated nicely through the smoothed out journals. 

Note: It is important to make sure the bushings are pressed in square and aligned from side to side, or top to bottom and then ream them clean. Creating a bind by tightening up the tolerance and not having the holes aligned will defeat the purpose of the excercise. Should you choose to use splined axles, then care must be taken that the width of the bushing does not exceed the width of the spline relief on the axle. Obviously if it does, you'll have splines grinding bushings and again defeat the point of the excercise. If I had any advice to give it would be to try yer luck at least once with a known crapper. It's good fun.

Were I to do it again, I would like to try some thicker wall bushing stock and actually hand fit/ream each individual journal to further close up the tolerance. Regardless it takes some time and effort and as Dennis states...you'll have some added expense.


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## Boosted-Z71 (Nov 26, 2007)

I have not tried Bronze, but did ream and fit the brass for a nice straight shot for the axle & arm holes, like was mentioned it was smooth, but I have built faster and farther rollers on plastic, gaged by the old hill / gravity test (think Hotwheels). I have not tried to heat treat the brass, I just cut my bushings from tube stock, install & then take them to the mill to finish the ream & polish to size. I have fixed almost all my JL's rear axle and they are much better, lately I just started using larger gage pins and just ream & polish the chassis. Just might look into either the bronze or try some heat treating just for fun.

Good thread, I appreciate all the views & info

Boosted


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## joegri (Feb 13, 2008)

i second that hornet i mean about the stuff the old man knew and i thought he was crazy. i give the man all the credit now! jeez i miss the the old man. sorry off roading a bit


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## Hornet (Dec 1, 2005)

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## partspig (Mar 12, 2003)

That is a lot cheaper price than even 20 years ago, but there is still the size problem. I, this is my JMHOFO again, believe that they are just too big. It is impossible to even bush the lower bearing hole for the driven gear cluster. It is also really tight to just bush the lower armature bearing. I think that bearings in those two spots would be out of the question. That still leaves 30 bucks worth of bearings to install on the rest of the chassis! It is like anything else, are you going to really gain that much for your 30 bucks, time and effort? To me the answer is no! Just like the question, will a 200 dollar Difalco controller make me a better driver? To me, the answer is NO! It may make you a couple tenth's of a second faster lap time wise, but it will never move you from the back of the pack to the front. So if I am a crappy driver, I really wasted 200 bucks I coulda spent on some burgers and beer, AND I woulda been a lot happier with the burgers and beer! :thumbsup: :woohoo:


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## K.L. VanAtta (Mar 23, 2009)

Fellow Racers,

As I remember LeGanke offered a thin walled brass bushing for the T-Jet armature; both chassis and gearplate, in the '60's. I had several and they were very fragile and easily crushed by 10 year old hands using the wrong tools.

By the time I began racing HOPRA in the early 70's in Michigan, many of the "fast" guys were experimenting with brass bushings at the rear axle and the gearplate. Many of these bushings were home made until Tom Coyne of TCP introduced a full line of machined brass bushings that covered all HO shaft diameters, 0.059" through 0.063", large flange and small flange, 0.015" wall and thicker.

In 1973, at a Michigan/Midwest HOPRA race it would not be out of place to see ( tech ) a fully bushinged AFX pan car for either the Amateur of Pro classes.

Be good,

Keith


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## Hornet (Dec 1, 2005)

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## partspig (Mar 12, 2003)

I remember those LaGanke bushings they were as fragile as eggshells. LOL ruined a few meself!! On the bearing note, I used the cheep offshore bearings in my RC cars, till I discovered that the manufacturers could not hold tolerances. One reason they were cheep, they were, for all intensive purposes ,,,,, JUNK!! Stock bearings were better. Seems, to make them more cheaply they relaxed the tolerances, which left tiny spaces for track dust to get inside them, well I think you can guess the rest of the story.


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## SDMedanic (Apr 21, 2011)

I can recall putting a TCP bushing in the bottom armature hole of a few AFX chassis. Trick was to change the top flange from a circle to a rectangle and make a recess in the chassis for the flange to fit into. Of course if it shifted during a race (and it did once with a plastic chassis) the resulting flash, meltdown and smoke screen was spectacular!

When installed in a 100% PC board car the TCP armature bushing was very reliable.


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## slotking (May 27, 2008)

we did not need any bushing for spectacular meltdowns in or any arm poly mag magnatraction class!!!!!!!:freak::thumbsup::woohoo: 

them home built arms provided lots of entertainment

I think they were racing 1 in Hiroshima around 1945


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## SDMedanic (Apr 21, 2011)

Yea but did you ever have a meltdown with the following,

1. Car going down the straight at full speed. Passing cars at will. No warning at all.

2. Flash like a lightbulb going off.

3. Huge smoke cloud.

4. Car rolls out of the cloud trailing smoke for about four feet till it came to a stop.

Motor was fine afterwards. Brush twisted, shorted the brush cups and melted the chassis. Battery power blew the phosporus bronze wipers that were used instead of pickups. You could see track damage at the point where the bushing twisted and the whole thing started. It was amazing.


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## slotking (May 27, 2008)

been close to it! LOL

not sure the car was faster than the others, but it did blow real nice!


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## fordcowboy (Dec 27, 1999)

What size of bearing would you use on a t-jet and where at on the chassis? thanks lendell


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## buzzinhornet (Jan 20, 2000)

fordcowboy said:


> What size of bearing would you use on a t-jet and where at on the chassis? thanks lendell


You can use bearings on a tjet on the chassis and/or gear plate. On the gear plate you can use them on the front hole (motor) and rear hole (cluster gear shaft). On the chassis you can use them on the motor shaft hole and axle holes. 
As far as size, the inside diameter of the bearing should be just slightly smaller than the diameter of the motor shaft (.063) and axles (.063) unless you use tyco axles (.059). You want to keep the thickness of the bearing walls thin so as not to interfere with the brushes. The length of the bearing should be the thickness of the chassis/gear plate.


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## buzzinhornet (Jan 20, 2000)

Here is some tjet bearings I bought from Umpfi's Slotbox (http://www.slotbox.de/) about 10 years ago when he was still selling to the US. They are really nice. One end has a flange. I haven't had much luck installing them. I'm not set up with a very good drill press/jig that it would take to get everything aligned good. I have used a few of them for front wheel spacers with good results. Too bad Axel Umpfenbach still doesn't cater us here in the states anymore.


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## slotking (May 27, 2008)

hard to see, so there is an inner and outer ring?


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## partspig (Mar 12, 2003)

only in belly buttons! :drunk:


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## Bill Hall (Jan 6, 2007)

slotking said:


> hard to see, so there is an inner and outer ring?


Eye dont see no steenking reengs neether!

Per the label...."Bushing".


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## slotking (May 27, 2008)

never mind

i saw


> Here is some tjet bearings I bought from Umpfi's Slotbox


but just now read the bottle label that says they bushings


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