View Full Version : tjet chassis bushings


joegri
08-15-2008, 07:51 PM
Hey all can anyone speak to the subject of bushings in tjet chassis. I have one that I bought on ebay and would like to make my own or buy some.I dont think It could be that hard or just blow up in my face.they sure do run smooth. thanx for reading this. also hoping Im in the right forum!:wave::wave:

gear buster
08-15-2008, 08:36 PM
I have made bushing for tjets from brass tubing you can buy from a hobby shop. I took an old axle I was using and tryed it in the tubing to get the right fit. Then drill the chassis to fit the tubing, Cut the tubing a little bit long, Glue in place and trim to length to fit the chassis.
When doing an axle drill both holes straight across. Place tubing in the holes,and square with axle to make sure it lines up just right.
If you get the hole exact you can press the tubing in without glue.
and remember to debur the tubing edges so not to cause no drag on the axles or armature.
Practice on an old JL chassis to help you get a better idea as to sizing.
Hope this helps...

joegri
08-15-2008, 09:15 PM
thhanx gear buster sounds pretty straight forwad to me.the 1 that i do have looks like it may be peened over.but I ll get a better look with my magnafying light.so they just press in .what is the tool to use to cut with dremmel cut off wheel and debur with stone.ok I think I got it.

Bill Hall
08-17-2008, 03:34 PM
Buster pretty well covered it. I'll add couple tricks of my own.

I over bore the gear plate and the chassis together in a wishfull attempt to keep things somewhat straight. The over bore is actually undersize of the actual bushing stock.

Prior to cutting the tube stock one end is carefully flat filed and deburred. Then the bushing is cut a hair long from that end. The other end is slightly tapered and deburred with a handfile. This is accomplished by driving a hard wooden toothpick into the bushing to use as a mandrel. It provides control as the small brass niblet is unwieldy.

The tapered end should just snag in the chassis over bored arm hole so one can go hands free. Using a drill press with a center punch installed into it's chuck the bushing is driven from the topside of the comm pit. I use a piece of old pine stock with a hole in it to back the chassis while pressing and allow the excess bushing material to come through. The excess is bucked off with the dremel cut off if it was left hugely long and then dressed and cleaned with a hand file. I run and old splined t-jet axle through the bores with a cordless drill on low speed to ream the bores. The upper part of the lower arm bushing can really benefit from a lapping. this is accomplished buy using and old armature shaft chucked into a dremel/drill on low and some valve grinding compound. A dab will do ya! ....the idea is to give the lower step of the armature shaft something smooth to ride on rather than a craggy slag heap.

The gear plate is done in the identical manner. One can also do the rear and front axle holes on this manner. By carefully trimming the excess material from the bottom of the new gear plate bushing one can limit the armature end float which can really help with your armature pinion to idler mesh and ultimately a more fixed postion for your comm brushes and springs.

Had some detail pics of all this once upon a time; but they are currently eluding me! :confused:

joegri
08-17-2008, 09:59 PM
Wow very informative/helpful .a chassis with this set up is silky smooth but I only have 1 to compare to. think Ill take some time tomorrow and go to hobbyshop maybe get a bag o trouble." Bushings in tjet chassis what will they think of next sticky tires and mo powerful magnets!"

joegri
08-18-2008, 11:37 PM
Let me just add a little. I picked up the bushing materials at the hobby store today and promptly and without any problems made 1 bushed chassis nice and smooooth.I cant thank you boys enough for all the good info I get here!"let em roll"

slotnewbie69
12-03-2008, 01:25 AM
hey joegri!slotmonsters has some great advice on tjet tuning aswell,talk to jet.really good info on cutting down friction,with step by step instructions/photos..not to suggest you aren'tin good hands here,of course!

joegri
12-03-2008, 08:56 PM
hey slot just happened to look at your reply.thanx for that.just a silly question is slotmonsters a web site if so could you send me the full addy always interested in tryin to make the little cars go quicker and silent. seems like there are guys out there that are way better than me at this hobby and gettin advise from all is helpful.

Bill Hall
12-03-2008, 09:39 PM
Let me just add a little. I picked up the bushing materials at the hobby store today and promptly and without any problems made 1 bushed chassis nice and smooooth.I cant thank you boys enough for all the good info I get here!"let em roll"

Great Joeg!

Glad to hear you hammered one out. Did you fix a new A-dubya or renovate a porked out t-jet?

Roddgerr
12-03-2008, 10:01 PM
Here's Slot Monsters web address
http://www.slotmonsters.com/

slotnewbie69
12-05-2008, 10:47 PM
thanks roddgerr for beating me to it!tjets are tinker tinker tinker...joegri hope ya find some useful stuff there.their tune up tips are great!don't forget about the good old boys here of course!

slotnewbie69
12-05-2008, 10:53 PM
and billhall...holy moly ya know your stuff!these things were toys when they came out.my drummer was joking with me the other night saying i needed to find a different age group to appeal to here to find some racers,and my first instinct was "what a bunch of older guys?"and he was no! abunch of twelve year olds!that's when his education about the slotcar scene began!if it weren't for diehards like you guys,this hobby wouldn't be thriving!

slotnewbie69
12-17-2008, 10:20 PM
what can i do about all the annoying shaft slop/play on my jl tjets?it bugs me and probably robs me of alot of performance...

resinmonger
12-22-2008, 11:48 PM
what can i do about all the annoying shaft slop/play on my jl tjets?it bugs me and probably robs me of alot of performance...


One solution would be to run Tyco 440 or 44X2 chassis...

martybauer31
12-22-2008, 11:59 PM
what can i do about all the annoying shaft slop/play on my jl tjets?it bugs me and probably robs me of alot of performance...

You could swap out that .059 axle and put in a .063 drill blank axle, that would fill up the slop pretty good. I have also heard of guys tightening up the chassis hole with a bb placed over it and pushing in the hole ever so slightly....

joegri
12-24-2008, 09:07 AM
after takin my time ive been able to bush-up 4/5 t chassis.i think if you bush gearplate and chassis (arm bottom) then rear axle holes friction will be reduced a ton and some speed will be gained.im just happy to do some type of upgrade to these old rides and spend some me time at the workbench.i cant speak for all but im havin the best time tinkerin with the small cars!!

Bill Hall
12-24-2008, 07:11 PM
Like Joe sez, if you take your time and do upper and lower armature journals, the driven journal, and both rear axle journals...then go to a t-jet driven/pinion cluster and a t-jet or aftermarket crown gear and axle you should have a very nice running t-jet facsimilie with a hotter arm and magnets. LOL!

Personally I dont re-do the front axle journals. I run on old "slop and doink ya" sectional track so I prefer the front a little looser. In every case I have found the AW chassis to be waaaaaay over sprung so you'll need to fiddle with the pickups.

http://s44.photobucket.com/player.swf?file=http://vid44.photobucket.com/albums/f30/modelmurdering/MOV05185.flv&fs=1&os=1&ap=1

If ya peek inside the back of this Copper you'll see a the brass driven gear. Not all AW's require the full meal bushing deal...some are just sloppier than others. Nor do all require the 9 tooth gear, it just depends on the technical aspects of your track. I have tight radii with intermediate length straights...hence the 9 tooth.

slotnewbie69
12-31-2008, 09:52 PM
Like Joe sez, if you take your time and do upper and lower armature journals, the driven journal, and both rear axle journals...then go to a t-jet driven/pinion cluster and a t-jet or aftermarket crown gear and axle you should have a very nice running t-jet facsimilie with a hotter arm and magnets. LOL!

Personally I dont re-do the front axle journals. I run on old "slop and doink ya" sectional track so I prefer the front a little looser. In every case I have found the AW chassis to be waaaaaay over sprung so you'll need to fiddle with the pickups.

http://s44.photobucket.com/player.swf?file=http://vid44.photobucket.com/albums/f30/modelmurdering/MOV05185.flv&fs=1&os=1&ap=1

If ya peek inside the back of this Copper you'll see a the brass driven gear. Not all AW's require the full meal bushing deal...some are just sloppier than others. Nor do all require the 9 tooth gear, it just depends on the technical aspects of your track. I have tight radii with intermediate length straights...hence the 9 tooth.
man i like this vid.besides the fact that"the cars" are playing in the background,you go on to say your track is "slap and doink ya"..if thats the case then mine is an old rutted gravel road!lol...oh!oversprung,eh...mebbe thats why my auroras stay in the slot so much better...should i snip my aw springs?

noddaz
01-01-2009, 12:25 AM
...should i snip my aw springs?

Maybe not... Sometimes you can get away with smashing them a bit between your fingers.
Then again, if you limit pick up shoe travel you might not have to do that...
(Now there is a speed secret... Don't tell anyone!) http://slotcarillustrated.com/portal/forums/images/smilies/spy.gif

Scott

Bill Hall
01-01-2009, 02:27 AM
I keep a selection of springs on hand so that I can quickly swap them out.

Nodz is right, the squish often works wonders, but it only fixes so much in the way of over tension. At some point you have to snife a half coil at a time until things settle down.

There is also a more advanced shoe bending technique that will lessen overall tension on the shoe without butchering your springs. Naturally it may not be legal everywhere. Essentially it raises the shoe hook fulcrum, but requires that one is comfortable adjusting contact patches and executing Z bends.

Remember that as one limits travel, shortens the window height, coil bind can also come into play.

http://howorld.fsmra.com/archives/howto/tuneup/tjpickups/tjet.html

Here's a good primer. The last line of paragraph 7 contains the true secret of shoe tuning. Knowing the difference between what is too much and what is not enough; and most importantly, "when to leave it alone" can only be learned via repetition and observation.

slotnewbie69
01-01-2009, 04:37 PM
I keep a selection of springs on hand so that I can quickly swap them out.

Nodz is right, the squish often works wonders, but it only fixes so much in the way of over tension. At some point you have to snife a half coil at a time until things settle down.

There is also a more advanced shoe bending technique that will lessen overall tension on the shoe without butchering your springs. Naturally it may not be legal everywhere. Essentially it raises the shoe hook fulcrum, but requires that one is comfortable adjusting contact patches and executing Z bends.

Remember that as one limits travel, shortens the window height, coil bind can also come into play.

http://howorld.fsmra.com/archives/howto/tuneup/tjpickups/tjet.html

Here's a good primer. The last line of paragraph 7 contains the true secret of shoe tuning. Knowing the difference between what is too much and what is not enough; and most importantly, "when to leave it alone" can only be learned via repetition and observation.

thanks guys!i had already read all of jets stuff on slotmonsters,but it,s nice to read it here,and howorld.thats a good website,to be sure!