# Question on JL/AW chassis



## martybauer31 (Jan 27, 2004)

Maybe this is a dumb question but I must ask it anyways.... Why didn't someone somewhere along the way when they made/copied the the old T-Jet and magna-traction chassis, make it so you could remove the rear axle assembly like you can on every other modern slot car?

They have changed materials, added colors to the chassis, made the magnets slightly larger (JL T-Jets), why not go one step further and let you pop in a new axle/gear/wheel combo in 2 seconds like the rest of the manufacturers?

Am I missing something? I assume it should be as simple as mimicking something that has been done on slot cars for years now.


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## noddaz (Aug 6, 1999)

Good point....


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## 1976Cordoba (Sep 20, 2000)

But that would make too much sense!

Yeah -- that's a great question, though. Maybe post it in the AW forum and see if Tom Lowe posts up an answer . . .

'doba


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## ParkRNDL (Mar 20, 2002)

I think the pop-out rear axle is a good idea, but I dunno if gear ratio changes will be that easy... Remember, on an inline car, as long as the pinion gear is long enough, you can use different crown gears with different numbers of teeth--but the teeth have to have the same pitch to mesh right with the pinion. On the Tjet setup, if you vary the number of teeth on the crown, you have to either make the crown a different diameter which won't be the right diameter to mesh with the pinion, or make the teeth on the crown a different pitch, which means they won't mesh smoothly with the teeth on the pinion. When you change Tjet gear ratios, it's done by changing the pinion--stock Aurora Tjet was 9 tooth, Aurora Hop-Up is 12 tooth, and Tuff Ones and JL/AW cars are 14 tooth. Crown gears are always 15 tooth. I'm sure there's a way to make some more variety in gear ratio possibilities, but it would involve making new pinion gears, I think, and spacing the crown accordingly...

--rick


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## Pomfish (Oct 25, 2003)

Super II gears are 19 tooth, you can use them on AFX, but there is not enough room to do it on Tjet.

Also the AFX 4 gear chassis uses a real small crown, not sure of the tooth count.

Thanks,
Keith


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## noddaz (Aug 6, 1999)

*Correction (Sorry Keith...)*



Pomfish said:


> Super II gears are 19 tooth, you can use them on AFX, but there is not enough room to do it on Tjet.
> 
> Also the AFX 4 gear chassis uses a real small crown, not sure of the tooth count.
> 
> ...


Correction, the 19 tooth Super II crown will fit a TJet.
Here is a picture of one of my chassis fitted with one...
(Guess I could have cleaned the silly thing first...)
Scott


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## ParkRNDL (Mar 20, 2002)

Oops. I forgot about that.

Hey, so if a 15-tooth AND a 19-tooth can both be made to mesh okay with the same pinion gear, then I guess this CAN be done by playing with pitch (or whatever the size of the teeth is called)... hm. 

Hey Scott, what pinion are you running in that thing? 9T, 12T, 15T, or ???

--rick


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## martybauer31 (Jan 27, 2004)

You're definitely right there, I guess for me it would be more about testing out different tire heights and widths than anything else. Something like that would be perfect at the fray... put on an axle with .360 or .370 wheels for a lock and joiner track, you then move over to a routed track, pop in a .340 or .350 wheel combo. Or even for trying out different shim spacing for your crown gears, it's such a pain in the ass now to realize that you went .005 too far and have to remove the entire assembly and start over....




ParkRNDL said:


> I think the pop-out rear axle is a good idea, but I dunno if gear ratio changes will be that easy... Remember, on an inline car, as long as the pinion gear is long enough, you can use different crown gears with different numbers of teeth--but the teeth have to have the same pitch to mesh right with the pinion. On the Tjet setup, if you vary the number of teeth on the crown, you have to either make the crown a different diameter which won't be the right diameter to mesh with the pinion, or make the teeth on the crown a different pitch, which means they won't mesh smoothly with the teeth on the pinion. When you change Tjet gear ratios, it's done by changing the pinion--stock Aurora Tjet was 9 tooth, Aurora Hop-Up is 12 tooth, and Tuff Ones and JL/AW cars are 14 tooth. Crown gears are always 15 tooth. I'm sure there's a way to make some more variety in gear ratio possibilities, but it would involve making new pinion gears, I think, and spacing the crown accordingly...
> 
> --rick


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## Bill Hall (Jan 6, 2007)

*Snap axle worked great!*

My junk (R&D) chassis box over flows from time to time with the "Fronkenshteen" projects I've inherited from others. :freak: Occasionally I still whittle a bit when I've got some fresh blades. I chose to attempt the snap in axle on a t-jet chassis that was still seviceable, albeit gruesomely vented at the magnet housing. A totally bonehead project, I know! A couple of neat slices with a freshy from the bottom up and you're there. The "v" cut just needs to incur at the rear axle hole with a minimum of material removed from the axle hole OD. It worked perfect.  At the time, I couldnt see the practical use as I usually set up a car and leave it alone, save for shuffling wheels and rubber around. Certainly a group of axle setups with crowns of different tooth counts and a variety of wheels and tires could be useful. I just couldnt see the point unless you had the corresponding motor gearplate setup with the appropriate pinion to snap in as well. At that point I "harrumpfed" and thought why not just have another complete chassis setup.  I did have some concerns about the longevity of the modified rear axle hole's integrity as the t-jet chassis material is easily distorted unlike the more rigid modern chassis designed for snap axles. I really couldnt say how many snaps it would take to pork one out past the point of no return, as the project chassis has returned to the R&D box for proper aging. It would seem that the quick change rear axle would only have racing applications. I'm no racer, just a door bangin' putter, but isnt the slightest chassis butchery a big taboo in most classes?


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## martybauer31 (Jan 27, 2004)

Yeah, doing this stuff to a T-Jet would be a big no-go in most race classes, although I know with the fray class of cars at least you can shave down the rails, I think it's more to be able to fit the chassis under some of the newer race bodies than anything else.

The thing is, they changed what the material is made of as I have read from a few people that you can't boil the new chassis to straighten them, they go bad real quick. I just figure, why not take the chassis and bring it about 40 years closer to being up to date and give them a few more modern conveniences?

It's a heck of a lot easier to swap out an axle combo by popping it out rather than having to break out your wheel puller, gear puller, gear press, wheel press. Why not make it simpler for the guy that wants to race with his kids, and needs to replace a part or two? Before I got back into this hobby last year, I ran my slot cars as a kid with no oil, no new shoes, brushes, etc. I ran them until they died and pleaded with my folks to get a new one because I 8 I didn't know I could do any more to them.

Making it a bit easier to replace some things might make it more fun too.


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## JordanZ870 (Nov 25, 2004)

Snapping the rear axle out, does make for easy removal of cat hair, yeah?! :thumbsup:


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## noddaz (Aug 6, 1999)

*It has a 14 tooth*



ParkRNDL said:


> Oops. I forgot about that.
> 
> Hey, so if a 15-tooth AND a 19-tooth can both be made to mesh okay with the same pinion gear, then I guess this CAN be done by playing with pitch (or whatever the size of the teeth is called)... hm.
> 
> ...


It has a 14 tooth pinion gear...
And it is too fast for my small track! lol
Scott


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## noddaz (Aug 6, 1999)

*Gears again*



ParkRNDL said:


> Oops. I forgot about that.
> 
> Hey, so if a 15-tooth AND a 19-tooth can both be made to mesh okay with the same pinion gear, then I guess this CAN be done by playing with pitch (or whatever the size of the teeth is called)... hm.
> 
> ...


You know.. Funny thing about those crown gears.
If you look at a regular 15 tooth crown gear you have to wonder how anything can properly mesh with it... :lol: 
Scott


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## Bill Hall (Jan 6, 2007)

*Crowns-n-Cats*

Ha Ha Scott! Those crown gears are even funnier under some magnification. Every time I look at one I'm reminded of Jughead's hat from Archie comics (dating myself). Have you had much success with any of the repop gears? Fresh outa' the package they seem to be even more "gritchey" to me, even with a polished, fresh pinion and a lapping. Am I missing something here?


joez870 said:


> Snapping the rear axle out, does make for easy removal of cat hair, yeah?! :thumbsup:
> Yarrgh! Joe thats just too practical! I've reconnciled that the odor of fryin' cat hair in a slot car is part of the ambience'. For me the attack of the atomically mutated giant feline (domesticus killa-car-is) is one of the classic scenarios in scale modeling. There's a dark, foreboding feeling among the inhabitants of slot car land when Gus is on the prowl. I use the the little cat hair swirls from the axles as bird nests in my scale trees. Maybe thats the attraction?


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## Mike(^RacerX^) (Mar 15, 2003)

noddaz said:


> You know.. Funny thing about those crown gears.
> If you look at a regular 15 tooth crown gear you have to wonder how anything can properly mesh with it... :lol:
> Scott


Wow.So its not just me then.I thought I was some kind of magnetic force in the tjet universe where by all of the bad crown gears ever made end up at my house.

Ive had moderate success looking at one under a glass and filing the teeth better.

Tjet chassis with a snap axle??????? The single one thing that could improve them in a big way.

Count me in on some of those.

Mike


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## Bill Hall (Jan 6, 2007)

*To (^Racer X^) RE: snap axles*

Hey Mike, The credit should go to John Adams from Germany, who put the idea in my head one day. Whip out your new #2 blade and have at it. Takes longer to run downstairs and put the bandaid on your finger than it does to make the mod. :drunk: LOL. (I think exactos should come with a secret compartment for band aids and tournequits!) The cut should make the rear axle hole look like an old fashioned key hole. A quick, tight little "V" is all you need. Truthfully I never pursued it much after a couple experimentals. At the time I used a dab of automotive cam lube to help the axle setups snap in and out with the hope of limiting the stress on the easily distorted t-jet chassis material. I like the cam lube cuz by design it tends to stay where you put it, and just gets better as it heats up. I imagine any goo will do. It all worked great but I was all geeked up on my super "slammo" drop axle chassis'. Therefore the t-jet snap axle chassis was uncerimoniously set aside. So any followup data as to actual longivety of the axle hole from the repeated wear and tear caused by snapping is an unknown. {Even further off topic:} Your applied universal theory on Junk Parts EMF is well founded, Consider my alternate theory that all junk parts have a hi-speed, one way wormhole like condiut straight to our parts boxes. This series of conduits radiates outwardly from a central junk parts black hole operating in reverse. It connects all our parts kits in a UGN (universal garbage network)! Our only weapon is the trash can.


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## Mike(^RacerX^) (Mar 15, 2003)

Bill Hall said:


> one way wormhole like condiut straight to our parts boxes.



Thats why I love this place,Bill..................
In a matter of days,something as basic as a snap in axle discussion devolves into two old guys engaging in a duel of wits about worm holes and conduits. :wave: 

American Idol scmidle.This place is much more entertaining.

Mike


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## Bill Hall (Jan 6, 2007)

*I concour!*



Mike(^RacerX^) said:


> Thats why I love this place,Bill..................
> In a matter of days,something as basic as a snap in axle discussion devolves into two old guys engaging in a duel of wits about worm holes and conduits. :wave:
> A little devolution is a good thing. Poor Hank. For him, moderating this bunch must be like a teacher trying to herd a bunch of pre-schoolers on the never ending field trip. :freak: Skill, meriment and good humored mischief were all part of my ancient slot history. To be able to devolve, with what I know now, is nothing short of fantastic. Slots is a great brotherhood that spans the globe. How cool is that?  In an attempt to refocus on crown gears, and axle setups check out E-bay item 140073604869. Yowza!


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## Mike(^RacerX^) (Mar 15, 2003)

Bill Hall said:


> In an attempt to refocus on crown gears, and axle setups check out E-bay item 140073604869. Yowza!


WOw.WHat the heck is going on there??????

Mike


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## Bill Hall (Jan 6, 2007)

*My jaw hit the floor!*

Hi Mike, I'd would have linked this up on a new topic cuz we're buried pretty deep in this thread. It's been kicking around on HO World for a day or so and I figured that somebody with better computer skills would see it anyway and create a new thread with the appropriate link. I think I know how now.  I've been using the internal front sleeve technique for mounting the nifty lookin' Accelerator wheels in the past. Thought I was pretty tricky too.  Then this guy comes along and pees in my cereal. :freak: Being 3/4 kraut myself I have to ask myself how did these guys lose two wars? I'm dyin to try one of those baby diffs. They're not cheap, just right up to the edge of wife wackin' me upside the head. I'm gonna lurk and see what kind of press it gets. With my luck there will probably be a back order list a mile long by then. It's a great innovation. I'm wondering about the added weight and of course durability. We've run posi for so long that it may take some getting used to. Logically to get the full beni the micro diff needs an independent front set up. I guess thats implied. Scrubbing off speed in the corners and over steer from our beloved posi may be a thing of the past. Whats next limited slip and rear steering? LOL!


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## TX Street Racer (May 8, 2004)

Hey guys, I have a couple questions pertaining to the JL/AW and Aurora Tjet chassis. First off, does anyone know if the armatures are interchangeable? How about axles and top plates?

Also, if I want to build a REAL quick car for shooting out of the corners what kind of gear setup would I shoot for?

Would I want the 19tooth Super 2 crown gear? What kind of pinion would I need to use?

I'm still trying to figure out the best way to get a couple different setups.....one for top end speed........and one setup for ultimate launching power out of corners and such.

Please let me know someone...when you get a chance, so I can get a few chassis built up here 

THANKS, Brian


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## jack0fall (Sep 8, 2004)

TX, I came upon this link a while back. It talks only about JL. It might help answer some of your questions. HTH

Jeff


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## TX Street Racer (May 8, 2004)

Jeff, THANKS a ton man.....BIG help bro!


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## martybauer31 (Jan 27, 2004)

Hey TX, I pulled this off of the Slot Stock group, thought it might help you, it's a gear ratio chart:

9 tooth with 15 crown 1:66
9 tooth with 19 tooth crown 2:11
12 tooth with 15 crown 1:25
12 tooth with 19 crown 1:58
14 tooth with 15 crown 1:07
14 tooth with 19 crown 1:35


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## TX Street Racer (May 8, 2004)

So if I'm getting this right....... this would be my most optimal setup to have the most punch out of the corners:

9 tooth with 19 tooth crown 2:11


Correct???

I know this will kill my top end power....but on a shorter track it won't matter.... I just want killer power out of the corners :devil:


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