# Armature plate question



## Boots Baker (Dec 10, 2012)

Will an original Aurora T-Jet aramature plate fit an Autoworld Ultra G chassis? 
Or vice versa? What is the real difference between the two? I know it is probably a remedial question but just getting back into running cars again.


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## Ralphthe3rd (Feb 24, 2011)

Yes & No, IE-you can swap(just) arms between Aurora and JL/AW ....altho Top plates *won't* interchange without a bit of surgery.
Technically the aurora and JL/AW arms are very similar, but not an exact copy. IMHO- the Aurora Arms were much better designed....just ask Jim Sgrig.
PS- I myself HAVE converted a JL top plate/Arm to fit an Aurora chassis(and the chassis wasn't modded), but it was just an experiment, and I didn't have much to lose if I butchered the JL Top plate.


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## Boots Baker (Dec 10, 2012)

*Arm Question*

I wondered about the surgery part, appears the the back of the plate won't fit, but could be modded, but the drive gear hole is also different it appears.


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## Ralphthe3rd (Feb 24, 2011)

To mod the JL top plate, I whittled down the index nubs to mate to the aurora chassis notches, and the cluster gear shaft hole was re-drilled at a very slight angle. Then everything lined up and meshed fine. BTW- I converted the cluster gearing to a standard Aurora 9 tooth Drive Pinion, ditching the JL Tuff Ones tall 14t pinion. The chassis is a lightning bolt now, albeit it may have sacrificed a little top end speed ?


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## Ralphthe3rd (Feb 24, 2011)

Foot Note: Was it worth it ? IMHO- NO ! I'll stick to all Aurora Parts, or a rewound aftermarket Arm for my NOS AURORA chassis. I'm done messing with JL/AutoWorld CRAP ! Their chassis and motors are so far out of spec, and made of crappy materials with lousy quality control during assembly, I just can't take inferior crap that needs rebuilt/blueprinted right from the box to make it run smoothly..... and FYI- the ONLY Reason AW went to the Ultra G chassis, with that stupid Neo Traction magnet, was to cover up the sloppy QC and out of spec tolerances of their chassis, which is a cheap imitation of an Aurora Tuff Ones Chassis. (End Rant) YMMV


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## beast1624 (Mar 28, 2009)

Ralphthe3rd said:


> Foot Note: Was it worth it ? IMHO- NO ! I'll stick to all Aurora Parts, or a rewound aftermarket Arm for my NOS AURORA chassis. I'm done messing with JL/AutoWorld CRAP ! Their chassis and motors are so far out of spec, and made of crappy materials with lousy quality control during assembly, I just can't take inferior crap that needs rebuilt/blueprinted right from the box to make it run smoothly..... and FYI- the ONLY Reason AW went to the Ultra G chassis, with that stupid Neo Traction magnet, was to cover up the sloppy QC and out of spec tolerances of their chassis, which is a cheap imitation of an Aurora Tuff Ones Chassis. (End Rant) YMMV


Preach on, brother Ralph! Only problem for us down here is some goober decided to make a 'box stock' AW class for our next series...7 races. How can you make one of these t^rds last for 7 races? We are figuring it out!


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## slotcarman12078 (Oct 3, 2008)

The top plate can be modified to fit, but getting the arm and pinion shaft to line up takes a bit of work. Also, the pinion shaft on the JL is smaller than the Aurora shaft. I have modified JL chassis to take an Aurora pinion gear by opening up the pinion shaft holes. You have to favor the drilling towards the rear of the chassis to get proper gear mesh (in the top plate and chassis pinion holes. If you don't have a gear press, it's best to use the JL driven gear with the Aurora shaft. Keep in mind when doing so, you'll need to swap out the crown gear with an Aurora crown to get it all together. I've done more than a few pinion gear swaps and it really tames a JL chassis to a drivable level. Even with NOS Aurora chassis at the 12.00 range, it usually winds up being cheaper to just buy the real deal, unless you have all the parts already to do the conversion, and the same number JL chassis to convert.


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## Boosted-Z71 (Nov 26, 2007)

Beast, I have some JL cars that were "Fray prepared" for such a similar race, I built 12 cars that were all bullets, and we only fried 2 arms, in the process, one was bad from the start, the other got ran to death. Normal prep techniques work really well and concentrate on the gear train & the electrical connections (shoe hangers) to get the speed out of them. They are very picky on adjustments and little adjustments either make milestones forward or backwards. Shoot for making the chassis run consistent, 

Boosted


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## lenny (Feb 29, 2000)

beast1624 said:


> Preach on, brother Ralph! Only problem for us down here is some goober decided to make a 'box stock' AW class for our next series...7 races. How can you make one of these t^rds last for 7 races? We are figuring it out!


The JL arm suffers mostly from really bad QC. The bushings on the arm are inconsistently assembled on the shaft, which results often in either the shaft being off center, skewed at an angle relative to the comm stack, or the lower bushing is pushed up too hard and too far resulting in a bowed, flexed or generally messed up comm plate. Add to that the tin that covers the copper on the comm plate (to protect the copper from oxidizing) and the inconsistent solder on the tabs and the arm in it's current form is generally not well made.


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## mahorsc (Mar 26, 2008)

beast1624 said:


> Preach on, brother Ralph! Only problem for us down here is some goober decided to make a 'box stock' AW class for our next series...7 races. How can you make one of these t^rds last for 7 races? We are figuring it out!


i have cars that i still race that were built 9=10 years ago all stock including brushes one has won the championship 3 years in a row they are like any car you have to spend time with them and learn what the want 
if you want i will build you one just send rules and a few chassis and i an put one togeter for you
kevin


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## mahorsc (Mar 26, 2008)

lenny said:


> The JL arm suffers mostly from really bad QC. The bushings on the arm are inconsistently assembled on the shaft, which results often in either the shaft being off center, skewed at an angle relative to the comm stack, or the lower bushing is pushed up too hard and too far resulting in a bowed, flexed or generally messed up comm plate. Add to that the tin that covers the copper on the comm plate (to protect the copper from oxidizing) and the inconsistent solder on the tabs and the arm in it's current form is generally not well made.


so does the t-jet arm 
how many arm did you go through to get a good one i have a couple hundred t-jets and i have 4 almost perfect arms the others have to be balanced and/or trued 
yes jls have issues but i dont think any worse than any other manf
my 2 cents


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## lenny (Feb 29, 2000)

mahorsc said:


> so does the t-jet arm
> how many arm did you go through to get a good one i have a couple hundred t-jets and i have 4 almost perfect arms the others have to be balanced and/or trued
> yes jls have issues but i dont think any worse than any other manf
> my 2 cents


I'm only speaking from my experience with trying to get a mass produced armature made. If the QC for AW improved, people might take that arm a bit more seriously because overall the materials are good, but the manufacturing is awful.


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## Dyno Dom (May 26, 2007)

For racers who want to get into running T-Jets without acquiring an inventory
of original chassis/parts to sort thru, the AW/JL chassis offers an option.
If a club bases a class on the AW/JL chassis, then everyone fares thru similar
product deficiencies. Hopefully, the upcoming Dash-Jet chassis will be a superior quality alternative.


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## alpink (Aug 22, 2010)

Dyno Dom said:


> For racers who want to get into running T-Jets without acquiring an inventory
> of original chassis/parts to sort thru, the AW/JL chassis offers an option.
> If a club bases a class on the AW/JL chassis, then everyone fares thru similar
> product deficiencies. Hopefully, the upcoming Dash-Jet chassis will be a superior quality alternative.


at a fair price


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## Ralphthe3rd (Feb 24, 2011)

Another forum member PM'd me to post some pix of my top plate conversion, so here they are, although it doesn't show much, it all kinda looks OEM !

Corvette Grand Sport-FrankenJet ! What Evil lurks beneath this Corvette Body !?









Looks like a standard Aurora chassis from the bottom 









Aurora T-Jet Chassis bottom, with a Jl/AW T-Jet top Plate & Arm. Combined together they make an F-Jet 

















The Aurora Chassis(bottom) is completely stock and unmodified, save for the wheels and axles. But the JL/AW top plate was modded to fit the Aurora chassis. The locator nubs were whittled down to fit the aurora notches, and the cluster gear shaft "hole" was slightly angle drilled to line up, and was then fitted with an aurora 9T drive pinion- but still uses the JL/AW Plastic top gear. The mesh is fine, and no worse than on a standard JL/AW chassis. The chassis also exhibits alot of coast when off throttle, even tho high strength AW magnets were used.
*Note- there is slop in the Cluster gear assembly when the top plate is off the chassis, but the excess slop tightens right up when assembled. If I recall, I also slid the pinion drive gear slightly down on the cluster gear shaft, so the shaft tip wouldn't extend so deeply into the chassis hole. So far, after dozens of hours of use, everything still looks cherry and tight. And FYI- this was the very First time i had the chassis apart since I built in TWO YEARS Ago !


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## mahorsc (Mar 26, 2008)

dont get me wrong i cant wait for Dash armsand chassis' it will be great to build a car and not have to go through a box of arms to get one to work or a flat chassis
i run a lot of dash products (magnets bodys) and the an amazing product even use his mags in jl/aw cars if the car likes them


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## Dyno Dom (May 26, 2007)

Ralph, Thanks for pics & info, nice clean build! :thumbsup:
Do you use independent/weighted front ends or slip on rears?


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## Ralphthe3rd (Feb 24, 2011)

Dom, Thanks for the :thumbsup:

As for tires and wheels, I use all kinds, depending on the car/chassis and type of course I'm gonna race on. I have used weighted front ends, both indy and joined. On this particular car, which has a warped chassis, I use two different sized fronts on an Indy Axle(simple T.O. axle/wheel combo) that is not weighted, but may look that way since I'm using Wide front wheels, but with narrow tires- after a few experiments, with both Wides and narrow fronts. BTW- I always use slip on tires, but use various rims, sometimes I use double flange delrin rims.


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