# X-Traction Mystery



## ropes (Jan 30, 2008)

Why is it when I buy all the parts for 6 complete X-T chassis and assemble them, they can in no way compare to the rpm or speed of any of my purchased pre-assembled X-T chassis? Has anyone seen similar results?


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## dlw (Aug 17, 1999)

That is weird........Do a run-through on your 'XT-parts' kits:
1 Check for 'cupped' or warped comm surfaces. Those are bad, speed- robbing culprits.
2 Compare pickup springs with the springs from a pre-assembled car, if needed, gently stretch them to match.
3 Check your bare chassis for comm-brush holders that hang down. you want them parallel with the chassis.
4 Check the pickup shoes for proper contact with the rail. New cars come with the shoes having this problem. Good chance parted-out shoes will be the same way.

Hope this helps.


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## TK Solver (Mar 18, 2004)

Great tips, dlw. 

ropes, one way to do a quick check of dlw's item 1 is to swap one of your "kit" gear plates (with the motor and gears in place) onto one of the factory chassis and see if the car is slower. In my own experience with over 100 X-Tractions, it's the "little things" like the length of the brush springs, shape of the pick-up shoes, and proper (but not excessive) lubrication of a few key spots where shafts sit in or pass through holes. Those are things you can tweak. Clean brush and comm surfaces help some too. A warped comm plate is tough luck...


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## twolff (May 11, 2007)

Most of the 3 cases of XTractions I've gone through wouldn't run for long, if at all, out of the package. These were the Fast and Furious and the release with the Green and Red flammed Nomads. Two of the chassis rip pretty good after I cleaned the grease out of them, oiled 'em up, glued the front tires in place, replaced the idler with a brass one, and adjusted the shoes. The rest are parts donors that didn't run at all, tore up gears in a few laps, or have "Flintstone" wheels.


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## TK Solver (Mar 18, 2004)

Bummer... the Fast & Furious chassis have been some of my best. I even like the gummy tire compound on those. I know I'm in the minority here but I often use those narrow, unstepped shoes on a flamethrower X-Traction chassis and the combination has improved the handling. The front tires don't stay on well though. I glued some but o-rings work best if you can get them cheap.

The releases prior to Fast & Furious were pretty rough. Many of the cars sat with one of the front tires up off the track. I don't want to go back there again...


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## slotnewbie69 (Dec 3, 2008)

*ropes...*



TK Solver said:


> Great tips, dlw.
> 
> ropes, one way to do a quick check of dlw's item 1 is to swap one of your "kit" gear plates (with the motor and gears in place) onto one of the factory chassis and see if the car is slower. In my own experience with over 100 X-Tractions, it's the "little things" like the length of the brush springs, shape of the pick-up shoes, and proper (but not excessive) lubrication of a few key spots where shafts sit in or pass through holes. Those are things you can tweak. Clean brush and comm surfaces help some too. A warped comm plate is tough luck...


if your comm plate is warped,and you have a gear press/removal tool,you can chuck the arm in a dremel and spin it,using a fine abrasive stone,it is possible to carefully true up that warped comm plate.check out slotmonsters,jet wrote a tune up thread for tjets,but a pancakes a pancake...also try to find some bb's and see how many each motor magnet will pickup.kind of like a poor mans gauss meter.this will match your motor magnets,more or less.some guys lap their gears in with toothpaste,aswell.i know it works great on my tjets,but haven't tried it on the plastic gears...


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## AfxToo (Aug 29, 2003)

I would be curious to know if buying all the parts to assemble a complete XT chassis is more cost effective than buying a complete rolling chassis, say from Buds at 3/$25 or 10/$70. Typically, breaking a car up and selling it for parts is a quick and easy way to make more money on it, whether it's an HO car or a 1:1 car. I've seen dealers simply pop the body off and sell the body + chassis for more than the complete car sold for. Go figure.

The cupped comm plate is due to the hard locking washer on the bottom of the armature shaft being installed too high on the armature shaft. The best way to fix this would be to find a gear puller with a small enough window to catch the washer and pull it down a tad. I don't have any such tool in my box but I was able to move the washer on one arm using less elegant methods and the comm plate flattened right out. In the end it didn't really change the performance noticeably and I deemed it "not worth the effort" without having the correct tool. The cupped arm simply gets relegated to fun runner duty, not racing. The occurrence of this manufacturing defect seems to have dropped significantly since the XTs started selling under the AutoWorld brand. Before that, I'd see a few here and there on both XTs and TJet500s. It's more of an usability issue on the TJet500s because of their domed brushes.

My gut feeling is that trying to true a cupped comm plate with an abrasive stone could lead to total arm destruction (TAD), especially when the depth of cupping is greater than the thickness of the comm plate. 

It's rare to find any new toy/hobby grade slot car that comes out of the package with the shoes properly adjusted and running flat. When you unpack a new car, run it around the track for a few laps, then take it to the bench and adjust whatever needs to be adjusted, including the shoes.

Of the dozens of XTs I have the best "out of box" runners are the F&F tuners (besides having the coolest bodies - oh yeah!) with the special tuner wheels. Yeah, the front tires fall off in a gentle breeze and need to be glued or replaced with o-rings, and they have the narrow shoes that need to be adjusted, but as a group the wheels seem to be consistently straight, mounted with the right clearance in the chassis, and run true. My sample size is only 8 dozen so I may have a freak lot of well assembled ones. 

The later wider shoes work well too, but they are still ultra thin and almost never flat. The most whacked handling XTs are the ones with the floppy front ends with the midi-width tires. I think AW bored out the front axle hole for the big wheel release and then returned to a narrow axle but retained the larger axle holes. Not a good combination.


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## dlw (Aug 17, 1999)

> The later wider shoes work well too, but they are still ultra thin and almost never flat. The most whacked handling XTs are the ones with the floppy front ends with the midi-width tires. I think AW bored out the front axle hole for the big wheel release and then returned to a narrow axle but retained the larger axle holes. Not a good combination.


That's what they (AW) did, AfxToo....Used the chassis mold from the 1st DoH/2nd Mopar releases, but reverting back to the original thin indy-front axles. This was done for the first 3 AWXT releases. They went back to the thinner axle holes starting with the R4 Flamethrowers.


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## AfxToo (Aug 29, 2003)

> They went back to the thinner axle holes starting with the R4 Flamethrowers.


Thanks, that's very good to know. I have the lighted release but they don't see a ton of track time because of the pickup spring thing, which takes some tweaking to get running well.


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## old blue (May 4, 2007)

Just my assumption, but don't sellers take apart cars and sell off all of the defective parts and make better cars from the parts they keep? Maybe I am too cynical.


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## Grandcheapskate (Jan 5, 2006)

old blue said:


> Just my assumption, but don't sellers take apart cars and sell off all of the defective parts and make better cars from the parts they keep? Maybe I am too cynical.


 Depends who's doing the selling. If it's someone who is cherry picking parts, there's a good chance that what is being sold is the second tier stuff.

However, a regular vendor realizes that some guys want only the chassis and other guys want bodies. So, you break the car down and sell them seperately. And of course the combined price for buying them seperately is going to be greater than the price of a whole car. But for the guy who only wants one or the other, he saves by not buying what he doesn't need.

No one is going to sperate the bodies and chassis and sell them at the same price as the whole car - why would anyone do that? Eventually you will probably get stuck with some undesireable bodies that you'll have to sell at a loss just to clear out the inventory. This is a business to some guys and they have to make money. The sum of the parts always costs more than the complete car.

Joe


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## NTxSlotCars (May 27, 2008)

O-ring front tires make a huge difference.


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## ropes (Jan 30, 2008)

Old Blue, I was thinking that was a possibility also....I too am cynical!!

NTxSlotCars, I like using the O Rings too. One of the cars I built with new parts sputters around the track until I put on a set of stock front tires, then it does OK at best. Its almost like the magnets were too close to the track and holding it back?

I only built them from parts to satisfy my tinkering bug. I'm a huge fan of Budshocars and will probably just buy new complete chassis next time. I appreciate everyone's input!!


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## Andrij (Jan 30, 2004)

The other day i pulled out 6 Johnny Lightning x tractions out of their boxes to use as runners. Well, 2 moved, 2 sat with the gears spinning, and 2 were rather sluggish.

I looked in my parts boxes, and found some of the old AFX gear clips. You know, the ones that go over the arm plate and hook onto the chassis. I replaced all 6 of the ones on the xtractions with the old AFX ones, and suddenly i had 6 runners. 2 were almost dead silent, and the other 4 ran with a touch of noise.

3 of the cars decided they did not like the front tyres they had, and proceeded to drop them on the track, so i ditched all the front tyres and replaced them with NOS "Goodyear" tyres. Now i have 6 relatively fast, smooth chassis that run really well.

I just wish that i could make my old AFX and magnatraction chassis run as well.

Well, that is my 2 cents worth.

Andrij

PS. I found amongst all the bits and pieces i have, about half a dozen female g-plus chassis with the clip in rear ends. They are narrow enough to slip under some diecast bodies i am in the process of converting.

As soon as i learn how to take proper pictures with my camera, i will post them up.


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## dlw (Aug 17, 1999)

Andrij, on your older Afx's, try checking those pickup and comm brush springs to see if they are compressed, and the comm brush holders. Gently stretch any compressed springs so they match a new one, and make sure the comm brush holders are parallel with the chassis. If needed, give your axles and arm shafts an oiling.


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## Andrij (Jan 30, 2004)

*Hmmmm*

Dlw, thanks for the tips.

I actually started replacing old parts in my old afx and magnatraction chassis's with NOS parts i have lying around, but still i have issues.

I finally started tinkering with a proper power supply i bought a few years back. It is a variable voltage/amperage unit, able to go from 0 to 30 volts and from 0 to 2.5 amps. I set this up for one lane only, for the time being, to try some things out. Cars at 30 volts 2.5 amps go too fast to control, if they last. 2 dead super g-plus chassis and a dead magnatraction chassis later, i turned the voltage down to 10 volts.Just about all my AW magnatraction cars run super smooth on this voltage, whilst my old school afx and afx magnatraction dont like it.I wired up a parma 45 ohm contoller instead of the tomy contolller, but still, my old school cars hate the voltage. Am i doing something wrong?

Well, i will be stripping down almost all the chassis, and rebuilding them. The auto world ones will get a clean and oil, the afx ones, hmmm, dont know what i will do with them.

Hopefully i can get 8 aw chassis to run similar times on the one lane, so i can have 8 parity cars for when my nephews and my son come over. Similar chassis with cars painted to match the lanes.

Well, have a good day.

Cheers
Andrij


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## Xence (Oct 2, 2007)

Andrij,

Here's a trick I learned from someone either here or on a t-jet board. I'm not a t-jet guy whatsoever but the concepts apply perfectly. Just as someone else stated earlier "a pancake motor is a pancake motor." 

Here is how I do it, people here can correct me if I'm wrong or add to it. There are literally just LOADS of tricks that can be done to these cars. I take my cars apart put the top gear plate on an old chassis without magnets or anything else but the rear axle & gear, put the top clamp and idler gear in as well. Once that's together I put the rear axle in a dremel so that now I would have a running set of gears when I turn the dremel on. Be sure to turn this to the lowest speed possible, that's what works for me at least. Put toothpaste on the gears, I use regular crest, and because of the abrasiveness it will de-bur your gears for you. Turn the dremel on for maybe 15-30 seconds, something like that. Once done just remove the plate from the top, try to leave the idler gear where you found it if possible, wash the toothpaste off and then re-install into the chassis you are desiring to use. I've got several VERY quiet and VERY good handling cars because of this little method I learned from someone else.

Oh and just so you know I have like 800 cars and most of those, no kidding, are either xt/mt's. I love that chassis, it is still my all time favorite.

Other people have other great ideas. Please don't hesitate to either steal or glom onto what I'm saying, correct it .... whatever. I always am looking for fun ideas for my cars. This is what works for me though. I hope it works for you.

Cheers,
Xence


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## Xence (Oct 2, 2007)

Oh and one more thing. I just noticed someone else here in this same forum did a REAL nice article on tuning & whatnot, take a look at that. Don't remember the post title. Alot of the time the good tuning tips that work on a JL500 will also work on an MT/XT. Not always but alot of the time.

Hope that helps.

Cheers,
Xence


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## Andrij (Jan 30, 2004)

Thank you

Will take a look at it when i get the time to spare.

Will try that toothpaste trick this weekend

Cheers
Andrij


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