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Discussion Starter #1 (Edited)
I just got all the parts and pieces to finish building an AFX/ magna traction chassis.I did ever thing as I always do but this time I had it apart 6 times with little improvement. It seems to run slow in forward but when I turn the car the other direction on the track it screams.I switched brushes and springs.I played with the brush tension and for a moment it came to life.Does anyone know how to check the resistance on these Pancakes. The windings seem to go to ground. Is this common. I appreciate any advice or ideas. thanx- :confused:
 

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Things to check for:
1. See if the Cluster Gear(the one at the back of the gear plate) is sitting at an angle(cocked to one side or the other). JW's sells steel screws to replace the rivet, the part number is X15 and you get 4 for $1.00

2. See if the center hole on the Idler Gear is damaged or drilled off-center.

3. Check your pick-up shoe spring tension......Here's a quote from you: "It seems to run slow in forward but when I turn the car the other direction on the track it screams." Does it scream while you are holding it, or does it actually "run" fast on the track??? If you are holding it, you may be a much better electrical contact between the pick up shoes and the rails, thus getting more current to the motor so it is running much faster.

4. Check the chassis for warpage.

How to check the OHMS on a pancake(T-Jet, AFX, M/T, JLTO, X/Traction)
1. Touch your meter leads to any two of the three commutator plates on the bottom of the armature. This will give you a reading of the resistance on the wire on the corresponding pole of the armature(Plus some of the resistance of the other two poles, since the motor is a complete circuit of three connected poles) Also, touch the center shaft of the armature with one of your leads and touch the other one to the commutator plates one at a time. If you pick up any resistance then you have a "short"(the insulation on the wire is damaged and is making contact with the pole of the armature) in one of the poles and the armature is junk.

If you need any parts for your M/T(or any other cars) or if you are looking for a VERY COOL place to race check out Jeffrey Stillwell's place in Marietta, GA.
His webpage is www.stillwellracing.com He has redigned both of his tracks so the pictures on the website are "out of date", but still pretty impressive. I have raced there(and work as a volunteer race official during the WinterNats which are there every Feb.)

You can also call Jeffrey in the evening at 770-971-0571 to get in touch with him. Just tell him some old bald guy who goes by the name of "Rawafx" (Raw-A-F-X) sent you.

Good luck with your M/T!!!


Bob Weichbrodt
"Rawafx"
A and H Hobbies
Winston-Salem, NC
 

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Another Thing to Check....

Is the brush holder tabs under the chassis. Sometimes they are sticking out under the chassis. Disassemble the chassis (don't lose those comm brushes & springs), and push those tabs upwards (but not too far). This will improve brush contact with the arm.

Also check the brush springs. Some of them may be compressed and may need a little stretching.
 

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Discussion Starter #5
Thanks Guys The Armateur Is Toast, After Checking With My Meter Found Out Its Shorted.just To Triple Check I Pulled A Plate From One Of My Runners And Car Runs Great. Thanx For The Info.
 

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doctorslotcar said:
Thanks Guys The Armateur Is Toast, After Checking With My Meter Found Out Its Shorted.just To Triple Check I Pulled A Plate From One Of My Runners And Car Runs Great. Thanx For The Info.

Hey Bruce, is that the arm and gearplate I sent you last week?? I just grabbed one from my parts stash box...never ran it myself. LMK if this is the case and I'll send you out another one man...... :( :eek: :freak:
 

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Discussion Starter #7
Yea, But Its All Good. Im Learning Alot And Havin Fun. You Got Another ?? Hey, Check Out My New Hangout Www. Stillwell Racing . Com Or Stillwell Enterprises. This Guys My New Best Friend. Thanx Brian
 

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I spent some time working on an M/T last night. This car ran lap times in the 10.50-10.60 range on my track, which has a 107' lap length.
I put some threaded aluminum rear hubs on the car(with a threaded axle of course) and a pair of Super Tires, the car had an older set of AJ's silicones on it.
I then increased the pick up shoe tension on one side so it was even. This perked the car down into the high nines. I then replaced the driven gear rivet with a screw from JW's, cleaned the whole car, put some "special" motor brush springs in, and fiddled with getting the shoes flat. Oh, I also replaced the rear motor magnet, I noticed two "air gaps" in the material. I got the car down to 9.1's but couldn't get it any faster. I tried a couple of different armatures in the chassis, seeing if I could find one with more RPMs. Well, I didn't. But............I did pick out a set of magnets that I thought looked better and put those in. 8.50's became very easy to run. My best lap was an 8.42. Not bad for a 15 OHM stock arm. That works out to 12.7 feet per second. My best M/T and my best X/T are still a little faster, but it's time to upgrade those.
And..... a big box of parts came today from JW's today so I am off to go do some work!!!


Bob Weichbrodt
A and H Hobbies
W-S, NC
 

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Latest M/T project

I did a quick cleaning of my best M/T and attempted about 50 timed laps on my track. I swapped the rear axle to a JW's threaded set-up, noticed some extra slop in the rear axle area(chassis was wron) so then I changed the whole chassis. This car had run a lap of 8.32. After the rebuilding I blistered the record down to 8.05(can the 7's be far off?)
I still haven't gotten into the JW's parts yet, maybe later this week.

Bob Weichbrodt
A and H Hobbies
W-S, NC
 
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