I posted a while back about an overheated arm in a storm. That turned out to be as simple as brush tension.

My daughter found another one in the box and ran a few laps until it got real hot to touch and smoked.

Now after adding a new arm in it and testing with a 9 volt battery, the arm kinda comes to attention but doesn't spin. Thoughts?

I replaced the stock magnets with another set and same result. I even tried another stock arm and nothing changes.

How do you know when the tension is enough?

I think the more I try to work with these armatures the more they hate me!?

Thanks in advance,
Tom

With the setscrews flush with the end of the brush barrels the brush tension should be just right.
Make sure there is a phenolic insulator on the front of the commutator,
and the armature bushings are snapped all the way down in the chassis.

I really can't think of anything more to it than that.
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Tom, Are you sure the 9v battery has enough juice? Did you try it on the track? Maybe first try it without the real axle. Make sure the arm spins with out binding.. did you have to add spacers to the new armature?

Are you sure you have the right magnets; on proper sides. (White mags on the passenger side)

Spring tension does not need to be a lot.. just enough to keep the brush on th commutator. Too much would be a problem.

Hope that helps,
-Robbie

1) Make sure you put in a stock replacement Wizzard arm or a Tyco arm and not a Tomy SG+ or LL arm.

2) Make sure you put in both a north and a south motor magnet. The motor magnets should be attracted to one another when in the position they go into the car. Sounds silly, but you never know.

3) Make sure you put in brush springs and that the brushes are both touching the commutator.

4) Make sure the arm spins freely when you mount it in the chassis with front and rear bushings, no magnets, no brushes, etc. The arm should have a little free play fore and aft, maybe 0.015" to 0.020".

Note that you can slide the magnets into a Storm one at a time from the top after the motor is mounted and spaced. This is a good time to make sure the arm is spinning freely, before you put in the motor magnets.

5) When you mount the arm, make sure there is a plastic spacer on the front of the shaft, against the end of the commutator. Don't put a metal spacer right up next to the commutator.

6) When you place the brushes in the brush tubes, do it one at a time with the brush tube facing skyward. Put the brush in loose, making sure it does not bind in the tube, and make sure the curved end of the brush mates up with the curve of the commutator. Gently tapping on the side of the car and maybe using a toothpick will sometimes help to orient the curve of the brush with the curve of the commutator. Once the brush is sitting nice, put in a brush spring and put on the set screw, leaving a couple of threads exposed. Repeat on the other side.

7) To put the motor magnets in, slide them in one at a time from the top. It sometimes helps to be rotating the arm in the same direction as the magnet is sliding in to ease it along.

8) Put a tiny drop of oil on the front and rear bushings where the shaft passes through and test it out on a 9V battery. If you got the brushes in correct there should not be too much arcing. If it's arcing a lot or the motor is speeding up and slowing down then start turning in the set screws a quarter turn at a time until the sound smooths out. Try to achieve a nice high pitched whine. Check the temperature. If it's cool then let the car run for 10 or 15 minutes on the battery to seat the brushes. The pitch should increase as the brushes get seated. If it bogs down the brushes may be too tight so back them off. If it starts sparking bad or the pitch fluctuates the brushes may be too loose. Always make small, quarter turn adjustments.

I always hit the brush area with compressed air before making set screw adjustments just to make sure you get all the brush dust out. There should not be a lot.

With stock electrical system, stock brushes, and 0.007 springs the set screws will typically be showing around two threads when the brushes are new. If the brushes are too loose and in danger of vibrating out then use a tiny drop of soft locking thread lock on the threads. I'm talking a toothpick tip worth. In a pinch nail polish will work. I like VibraTite but others like the lowest strength Loc Tite. Don't forget, a very little speck of thread lock.

9) The best way to setup the brushes is with an ammeter but once you get a feel for the pitch of the motor with the rear end out you can do a reasonable job "by ear."

10) Once you get the arm running good on the bench, put on a pinion gear and mount the rear end setup. Make sure you can spin the rear wheels freely and there is nothing binding. Long time users of this type of car, which includes Tycos and Slottechs, can get a general sense of whether the brush tension of the car is set up correctly by running the rear wheels across their fingers. At the very least, if you hold the car by the ends of the rear tires, the weight of the car should allow it to rotate from horizontal to the vertical. If you can hold the rear end between your fingers and the car stays horizontal, the brush tension is too high.

I really do appreciate your replies!

After reading them I did what all of you would do....disassemble and reassemble.....and repeat.....over and over..same thing. Apply the 9volt, the arm straightens and nothing else.
switch arms, same thing.
I even took apart another storm swap one of the arms I had in the first and runs fine. Although I dropped and lost one spring when the phone rang. AHHHHHH!
I'm gonna pick up new brushes and brush springs and try that.
What do you think?

Apply the 9volt, the arm straightens and nothing else

What you're describing really sounds like either same-polarity mags or a G-type (Tomy) arm being used. Since you said it was running before, the mags ain't likely the problem.

Just in case you don't know how to tell the different arms apart:

On both Tyco and Tomy style neutral-timed arms, the crimp tabs that hold the wire are centered between the armature poles. What you need to look at are the slots between the commutator sections. On a Tyco-style arm, used in Wiz and Slottech cars, the slots line up with the centers of the poles. On a "G" (Tomy) or LifeLike arm, the slots are offset to the right of the pole centers when looking nose first at the arm.

OK, now I've got a dozen arms in front of me.

You've got the three sectional contact areas, the three wire connections(poles?) and the split between the stacks. If I am following you,Gene, the wiz use the ones that have the center of the contact section, the wire connection and the split all lined up, right?

OK, now I've got a dozen arms in front of me.

You've got the three sectional contact areas, the three wire connections(poles?) and the split between the stacks. If I am following you,Gene, the wiz use the ones that have the center of the contact section, the wire connection and the split all lined up, right?

Yes, those would be correct.

On G or LL arm, the "center of the contact section" would be offset.

Wow, that simple, huh!

Alright, the first arm that smoked was not stock. It was balanced and blue, not dyed kinda painted, but it fit the tyco description. Since I didn't know about the differences, it was about 50/50 the others I tried were tyco or G. I'll rip it apart again tomorrow and post result.

Thanks again, Gene

AFXToo had me at item #1, but I didn't know the diff.

Anytime, dude. :thumbsup:

Here's a better description, a pic of some worn-out arms...but they make the point.

On on the left is a G-style arm, on the right is Tyco-style. Note where the gaps between the commutator plates are in relation to the wire tabs.

http://i38.tinypic.com/2jdnekw.jpg

Pick up the arm and look straight down the axis of the arm shaft from the front. Rotate the arm so one of the gaps between the commutator segments is aligned straight up.

1) On a zero-timed Tyco style arm (stock) the gap will be aligned exactly with the centerline of the laminations on a pole.

2) If the arm is "high timed" or "advanced timed" (custom arms and Storm Vortec) the gap will be to the left of the centerline of the laminations on a pole (i.e. the commutator is moved counter clockwise versus the zero timed arm). Since the arm in the Storm rotates counter clockwise, having the commutator moved counter clockwise advances the timing. If you wanted to retard the timing you would have to reverse the motor magnets so the arm rotates clockwise and thus the commutator is moved opposite to the rotation of the motor.

I suspect your original motor was high timed so the gap may not be exactly on center.


3) If you apply the same rules, thinking you are looking at a Tyco style arm when it is really a G car style arm, the arm will appear to have extremely retarded timing. Arms are rarely if ever set up this way. What appears to be "extremely retarded" timing is a hint that something is wrong, which is your assumption about it being a Tyco style arm. While the G car arm also rotates counter clockwise, it's brushes are offset by 90 degrees compared to a Tyco arm so the arm timing is not retarded at all.

Note that the upcoming Tomy/Racemasters Mega G car uses a Tyco style arrangement so we're all going to have to be more explicit and say "Tomy Super G+ and BSRT G3/R" instead of "G car."

Incidentally, Tomy Super G+ and BSRT G3/R cars have user adjustable timing. With these cars you are rotating the brushes, not the commutator. So with these cars you move the brushes opposite to the motor rotation to advance the timing and with the motor rotation to retard the timing.

If you are running Storms just for fun, a stock Wizzard arm or a Tyco arm is a pretty good choice. The more expensive "hot stock" arms are good for racing but they will set you back around $10. The main difference between a stock and hot stock arm is the hot stock arms all balanced and dyed. They may or may not also be high timed, they sell both. A high timed arm may give you a little more top end rpm but at the expense of some low end torque.

That was it!!
But, you already knew that.

Thanks!

Tomy/AFX armature in a Wizzard car.
Oh no, what next ? http://i38.tinypic.com/2a6tj4p.jpg

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