9V Buggy Motor Question

[topo84]

This seems like a dumb question but I thought I'd ask anyways.

I've built a small Technic model with a 9V buggy motor (part 5292) attached to a 9V battery box (part 2847c01) and I've become worried that this isn't the best combination. After a few seconds of running through the battery box, the motor will wind down and stop turning unless I give the motor a second to rest before trying again. I assumed that was normal, since this is a high-energy consumption motor after all. But when running the motor at the top speed it would go, I noticed little blue sparks in the vents at the bottom of the motor.

Is that normal? Is it safe to run that motor through that battery box? Will I burn out my motor if I keep using it in that battery box? Am I being too cautious? Is this too many questions?

I just realized that the Mobile Crane (set 8421) has the same motor and battery box, but I'm assuming that models motor is geared down to some extent while my model is geared up.

Any insight would be much appreciated. Thanks!

[TechnicRCRacer]

The sparks I am not sure much about how safe it is, but the slowing and stopping is definitely normal. The buggy motor will stop when it gets too hot to protect itself from damage.

[Andman]

Never seen blue sparks coming out of my buggy motors. Could the motor be worn out?

[aol000xw]

That battery box is the intended counterpart to this motor.

I am not sure but I don't think it is a brushless motor so the sparks probably are the brushes moving from one conmutator segment to the next. Maybe the brushes are worn down, or the springs have wakened. Dust, particles from the brushes, even humidity can cause that.

The slowing and stopping sounds like a thermistor protecting the motor.

Edited October 22, 2019 by aol000xw

[LegoTT]

I can't find the reference of your battery box on internet or bricklink. Maybe a typo ?

[topo84]

UPDATE:

I think I solved the issue with a bit of experimenting.

One thing I failed to mention was that the motor was geared up, as well as spinning two large Technic wheels. The quick rotation of the wheels might have been spinning the motor too quickly, causing the overheat-shutoff and the sparks (which I haven't seen since my last post). Just an idea, but sounds plausible to me. I tested the motor without anything attached to the battery box and had no issues. Thanks to all who gave suggestions.

1 hour ago, LegoTT said:

I can't find the reference of your battery box on internet or bricklink. Maybe a typo ?

 I pasted the part number I posted into Bricklink and got the right battery box, I'm not sure what the issue was. Sorry about that.

[Maaboo the Witch]

If anyone's wondering, the battery box the OP mentioned is this one: