Coasting...

[Dogsbody]

We are a non-mag club and a few racer's cars (Revoslot for example) seem to have a longer coast when the power is shut off at the end of a heat. We all use the same PM controllers with the adjustment for throttle and brake. Any ideas on what is going on here?

[chappyman66]

Coast has a couple of main elements.

1) Friction in the drivetrain....axle to bearings and gear mesh both impact the coasting. The better everything is aligned, the longer it takes to slow down.

2) Motor - primarily brush tension but also magnet strength and distance to the armature (the actual winding also matters) as well as alignment of the can and endbell bearings. You can see motors with strong "brakes" not coast as far as those with less "brakes" (Carrera motors vs Scalex). Having said that....ball bearings in the motor make a difference as well.

So.... it's worth looking at both areas.

[slothead]

This was a big deal when I used to race on a commercial track and in an oval racing club. There might be a car you were battling to get by, then on a power call being able to coast past them and restart ahead was an advantage. The guy who was tops at it was meticulous in how he set up his cars. Every week he'd tear everything down, clean everything, and reassemble. Motor alignment in the chassis, gear mesh, and axle-bushing fitting and alignment were things he spent a lot of time on. It's all about reducing friction where you can.

We also both made sure our front wheels were able to rotate independently since all 4 tires had to be weight bearing during tech inspection. That was easy to do on wheels with slide through axles and set screws by soldering a small washer on one side and removing the set screw. Not sure how to do this with press on plastic wheels, so using the nail polish technique might be the best bet.

[RichD]

Since your cars coast more when the track power goes off I suspect that the track power relay is in the wrong place. If that was the case brakes would be disabled any time the power was off. If your track has standard positive polarity wiring try moving the relay to the plus side.



If your track has negative polarity wiring put the relay in the negative side.