Motor braking. - RC-Monster Forums

BrianG · 05.20.2007, 04:40 PM

If I read his post correctly, he was using a scotchbrite pad to hold the motor and the abrasion wore away the anodixing off...

GriffinRU · 05.20.2007, 05:13 PM

I can explain to R&D engineer how it works and why, here we have other problems...

Post the Q and I will answer! But it is very difficult to explain how it works if there such big gaps in theory...

Bring, I am sorry but while your experiment is great, but the way how you explain what happen is really bad!

Do not treat it simple and do not make as complex as it looks..

BrianG · 05.20.2007, 06:16 PM

Quote:

Originally Posted by GriffinRU

...Bring, I am sorry but while your experiment is great, but the way how you explain what happen is really bad!

Do not treat it simple and do not make as complex as it looks..

Well, sometimes the answer is simple. I mean, if the FETs short the windings, how is that different than the experiment? The experiment would display the absolute most braking ability since there are no losses in other components since the windings were simply shorted, and there was no PWM action to reduce the effect. Please forgive the ignorance, but I am trying to learn the same as many people here.

zeropointbug · 05.20.2007, 07:06 PM

I agree with you Brian, that is the most it can do when shorted.

I think a better experiment would be to bring up to speed the wheels of a MT, and have motor connected with no ESC (motor is on motor mount). And then short them out and see how fast it slows it down. Keep in mind, it doesn't take much resistance further up in the drive train to slow things down wind (wheels).

The drill experiment shows lots of resistance, but that is a drill, and a drill only puts out more torque the slower it spins.... so it doesn't show us how fast it would slow it down. I'm thinking a flywheel experiment?

Artur, is there a diagram that you have, or COULD make that would show us exactly what is going on during braking in the FET; AND/OR when the voltage is high enough to charge batts?

zeropointbug · 05.20.2007, 10:55 PM

Just a thought, another way to brake an R/C car is to use alum. disc with neo magnet (disc type) and have a servo driven actuator to bring it into very close proximity to the disc. This creates tons of shaft resistance, and would not stress motor or anything. BUT, would not be super responsive as the servo would have to move it in and out. But would always work.