4th-Jan-25, 11:38 AM
Looking at my photo archive I see it was January 2019 when I first started running 1/32 scale digital slotcars with brushless motors. At the time they were sensorless brushless motors. The cars ran fast, no slow speed control and no brakes - they certainly needed some taming!
Wind forward six years and I’ve returned to the challenge.
The first sensorless trials will use a 7.5V DC powered track and the 4300KV 1625 motors. Theory says these motors should spool up to 32,250 RPM at 7.5V with full throttle. Measured with a tacho (i.e. in the real world) they read 32,800 RPM. That’s a difference of less than 2%, not a bad starting point.
Also, the ESC (electronic speed controller) which I am using has an option for proportional braking when the transmitter’s trigger is pushed rather than pulled. This is working nicely too.
Next step… full assembly onto the NSR Z4 then some testing using the H & B Test Bench. This will provide some rolling road m/s figures and current draw figures.
c
Wind forward six years and I’ve returned to the challenge.
The first sensorless trials will use a 7.5V DC powered track and the 4300KV 1625 motors. Theory says these motors should spool up to 32,250 RPM at 7.5V with full throttle. Measured with a tacho (i.e. in the real world) they read 32,800 RPM. That’s a difference of less than 2%, not a bad starting point.
Also, the ESC (electronic speed controller) which I am using has an option for proportional braking when the transmitter’s trigger is pushed rather than pulled. This is working nicely too.
Next step… full assembly onto the NSR Z4 then some testing using the H & B Test Bench. This will provide some rolling road m/s figures and current draw figures.
c

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