RE 385 Motors

[Semmy]

Just looking at slowing down my KV1 a little as I don't want a speed machine!

I already have the 3:1 uprated gearboxes (Asiatam I think) and was pondering a change of motor to the Mabuchi RE385 (also MFA similar spec) motors. This should if the figures I have seen are correct, roughly halve the speed @7.2V with a current draw of up to 1.4A.

Anyone had experience of these motors?

[Andy in Cheltenham]

You'll loose a lot of torque for starters. I used 380s in my first RC car. A 540 was a big improvement. Why don't you restrain your speed controller? Is that possible?

[Semmy]

That would depend on the spec of the motor currently fitted, after all a similar power motor at a lower speed will have a greater torque....

Mabuchi RS-385SH 12V 8170rpm 0.89A 7.89mN.m 6.74W

MFA/Como Drills RE - 385 12v 9281rpm 0.837A ?? 6.21W

Current beastie appears to be a 380 sized motor but is unbranded so it's tricky to pin down a spec. Even different manufacturers versions of the same motor differ!

[Semmy]

You'll loose a lot of torque for starters. I used 380s in my first RC car. A 540 was a big improvement. Why don't you restrain your speed controller? Is that possible?

The 380 motor is a different beastie altogether, 540's will not fit, why add a resistive load to the controller to reduce the speed, this will just flatten the battery quicker?

[Andy in Cheltenham]

Sorry, I didn't know what you currently had.

[Semmy]

No worries!

It amazes me how little information is available for such an integral component.

The aims of switching to lower speed higher torque motors are as follows:-

1, Lower speed to mimic scale offroad speeds (not the road speed which is most often quoted)
2, Reduced gearbox input speed to reduce "oil fling" and thus increase gearbox life
3, Lower pinion speed will reduce gearbox noise
4, Should give more progressive speed increase

[Saxondog]

Gearbox/motor calculator program on this forum. here is the link, Saxondog

http://www.rctankwarfare.co.uk/forums/d ... ftware.php" onclick="window.open(this.href);return false;



Using the program you can change the pinion gear field to alter,speed and torque. The speed rating for the different size motor based on RPM is not the best way to change the values, gearing changes like the pinion gear will be the simple method and the least expensive.

[Semmy]

Fair comment on the cost aspect! hough I am looking at the other possible advantages if possible (I tend to do quite a bit of experimenting).

[Semmy]

MFA Torpedo 400 motors seem pretty good, will have some numbers together over the hols.