Twist-55 and Schulze U-Force 75

[captain harlock]

then this means 16khz= hotter esc and higher rpm. Right?

[RC-Monster Mike]

It may or may not mean a hotter esc. A lower switching frequency trying to keep up with a high rpm motor may well run hotter. Typically, a higher switching frequency is required for the higher rpm motors. You will have to try it and let us know!

[captain harlock]

Well I've already tried it on 8 khz and the controller became hot in a short period of time. The running took place inside my house. Now I have switched to 16 khz and I will most definitly inform you about the out comes.

[RC-Monster Mike]

Running high rpm motor in such a confined area will surely heat up the controller. I am curious how the frequency affects your temps, though. Particularly with the same running conditions.

[captain harlock]

I've just changed the gear ratio from 6.5:1 to 8.0:1 and also shifted from 8 to 16khz. I've tried it inside my house once again and it seems that the motor and esc are working fine and I also added a 5V cooling fan to do the cooling job, but it seems that I have to take it for a real test. Well Miky, what speed am I going to get with this motor and the newly changed FDR( a guess will not hurt at all).

[RC-Monster Mike]

35mph is my guess, depending on tire size.

[captain harlock]

I thought this thing is supposed to take down a 9t brushed motor? 35 mph is a bit an underestimation. All I want is a decent speed at 7.2 volts and remember, its a touring car that I'm going to use and not an off road rig. Even the N.SS5800 system when it was tested in a b4 by Extreme Racing magazine did a speed of 39.7 mph as far as I can remember and you think the Twist-55 would only push my touring rig to 35mph? Are you joking by the way?!!! That would be different story if you are joking. I'm not pissed off at all, though. Thanks for guessing.

[RC-Monster Mike]

I did a quick calculation with the FDR and came up with around 35mph. I guess you could bring the FDR back in the other direction to get some speed. The motor/controller will easily push your car over 40 with the right gearing, but I think my initial FDR suggestion was a bit conservative (I start conservative and go from there when suggesting gear ratios)!

[captain harlock]

Oh, I see.

[RC-Monster Mike]

By the way, a 9turn brushed motor would hang with that motor pretty tight (except it would get a poor runtime and needs frequent rebuilds).

[captain harlock]

You mean my only chance is to build up a 7 cell pack? I want to take it ( the 9t) down no matter what.

[RC-Monster Mike]

I wouldn't say the 7 cell pack is your only chance, but it would give you the easy win!

[captain harlock]

Tall gearing is another one. Right?

[RC-Monster Mike]

Right. On a tight track, tall gearing may thermal the controller (fix this with a fan).

[captain harlock]

I guess a small 5v fan is enough for cooling. Dont ya think so?