Twist-55 and Schulze U-Force 75
 

The Schulze 75 has an option to choose between 8 mhz or 16 mhz for the motor to be used (brushless that is) and I dont know which to choose 8 or 16? some help would be...a.a..helpful.:P:

Normally it depends on the type of magnet of the rotor. in this user manual it says it is best to choose the setting that keeps your controller the coolest...

yes it does and the magnets type is neodym. So...

Let me know how the twist motor works out! I may try one in my sedan or xxx-t.

So do as the user manual discribes?

But I've tried to programm it and I simply could not do so. The manual says that once you connect the battery the esc should give one beep, but mine gives an escalating number of beeps from a low and faint beep and up to a loud and clear one. Whats going on around here???!!

Ok, ok.. I've just figured out the problem. The rceiver jumper was plugged in the wrong side (I know...Veeery stupid of me) and now its working fine, but I would like to know if its possible for me to cut off the winding that is coming out of the motor that is similar to a wire, because I want to extend it in the right way that will suit my touring shaft driven car.

Well?!..is it possible to cut the winding cables that is coming out of the twist-55?

Never cut the motor wires on a brushless motor.

Those are litze cables, and it are very much small copper shielded wires. If you make those cables shorter, you probably need to strip the isolation of the individual cables. Don't shorten them, because you need a special chemical stuff which solves the isolation.

Well then is it okay to bend them?

Yes, no problem at all.. Don bent them over and over and make sure that they don't have stress on the contact area of the connectors to the speedo.. (might damage those plugs on the long run)

Instead of bending the wires I've finally made my decision and connected three deans 12 guage noodles to the motor and I've finally had the chance to try and feel the power of the twist-55 in a touring car and all I can say for now is: WOOOOOOOOOOOw too much power and acceleration.

there is no such thing as too much power.. :)

Well you're maybe right.:p

So Serum do you think that the twist-55 can go head to head with the high end brushed motors like the 9T and the 8T since it is almost as powerful as the Basic 5300? what speeds is it capable of? Also is this gear ratio suitable for the motor/esc in a touring car: 6.40:1?

I really have got no idea about the quality or the specs of the twist-55 motor. If it is as powerfull as the 5300 as you say it is, you don't need to worry about speed. 65mph would be easy to achieve then.. though it would be insane.. are you planning on running lipolys, or 6-7 nimh's?

The twist 55 is similar to the hacker c40 (smaller rotor than the lehner, so less torque, but quicker acceleration). That motor can compete with a 9 turn brushed motor.

What I know is that the hacker C40s is 600 watts rated, but the twist 55 is 750 watts which means its a bit more powerful. What I truly want is a speed around 45-48mph at 7.2 volts. And once again, do you think that the 6.4:1 FDR is reasonable?

The ratio is kind of tall, actually. 8:1 or 9:1 is more along the lines of where I would start for the FDR.

Do you use the same FDR for the 5300 motor? like 8:1 or 8:9

I would START with this ratio and adjust from there, based on performance, heat, runtime ec.

What speeds do you get out of these motors at 7.2 volts? my tb evo 4 shakes like crazy when I pull the throttle to 40% at 7.2 with the ratio I've mentioned and ofcourse with out making the wheels touching the land.

Mike, what is best for the K.T-55 motor: 8 mhz or 16 mhz? I want a guess from your mind. I think your guess will not disappoint me at all.

My guess is 16khz. I hope to not disappoint!

What reasons support your guess? and ofcourse whether your guess is right or not it doesn't mean that it will disappoint me for real. Its only a guess in the end. Thanks any way buddy.

I hope you guys are talking khz's instead of mhz?

Just do as discribed in the manual; use the setting that keeps the setup the coolest..

The reason for my guess is the higher rpm of the motor. Generally, these high rpm motors like higher a switching frequency. The only way to really know is to try both ways.

Okay, whats the whole thing about switching frequencies? what's the work of this function? And I'm sorry for turning things upside down. It is truely khz and not mhz. Thanks for correcting me Serum.

It is a bit hard to explain, but that frequency is needed to build up the signal. It are all pulses, and a combination of quick short pulses acts like 1 large puls.

It simple is the speed the controller have got to create one large pulse. That is why higher frequency allows you to run the motor in a higher rpm range, because the faster the motor turns, the shorter the pulses need to follow up/combine. Thought the higher the frequency, the more your controller has to work...

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

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!

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.

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.

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).

35mph is my guess, depending on tire size.

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.

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)!

Oh, I see.

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).