Castle - Make A Special Edition Monster

[GriffinRU]

Originally Posted by BrianG

Speaking of crawlers, wouldn't a stepper motor be a better idea altogether? Granted, the wiring would be a PITA depending on the number of steps...

It would overheat in no time.

[BrianG]

Originally Posted by GriffinRU

It would overheat in no time.

Really? Hmm, I would've thought otherwise. Make the motor large enough and do some electronic trickery to reduce the current X number of seconds after each step coil is energized, or something like that.

[GriffinRU]

Originally Posted by BrianG

Really? Hmm, I would've thought otherwise. Make the motor large enough and do some electronic trickery to reduce the current X number of seconds after each step coil is energized, or something like that.

Stepping through the rocks would be hard, while smooth rolling would be great. Stepper's are good when you need holding torque, but they are not efficient as you can see. While at mid-to-high RPM you can stall them at unexpected load.

[Pdelcast]

Originally Posted by BrianG

Really? Hmm, I would've thought otherwise. Make the motor large enough and do some electronic trickery to reduce the current X number of seconds after each step coil is energized, or something like that.

Brian,

Think about a brushless motor as a stepper motor with magnets and a synchronous controller. :)

[BrianG]

Yeah, I understand that, but I figured since there are so many more phases to get more samples from, slow running would be smoother. In effect, a hundred-phase BL motor.

In a regular 3-phase BL motor, you have to get so many revs before you can get a good reading on actual rotation, so slow/stall conditions are harder to deal with.

Just throwing ideas out, sometimes it's nice to think outside the norm...

[GriffinRU]

Originally Posted by BrianG

Yeah, I understand that, but I figured since there are so many more phases to get more samples from, slow running would be smoother. In effect, a hundred-phase BL motor.

In a regular 3-phase BL motor, you have to get so many revs before you can get a good reading on actual rotation, so slow/stall conditions are harder to deal with.

Just throwing ideas out, sometimes it's nice to think outside the norm...

There are 2 phases (sometimes 4, still wired as 2) and just 200/400 slots rotor, think sync as Patrick said. The only feedback is encoder...

[johnrobholmes]

I have done some research on stepper type motors for crawling, and the main issue is the resistance of the phases (in effort to prevent ridiculous amp draw) and that the ESC would have to be matched to the motor in terms of PWM so that the coils didn't blow under load.

It would be much simpler to just throw a sensor on an outrunner to bump up the starting torque and zero rpm sync, then switch to sensorless at around 500 to 1000 rpm depending on motor. Some over current protection might be a good idea.

[bdebde]

I guess I will have to install the MGM in my truck this weekend (just got it back with 3.23 firmware), since it looks like I will have to wait a while on the MMM sent in for replacement. Maybe the new firmware on the MGM will allow me to run reverse without all the quirks (crosses fingers). Castle IS by far better on the software side, I run reverse on the mm's (as well as the MMM for the whole 5 min I got to run it) and never worry about it, until I need it, it just all works like it should. I have had all kinds of wierd things go on with the MGM at one time or another. One nice thing on the MGM is the ability to read out the max temp (internal) and the amps (hint, hint Patrick).

[lutach]

Originally Posted by bdebde

I guess I will have to install the MGM in my truck this weekend (just got it back with 3.23 firmware), since it looks like I will have to wait a while on the MMM sent in for replacement. Maybe the new firmware on the MGM will allow me to run reverse without all the quirks (crosses fingers). Castle IS by far better on the software side, I run reverse on the mm's (as well as the MMM for the whole 5 min I got to run it) and never worry about it, until I need it, it just all works like it should. I have had all kinds of wierd things go on with the MGM at one time or another. One nice thing on the MGM is the ability to read out the max temp (internal) and the amps (hint, hint Patrick).

Let me know how your MGM does with the Neu.

[bdebde]

Originally Posted by lutach

Let me know how your MGM does with the Neu.

Sure thing.

[TexasSP]

I have the new software and run it with the medusa with none of the reverse quirks that it had running the 600xl. The medusa's being four pole should be quite similar to the neu in behavior I would think.

[bdebde]

Originally Posted by TexasSP

I have the new software and run it with the medusa with none of the reverse quirks that it had running the 600xl. The medusa's being four pole should be quite similar to the neu in behavior I would think.

What version is yours.

guess I better get busy and get the thing installed.

[lutach]

So the new version of the firmware is working good then. Is any of you guys with the new firmware experiencing acceleration when braking? what about no braking at all when it doesn't accelerate?

[TexasSP]

Originally Posted by bdebde

What version is yours.

guess I better get busy and get the thing installed.

3.22, I bought the controller from another guy on here who had sent it off to MGM to have it updated.

Originally Posted by lutach

So the new version of the firmware is working good then. Is any of you guys with the new firmware experiencing acceleration when braking? what about no braking at all when it doesn't accelerate?

On the 600XL I experienced the issues with acceleration when braking and different reverse quirks, however on the medusa these are nonexistent.

[lutach]

Originally Posted by TexasSP

On the 600XL I experienced the issues with acceleration when braking and different reverse quirks, however on the medusa these are nonexistent.

Ok, I guess I won't be selling my 2 MGMs now. I will just send them to MGM and get the 3.23 firmware and after I get them, I'll report back.