Brushless drive ESC

[maddox10]

6-1 gearratio to 90mm wheels on 3S.

I have 42-35's 750 KV as backups, but implementing those is another matter.

[overkill]

Its hard to smoke a Colson - just breaking traction at low speed is a very good sign the motors are adequate. A 19:1 gearbox and a higher KV motor should do even better. Its good to see us Aussies leading the way on brushless drive!

[maddox10]

In Nebelwerfer 2 the Frankensteined Gimson GR02's 24/1 with HK 2838 2850 KV inrunners mated to the Trackstar 25A sensorless speedo's work fine. And that's with large, soft 130mm RC wheels. And that one is standing by for months now. On the other hand, that's a 6 kg raptor.

And yes, it's the starting speed that is a problem with the current Calliope drives. Once it goes, it goes well.

[Daniel]

NTM 42-38's with Trackstar 80 controllers on a 4-cell battery. 10:1 onto 100mm wheels but the total setup is only 6kg and has problems with the chains and can't afford to rebuild it yet.
This is a sensorless setup and as you can see the delay isn't noticable.

I also forgot this older test with the same brushess motors/ESC but with 25:1 onto 250mm wheels. It was a 10kg setup. Video was origionally posted 12 months ago and I still keep reading that sensorless outrunners won't work. Really wish I could afford to build the new robot the drive was origionally brought for.

[cavecrusher]

I'll just post this link again. Maybe someone is interested in some.

http://vedder.se/2014/01/a-custom-bl...or-controller/

[Mouldy]

That esc looks bang on Tim- shame there not sold pre-built.

[leorcc]

So far our test results are promising, but like Mario said in Caliope we married a too small a motor with too small of a gear ratio. I'm convinced that with a dual stage gearbox the drive would have been fine. But as it is it is not taking off and stopping fast enough. The Brushless drive in de raptor performs really well, similar performance as the Scarifier video from Daniel.

[daveimi]

Aren't Botbitz a brushed ESC originally?

[overkill]

No, the TZ85 is originally a brushless plane ESC that Steve reprogrammed to be a bi-directional bot ESC. Its a little ironic that the same people are now leading with brushless drive motors.

[Eventorizon]

In my process for designing a machine for live events I was looking at these as a combination:

http://www.hobbyking.com/hobbyking/s...grammable.html

http://www.hobbyking.com/hobbyking/s...tor_730KV.html

Running on 4S, 73mm wheels with two 3:1 belt reductions (9:1 total) it would be able to do just over 10mph.
Looking at the PDF, the ESC is capable of Forwards/Brake/Reverse and Forward/Reverse:

http://www.hobbyking.com/hobbyking/s...7X53414X36.pdf

Unless the ESC can take the large back currents during braking/soft breaking it may have to be run in simple Forward/Reverse.

The alternative would be to get a large diameter outrunner with lots of torque to help compensate for the lower starting torque. But from the vids and other combinations people have done it may not be necessary.

Thoughts?