[Stepper Monkey]

They make both 300 and 400 watt versions, and versions for both fixed rotation directions. Luckily the rotation direction we want are the cheap ones, as they go on the wrong side for bicycle conversions. The other direction is more than twice the cost for that reason alone, if you are wondering why different part numbers sell for such different prices. They have the PWM controller built right in, just add power.
You just discovered one of my secrets. I buy the 400 watt motors by the case for spindle drives from a guy that is sitting on a warehouse of them from a canceled order. They have no nameplates, but are Kollmorgen motors, and the cases have Danaher Motion labels and seals on them. They are made in India, but I wouldn't have guessed it by the rather nice build quality. They work great - light and quiet. Being designed to directly drive a scooter they have plenty of torque and sturdy bearings. Add power supply and a 5k pot and go, and/or wire it up to Mach for speed control that way.

Only major hangup is that the drive stub is very short, and stepped. It's two different diameters, and both in metric. That and it really is a stub - it only projects about a half an inch. Impossible to put much on it that way, I have to use specially built shaft extender/adapters that are turned out to match the stepped shaft and bring it up to a standard shaft size for pulleys. You could make one yourself if you have a lathe and a lot of patience, it is pretty straightforward but they are kind of a distinct pain in the butt to get right the first time as you have so little space to work with, and have to cross-drill it for a roll or taper pin to secure it properly. Otherwise, PM me and I will send you one of my adapters or just a sell you a whole motor with the shaft extension already pinned on and ready to go if you want to try one. I only have about 6 or 8 extras in stock right now, I usually don't keep more than I need for myself. I guess if people are really interested I could make up a batch of them for the folks on here if there is much interest, or send samples out of the shaft adapter mod if someone else wants to make them for sale - I really don't have the time or interest.

Biggest problem I see is the lack of 25 amp supplies, that might be the biggest damp to interest. However, they are designed to tolerate being driven from batteries that vary in voltage radically in scooter usage, so they are tolerant of power supplies much less stable than required for our CNC drives. Maybe one of the power supply gurus on here could come up with a really cheap and not-so-stable supply that fits this bill. If they can, I have a feeling all of us will be using these things in a year. They kick ass.