Starmill stepper *ratings*

[DeckelHead]

There has been some talk here about the StarMill stepper model numbers, but I haven't been able to correlate this with actual oz-in of torque. Does anyone happen to know the specs on the two different types of motors in the mill? I'm retrofitting the machine to use closed loop steppers. The X and Y axis have tiny little things, so I'm pretty sure any motor I get will have more power then those. The Z motor is a little bit of a different question though. I think that is the guy that I'm most curious about.

For what it is worth.... yes, the Y and Z axis are a little problematic. The size of those definitely is critical as they can interfere with the spindle motor, thereby limiting the throw of the Z axis. As a result, I am planning installing the motors 180 degrees from their current orientation. I'll have to put a "cap" on the top cover to protect the Z axis stepper. The Y axis will extend into an electrical box that I plan on bolting onto the back of the machine. In addition to this, I'll be mounting a "control head" on the main casting. I am a little on the fence right now, but I will use either LinuxCNC or DDCS Expert. I'm leaning towards the latter because it will be the fastest conversion for me. This machine is something I actually bought for my brother, and I would like to get it to him as soon as possible.

The machine itself was originally in a trade school. It clearly did not see too much use, and the spindle is pristine. I do not know the condition of the bearing right now because the machine has not been under power for some 15 years. However, all of the parts are available, which is good.... it is just labor. Hopefully the spindle will be fine (fingers crossed).

The machine has a tool changer that I'll eventually get working, but that isn't my primary focus. Right now I just want to get the machine to run.... When I do setup the tool changer, I'll probably do this with an Arduino and interface it to the control through a simple binary set of inputs and outputs (because they are cheap and I'll have extras). 00, 01, 10 for the ID of the tool position to index.... 00, 01, 10 for the current position. 1 for advance the tool changer, 1 for confirmation. So, 3 inputs and 3 outputs... Dirt simple. Maybe 1 more input for 'error'

[SamD]

Hi, from my own findings, the Z axis stepper motor on a StarMill is a Centronic Dynamics HY-200-3424-310-A8.

The Italian company, MAE Offanengo, still make the HY200-3424-310A8 stepper motor under the same part number, which is a NEMA 34 hybrid stepper motor, with 200 steps per revolution, is 2.4" long, 3.1A per phase, and typically has a holding torque ranging from 116 to 193 Ncm (164 to 273 oz-in) depending on the wiring configuration.

I also purchased a StarMill that had been sitting for a number of years, and the spindle bearing greased seemed to have dried out a little, but by adding a little oil to soften it, it seems to have come back to life and now runs OK.

Hopefully that helps.