From: Charles Hopkins <chopkins@mip.net>

Hello Peter
I will answer all questions in place.

Thanks for the Ah-ha review. I am hearing good things about their kits.

I have made my living off my Ah-ha system for the last 5 years

What you say about building my own the first time makes sense. I don't want
to screw around with the set up forever. Many systems will not compete in the Job Shop market. Ahha will get you running very easily.

You say you have 650 oz-in motors. The Ah-ha sales guy, Mike, told me that
the highest they can go with the RC-500 driver/power supply box is the 450
oz-in motors they sell.

They told me I could run 1650 motors with this setup.

This is because the power supply can supply only up
to 6 Amps/phase and their motors draw about 5.6 Amps. However, I have seen
stepper motors with torque much higher than 450 oz-in with current draw of
less than 6 Amps.

I run my motors at 10 amps which is a little over the 8.6 amp rating.

Do you have the RC-500 box or the bigger one from Ah-ha?

I thought the RC-500 was the big box? I have SD122 Microstepping Drivers.

Did you purchase your motors from Ah-ha?

Yes

What brand motors and what are the specs (model #, amps/phase,...)?

The motors are from Ah-ha part number STM650
They are 8 wire motors rewound by Ah-ha rated at 8.6 amp

What type of milling machine do you have?

I have a standard "J Head" Bridgeport

What type of couplers did you use to mount the motors?

I used 1 1/2" belts geared 1.5 to 1
(Mike suggested
helical couplers but I don't know what these are.)

These are spring looking direct couplers I think

What limit switches do you use and how repeatable is your homing accuracy?

I used the Ah-ha switches. They don't repeat worth a damn. I don't home my machine, I use an indicator to locate a reference point. Usually this is a reference point for the job. I then set indicators to the table out where I want to do a part or tool change. If I loose power or have some other crash, I jog to the indicators and then move to my part reference and reset absolute zero.

Have you used the Ah-ha system for contouring? If so how well did it
perform?

I have not had software to generate a true contour, but I have no reason to think it won't take it. I have loaded demo files and it would read them. I have never actually made chips on a 3d contour. Lots of complex 2d stuff with no problems.

I really do appreciate your help.

Hope this helps.

Charles Hopkins