Help with step timing on EMC/Sherline w Vexta PH266 and L297/8 driver

[mgjones]

I am a complete noob here.. and I need some help.

I recently acquired a D&M 4s mini mill that a friend and I converted to parallel control with a breakout board from Campbell designs.

The mill is basically a early 90's vintage 5000 series Sherline mill with Vexta PH266 stepper motors with Thompson L6203 and L6506 drivers.

Maximum torque:6kgcm (83 oz-in)
Current: 0.6A/phase
Voltage: 12 V
Resistance: 20 ohm/phase
Rotor inertial moment :135gcm2

The break out board is feeding a set of L297/298 "chopper" stepper drivers that drive the motors.

A few people on other forums are telling me that the stuff is just old, obsolete and should just be trashed and replaced. Unfortunately that's not a reality right now.

I'll eventually be replacing the stepper motors with something newer along the 300 oz-in track, and possibly Gecko drivers (a little out of my budget right now).

The system isn't much, but it's what I have and the system is currently running OK... but I don't think it's running as well as it could. I'd like to at least get it running the best it can. What I need is some help optimizing the step timing signals from EMC to the motors.

Is there anyone that can give me some insights on what the system needs, what to look for, or where to find more information that what I have now, or am I just stuck just guessing and tweaking the numbers?

Thanks,

Michael Jones

[vlmarshall]

Ha, another D&M, welcome to the (small) crowd. I've had mine for a few years, and I'm really happy with it, and EMC.

I've refit the mill with Xylotex kit, but I really wish the Gecko had been around at the time, it's an excellent controller system. The higher voltage makes a huge difference...but I guess you've heard all that.
At any rate, I guess I'm not much help, but I had to reply when I saw "D&M".

[pminmo]

There are a lot of machies running "old obsolete" components that do just fine. A lot of the time the problem is bacuase the componetns are not matched well. What kind of power supply is being used? Do you have any picture of the pieces you can post?