[Astroboy]

I have a Hardinge HC lathe that the Lord gave me which was converted to CNC by Hasbach. Mechanically, it is in great shape, but unusable due to the rest of the controller being on the fritz. It has a Bandit control which drives the X,Z stepper drivers. When I turn the unit on, the steppers get rock solid which means the output drivers are working fine (they can support 7.5 amps so why not use them).

I would like to get a breakout board and use a PC to drive these steppers using Mach3. I have the schematic for the board, and I am not sure how to control all those inputs (they come in on a 16 pin ribbon cable).

Here is a list

1 PHB1 These three connect (eventually) to B1, B2 outputs to stepper
motor
2 PHB2
14 PHBC
3 PHA1 These three connect (eventually) to A1, A2 outputs to stepper
motor
4 PHA2
15 PHAC
5 12 V on motor logic (says +E in that schematic), but does not seem to
be connected to driver card that I can see, but may have been left off.
6 REV Inside motor logic is connected to 16 across a diode in /
transistor out - looks like Opto-isolator, but inside motor driver it is connected thru resister to TB1 Rev Lim
7 FWD Inside motor logic is connected to 16 across a diode in /
transistor out - looks like Opto-isolator, but inside motor driver it is connected thru resister to TB1 Fwd Lim
16 LIMCOM goes to +E
8 GND
9 ENAL 9 & 10 are connected thru diodes to +E and motor current pot
and lots of other circuitry including the AA (COM) & BB (COM)
10 ENAH
11 GND-X From motor logic, but driver schematic does not show
connections to driver card
12 NC
13 NC

I was an electronic tech in the Navy, so I can read the schematics and I can wire up something just need some help.

If there is anyone that has used these drivers with success, please let me know.

Thanks - Astroboy

[hybidder]

No experience with your driver cards but from your motor specs they should work well with Gecko 203V's and a breakout board.

[123CNC]

A great guy, Kirk Wallace has posted his path of discovery on the Bandit drivers in this thread, http://www.cnczone.com/forums/showthread.php?t=53570

Of course his plan is implementing EMC. You would still need to figure out the signal coditioning from step/direction to Bandit.

Unless you just want to try to use the Bandit drivers to keep it cheap, a new step/dir drive will be far easier to implement and probably better use your motors. The aforementioned Gecko's are a great choice.

[DennisCNC]

In the beginning of my cnc hobby I always tried to keep as much of the old electronics as possible when refitting a mill or router and come to a conclusion that most of the time it is not worth the work. Just buy three new drives and they will run smooth for very long time.

[Astroboy]

Yes, I think it would be a lot easier with the Gecko's, but since the current drivers are already hooked up I figured I would try this first.

And thanks for the lead to Kirk Wallace. I think that what he has done is closely related to what I need. I will start asking him questions.

Once I can control the X & Z steppers, then my next task is speed control. My understanding is that using a VFD lowers the HP when the motor is going slow, or won't allow it to go as slow as originally possible. Since my machine is so under powered, I would like to keep all that I have.

Since my speed control uses a DC motor to turn a leadscrew which moves a yoke that holds a shaft with pulleys on it, I figure that I can write a VB macro to check the digital encoder on the spindle (via belt on back end of spindle) and compare that with what RPM I want to go and then 1. Change the motor speed (Lo, HI, both) to get the correct range and 2. Adjust the leadscrew to raise or lower the spindle speed until RPM matches my desired RPM and stop. That does not actually seem that hard (but it may be).

Thanks again for your help!

[R Pikula]

I can't help with your problem, but maybe you can help with mine. I'm looking
for a bandit control(working or not). Rigger moved my Bpt and dropped bandit control off truck! I'm a retired machinist and feel very comfortable with the ole Bandit.
Thanks,
Robert........... [email protected]