spindle speed control borked on SEIG x2

[imf]

Anyone out there have any idea where I might need to look for a problem on my SEIG X2 mini mill?

the speed control switch clicks into place at its most anti-clockwise position. When I disengage the saftety switch, the machine immediately kicks on (and sometimes blows a fuse when not under load).

The manual seems to say that when the dial is at that position it should not be on and only as you turn the dial should the spindle come on. That is not what is happening.

On the wiring diagram the wires from the POT speed control dial are labled P1, P2, P3. I checked P1, P2 and P3 for continuity (that was ok) and checked it on a volt meter. P1 to P2 is low resistance at the most-anti clockwise position and p2 to p3 is about 4.8k. Since the POT is marked 4.7k I think this is ok. P2 behaves like I would expect slowly going from a lot of resistance to P3 to no resistance to P3.

Hooking the pot up backwards (p2 to p2, p3 to p1 and p1 to p3) did not seem to alter the behavior of the mill. I could still unbolt the saftety and get it to run again.

Have I got a dud? Anyone got a complete schematic for the X2 controller board?

[imf]

... I checked for cold solder joints.. remelted a few. There are some pots marked speed and torque.. I dont want to mess with these, but would misconfiguration of these cause what I'm seeing?

The wiring seems good in the control box and the main box on the back of the mill..

[motomitch1]

There was a guy here a while back that had that problem and his spindle preload was to tight a think you can put it in neutral between high and low gear just to see if motor will run and if that checks out good then fix the preload on the spindle.

[motomitch1]

I re read your post thats probably not the same deal i had a x2 that acted that way sometimes but it never blowed the fuse.

[imf]

yeah, put it in neutral.. it is still a no go

what is weird is it seems like it kicks "on" in what is supposed to be the "off" position at a fixed RPM. Then the speed dial has no effect. If I switch the speed dial "on" but at the lowest RPM the little yellow overload lamp comes on. If I then switch it off so it clicks the motor kicks on at a fixed speed.

This thing it totally borked. It seems like PWM is not working (seems like it uses some form of pwm? am I wrong?). I'm not really sure what is going on because it is hard to follow the traces on the PCB and figure out how it is supposed to be.

At this point I have checked the simple wiring diagram vs. how it is wired and (if the wires are labeled right) that much is 100% right.

[pastera]

Talk to Jim Rabidwolf about the controller
http://www.unclerabid.com/

Aaron

[imf]

So far, Jim's been really helpful. I decied to send my board to him for repair. We went over the LM324s and checked the mosfets but I'm just not seeing it. Fingers crossed it is a cheap repair!

I have a cummins 7877. I picked it up at a slight discount off the website price AND I did not have to pay frieght! BOY WHAT A DEAL I thought. Yeah, I got screwed.

Cummins Tools has not returned my calls or emails. Even thought I just bought it, I'm having to pay to have it fixed. I'd sugguest folks out there stay away from their truck sales! Someone had warned me that all that stuff was scratch and dent.. but when I hooked it up, it worked. I didn't think to check the speed control! I have On and Off. But that is about it.

Ulgh.

Thanks for the input. I'll post again once I get it back.

[MIKE JEFFERS]

dunno if the x2 is the same stuff as the x1 but i had this problem with my x1 after
doing a belt drive conversion.fire it up it would trip -backed off the belt tension
and it would run but tripped if i increased the speed too quickly.
inside the control there are 2 trimmers/pots(etc), noted were they are to start with
then tweaked them whilst running the spindle after a bit of messing around the
mill now starts and runs all the way up to 9500 rpm with no stall outs.
this may or may not have some bearing on your problem,hope it helps.
mike