Help with a usb BOB Spindle problems

[Lahdiel]

if you think its the motor do you think it would be worth taking out to take a look at and clean out? thinking about it it might have been my fault it started doing it as it only happened after taking off and putting the motor cover back on to see if there was anything that needed oiling like the ways do but i see there isn't

[Doddy]

It's the next logical step. Or the first one, depending how cold your workshop is!

Clear out the spiders and clean up the commutator, de-grease and get rid of any carbon on the inner casement.

What better way of spending the new year!


The idea of testing with a bulb (or any other load) is to isolate the fault to the motor.

[Lahdiel]

Will still try that when i can find a proper load for it but for now the motor seems fine, ran smooth without any problem on my bench supply. Still can't really figure out whats causing the motor controller to try move the spindle as soon as it gets power, i'm assuming thats what's tripping the breaker in the cabinet

[Doddy]

Will still try that when i can find a proper load for it but for now the motor seems fine, ran smooth without any problem on my bench supply. Still can't really figure out whats causing the motor controller to try move the spindle as soon as it gets power, i'm assuming thats what's tripping the breaker in the cabinet

How's the Lenze "Controller Enable" input wired?

[Lahdiel]

i tried changing that too, normally the two pins are just jumpered with a small wire, i tried putting them between a relay but still popped the stop circuit as soon as the machine was turned on, starting to suspect i killed the isolator board and its just stuck somewhere its trying to spool up as soon as its powered

[Doddy]

Isolate the isolator board. Connect the +Ref on the Spindle board to the sense line to force full speed. Test. If pops then either spindle or Lenze. Proceed as earlier with incandescent lamp to verify if spindle, or not.

[Lahdiel]

been using the mill fine using my external bench supply for the spindle, tempted to just ditch the lenze and buy a cheap pwm 60v controller and be done with it since my psu can only do 32v
is that a terrible idea

[Doddy]

Not the best.

I'm surprised that the motor is only rated at 60V... whoops... a quick google confirms someone else with a VMC190 with a 60V spindle... so let's go with that.

Using a standalone PSU you've only isolated the supply to the spindle - in other words isolated the spindle from the RCD. You[ve not fixed anything, just avoiding the protection normally offered. Did you get around to cleaning the spindle motor?, or testing the Lenze?

(full disclosure: I did pretty much what you're suggesting - replacing a spindle motor and controller card when it was cheaper than replacing the OEM controller card - so call me a hypocrite)

[Lahdiel]

i don't know if i mentioned it properly but it stopped popping the RCD and instead now just trips the breaker actually in the machine, i did take the motor out but its pretty much spotless and everything about it looks next to brand new
still not tested the lenze with a different load yet
just for reference if i did decide to do the same what motor did you end up replacing it with?

[Doddy]

i don't know if i mentioned it properly but it stopped popping the RCD and instead now just trips the breaker actually in the machine.

I think you probably did, but I've forgotten that bit. I can understand your thought process here.

just for reference if i did decide to do the same what motor did you end up replacing it with?

Hah, no, that's a special case. I needed to replace a NEMA34 sized BLDC motor with something that would fit the same space envelope, and give me an easy spindle-speed control (the original Sieg SX BLDC had a very fragile controller card [blown it up twice] that only supported a "speed up" / "speed down" control). In the end I plumped for a Chinese AC servo which gives me a stupidly easy speed control (simple step/dir with electronic gearing).

That's not necessarily a solution for all, but it got me the power/control I wanted into the cast-iron spindle-head enclosure on my SX2.7. Not particularly cheap (£261.11 all-in)... compared to a replacement BLDC controller card (£247.48... fragile as F.. and no easy speed control).