VM17 Spindle drive problems

[Ozfab]

I have a problem with my VM17 which seems to be causing a lot of symptoms but I think it is the vf drive.

I have a CSM drive and "4 speed" 20 hp spindle.

With the spindle disconnected from the vf drive I can select M41, M42, M43 and M44 with no problems and the led for the appropriate relay (CR41 - CR44) comes on. When I try this with the spindle connected to the vf drive M41 and M42 are OK but M43 and M44 cause the machine to shut down.

With everything connected if I put in M03S630 the spindle spins at 630 revs and all seems good. 630 rpm is the highest speed for the first speed (M41). If I adjust the spindle speed to 90% the spindle slows appropriately but makes a noise. The same happens if I adjust it to 80% but the noise gets louder. The noise is a rumbling noise like a bearing noise. At 70% the noise gets louder and as I decrease the speed more the noise gets even louder.

The same happens in "speed 2" (M42). The maximum rpm for that "speed" is 1470 rpm. f I put in M03S1470 the spindle spins at 1470 revs and all seems good. If I adjust the spindle speed to 90% the spindle slows appropriately but makes a noise. The same happens if I adjust it to 80% but the noise gets louder. The noise is a rumbling noise like a bearing noise. At 70% the noise gets louder and as I decrease the speed more the noise gets even louder. Yesterday when I adjusted it to about 60% the machine shut down (error 449 I think).

If I select M03S3000 (the top speed for "speed 3) the machine shuts down.

The "reset" led on the vf drive is on most or all of the time but nothing happens when I press the reset button on the lower left hand corner of the vf drive box.

I have had trouble for a long time with the brake (I have to program in steps to slow the spindle in about 300 rpm steps as the machine shuts down if I just program in M05 from, say, 1500rpm) and I now have these problems with not being able to get certain spindle speeds and I am also now having trouble with spindle orientation for changing tools.

Sprotybob has been great helping me to eliminate some possible causes late last year but I think there are limits on how much time one person can spend helping another and so I'm throwing this out there to see if anyone has had any similar problem or can help me with how I can test the vf drive or give me an idea what I can replace it with.

I think I have narrowed it down to the vf drive as the relays on the spindle seem to work (I can hear them clicking in and they don't drop out plus they all need to come on for speed 1 (M41) to operate and since the machine seems OK in that speed that seems to mean the relays are all working). It also seems the parameters are OK (because I can get M41, M42, M43 and M44 to work fine if the spindle is disconnected from the vf drive). But when there is (minimal) load on the vf drive it all seems to go bad.

Thanks in advance for any help you can offer.

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[sportybob]

HI Ozfab, PM me again. If the drives needs repair there is only one place I would send it to. Last I checked it was about US $3K for the repairs / rebuild.

Sportybob

[E_N]

Hello from Finland.


This thread was close to my machines problem.
I have milltronics VMD30 machine serial# 4004.
It has 10K rpm spindle with CSM 20hp 4 speed motor that doesnt work right.

-at any speed when potentiometer is on 0% speed spindle crawls 5-15rpm

-speeds under ~1000 when pot is 100% spindle revs 5-10% too high speed. Example-> commanded 500rpm, real 550 at 100%

-speeds ~1000-5000 spindle achieves commanded speed when pot is about 70-80%. When pot is turned to 100% spindle motors sound changes but speed doesn't change.

-in any condition it never reaches full 10000 rpm. Only about 8500 at maybe 70% pot and then voice changes again.

I have replaced spindle drives IGBT's but no help.
Any ideas finding what is wrong in my machine appreciated.

Thanks.

[sportybob]

Hi E_N, sorry I forgot about you ;-(
It sounds like parameter settings for the spindle over ride % and the spindle speed parameters on the MICS parameters.
The override settings are usually set in increments of 10% ( 1 is 0, 2 is 10, 3 is 20 etc these leaves #11 at 100%.
The spindle parameters in the MSC parameters has spindle speeds for each of the 4 speeds and then a "max spindle speed" setting. it may be set on 8500. these CSM motors do not like to be run at full RPM all the time. so someone may have just backed it off.
Give that a check and let me know.

sportybob