Spindle stalling after running

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Mihail
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Joined: Mon 28 Jun , 2021 17:47 pm
Hardware/Software: Denford Novamil

Spindle stalling after running

Post by Mihail » Mon 23 Aug , 2021 17:23 pm

Hello All,

I have a Novamill converted to Mach 3, running on a UC400ETH and a CP0-10V BOB.

Has anyone encountered the spindle stalling even when not under any load, with the Sprint 400 board stall light coming on after running it for what seems to be about 1 minute? At 5000rpm, at 4000rpm and 3000rpm.

Also, what PWM frequency do you have set in the spindle setup? I tried anything between 10 and 300 with no difference.

Any suggestions on troubleshooting would be very much appreciated. I am trying to avoid changing settings on the Sprint 400 on the basis that the configuration should be right for the motor, but then again since it's a 3rd hand (at least) machine it's hard to tell if someone changed something before.

Thank you!

Mihail
Posts: 13
Joined: Mon 28 Jun , 2021 17:47 pm
Hardware/Software: Denford Novamil

Re: Spindle stalling after running

Post by Mihail » Mon 23 Aug , 2021 19:50 pm

Further updates, checked the UC400ETH status and it was getting errors as soon as the spindle was turned on.

My thoughts are:

1- check with a different network cable

2- the isolated board isn't isolated enough and it is interfering with the controller (on the plus side, if that's the case, it is isolated enough not have fried it yet)

Will gladly accept other thoughts please :)

Edit: Also, forgot to mention, the RCD's in my shed keep tripping when the control box is switched on, but it seems to be intermitent (the best kind of problem). It is intermitent enough that it is never clear if something I am doing (like spinning the spindle manually a bit) or waiting for a while for the RF filter/capacitors to have discharged or anything I do is actually helping.

DavidB
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Re: Spindle stalling after running

Post by DavidB » Mon 23 Aug , 2021 22:32 pm

It may be worthwhile having the RCD checked to ensure it's functioning correctly as I had my house one trip whenever I turned on my TIG welder which hadn't happened before so had the welder tested and it was fine. I called in an electrician I know and he checked the RCD and it was bad so replaced it and all was good again and I could use my TIG welder again. He mentioned that the new RCD recommended using the test facility about every 3 months to exercise them, some other makes recommend a more frequent test schedule.

Mihail
Posts: 13
Joined: Mon 28 Jun , 2021 17:47 pm
Hardware/Software: Denford Novamil

Re: Spindle stalling after running

Post by Mihail » Mon 23 Aug , 2021 23:51 pm

Thank you David, will investigate. It tripped 2 RCDs but not the one in the middle. The extension cord has an RCD plug, the socket is RCD and the fusebox as an RCD, and it would trip the Socket and the fusebox.

I mentioned it in case it gives more context into the issue I am having with the spindle.

Mihail
Posts: 13
Joined: Mon 28 Jun , 2021 17:47 pm
Hardware/Software: Denford Novamil

Re: Spindle stalling after running

Post by Mihail » Tue 24 Aug , 2021 18:30 pm

Even further updates...

Hopefully the light bulb will appear will typing or someone will get enough information to figure it out.

I changed the network cable between the Windows 10 PC and the UC400 ETH and the number of errors reduced but not to 0.

I disconnected the 0-10V output from the BOB to the Sprint 400 board and replaced it with a 10K pot, same thing happens, at any speed other than what seems like idling while cutting air after about a minute the stall light on the board lights up and the spindle stops.

Disconnecting the 0-10V output reduced the number of errors to 1 for the duration of the connection.

Next ideas:

1- find a friend to help move the mill out of it's current place and try and have a look at the brushes.

2- replace the motor driver with the one I was hoping to use for another project, a KBIC 240D with SI5 signal isolator and see how it behaves then.

3- order a tacho off amazon and check the spindle speed

4- take the Baldor spindle motor off and take it to a motor servicing shop and see what the people there say.

Mihail
Posts: 13
Joined: Mon 28 Jun , 2021 17:47 pm
Hardware/Software: Denford Novamil

Re: Spindle stalling after running

Post by Mihail » Wed 25 Aug , 2021 20:39 pm

The saga continues.

Changed the controller to a KBIC 240D and it spins well, need to tune the KBIC as it spun up the spindle to over 7000rpm (according to the cheap amazon tacho).

Do you kind folk think it is an issue with the sprint 400?

Many thanks,

Mihail.

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Steve
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Re: Spindle stalling after running

Post by Steve » Thu 26 Aug , 2021 8:52 am

What DC voltage are you sending to the spindle motor.

The motor will run overspeed if it has become demagnetised but if you spply too high a voltage to it you will get arking on the armature and may cause permenant damage to the motor.

Mihail
Posts: 13
Joined: Mon 28 Jun , 2021 17:47 pm
Hardware/Software: Denford Novamil

Re: Spindle stalling after running

Post by Mihail » Sat 28 Aug , 2021 13:50 pm

Hello Steve,

Thank you very much for taking the time to read through this!

I went and checked, it is doing 5000rpm (according to the tacho) at 180V DC on the KBIC240D, didn't do the same check with the original Sprint 400 board, if you think it would be useful to do I will rewire it and check?

I didn't trim the KBIC 240D yet as I am waiting on a replacement Sprint board, hoping it will have the same footprint and went for the isolated version 400i . I am using the tacho and adjusting the speed with a potentiometer on the KBIC currently.

I only allowed it to stay at 7000rpm for a few seconds the first time I connected it to the KBIC and not under load,since then I always go from minimum to the desired speed while checking with the tacho.

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