Warco WM16 CNC converted spindle motor problem

Hi All.

I already posted this as a reply on another topic, but obviously wasn't the right thread to post on. so here it is.

I have a WM16 that was converted some 12 years or so ago by John Stevenson (did a great job!) - it was originally a Warco CNC, which was crap (it still had Acme screws and not the ball screws as I had been told - so accuracy was about as far out as the moon!). In the upgrade, John also fitted a 1:1 tooth belt drive from the motor to the gear spindle, so increased the main spindle speed to around 4300rpm max - I run mainly at 4000rpm and has run happily at this. I did have error problems with glitches in communication between the computer and the mill from time to time, but this was solved with the addition of SmoothStepper. Excellent.

I only use it for small model engineering hobby projects so is not in constant use, but it has done a few hundred hours of reliable running.

My problem now is that after experiencing a sudden build-up of chatter over a short period, I replaced all the bearings in the head and tightened up all the gib strips. Now I still have a vibration at high speed - removing the belt from the pulley and running the motor by itself, there is a vibration there, although not as much, but still there (it may be amplifying through the gear train) so need to replace the motor.

Does anyone know of a higher-speed motor (say 5000rpm) that would be a direct replacement for this one? Or will I have to go back to Warco for the motor?

Regards,
GeoffB

I don't know what power you need but over on the Model Engineer forum a few people have mentioned modern brushless sewing machine motors and found them very good.

https://www.tysew.co.uk/industrial-a...ng-servo-motor

I think you'd struggle to get a different motor that would be a direct replacement.

Is the vibration a mechanic vibration, or an electrical stutter?
I'm assuming this uses a DC motor, in which case the SCR type controllers can fail and cause motor stuttering.

Personally, I'd look at fitting a servo motor, but the 5000RPM requirement would likely involve changing the drive pulleys to step up the speed.

Hello Guys,

well thanks for the replies. I had a lot of searching and it looks like the direct replacement with higher speed isn't available. I have considered changing to brushless motors, but to be honest I'm wondering whether the time to machine the necessary fittings is worth it as it has done well for a number of years at the 4K+ speed.

So, many thanks for the replies, but have ordered a replacement from Warco - arrived next day.

Regards,

GeoffB