OT: frequent motor reversal questions

[Jasondelane]

What exactly is the application?

 

[ndzied1]

- soft start if you don't need the rapid acceleration of across the line

Be careful with soft starts and look at the number of allowed starts per hour. We have seen actual fires when this was not considered!

 

[PapaSmiff]

Servos and new drives are expensive but you may not have a choice. Would it be possible to brake the load and/or instead of the motor?

 

[gbeaker]

Thanks for all of the replies guys.

Application is a tapping machine with a very small tap.

I have to disagree with the comments about this not being an application for an electric motor. I have 10 or so of these machines in service for 10-20 years on the original motors. Check out Desoutter lead screw tappers if you are interested. The motors are built for this application with the duty cycle in mind.

The problem in this case ended up being the DC brake. It is not an injection brake but a mechanical brake with a DC coil to pull out the brake disc. I removed the brake and let motor coast to a stop at both ends and it is cool to the touch now. The other 10 machines do not have brakes and I over looked this somehow.

 

[Caveman]

Maybe use two motors running opposite directions with a Warner brake/clutch on each, kinda like a sawmill setworks.

 

[danatomega]

An automatic reversing tapping head is also available.
Just google it : "tapping head".