stepper/indexer motor failure

[myxpykalix]

I have a friend who is using someones shopbot having been put in his shop. It is probably 8-10 yrs old and one issue he has is that when he starts the indexer turning he can reach down and grab the spinning stock and the indexer will stop spinning.

I am sure it probably is a standard machine and the problem is that when he puts bit to wood it wants to stop. It initially sounds like gearing is stripped but i am unfamiliar with these older motors and what it might take to fix this.

What would be the first thing to look at to try to figure out if it is a mechanical issue within the indexer head/gearbox or if it is some other issue?
I need to first get motor brand name model numbers...then what?

[ken_rychlik]

Jack,

If it is the same motor as another axis on the machine, swap out with another motor and see what happens.

If that fixes it then the motor is bad. If it is the same, you may want to think about a gear reduction on it.

Kenneth

[blackhawk]

Jack - You could also have a problem with the drive where it is not putting out enought current/voltage as it should.

[bill.young]

It's hard to tell without a lot more info. It could be a bad motor but they're pretty bulletproof so I feel that's pretty unlikely. My first instinct would be that he's trying to turn too fast, especially if it's a Standard, and that he's missing steps. Get him to try cutting the speed in half and see if that makes a difference.

The next most likely in my book is a blown driver or a bad cable connection. Be careful switching motors and drivers without first making sure there's not a short in the cable...there have been people that have blown multiple drivers by plugging in a bad cable to several drivers to test.

I'd think about a bad motor after checking those things.

Just my un-official opinion,
Bill

[myxpykalix]

Bill your "unofficial" opinin is far more knowlegable then my "official" one!

He traded motors with one off a second Z that was on the unit and it spun without being able to be stopped. I'm not sure if it is the same gearing on the Z steppers but that test at least confirms the failure of the indexer i presume and the working of the controller, cables, ect.

I'll let you know how it goes.....thanks for the advice all.