[mhopkins74]

Hey guys,

I have been having trouble with my x axis motor not wanting to move.
If i don't use the mill for 2 or 3 days this happens to me. It's like it is froze up or something. I can here the motor trying to move with a very light high hum to it when I try and jog it. After a while of trying to jog it back and forth it starts kicking in and moving again. But it wants to sometimes lock up in a rapid move from time to time. When it start jogging better it almost sounds like rough bearing on one end but then it goes away. What could be causing this. I have made sure my ball screw is oiled every time I use it. Anyone have this happen on there nm145.

Thanks,

Mike H.

[LeeWay]

Sounds like you may not be getting enough oil on the ways and it is sticking. I would check the lines.

[mhopkins74]

Well once I get it moving again I try and take my oil can and run it all the way to one side and shoot oil on the ball screw and ways and then I jog it all the way to the other side and do it the same way. Still seems to do it after only a short period of time sitting though.

[AUSTINMACHINING]

Have you checked the gib tightness?. I would start by loosening those up and run some tests to see if the problem goes away.

[mhopkins74]

Well after checking everything out I decided to dismantle everything. took my vise off and my 3 jaw fixture off my hold down plate I made. then took my hold down plate off the bed since i made it to go all the way across the x axis motor to keep coolant off of the motor itself. tore off the left side of the coolant enclosure to get to the motor better. popped the motor off and set it on the bed and fired the mill back up. The motor itself still locked up sitting there. So I decided to see how a stepper motor works. Started to pull the top cover off where the disconnect is for the plug wires. opened it up and the red wire had broken off of its solder joint on the pin connection. simple fix so I soldered it onto one of the spare pins that weren't being used in the plug and put it back together. Still the motor wants to lock up just sitting on the mill bed. I think the red wire when it broke off it might have shorted the stepper motor out inside. Does anyone know what size motor the x axis is for torque rating. I thought I saw somewhere that it might be like 653 oz/ in for the x and y axis on the nm 145 mills. Can I use a 1200 oz/ in motor in its place. the only difference is it doesn't have the nice little cover with the cannon style quick disconnect plugs on it. I have one available that I can pull off my shoptask 3 in1 mill lathe combo to get by until I find a suitable one. what you guys think. I heard that I should match both x and y axis motors with the same torque rating also. is this correct.

Thanks,

Mike H.

[UniqueMachining]

Drop an email to [email protected]. He should be able to take care of your issue.

John

[LeeWay]

If John has the answers, then this is the place to post them.

[mhopkins74]

Well I figured it wasn't going to hurt anything to figure out how a stepper motor works. So I started to tear it apart. Have you ever had one of those (there is your problem) moments.

I wondered why I couldn't turn the shaft on the stepper by hand when I knew I could . well after popping the lower end bell off it could see why then. The entire motor was caked with dried up coolant.it was the same way on the top also. The one side of the rotor was also starting to delamination from rust. The top end one actually came off when opening it up.well I figured I would clean it up. 10 hours later I is all cleaned. I also took some red loctite and dripped it in to all the layers that were coming apart on the rotor. I then put it in my press and let it sit under pressure for a couple hours. Cleaned it all up for leftover loctite and it looked pretty good. I put it all back together and was then able to turn it by hand then. Plugged it back in and fired up the mill and it works like the day I got it up and running a couple years ago. I went ahead and got some epoxy and coated the outside of the motor. Also took some silicone and ran a bead around everything to try and keep the same thing from happening again. I still think I better get a spare on order though.

[SCzEngrgGroup]

While it may work, I can promise you it is not "like the day I got it up and running a couple years ago". You have most certainly reduced its torque capability considerably simply by disassembling it. Stepper motors should NEVER be taken apart, as they will partially de-magnetize, and can easily lose as much as 50% of their torque capability. That said, if those motors are similar to the ones on the Pulsar and Pro, they have FAR more torque than is needed, so may still work just fine for the application.

Regards,
Ray L.

[mhopkins74]

Ran the mill all afternoon into the evening. Seems to be working fine. I'm still going to get another on order though.