Spindle/brake problems with Bridgeport Jhead

[CaptainNemo]

Hello All,
I have a Jhead round rod mill from the 40's. It was working fine, but now it seems there is no connection between the spindle and the motor. I went to remove the tooling in the collet and at first it was hard to turn, but then it would just spin, even with the brake engaged. It seems the brake is working, because I can manually turn the pulleys with it off, but not with it engaged. The motor spins freely, but there is no turning of the spindle. I've tried in main and back gears, but there is no difference. It looks like I am going to have to take the head apart, but before I do, I wanted to ask if there were any thoughts on the most likely cause of the problem.

Thank you,

 

[HW_Head_Repair]

Sounds like the splines on your spindle and/or the splined gear hub have completely disintegrated. There is a company we work with that does not use their machine properly and this happens within six months like clockwork. This can happen if the splined gear hub has never been changed in 80 years with heavy use.

 

[jccaclimber]

Sounds like the splines on your spindle and/or the splined gear hub have completely disintegrated. There is a company we work with that does not use their machine properly and this happens within six months like clockwork. This can happen if the splined gear hub has never been changed in 80 years with heavy use.

I understand you can only go into so much detail, but what do you have to do for that to happen in 6 months? I’ve seen a lot of non maintained machines that have been abused for decades and not done that.

 

[HW_Head_Repair]

I understand you can only go into so much detail, but what do you have to do for that to happen in 6 months? I’ve seen a lot of non maintained machines that have been abused for decades and not done that.

Their set up is not normal. They do not have the head on an actual mill base and have it sitting horizontally. To be honest they need a completely different kind of machine to do the heavy cuts they need but, they don't want to spend the money on a brand new machine.

 

[CaptainNemo]

Thank you for the reply. The good news is that my mill is working again. The bad news is that I don't know why. As I started getting ready to disassemble the head, I noticed that the spindle turned when I moved the gears. When I had first noticed it was working, I had tried it in regular and back gears without any effect, so it's unlikely that it was in neutral. But I can't think of anything else if might have been.