The Home Machinist!

Recently I have been involved in repairs to a well worn Jet vertical milling machine that appears to be a clone of a Bridgeport Vertical mill featuring the 1.5 or 2 HP motor on the vari-drive head. I am unable to find a manual on line that covers the part numbers for the vari-drive belt and the timing belt. Both belts are in poor condition after 28 years of use.

I have been told that some of the Bridgeport parts will act as a direct replacement for the same parts on the Jet clone.

Does anyone know for sure is such parts from a Bridgeport will interchange with the Jet clone?

Give H&M a call on Monday ,they would probably have the best info as to fit. Or call Jet as they are still very much in biz.

Here's a JTM-4VS with a 2HP single phase motor.

http://content.jettools.com/assets/manu ... man_EN.pdf

Is that it?

Bill

Bill,

That model is the later version of the mill I am trying to make operate again. It has the later head design that is designed to be easier to replace the varidrive belt. I downloaded that manual to see if it would be of help but found little to answer my questions.

Robert

Well.....I tried.....
I would contact Jet, or a Jet dealer if you have one close. They are pretty good about getting information to people, or at least they were when I was a Jet dealer.

Bill

Completed repairs to the 28 year old Jet vertical milling machine. All of the varidrive bearings were either showing signs of distress or ready to begin making noise. All bearings of the varidrive unit were replaced along with the drive belt which was almost wore out. Found many bits of the belt spread about inside the head of the mill like a fine coating was sprayed on. It was no wonder the head was making noise and sounding worse by the hour. It appeared that the person that assembled the head did some custom adjustments with a milling machine during final assembly. Had to make a couple of shims to make things clear correctly. Could have been a big factor for some of the noise. The head is much quieter now and does not heat up near as much when in use. Some in the shop claimed I would not get it back together without the factory manual. Sure proved them wrong and they now have a greater respect for what I can do.

I'm a little late to this since it apperars you've got it all back together and working. So fwiw Jet as far as I know doesn't actually manufacter anything. There a high volume dealer much like Grizzly and many others around the world who sell enough to have the factorys building the machines paint and badge them with there corporate paint colors and logos. What I didn't know until a few years ago is they can pick from an option list how they want the machines set up. Step pulley or variable speed heads, spindle tapers, table size, power spindle feeds or not for your example. For an offshore machine of that age it's unlikely Jet themselves have any records about exactly what factory built yours. I know Bemato in Taiwan built some models of Jet badged mills and the same thing with there name on it so I'd assume there could be dozens of factorys doing the same for the various Jet machines. Some Bridgeport parts do fit some of the offshore mills, but I don't know of any way to tell which machine's those are and be 100% sure of it.