Belt for Jet 1236

[Ian57]

I have an older version of this lathe which I recently purchased used. It has the original purchase reciept 1995. My question is does anyone one know the dimensions of the original belt VB-M22 as quoted in the owners manual. I have been to the Jet site and cannot find the belt dimensions.
I am having trouble getting the lathe to engauge the slower speeds. I think this is because the belt is a little too wide at the top of the vee. BTW it is 3/8 of an inch.
Cheers
Ian

 

[frank123]

A V belt (I'm assuming this is just a V belt, don't know the specifics of the lathe) should be even or almost even at the top of the pulley V to give full engagement of the driving and driven surfaces.

This may help: Conventional V-Belts - Belts Sizes A - B - C - D - E Section Belts

You can roughly calculate proper length in a two pulley system by using 1/2 the diameters of the pulleys plus distance between center's of the shafts to get in the ballpark of the size needed. (roughly) Or use this to get exact: V-Belt Length Calculator

Most belts have an identifying number on them somewhere, if you have your old belt clean it off and look for it.

 

[DaveM]

The replacement belt size listed in my old documentation is 3L240, which is 3/8" wide at the top, 7/32 deep, and 24"o.d.

 

[Hexhead]

When my jet 1236 had that problem the inner pulley was broke so I replaced it. I used to puller to get it off. I thought I was being careful not to damage the threads in the shaft, but I did. The threads in that shaft are left-hand 12 TPI. I searched everywhere to try to find that tap but It was nowhere to be found. They just don't use 12 TPI anymore they use 13 TPI. Finally MSC searched and found it so I thought I'd get the tap and the die as I damaged the pulley threads slightly when I tried to attach it. They emailed me back and said it was $115 for the tap and 115 for the die!

I tried to clean it up with the Dremel tool without success so I decided to order another shaft 50 bucks still cheaper than a tap and die. I waited and waited and finally get an email from jet that it's on backorder and a unknown time when it would be restocked.

I went back to work with the Dremel tool on the shaft threads, and ground off the first thread on the pulley. Finally I got it to catch a thread and go on in.

The moral to this story is be very careful not to damage the threads in that shaft if you have to replace the pulley.