Cog belt help

[1Bender]

I finally got my US machine VT mill wired up and running(I use that term loosely…) now my issue is the belt which drives the gearbox for the head is missing the belt…I threaded a piece of paper into the spindle and around the other pulley on the gearbox as well as measured the width of the groove in said pulley on the gearbox and came up with a 3/8x17” belt being needed…then I measured 10 teeth on that pulley and got 57mm which you divide by 10 to get 5.7mm it’s at this point that I am lost…I am certain that it’s a imperial belt being that the mill was made somewhere around or before WWII…can anybody help a feller out with this? I found this belt on zoro which you gotta buy 5 of them but I got no issue with having extras but if I’m understanding correctly the t85 means 85 teeth total? See I’m all kinda confuzzled now…

 

[piper184]

IF, and this is a big IF, the T85 actually means 85 teeth, then that works out to 5 teeth per inch (85/17).
1/5 = .2" per tooth which is really close to 5mm. This seems considerably smaller than the 5.7mm you got from the pulley. I would use a seamstress tape (wife's sewing box) to measure 10 teeth on the pulley to see if 5 teeth per inch will fit, forget the metric conversion. Measure center of tooth groove to center of tooth groove. Another method would be to pull of 3 or 4 inches of duct tape and put on the pulley and mark several teeth. Take the tape off and lay flat for a more precise way to measure.

Zoro is also showing out of stock on that item and an extended lead time besides the minimum purchase of 5.
Using the Mfr. number listed, it comes out that this is a standard Gates number. Amazon shows them in stock for ~$17.

I take it you don't have the old belt. Can you easily get one of the pulleys off? I would try local auto parts stores such as NAPA, take the old belt or pulley along if you can. Start with the Gates 170XL037. If you get it local, returning it if it isn't right is much easier.

​

 

[markba633csi]

17 is the inches length, 037 is the width (0375) and 85 is the number of teeth (5 tpi)
Standard extra light belt (XL)
Should work fine

 

[1Bender]

IF, and this is a big IF, the T85 actually means 85 teeth, then that works out to 5 teeth per inch (85/17).
1/5 = .2" per tooth which is really close to 5mm. This seems considerably smaller than the 5.7mm you got from the pulley. I would use a seamstress tape (wife's sewing box) to measure 10 teeth on the pulley to see if 5 teeth per inch will fit, forget the metric conversion. Measure center of tooth groove to center of tooth groove. Another method would be to pull of 3 or 4 inches of duct tape and put on the pulley and mark several teeth. Take the tape off and lay flat for a more precise way to measure.

Zoro is also showing out of stock on that item and an extended lead time besides the minimum purchase of 5.
Using the Mfr. number listed, it comes out that this is a standard Gates number. Amazon shows them in stock for ~$17.

I take it you don't have the old belt. Can you easily get one of the pulleys off? I would try local auto parts stores such as NAPA, take the old belt or pulley along if you can. Start with the Gates 170XL037. If you get it local, returning it if it isn't right is much easier.

​

There was no belt on it when I got the mill however it was the only belt missing as well so I got lucky there…to install it I’ll have to disassemble the head as it wraps around the spindle inside the head then comes out to a external gearbox which I can use to check proper fitment of the belt on beforehand…while I have plans to disassemble the spindle anyway to get measurements for a r8 replacement spindle (currently it has a B&S9 if it’s original) as well as to clean and check things out but I’d like to know everything is in working order first if possible as I believe finding replacement parts will be like pulling hens teeth…

 

[piper184]

Cool. Completely understand the one step at a time thing.
I bet the Gates number is probably the correct one.
Here is another idea. Take an inch wide strip of paper and tape it over the exposed pulley. Then rub with a soft pencil to transfer the pattern onto the paper. Take the paper to the auto store for comparison.

Good luck on your search and please post pictures of your machine

 

[1Bender]

Cool. Completely understand the one step at a time thing.
I bet the Gates number is probably the correct one.
Here is another idea. Take an inch wide strip of paper and tape it over the exposed pulley. Then rub with a soft pencil to transfer the pattern onto the paper. Take the paper to the auto store for comparison.

Good luck on your search and please post pictures of your machine

I’ve hit every local auto store there is…apparently this belt is made of unobtainium…ordered two online…now I wait and hope it’s the correct one for the machine…if I remember right I posted pics of my mill when I joined but here’s a few just in case