Hey all,
I recently purchased a General contractors saw (50-185) and was going to swap out the belt with a link belt – there was some vibration when I started up the saw. I didn’t see this as a big deal – I was sort of expecting to replace the belt anyway.
However, the standard saw belt is a 3V and the only link belts I’ve seen are 4V’s. No problem, right? Just swap out the sheaves/pulleys. That’s what I thought. The existing pulleys on the motor shaft and arbor are extremely bizarre. I even took them into a machinist supply shop and had them looked at. Here’s what I found:
Driver: 2.5 OD, 5/8 ID, 5mm key (yes, both english and metric measurements)
Driven: 2.0 OD, 37/64 ID (yes, you read that right), 5mm key.
The guy that helped me at the supply shop said he’d never seen this before. Has anyone tried to replace the belt on a General contr. saw before and run into this problem? Anyone else out there with some advice?
Thanks in advance,
Jason
Replies
Jason,
Every contractor's saw I've seen takes a standard A or 4L type of belt, 1/2 inch wide at the top, and the Fenner A/4L link belt fits without a problem. Fenner does make a smaller 3L size that is 3/8 inch wide across the top. I've never seen a saw use this size, but anything is possible.
Fenner link belts normally ride high in a standard pulley, especially in a situation like a contractor's saw where there isn't a lot of tension on the belt. This may be what is making you think that the belt isn't fitting properly but it is normal to have a portion of the belt ride above the rim of the pulley. Before you go through a lot of trouble, I'd try a Fenner A/4L belt and see if it works in actual use.
I haven't searched extensively, but I can't find a reference to a 4V belt size being used currently, and that series of belts is a high horsepower, industrial belt series and not likely to be used on a contractor's saw and, in any case, it appears that a Fenner 4L belt would probably fit a 4V pulley.
As for the arbor pulley not being a standard bore, that is fairly common on most machines these days. I'm not too surprised that the keys are metric, these machines are being made in countries that are entirely metric after all and in a world that is almost entirely metric. Keys, if needed, can be filed with a step in them to accommodate two different size keyways when the shaft keyway is one size and the pulley is different.
John W.
John,
Thanks for the insight. I applogize - I meant 3L not 3V, as I wrote in the original post. I did indeed try the 4L link belt on the factory pulleys and (even though it was really obvious) I started up the machine and they popped right off. Thankfully, no damage was done. Indeed, the pulleys will fit with a 3/8" wide belt.
But...I didn't know Fenner made a 3L. That's my solution! Thanks. I'll check out the Fenner web site.
Jason
Grizzly also sells Power Twist link belt in 3/8" width - item G3639.
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