Unisaw #4: External control decided. Vibration found.

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Blog entry by barecycles posted 03-25-2012 11:06 PM 2083 reads 0 times favorited 2 comments Add to Favorites Watch
« Part 3: VFD bench testing 3 phase 3HP Part 4 of Unisaw series Part 5: VFD mounting, T2 fence and nursing homes »

Well I decided how I want to control the saw. I wanted to keep the existing LVS ‘cause I think it’s cool, so I wired the VFD to handle it. Just needed to flip 1 DIP switch and reset some of the external control functions and it works nicely. The location of the VFD in the video is just temporary (it will either be going on the underside of the the table or on a wall). I set it up like this to show a vibration.

I configured the motor to accelerate to speed in 1s and decelerate to stop in 1s. As you can see in the video it does that fine but you’ll also notice what I happens when I placed a knock-out plug on the table surface, it dances right off. Now, I had a matched set of belts for this thing and now I can only locate 2 so the saw is currently running on 2 belts.

My question…will running on 2 belts cause such a vibration?

More info: I have new arbor bearings but I did not replace the motor bearings.

Thanks for watching!

-- Sweeping up sawdust in Texas

2 comments so far

View Ken22F's profile


23 posts in 3231 days

#1 posted 03-26-2012 07:17 AM

For vibration check for
Loose tension Belts (loose belts flap around)
Old stiff Belts (they need to be flexible)
Out of round Pulleys (use quality machined steel) not pot metal.

Matching belts don’t allways match.

View b2rtch's profile


4851 posts in 3015 days

#2 posted 05-15-2012 11:53 AM

My Unisaw also vibrates, not bad and it is more like a rumble than really shaking. I had the original belts that I was to keep because they look like new( 25 years old but in very good condition) because of the vibrations/rumble I decided to replace them. I was going to put other V-Belts on but now I am considering the HF link belts.
I was told several years ago that since the production of V-belts is now fully automated and computerized, there is not longer “matched” sets of V-belts, they no longer exist as the belts are now supposed to all be exactly the same length

-- Bert

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