Tightening Dual V-Belts?

I've got a Champion compressor with an R15 pump and a 13HP Kohler engine on it, and it's got about 2 hours use on it since it was brand new.

Consequently, the belts have stretched some during break-in, and I need to tighten them up. The manual offers some useful generic advice such as "loosen bolts securing engine and move engine until belts are tight."

The problem is, getting two BIG v-belts tight and aligned by hand is a losing battle. I used to see a device advertised that was like a turnbuckle between two curved shoes that fit in the grooves of the sheaves and you turned it with a wrench to put tension on the belts while you tightened the bolts... but I can't find anything resembling that anymore. I suppose I could make one.

Anyone have any suggestions for getting tension on the belts otherwise? The gasoline engine is what has the slots for adjustment.

Here's the machine in question:

I recently faced the same exact problem, what I did was to make up a tool to do the job.

This will sound like a lot of work but honestly, it was all of 10-15 minutes to do.

I went to the hardware store and bought a turnbuckle (I think 5/16 threads). These are the type with two "eyes", one on each end, used for tightening cables, gate hardware, etc. I think it was $3.

As you probably know these things have two threaded ends, one left-handed and one right-handed, so when you turn the center, the threaded ends will expand in-out.

So what I did was to cut the "eye" ends off of each end, and then I bent up two small pieces of scrap metal tubing I had, to make two "V" shaped parts which would mate with the radius of the compressor flywheel and the motor pulley. Didn't have to be an exact fit.

I then welded the "V" parts onto each end of the turnbuckle threads where I had cut the "eyes" off.

You just loosen up the motor bolts and then install the tool between the compressor flywheel and motor pulley, then expand the tool, thereby tightening the belts.

It worked like a charm!!

Prior to making the tool, I had struggled for a half hour trying to get the twin belts equally tight, without any success...

I tied the tool onto the back of my compressor with a wire, so it will always stay with the compressor.

I'm sure there is a commercial tool that can be bought for this purpose, also, but it was extremely easy to make one.

Nice compressor, by the way!

Thanks, I came up with a similar solution, just a little faster and nastier

Posting this kind of served as thinking out loud for me, I headed back out to the shop and came up this: I cut a handy piece of 2x4 to the radii of the belt sheaves, and used two pieces of 3/8" all-thread between them. The holes the all-thread fit in just keep the rods from falling out basically, the nuts are tightened against the wood to spread the tool so I didn't need a right-hand, left hand thread arrangement.

It worked like a champ and used material I had on hand, the machine's tensioned back where it should be and buttoned back up.

There you go! Good Job!

Now, put that tool somewhere where you will be able to find it in the future!

I have a few of the C Man bar clamps that are 18 or 20" long. I forget what they are called put you can reverse the bar and make it a spreader.

That is what I use.

Like this but C Man:

http://www.amazon.com/dp/B00004SBCL/?tag=atomicindus08-20

I like the pulley spreaders.
My concern would be that you might end up with the pump or motor cocked out of alignment because you are working at only one end of the shaft.
I would use a combination of the pulley spreader and the clamp flipped to be a spreader.
That way you can put the force equally at both ends and keep things straight.

It's ideas like this that I really like about garage journal.

I have the habit of over thinking stuff.... The wood spreader is quick and simple as well as the idea for reversing the "quick-clamp".

I have done this many times on industrial equipment using clamps and levers.
Check the alignment of the pulleys with a straight edge after tightening.

Torque1st said:

Check the alignment of the pulleys with a straight edge after tightening.

Click to expand...

Alignment is critical on this application, since the engine slots have significant clearance and any misalignment causes the belts to lope. Alignment was verified with a 36" straightedge, which was easy because these sheaves are big and flat-sided.