Home Forums Hunting & Shooting Hunter's Campfire OK, you math whizzes

I can cypher, but don’t know formulas. Trying to revitalize and old two-wheel tractor.

One 6” pulley, one 10” pulley, 15” between the centers of the pulleys - how long of a drive belt do I need?

It ain’t the length, it’s the width.




P

calculator
https://sudenga.com/resources/figuring-belt-lengths-and-distance-between-pulleys/

Twine and a tape measure.

Yo have access to this equipment?

Piece of rope for initial run,

Then measure that length?

Thinking you’ve heard this before…….LOL.

Or you can run a cord around it. I'd go with the formula above, tho, otherwise you might have to try several belts bfore getting the exact right one. And as said, width also matters.

I should probably buy new belts for the 30-years-in-storage lathe I''m setting up - the old ones might be a bit rotten, but I've them to model. The paint job looks good tho.

Perfect.

I had a piece of twine and it gave me 59”. I picked up a 59” belt and it was about 2” too long. I also noticed that I needed smaller pulley so it wouldn’t rub on the axle, so put that on, but don’t want to make numerous trips to the shop. Figured there had to be an easier way to measure the belt. There’s not much room for adjustment on the belt.

Half the diameter of the pulleys , plus the distance between them.

We had. a Gates measuring tool

have you ever used "adjustable pulleys " , i worked with a high speed mixer with adjustable pulleys and it worked great.

Used to borrow cloth tape measure from wife when I needed circumference measurements, especially for odd shapes. Much easier than trying with a steel one. One of my own in is in my tool kit now.
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Use the link belts. They run smoother anyway and can be adjusted to whatever length you need.

That's only 38", the belt calculator shows 55". You doing some sort of Iwegian math?

Without thinking too hard, I bet double the CTC and 1/2 of each CIRCUMFERENCE might get you close.

Oh please you 2. The way Wabi wrote it, it would come up to 25 1/2.

55 1/8"

Not my fist mistake.

Close. Half the circumference of both pulleys plus twice the distance between centers.

Or half the circumference of each plus two times centerline distance .