Looking for some belt wisdom

[hobgobbln]

I'm working on a project for a guy that's going to need a custom length drive belt and I don't even know where to start looking or what to look for. I've replaced a bazillion serpentine and v belts but never needed a custom one, never mind a flat belt.

The belt would be flat, less than 5/8" wide, roughly 24' long and run over/around 2" diameter smooth pulleys. The belt won't be transmitting any torque more than what it takes to turn the pulleys and it will be turning as close to 1 rpm as I can get it.

It's an art piece he's building that he asked me to make move. The "pulleys" are actually aluminum film reels that he's mounted on some other contraption that i don't know how to begin to describe. The reels are a super loose fit on the axles they're riding on which I think is going to be a problem but I'll worry about that later. What I'm hoping to get some insight into is if anyone has a line on somewhere to have one made or if there's a source for the material that I can join the ends together myself if need be. I'm concerned about the tight radius wearing the joint out quickly even though there is very little force applied because it changes direction like 15 times in each revolution.

Anyone have any ideas?
Griz

[Bill Shields]

Get a leather later belt with alligator clips to make the joint.

If low torque is really the case, then you can skive a tapered joint and glue it like we used to do decades ago.

Loose pulleys will be a problem...

[hobgobbln]

A search for “Leather later belt” didn’t bring anything up so I’m guessing that’s a typo?

Yes, the torque will only be whatever friction builds up in the system which I’m hoping to be minimal because of the thin aluminum the reels are made out of. Would a glued joint hold up to being bent back and forth?

[Bill Shields]

lathe belt....any idea on length / width?

[hobgobbln]

5/8” or less wide and somewhere around 24 feet long.

[rmac]

Loose pulleys will be a problem ...

So will tracking.

Griz, are you making the pulleys? If so, you'll want to crown them so the belt will want to stay on the pulleys rather than wandering off to one side or the other. (By "crown", I mean the pulley diameter should be slightly bigger in the middle than it is on the sides.)

I'm guessing that Bill meant "leather lathe belt". But maybe not.

Also be warned that we're going to need to see a picture of this thing when it's done.

-- Russell Mac

[hobgobbln]

Griz, are you making the pulleys?

I wish I were, but no. They are old film reels. The OD of the reels are 7” but the diameter in the center where the belt will run is 2”. Tracking shouldn’t be an issue as far as the belt falling off, but keeping the belt from dragging on the outer edges will be a problem I’ll deal with later.

Griz

[Russ Hanscom]

There are sources for thin flat belts, I have a Delta overarm router that uses a thin belt about 1" wide and maybe several feet long. I did a search for custom flat belts and found several places that make custom belts. Probably overkill for your application.

For your project you might look at webbed nylon belts or straps; available in many widths and thicknesses.

[Bill Shields]

how long / wide a belt are you going to need?

2" diameter is certainly negotiable by a glued skived joint

[rmac]

I wish I were, but no. They are old film reels. The OD of the reels are 7? but the diameter in the center where the belt will run is 2?. Tracking shouldn?t be an issue as far as the belt falling off, but keeping the belt from dragging on the outer edges will be a problem I?ll deal with later.

Got it. In some ways, it seems like the best "belt" to drive old film reels in an art project would be old film! Does that make any sense at all for what you're doing?

-- Russell Mac`

[hobgobbln]

For your project you might look at webbed nylon belts or straps

That is a really good idea I hadn't considered. I'm not sure if the nylon will be too slippery since I'm trying to keep the tension as low as possible, but it should be cheap enough to try.

how long / wide a belt are you going to need?

5/8" max width and around 24 feet long

In some ways, it seems like the best "belt" to drive old film reels in an art project would be old film! Does that make any sense at all for what you're doing?

That was actually my first idea when he approached me with the project. Then I realized I know nothing about film, never mind if I could use it as a belt. I fixed plenty of cassettes and VHS tapes that were eaten when I was a kid, but my expertly crafted scotch tape repairs never lasted long

[rmac]

I'm not sure if the nylon will be too slippery since I'm trying to keep the tension as low as possible.

I bet you'll have to put some kind of rubberish tire on the reel hubs no matter what belt material you wind up with.