Calling Engineers: I need to build this- looking for a wide pulley/sheave/drum.

[Malcolm Schweizer]

I am building an uphaul mechanism for a centerboard for an upcoming boat build. They want $750 for a factory one. No way, Jose! It should be easy to build. I am looking for the wide pulley in this picture. The good news is as long as it's between 12" an 18" diameter, it will work. Purchase will change, but it will work. So far I have found a Harley Davidson belt drive pulley that may work, but I would have to add sides to it. It only needs to hold about 10 feet of 1/2" rope. It needs to be bronze, stainless, or aluminum. It's not going to take much strain- the board will come in at around 180 pounds. Rather than wire on the small pulley, I will probably use nylon strap. I am also looking for an appropriate pulley for that, although it will work to just mount it to the shaft if the larger pulley has a large diameter shaft. Again, purchase will change based on the size of pulleys, but I've got a very wide range to work with. As long as I can pull it, I'm ok.

The one pictured was custom made for a boat for someone with much deeper pockets than I. I've been looking at places like Granger, McMaster Carr, etc. I was hoping someone here sees this picture and says, "Hey, that looks just like the pulley off a _____."

CBpulleyreducedWeb2 (1).jpg

[Malcolm Schweizer]

Hmmmm.... Just had a thought- 12x4.5" aluminum trailer rim. Just have to find a stainless steel hub for that, and this could be easier than I thought.

[Jamie Buxton]

Or a motorcycle wheel?

[Malcolm Schweizer]

Or a motorcycle wheel?

Yes, I am looking at those as well. I found a stainless hub for the trailer wheel, to which I could bolt a smaller pulley on the other side, and then I would have a greased sealed bearing on the hub, and would only need to figure out what diameter the inner bearing is in order to make the axle out of stainless. Do trailer axles have a tapered end? Please say no, because that would make this easy!!! :-) I'm on vacation this week and I'm going to do some research. Still open to all suggestions. Keep in mind this needs to be non-ferrous metal whatever the solution is.

[Marc Jeske]

"mini bike wheel" looks good, BUT only about 10" max diameter..

https://www.mfgsupply.com/az1177.html


https://gokartsusa.com/Gokart-Wheels...res-Parts.aspx

[Marc Jeske]

https://www.google.com/search?biw=12...CB71Kc8hewUJM:

[Marc Jeske]

I understand wanting non ferrous, but a world of possibles in Steel would be available if you could put a high quality finish on it.

And probably lots cheaper.

Just an idea.

Marc

[Marc Jeske]

Have an AL welding /machine shop put sides on this and true it up overall, etc.

'https://www.ebay.com/itm/VINTAGE-SOLID-ALUMINUM-FLAT-BELT-PULLEY-12-ROUND-X-3-WIDE-1-BORE-/183285845914

Lots of possibles here, but most are cast iron, more complicated to weld side flanges to.

'https://www.ebay.com/bhp/flat-belt-pulley

[Jerome Stanek]

You can buy just the spindle for a trailer wheel that would have the bearings and bolts to mount

[Adam Herman]

usually the inner and outer bearings are different diameters but they are not tapered. 1.75 inside and 1.25 outside I think? I keep thinking of things and then going... damn.. that's gonna rust. I don't think I have ever seen a stainless spindle, as stainless would be a poor choice for the strength/bearing situation in a trailer spindle and it is generally filled with grease.

there are stainless trailer winches set up for nylon strap. you could use the gearing to decrease the size of the larger pulley.

most of the large flat stuff is either steel or for a gear belt. ex. a blower pulley on a drag racing car. lots of billet options for automotive applications, but i don't think i have seen anything that large on a car.

have you thought of going to a boat salvage yard? are you near a coast in the states? do any diving down there?? haha

[Marc Jeske]

Or a motorcycle wheel?

What's the smallest rim normally available?

If that isn't too big , maybe a bike salvage yard could yield a find ?

Marc

[Marc Jeske]

10" ???

https://www.bmikarts.com/10-Douglas-...el_p_1543.html

Steel - https://gokartsusa.com/Chopper-Front...0in-Black.aspx

[Marc Jeske]

It looks like, from what I see, from your photo on a different boat, that a smaller diameter than your proposed would still give you plenty of mechanical advantage to easily lift a 180 lb board.

Up to 18" as you allow seems WAYYY needlesly huge.

Even 10" should be easy to lift and would take only 3-4 wraps.

Pulling force could be easily calculated.

Just thoughts.

Interesting project.

For that matter - What about Wood of some appropriate species, or even plastic of appropriate type?

You are talking super low rpm's, non frequent cycling, and only 180 lb load.

Lots of possibilities.

Marc

[Marc Jeske]

Ya, I'm taking the day off after a long work weekend... like to google fer stuff -

https://www.niagaracycle.com/categor...RoC6UoQAvD_BwE


https://www.google.com/search?biw=12....0.G5s5OTuSILk


12" - https://www.google.com/search?biw=12....0.xT9UAKtP0nw

[Marc Jeske]

This may be your destination -

https://www.skywaywheels.com/products.htm

For example, buy one of these and then cut off and scrap the tire, and Bob's yer Uncle.

https://www.skywaywheels.com/products_005.htm