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 _____."

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[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-Minibike-Tires-Parts.aspx

[Marc Jeske]

https://www.google.com/search?biw=1229&bih=608&tbm=isch&sa=1&ei=Tj06W8a5Bsy0zwKrw4SYBQ&q=flat+belt+pulley&oq=flat+belt+pulley&gs_l=img.3..0l4j0i30k1l2j0i5i30k1j0i8i30k1l3.51886 9.527256.0.527499.31.23.0.0.0.0.86.1582.21.21.0... .0...1.1.64.img..14.17.1277.0..35i39k1j0i10i67k1j0 i67k1j0i10k1.0.vp19OWNL0-4#imgrc=TCB71Kc8hewUJM:

[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-Polished-Aluminum-Front-Wheel_p_1543.html

Steel - https://gokartsusa.com/Chopper-Front-Wheel-10in-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/categories/skyway-tuff-wheel-mag-front-wheel-3-8-nutted-16-x-1-75-black?utm_source=TPA%20On%20Google%20Shopping&utm_campaign=Top%20Placement%20Ads%C2%AE%20(SPLA)&utm_medium=cpc&utm_term=People%20Searching%20For%20Bike%20Parts&utm_content=Google%20Shopping&product_id=51600&device=c&loc_physical_ms=9028570&gclid=CjwKCAjwmufZBRBJEiwAPJ3LpiwueWXUDJNcB9Oq426M q5tMDBydJqyNv7B5G4iz3vjTgLUW4BHsNRoC6UoQAvD_BwE


https://www.google.com/search?biw=1229&bih=608&tbm=isch&sa=1&ei=iVM6W52RNMH7zgLJs5m4BA&q=16+%22+bicycle+mag+wheel&oq=16+%22+bicycle+mag+wheel&gs_l=img.3...1241624.1244195.0.1244699.5.5.0.0.0.0 .70.305.5.5.0....0...1.1.64.img..0.0.0....0.G5s5OT uSILk


12" - https://www.google.com/search?biw=1229&bih=608&tbm=isch&sa=1&ei=Z1g6W8maKIu3zwK-kr34BA&q=12+%22+bicycle+mag+wheel&oq=12+%22+bicycle+mag+wheel&gs_l=img.3...172274.173367.0.174375.2.2.0.0.0.0.67 .127.2.2.0....0...1.1.64.img..0.0.0....0.xT9UAKtP0 nw

[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

[Marc Jeske]

O ya, and seeing as how it's lowww slowww speed, and exposed in bilge.. do not think "Bearings" but rather bronze bushings wherever needed in your setup, and maybe some non ferrous shaft and hardware.

If desirable, one should probably be able to drill out and press in a bronze bush into these wheels.

Basic bronze bushings aka sleeve bearings couple bucks readily available at hardware store in the little Hillman drawers.

Certainly much larger selection like at MMCarr.
Marc

[Malcolm Schweizer]

I'm glad I asked- this has been fun. I found this and it is perfect, because it has a key way. Apparently the drive wheels have them. I can even run my line right through the valve hole. It's like it was made for me. Now to order all the bits and pieces. Will let ya know how it comes out.

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[Bill Dufour]

I have seen spoked "mag " wheels for bicycles made of molded plastic. for BMX type bikes. I would use a plastic bushing. Check wheel chair wheels for similar designs.
Do a google search for "Plastic wheelchair wheels"
Insttead of pulley search for "plastic sheave"
Bil l.

[Malcolm Schweizer]

I have seen spoked "mag " wheels for bicycles made of molded plastic. for BMX type bikes. I would use a plastic bushing. Check wheel chair wheels for similar designs.
Do a google search for "Plastic wheelchair wheels"
Insttead of pulley search for "plastic sheave"
Bil l.

Yes, the above is actually one of these wheels. I didn't make that clear. It's a 12" bike wheel by the guys that invented "Tuff Wheels" in the 1970's.

It is kind of funny how if you call it a wheel, it's $50, but make the same exact thing without the hole for a valve, call it a sheave, and it's $150. ;-)

[John C Cox]

Don't bother with a second small sheave - just let the line wrap on your shaft.

All you need for this now is a shaft with the right key and 2 pillow block brass bearings.

The cable connected to the board attaches straight to the shaft.
Turn the big wheel and up/down it goes.

[Malcolm Schweizer]

Don't bother with a second small sheave - just let the line wrap on your shaft.

All you need for this now is a shaft with the right key and 2 pillow block brass bearings.

The cable connected to the board attaches straight to the shaft.
Turn the big wheel and up/down it goes.

I’m kind of thinking that. I am worried now that I will have to pull too much line if I do that. It would make it something like 12 turns to just pull 24” of working end.

[John C Cox]

I guess you have to consider how much mechanical advantage you have vs how hard are you willing to pull....

A 10:1 advantage gives you an 18lb pull to raise the board.... That neglects friction/sticking. But that also gives you the ability to use 30lbs + of pull initially to get it going (or about double to unstick it)... Say you change it to 5:1.. That means the raising force is 36lbs but unsticking may take 50-70lbs on the rope...

You could always try it out and see how it feels. It would be easy enough to clamp a split pulley onto the shaft if you want to increase it's diameter.....

[lowell holmes]

We are woodworkers, make one using wood.


https://www.woodmagazine.com/materials-guide/lumber/outdoor-lumber

[Malcolm Schweizer]

I guess you have to consider how much mechanical advantage you have vs how hard are you willing to pull....

A 10:1 advantage gives you an 18lb pull to raise the board.... That neglects friction/sticking. But that also gives you the ability to use 30lbs + of pull initially to get it going (or about double to unstick it)... Say you change it to 5:1.. That means the raising force is 36lbs but unsticking may take 50-70lbs on the rope...

You could always try it out and see how it feels. It would be easy enough to clamp a split pulley onto the shaft if you want to increase it's diameter.....

We are on the same page. There will be a small winch (ratcheting sailboat winch) to add purchase at the other end of this. 5:1 is kind of what I am thinking as a minimum minus the winch. I have two options for the large wheel- 8.5" and 16". They use a 5/8" shaft. I was leaning towards the 16" with 3" smaller pulley for 5.3:1 ratio, but I would have to pull 10 feet of line to get the 24" of line moved at the working end. That's a lot of line to pile up in the cockpit. I could use the 8.5" wheel and 1.5" smaller sheave and get around 5.5:1 and need to pull almost 12'. Ugh. Nothing is ever simple. I also considered a 14" hand wheel that I found, and using a chain to drive the smaller pulley. Advantage: no line in the cockpit. Disadvantage- let go of the wheel and BAM- centerboard free falls. Easier to accidentally let go of a wheel than a line. Also cleating a line is easier than chocking a chain drive and also safer.

Keep in mind that although the centerboard weighs 180 pounds, it pivots on a pin which will take some of the weight. There is an extended arm to add mechanical advantage. I'm too tired to do the math, but you are lifting much less than 180 lbs. Another builder of the same design uses a 5:1 purchase and says it easily lifts it.

389049


We are woodworkers, make one using wood.


https://www.woodmagazine.com/materials-guide/lumber/outdoor-lumber

It's on my mind, but if I could get a ready-made part and focus on the build, I would prefer that. If I made a sheave, it would be laminated and have an accent stripe.

[Malcolm Schweizer]

389068

Look what I just bought. Just need to make a flange which can bolt into those free holes. This is so awesome.