Many times I have spent a small fortune on small pulley, and also wasted much time trying to manufacture my own. It hit me about three years back and it is so simple, Motor cycle /bicycle chain, every link is composed of two small barrel that spin on a center shaft, or should I say pulleys.
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Carrier end design with notching to make it nice and professional . With all this being said in one chain you get about 50 links. The best for separating them is an angle grinder, to grind the pins, then with a pin punch push the pin through wit a hammer and you have one pulley, and so many more still there for later.
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In this picture I have used three back to back to turn the out put of the crank mechanism 180%. One for the lateral containment and then I could have gotten away with just one more for the 180 turn ( hind sight is always 20 20), but I did use two .
For the center on the main control rod I used a 1 1/2" washer with three 120% holes for the leader clips (fishing gear is mighty handy with rigging Halloween stuff.
In this pic you might be able to make out the 15" pulley is merely 3/4" ply wood with a 30% cut twice to accomplish the grove for a V belt. You can save a lot of money and time by making your own wooden slow speed pulleys. After you cut your radius OD, set table saw height and then mark center of the blade on the table for reference, then free hand your first cut through. then shut the say down and put the pulley centered on the blade, and use two 3/4 blocks front and back of the pulley and fasten them to the table saw with clamps. Now you are ready to turn the groove with feed of course into the blade, just roll it right around . then spin the pulley end for end and do the same to the other side. You have just made yourself a pulley for next to nothing. My porch automation system is comprised of a 1/4 HP motor with a gear reducer to 60 RPM with a 30" wooden wheel to give me a 28" pull on multiple location anywhere I need on my porch. Also for their I use the same system but feed a 3 1/2" pulley to a 15" pulley to accomplish a 6 RPM for my crank ghost . Think out side of the box and you can build any thing, if you need help on the hard stuff drop me a note. Always willing to share some of my 38 years in the construction trades. Stair builder/ designer is my specialty, so the twisted and curved stuff is right up my alley. Be Cool.