There are several different ways to build one - I went with a chain drive system powering three sprockets. Overall cost with shipping was under $50. I built the case from scrap plywood and pine boards I had laying around which I've reclaimed. The case is a bit different than others I've seen. I wanted the tension on the chain to be adjustable for when it stretched. The upper portion of the case can slide up and down thus moving the top sprocket and tensioning the chain. There are most certainly different ways of doing this - but this is what I came up with.
Chain, sprockets and bearings from surpluscenter.com |
The case is of 3/4" birch plywood - certainly strong enough for the task and overbuilt - you could go lighter I'm sure. The front is secured to two side pieces. The top portion has full length "rails" which slide in a channel in the lower portion of the case. The back panel screws into the lower portion and clamps the rails firmly in place thus setting the height of the upper portion and the chain tension.
Case and chain without tension. |
I used #25 chain and sprockets from surpluscenter.com, along with some of their 5/16" bearings. The only other parts I needed were purchased from The Home Depot; namely some 5/16" washers which are oiled and used as thrust washers, then three 5/16" laundry line hooks which are the perfect size for this project.
Case and chain tensioned and ready to go. |
Shown below are the first pieces of rope to come off the machine. I had the hardest time with the ones made from straight up twine - I was over twisting them and causing them to break. It's a learning process and for certain different than the power drill method. It has good potential for long pieces done quickly too - I'm excited.
First test pieces - it can spin very tightly compared to the drill method. |
#25 chain: https://www.surpluscenter.com/item.asp?item=1-1163-25&catname=powerTrans
#25 11-tooth sprockets with set screws: https://www.surpluscenter.com/item.asp?item=1-2742-11-B&catname=powerTrans
5/16" bearings: https://www.surpluscenter.com/item.asp?item=1-3094&catname=powerTrans