Submitted by luseedhead on Sun, 10/30/2016 - 7:51pm Tool Concept Stage: Ready to Build License: This work is licensed under a Creative Commons Attribution 4.0 International License. Description: Complete instructions for making a bicycle powered thresher. Thresher works on various crops including dry beans, wheat, rice, rye, einkorn, and lupine. Threshes about one pound per minute. This is the first of three tools for small scale grain processing designed to allow small farms to dabble in grain. The other two tools are the bicycle powered fanning mill and the bicycle powered de-huller/flour mill.Add new comment Submitted by FarmerMark on Sat, 12/23/2017 - 11:12am I don't suppose you have a bill of materials for this project? Maybe at least a wood list? I am planning to build from 3/4 plywood unless persuaded towards 1" planks. Log in or register to post comments Submitted by FarmerMark on Sat, 12/23/2017 - 12:07pm And why does the drive reduce in speed between the drive cycle and thresher? Is this important? Thanks Log in or register to post comments Submitted by luseedhead on Mon, 12/25/2017 - 8:09am There is no bill of materials. There are so many materials substitutions and adaptations (like plywood for 1X pine) that what i recommend is printing out the instructions (pdf link below) and then on each page of the instructions write in the materials you will use. If you plan to acquire the materials all at once you can collate the pages to make a master list. This exercise will also help you get familiar with each step in case modifications you make in your design (example: substituting 3/4" plywood for 1" pine) cause changes in dimensions and other possible changes in the instructions which will need to be penciled in to your instructions. Incidentally, i also use the instruction sheets to make other notes and to keep track of time and cost for each step. Log in or register to post comments Submitted by FarmerMark on Mon, 12/25/2017 - 9:38am Good point. Thanks! I hope to get into this in the next couple of days. I'll try to post some pics. Log in or register to post comments Submitted by luseedhead on Mon, 12/25/2017 - 8:25am The gear reduction between the exercycle and the thresher drum is not very important, and can be adjusted easily as an afterthought. Exercycles come with all sorts of gear ratios between the cranks and the flywheel. The thresher drum will work best at somewhere around 200-300 rpm. Too slow and the grain won't get threshed. Too fast and the wobble in the axis will shake the machine apart. Some wobble, remember, is good, as it shakes the seeds down. The bike chain part of the transmission will be happy with a larger ratio; the v-belt part of the transmission will be happy (there will be less friction) with a smaller ratio. In general, the flywheel stores more energy if it is turning faster (kinetic energy increases with the square of speed), so there are some reasons to have a large ratio to the flywheel (ex. 4:1 increase), and then a small ratio to the drum (ex. 1:1.2 decrease). I hope this is helpful! Log in or register to post comments Submitted by FarmerMark on Mon, 12/25/2017 - 9:39am Thanks for your insight and target rpms. I will factor them. Cheers! Log in or register to post comments Submitted by FarmerMark on Sat, 02/03/2018 - 5:44pm So I just ran my first samples through this thresher today. Overall it worked pretty good. I'll see if I can post pics somehow. It threshed the hulless barley pretty well with the wood flails. The spokes did pretty good on the beans as did small chain. Now to finish the fanning mill..... Log in or register to post comments Documentation Video: Attached Files: THRESHER_FINAL_UPLOAD.pdf introduction for grain bikes.pdf Related Tools This tool is a branch from these other tools: Small Scale ThresherSmall Scale Threshing Machine I like this tool up3 users have voted. I built (or modified) this tool up0 users have voted.