9 Inch Wooden Lobe Cam
I built this wooden cam with parts from my garage. Everything on it came from the local hardware store and has been repurposed into an actual functioning unit. The stem and axel are steel pieces and are very strong. The limiting issue is the wooden cam lobes, they are weak and would break under anything more than body weight.
I use this in displays and for a fun conversation starter but it has held approximately 200 lbs. of static load in a parallel sided placement. The cam lobes were designed by scanning a lobe from a #2.5 Friend on my flatbed scanner and then blowing it up to the desired size. I used the resulting image as a template to cut out the 4 lobes from 3/4 inch plywood. Shaping, drilling, sanding and applying a few coats of stain and clear epoxy sealer and they were ready to go.
Every other part was simply bolted together using whatever I had on hand. The “springs” were made from bungee cord Gorilla Glued into each cam lobe. The trigger was shaped from scrap plywood and the wires were also Gorilla Glued into the lobes. Cam stops were fashioned from brass plumbing nuts because they looked better than other options I considered. The stem is made from 3/8 inch eye bolts. Sleeve nuts connect the home made aluminum stock thumb bar.
If you want to make one yourself send me an email and I can answer any other questions!