Rotary motion to reversible linear motion

[Brian Rupnow]

I spent a goodly portion of the day modelling all of the components into position and developing wooden bracketry (pale green), pulleys (yellow), and drive belts (black). I also received my package of 50 rubber o-rings from McMaster Carr. Right now I'm rooting thru all my metal supplies to see if I have enough material to make all the pulleys from.

 

[Brian Rupnow]

YES!!!---I've got enough material to build all of my pulleys for this project. This afternoon I installed one of my new 1/4" cross section rubber o-rings on my driven shaft, and the results are less than stellar. This is probably because I am using solid bronze or brass pillow blocks on the driven shaft, and I may have to make new pillow block bearings that actually hold ball bearings to avoid the friction I am getting. Fortunately I have a couple of 5/16" ball bearings that I have recovered from an old project.

 

[Brian Rupnow]

Today I made up the first of my many pulleys, this one fitting on the engine. I make the grooves the same width as the o-ring that I am using for drive belts. I made up a 1/16"wide knurling wheel a few years ago, and I use it to knurl the bottom of the o-ring slot so that the pulleys don't slip when driving the o-ring. I would have liked to use timing belt style pulleys and belts for this job, but they cost way too much. The last time I bought a timing belt and two small (about 2" dia.) pulleys, it cost me more than $150 dollars.