Quote:
Originally Posted by GB SISSON
Well I woke up in the middle of the night last night and worked out a few more details in my head. The .750 teflon rod won't be here til Monday so I had to try my methods out with a 3/4" hardwood dowel. Don't worry, I won't make any of the actual ones out of wood, though I think something like locust or a tropical wood would be fine  The disc sander has a stick with a groove to hold the rod and the pivot point is half of the 3 3/16" piston creating a domed end that matches the cylinder wall's radius. I fashioned an end stop from a piece of 3/4" poly pipe with a saw kerf down it's length so the feed of the rod into the sander would be uniform. A stainless hose clamp holds the stop in place. While I am sweeping the arc with the pivot stick I am slowly rotating the rod with my fingers. After that it goes to the router jig with a 1/2" straight cutter in it. I have the depth of the router set to make a tenon or shoulder that's a nice press fit into the hole in the wrist pin. This cutter depth will no doubt change when the real teflon arrives as this dowel is a about .010 undersized. Next I lop of the head with a pull saw, and it's done. Because the router bit has it's carbide tips back cut and proud of the rest of the bit for plunge cutting, it creates a very nice 'barrel' shaped tenon that starts easily and then gets resistance as it gets half way. The completed pin assembly with both buttons installed is about .008 less than the bore which incidentally is .030 over. I'm thinking this just might work. |
Yep nice job.
Here is the 40 not Bert Munroe.