turbotadd
Aluminum
- Joined
- Jul 22, 2010
- Location
- Stillwater, MN
I know some of you might prefer to not have this thread here because it's a "hobby" machine, but I think there will be some good info.
I was documenting my efforts on another forum, but I noticed Richard was no longer posting over there, and I really value his input as he taught me how to scrape.
Anyways...
I started the project with the compound rest and finished that a year or two ago and finally decided to get after it again.
I had measured about .005" wear on the v-ways so I had all of the surfaces on the bed machined by a machine tool rebuilder. One nice thing about the size of the 9" is that the bed fits nicely on my 36" surface plate. Measuring the flat tailstock way showed no needle movement along the entire length. I hesitated for quite a while before scraping the ways for fear of screwing up the nice flat and true surface, but I decided that I do want a scraped finish on the ways. I started practicing on the bottom of a cast iron lapping plate with my old blue Biax and a 60R blade. My goal was to do one pass in each direction and get a nice checkerboard pattern. I finally got comfortable and was happy with how things were looking, so I did the flat tailstock way. Just for the heck of it, I blued it up with a 36" straightedge and did a couple cycles to knock down any really high points. I was pretty happy with how it looked, so I moved onto the tailstock v-way. I used the biax on the inner surface of the V-way, and hand scraped the other surface.
I plan on putting .016" Turcite on the saddle to bring it back up to height, so i scraped off the ridges to get down to the plane of the worn surface, then I put the bed up on my plate, put the saddle on shims, and checked the fit with the apron bolted on. I established that a few thou off of the surfaces of the saddle should work well with the .018" thickness of the Turcite and epoxy combined.
I hauled the saddle into the shop at work and indicated it in using both the machined shoulder where the block that captures the rear way bolts on, and a 5/8" ground shaft in the V's. Both readings agreed within a thou.
Next steps will be to wrap up scraping on the bed, then apply the turcite to the saddle.
I'll post more as I go.
I was documenting my efforts on another forum, but I noticed Richard was no longer posting over there, and I really value his input as he taught me how to scrape.
Anyways...
I started the project with the compound rest and finished that a year or two ago and finally decided to get after it again.
I had measured about .005" wear on the v-ways so I had all of the surfaces on the bed machined by a machine tool rebuilder. One nice thing about the size of the 9" is that the bed fits nicely on my 36" surface plate. Measuring the flat tailstock way showed no needle movement along the entire length. I hesitated for quite a while before scraping the ways for fear of screwing up the nice flat and true surface, but I decided that I do want a scraped finish on the ways. I started practicing on the bottom of a cast iron lapping plate with my old blue Biax and a 60R blade. My goal was to do one pass in each direction and get a nice checkerboard pattern. I finally got comfortable and was happy with how things were looking, so I did the flat tailstock way. Just for the heck of it, I blued it up with a 36" straightedge and did a couple cycles to knock down any really high points. I was pretty happy with how it looked, so I moved onto the tailstock v-way. I used the biax on the inner surface of the V-way, and hand scraped the other surface.
I plan on putting .016" Turcite on the saddle to bring it back up to height, so i scraped off the ridges to get down to the plane of the worn surface, then I put the bed up on my plate, put the saddle on shims, and checked the fit with the apron bolted on. I established that a few thou off of the surfaces of the saddle should work well with the .018" thickness of the Turcite and epoxy combined.
I hauled the saddle into the shop at work and indicated it in using both the machined shoulder where the block that captures the rear way bolts on, and a 5/8" ground shaft in the V's. Both readings agreed within a thou.
Next steps will be to wrap up scraping on the bed, then apply the turcite to the saddle.
I'll post more as I go.