lathe_construction

machine#designs: lathe: lathe_construction
Dave_Gingery: series: lathe: lathe_construction

Lathe Construction Notes

Cost of building the lathe:
I wrote up a list of everything I spent on tools and such while building the lathe. I will try to reduce this to the things that actually ended up in the final lathe and post the results under lathe_construction_costs.

Microwave Baked Cores:
I had a problem with the cores breaking out of the lathe bed pattern when it was drawn. Turns out I put draft on the cross braces in the wrong direction on the ends. So, I decided to pack them in the bed first, strike off the cores flat, add parting to the bed, ram the mold the usual way, then remove the core from the bed and put it in the mold. I had to do this twice since the ends would not come out in one piece. While I was at it, I put the cores in the microwave for a minute or two to dry them out. Always one to get carried away with something, I decided to cut X-braces in the cores with a hacksaw. I cut each core into two pieces, one cut along the diagonal. The direction alternates with each core. lathe_modifications_xbrace

If you want to save a lot of time finishing the castings, use an oil-bonded sand like petrobond. The oil-bonded sands give a finish that is many times better than the water-bonded sands that most beginners use.

Painting the lathe:
A good paint to use on the finished castings, if you want to paint them, is Hammerite. Don't confuse Hammerite with Rustoleum Hammertone--they are NOT the same thing. Hammerite is available at REAL hardware stores, not the big-box retailers like Lowe's or Home Despot. The paint is extremely durable and dries in less than 1 hour. The downside is that it can take up to six weeks to cure.

More information on Hammerite can be found here: http://www.masterchem.com/pages/default.aspx?NavID=42

Pre-ground Ways:
Gingery talks about using cold rolled steel for the ways. Save yourself a lot of time and buy either flat ground tool steel or flat ground 1018 stock. It is available from major industrial supply houses like MSC, J&L, Travers Tool, Victor Machinery Exchange and KBC Tools, just to name a few. No, it is not cheap, but it is typically ground within 0.001" flat and the edges are square within 0.003".