lathe solid toolpost
Monday, Feb 10 2020
It’s been a long while since I added any machinging related pages. I mostly use my lathe and mill as most other tools: they are used to do a specific job when working around the house or on my motorcycle. Many of the things I might have done in metal a few years ago I now do in plastic with my 3D printer.
The last time I needed to use the lathe I became frustrated with excess vibration in the compound slide. I added locking screws on the slide gibs, but I could still feel vibrations when trying to take all but the litest cuts, especially in steel. Since it is rare that I need the slide – cutting tapers or screw threads – I thought I’d try a solid block to hold the QCTP. It’s not much more work to swap between a block and the compound slide than it is to change the angle of the slide.
This is what I have now. It seems to be doing its job in the little bit of testing I’ve done. It is made from a piece of 2" x 3" 1018 cold rolled steel. I got a 6" cut off on ebay for not too much money. It was a slight hassle to cut as my portable band saw only has a 2" mouth. I cut about 80% with the band saw and finished the job using a hand hack saw.
I started to square up the block in my mill. I could get a decent finish with a fly cutter, but could only cut about 0.002 inch at a time. I put a 4 jaw chuck in the lathe and finished squaring up the piece and getting it to size. Then I went back to the mill to drill mounting, alignment, and tool-post holes. I threaded two holes for the tool post so I can mount it forward or toward the back. That gives me a bit more range than when using the compound. You can see a bit of tape covering the forward hole in the picture. I did that to keep swarf out.
Before doing the work in steel I 3D printed a mock up to check hole alignment and sizes. The design I used (pdf) is here.