CaptainPugwash
Member
- Messages
- 105
- Location
- North West England
Today I've had my first go at screwcutting with my Boxford lathe.
I'd like to thank 'Double-boost' (I'm aware he uses this forum) because I went 95% off his videos for this. I appreciated how clearly he explained it/ his way about the job.
I'm still an amateur with machines and have no experience with machining or welding to speak of although I do have a different engineering trade; this forum is great.
It went ok-ish considering a first attempt IMO.
I did an external 1.5"OD 8TPI whitworth form thread in mild steel bar. Fairly big chunky thing.
Problems:
The tool slipped slightly in the 'import' adjustable tool holder part way through the operation; I think it was at this point that the Tool steel i'd ground up lost its edge. I think this is why the threads ended up losing their definition: more U than V in the end. Rather than nice 55 degree Vs.
I've somehow ended up with the threads slightly under 1.5" dia.
I suppose these two things are why the thread is a bit loose when screwed into a shop bought female item.
In hindsight I should have ground up the tool on some 12mm square tool steel rahter than the 3/8" stuff I had to hand. And really writhed up the tool holder once at centre height.
I'm not sure if the boxford's motor liked going into reverse repeatedly with it loaded up in gear, but never mind.
Positives:
The machine got the TPI pitch spot on.
Chance to use my little Moore and Wright thread tool template and pitch gauges
I'd like to thank 'Double-boost' (I'm aware he uses this forum) because I went 95% off his videos for this. I appreciated how clearly he explained it/ his way about the job.
I'm still an amateur with machines and have no experience with machining or welding to speak of although I do have a different engineering trade; this forum is great.
It went ok-ish considering a first attempt IMO.
I did an external 1.5"OD 8TPI whitworth form thread in mild steel bar. Fairly big chunky thing.
Problems:
The tool slipped slightly in the 'import' adjustable tool holder part way through the operation; I think it was at this point that the Tool steel i'd ground up lost its edge. I think this is why the threads ended up losing their definition: more U than V in the end. Rather than nice 55 degree Vs.
I've somehow ended up with the threads slightly under 1.5" dia.
I suppose these two things are why the thread is a bit loose when screwed into a shop bought female item.
In hindsight I should have ground up the tool on some 12mm square tool steel rahter than the 3/8" stuff I had to hand. And really writhed up the tool holder once at centre height.
I'm not sure if the boxford's motor liked going into reverse repeatedly with it loaded up in gear, but never mind.
Positives:
The machine got the TPI pitch spot on.
Chance to use my little Moore and Wright thread tool template and pitch gauges
