Member postings for Dave Rawding

Thank you all for the replies, It does seem that it should have been 11.5TPI not 12.5. I seem to have a fair collection of gears so I should be able to find a combination of gears to do the job. The information about the leadscrew pitch and setting the gearbox to 8 TPI to make it 1:1 is very helpful. armed with that information I can tackle the job with a bit more confidence. The information about the charts and tools to calculate rations is great as well.

I've not looked yet at changing the gears in the drive train but would I be right in thinking that the quadrant and gears that presumably came as standard with the lathe would be used in combination with the quick change gearbox for cutting the common imperial threads. For anything else I should change the quadrant to the one that I had previously assumed was for cutting metric gears. I assume that this quadrant gives a bit more flexibility for using different combinations of gears and so is best for metric or unusual pitches?

Dave

Can anyone help? I have a myford super7. I seem to be able to find more information on cutting metric threads than imperial ones. perhaps thats because the common imperial ones are easy to select on the quick change gearbox.

I want to cut a 12.5 TPI NTP thread but it's not listed on the chart on top of the gearbox. Should it be easy to select this pitch?

I was thinking that its close enough to 2mm pitch and for my requirement I could probably make that fit, I have the gears that I'd need to cut a 2mm thread but thought that since its an imperial lathe and I want to cut an imperial thread there is perhaps something that I'm overlooking?

Dave