Viceroy Lathe 38 Tooth Stud Gear For Imperial Threads

[molyneux.mike]

I found a topic on the Viceroy Lathe section, showing a calculator for cutting imperial threads using a stud gear and standard 5-position Viceroy Metric Gearbox. I have made a 38 tooth stud gear which will allow you to cut the following imperial threads:- 4 8 16 32 64 64 67 75 107 128 134 150 T.P.I. threads. It only just fits the gear train. The quadrant clamping bolt might need a little filling to give the correct play between the new stud gear. Anyone interested in one send me a personal message from here.

38T Stud gear edit 1.jpg (15.31 KiB) Viewed 8920 times

[Andy B]

I have made a 38 tooth stud gear which will allow you to cut the following imperial threads:- 4 8 16 32 64 64 67 75 107 128 134 150 T.P.I. threads. It only just fits the gear train. The quadrant clamping bolt might need a little filling to give the correct play between the new stud gear.

A 19T stud gear would give the same range except for 4TPI and fit in the gear train much more easily.
Should also be quicker to cut, so maybe another / cheaper option to add to your growing catalogue of parts.

How long before you do a 17 or 34, 23, 29 & 37? That will cover most TPI sizes from 6 upwards except multiples of 10 with an error of less than 0.4%.

Andy

[jpubmail]

ive got 19T locked - the way you introduce your 38T stud, interest me.. im thinking about your 38T , but before I get near to it.

This is for the standard specified inch threads between 4 and 160 TPI plus feeds down to .0021" per rev. It does not cover unusual threads, such as 19 TPI used for British pipe threads, nor does it cover Metric, DP, or Modular threads.

help

[Bogus105]

What error when cutting 8 TPI with this 38T stud gear? Is it accurate enough to use this 8 TPI thread when making precision tooling mounted on lathe's spindle?

[RodT]

If you can make these change wheels, I could do with a 34T wheel to get closer to 24TPI.

If anyone is interested I can send you a spreadsheet which shows all mm pitch and TPI threads possible with the standard (16,18,22,24,26,27 and 35 T change wheels) and other settings.