Thread Cutting Change Gear Calculator

[editor@glue-it.com]

Just thought I would make a simple online Thread Cutting Change Gear Calculator

Uses number of teeth on each of the four gears and the leadscrew pitch - works with TPI and mm



Let me know if it is useful or you need other options or even calculators

[DIYSwede]

Thanks for sharing, Nigel. Works great.

Note to Metric users: -Only remember to enter a decimal point (instad of a comma) for Metric leadscrew pitch.

My two cents: Personally I almost always need to know the change gear combo to reach (or nudge) my desired thread cutting pitch,
rather than the other way around: Enter all the gears to find out what pitch I'll get then.

Keep up the good work!
Johan

PS: I've thus far been satisfied with Dr Al's Mini Lathe Gear Calculator
(particularly when cutting Imperial threads on my Metric mini lathe, by just 3D print a few extra 21, 50 & 63 T gears):
https://www.cgtk.co.uk/metalwork/cal...ears/minilathe

[editor@glue-it.com]

Thanks for sharing, Nigel. Works great.

Note to Metric users: -Only remember to enter a decimal point (instad of a comma) for Metric leadscrew pitch.

My two cents: Personally I almost always need to know the change gear combo to reach (or nudge) my desired thread cutting pitch,
rather than the other way around: Enter all the gears to find out what pitch I'll get then.

Keep up the good work!
Johan

PS: I've thus far been satisfied with Dr Al's Mini Lathe Gear Calculator
(particularly when cutting Imperial threads on my Metric mini lathe, by just 3D print a few extra 21, 50 & 63 T gears):
https://www.cgtk.co.uk/metalwork/cal...ears/minilathe

Hello Johan,

Thanks for the feedback. Based on this I've added a change gear calculation sheet to my workshop calculations download (free download for all)

This now has a calculator as per the online page.

Plus a calculator where you enter the thread pitch you want to cut, the leadscrew pitch and then 3 gear options for each position on the gear train. This then calculates all combinations, highlighting the exact matches green and any with <2% ratio error in amber.

I need to perhaps write some more notes, but hope this helps.

Best regards, Nigel

[editor@glue-it.com]

A snapshot of the worksheet here:

[2-hack]

Nigel:
Thank You for posting!!!
My 1908 Reed leaves me guessing most of the time. After a century of use the "standard gears are very worn or missing all togeather, so some very unusal combinations are required, and your varibles take the ?? out.

I hadn't thought of using "printed" gears can you suggest a particular grade/ type of plastic to use? How about aperson that has done gears sucessfully?

Many thanks,
2-hack

[DIYSwede]

I hadn't thought of using "printed" gears can you suggest a particular grade/ type of plastic to use? How about aperson that has done gears sucessfully?

Many thanks,
2-hack

@2-hack : For me ordinary PLA gets the job done. YMMV.
My page on this: Imperial threads on a Metric lathe.

Thanks Nigel for sharing!
ATB
Johan

[NortonDommi]

I have been using 'Lathe Gears' by Vernon van D. for years and swear by it. You have to work out your gearbox ratios if not listed but worth the time. Amounst my all time favorites.
I have tried to upload the program but can't so here is the link: https://lathegears.software.informer.com/

[DIYer]

Thanks editor@glue-it.com! We've added your Thread Cutting Change Gear Calculator to our Machining category,
as well as to your builder page: editor@glue-it.com's Homemade Tools. Your receipt:

Thread Cutting Change Gear Calculator by editor@glue-it.com

tags: threading