Thread gearing

[Kram]

Just about to cut a thread but the pitch is not on the diagram Could anyone help me work out what I need for 0.75mm pitch?
Based on 0.5mm example, a 45 tooth gear could replace C but I dont have one.
I will buy some extras, but can it be done with the ones I have?

 

[Pete.]

Look at 1.5mm pitch then halve the leadscrew speed by halving the tooth count of any driver or doubling any driven.

 

[mikegolding]

Look at 1.5mm pitch then halve the leadscrew speed by halving the tooth count of any driver or doubling any driven.

using the 1.5 setting with c replaced with a 30 tooth would give the ratio you need, gear b is an idler so doesn't alter the ratio you may need to change it to a larger one to allow the rest to mesh.
Mike

 

[Dr.Al]

Just about to cut a thread but the pitch is not on the diagram Could anyone help me work out what I need for 0.75mm pitch?
Based on 0.5mm example, a 45 tooth gear could replace C but I dont have one.
I will buy some extras, but can it be done with the ones I have?

View attachment 319976

If it helps for future threading requirements, I can have a go at making a change gear calculator for your lathe; I've already got them for the mini-lathe, M250, M300 and LZ4P (the latter two haven't been verified by owners of those lathes so haven't been properly published so you have to know they're there!)

 

[Seadog]

This threading calculator was developedby a NZ chap on the Boxford group. It covers just about every possibility on any machine. It even shows percentage error where you may have a limited set of change wheels.

Ride The Gear Train free software by Evan Lewis

 

[Kram]

Ow my eyes! That has got to be one of the worst website designs ever seen! However it does work, quite well when you get your head around the menu pages. May be easier to edit the url for next time. Thanks!

Ride The Gear Train free software by Evan Lewis

ridethegeartrain.com/index.php?gearboxbrand=Mini_Lathe_No_Gearbox_Leadscrew_2mm&previouslathe=Mini_Lathe_No_Gearbox_Leadscrew_2mm&gearboxfitted=no&lathetype=metric&threadrequested=mm&threadtype=metric&threadsize=0.75mm&compoundincluded=2&autocompound=yes&eulachecked=yes&errormax=0.5&maxresults=2000&changegearstring=20%2C24%2C30%2C33%2C35%2C40%2C50%2C52%2C60%2C66%2C72%2C80%2C80&leadscrew=2&powerfeed=no&carriagefeedratio=1&crossfeedratio=1&changeablestud=no&studgear=40&changeablelsg=yes&leadscrewgear=75&range=single&lolim=4&hilim=8&interval=1&prefinputtext=yes&prefspecstext=yes&prefgeartables=yes&prefgearboxtables=yes&prefintro=yes&lsg=75&fcounter=1&gearboxfitted=no&numn=1&numl=1&numgears=13&primaryratio=1&stdcarriagefeedratio=1&stdcrossfeedratio=1&stdstudgear=40&stdleadscrewgear=75&stdleadscrew=2&stdchangegearstring=20%2C24%2C30%2C33%2C35%2C40%2C50%2C52%2C60%2C66%2C72%2C80%2C80&stdchangeablestud=no&stdchangeablelsg=yes&stdcompincluded=2&stdauto=yes&pagename=run&mode=run&helplabel=

 

[Seadog]

Ow my eyes! That has got to be one of the worst website designs ever seen! However it does work, quite well when you get your head around the menu pages. May be easier to edit the url for next time. Thanks!

View attachment 320017

Ride The Gear Train free software by Evan Lewis

I hadn't noticed the URL, all I got was a hyperlink "Ride the gear train"

I hate unnecessarily long URLs

 

[Kram]

I hadn't noticed the URL, all I got was a hyperlink "Ride the gear train"

I hate unnecessarily long URLs

Thats my url for next time It'll be easier to edit that than go though all the menu pages. Plus, I didnt see a page to enter my gears but the url will let me. A few of the defaults dont match mine.

 

[Seadog]

It is completely configurable, though. I've not had need of it, other than when trying to cut a 19tpi thread. I've a complete set of change wheels, plus Norton gearbox and compound, so can cut any Imperial or metric thread that I'm ever likely to need.