Myford gear trains

[firebird]

Hi

I have owned my Myford ML7 for about 5 years now and have got to know the machine pretty well. Up to now I haven't bothered (or needed) to do any screw cutting. The set up that the lathe came with gives a fairly fast lead screw speed, I'm sure of the exact speed, but too fast for a power feed when turning.Over the weekend I decided to have a go at getting my head around setting up the gears. I have the book THE MYFORD SERIES 7 BY IAN BRADLEY so sat down and had a good read. Now I must admit that maths is not my strong point but fortunately the book has a clear explanation and decent drawings. More importantly it has tables already worked out for you up to 120tpi and slightly beyond which gives feed per revolution of .0037 That should do it I thought so out in the workshop I dug out the box of gears that came with the lathe only to find they won't fit, they are not Myford
A quick order to RDG Tools (usual disclaimer) on Sunday saw me with 6 new gears arrive on Tuesday, good service that. Set the lathe up tonight and cut a bit of scrap steel with the power feed. Its a great improvement on what it was but I feel the feed is still not fine enough. Here's the question, are there any Myford owners out there who know of a set up that would suit, i.e. much slower feed or someone who could work the maths for me.

Cheers

Rich

 

[fcheslop]

Hi Rich ,do you have the fine feed tumbler fitted ? typically of Myford its an extra.
regards Frazer

 

[tel]

Yo Rich, I forget what feed this gives, 'cos I've used it for years but ....

My fine feed set up uses 20, 65/25, 70/20, 75.

Gives good results on my machine without sending me to sleep!

 

[arnoldb]

Hi Rich

I'm fortunate enough to have the 12 tooth fine feed tumbler gear though I rarely use it.
It replaces the tumbler gear completely instead of changing the gear on the normal driver.
If you look in Bradley's table, this one gives .0018" per rev feed.

Tel's setup is the finest you can get with standard gears - that gives your .0037" feed.

Regards, Arnold

 

[djc]

Here's the question, are there any Myford owners out there who know of a set up that would suit, i.e. much slower feed or someone who could work the maths for me.

Have you seen the ML7 gear calculator here: http://www.duncanamps.com/metal/software.php

If you edit the data file to include the gears you have, you can pick a fine feed (i.e. a thread pitch) and see how close your gears will get you. The beauty of the application is that it only suggests combinations that actually fit.

 

[firebird]

Hi

Many thanks for the replies Frazer Tel and Arnold.

Djc. That little program is brilliant. I've just been playing with it and can get 252 TPI with the gears i have. I haven't tried it any higher than that yet. This is a highly recommended download for Myford owners.

Cheers

Rich

 

[John S]

Hi



That little program is brilliant. I've just been playing with it and can get 252 TPI with the gears i have.

Cheers

Rich

It's a bastard making the nut for it.

John s.

 

[arnoldb]

;D The program even runs under WINE on Linux!

It's a bastard making the nut for it.

:big: John you got further than I did; I stopped dead at thinking what it would take to grind a threading bit for it!

Regards, Arnold

 

[firebird]

Hi

Using the programme that DJC linked to I now have the lathe set up to 273 tpi. That works a treat, very slow fine feed and gives a very good finish.

cheers

Rich