Myford Lathe

Hi I am looking to cut a metric thread of 0.8 pich The chart tells me I need a 21T gear on the driver but this gear is a different size to the rest It has a roughly 25mm bore with a spacing shoulder, On looking on the net for one nobody seems to have this gear am I looking at the wrong one the driver is the one on the spindle? mine currently is 30T

ATB Alan

Alan.

All change wheels for screw cutting on a Super 7 have the same bore of 5/8". Yours sounds like an odd-ball gear not intended for screw cutting on a Myford lathe.

Look at page 33 of the handbook for the piture JS refers to i.e. set up 2.

Lambton,

​I think JS gave the explanation correctly, the clue lies in 30T.

​Alan is probably looking at the gear on the spindle and the same sized gear after the tumbler reverse cluster.
​For his benefit the screw cutting gearing starts from the second of these 30T gears and the tumbler set does only what it says in the name and reverses the drive into the gear chain down to the leadscrew.
​It is flanked by identically sized gears above and below to keep the speed unchanged from that of the lathe spindle.

​Myford in their literature call the short shaft that the second 30T gear runs on the 'Mandrel'

​I hope that makes the table easier for you to understand Alan

​Regards
​Brian

Thanks everyone for thr help, looks like I need to get a picture of gears my chart dosnt have one or purhaps a manual any sugestions on were to get one

Plenty of downloadable PDF manuals on the net if you google ML7 manual.

To cut all/most of the metric threads you will need 2 of the 21 tooth gears. If you look on the inside of your side cover it shows this. As mentioned earlier the manual shows a diagram. Sorry if I have repeated what others have confirmed.

.

Alan,

Here is the screw-cutting chart with gear trains shown **LINK**

https://goo.gl/images/p9O7RR

MichaelG.

Thanks much clearer now with a picture The chart on the door doesnt have any pictorial help. but will now get a manual thanks again for all the help