Excellent TOS Lathe video.

Hello, stumbled onto this U tube video by mistake. Its called Internal Milling Under Power on my TOS lathe, YES ! by Michael Reggie. Its about milling grooves in a tube held in a fixed chuck, with an angled milling cutter held in an electric drill powered spindle held on the topslide, with the headstock in neutral but carriage on powerfeed !. He says the TOS lathe is unusual in this respect, but perhaps this operation could be done on any lathe where the spindle can be set in neutral ?.

Anyway, see what you think. Cheers.

And the link is  http://www.youtube.com/watch?v=iSVclhnpBcc

Edited By John Stevenson on 10/08/2013 18:12:31

On that model TOS, the SN40 and 50 the drive from the motor is taken direct to the gearbox which is a big unit on the far left of the machine, the bit with the levers on it but iit extends down the full length behind the screwcutting box, weighs about 1/2 a tonnne

From there the drive is taken to the feed and lead screws and to the spindle by a hollow splined coupling.

In fact the main gear box shaft is hollow and sits on the end of the spindle so long parts go thru it.

The headstock on these is just a spindle supported in 4 bearings, nothing else. thats the plain looking bit that sits on the bed ways.

Most other lathes drive the spindle and everything is taken off that, on the TOS it's the spindle that is driven.

I used to have this same model lathe until I scrapped it last year, but I still have a smaller one but this isn't the same build up and like most lathes relies on the spindle running to drive the gear train.

Edited By John Stevenson on 10/08/2013 18:25:56

John, gotcha !. Its all a bit clearer now. Did you ever try out this method on your lathe before you scrapped it ?.

No because to be honest until you posted about this video I never realised it could do so. I had to think for a minute [ OK five ] to work out that yes it works as I wrote.

Closest I got to this setup was when I wanted to put some big keyways into some hubs, think they were 20mm keyways and I don't have a 20mm broach.

I used the Bridgeport mill with the optional Quillmaster and right angle drive.

Had to keep winding the bed up and down for feed though.

One reason to scrap this POS and buy one with dedicated power feed to the knee.

Edited By John Stevenson on 10/08/2013 18:55:35

My chester comet vs can do that too, you can disengage the spinde but keep the power feeds going. Never thought of doing a job like the above tho.

I can see there is a TOS Trencin SN40, same as i used at school for mechanics. It has a large spindel bore at 50 mm and a rpm range from 22.5 to 2000 revolution per minute.

Smart to use the milling tool of hand drill inside the sleeve at lathe.

Edited By Jens Eirik Skogstad on 10/08/2013 20:27:14