Newbi

[JOHN BURNELL 1Participant @johnburnell1]

Just joined the forum, i repaire Antique clocks, so picked up a very nice Cowells 90 i think i have no paperwork with it so i have ordered the user guide of amazon, i am not very experienced with lathe work other than polishing pivots actualy making parts im very green, i had a little play with my new toy today had some lathe tools i got for free of a mate, hss and put in a peice of round 3mm brass just moved along taking it down, as i was moving back to the start the tool was still touching the rod so made lots of scratches, and to be honest the finish was a bit rough, my thought is set up wrong, any way still totaly enjoyed myself,

regards john

[JOHN BURNELL 1Participant @johnburnell1]

introduction

[Chris Evans 6Participant @chrisevans6]

Welcome John. Your first tip from the board is to wind the tool back away from the work when returning to start point. Just zero the dial or make a mental note of the setting and no more scratches.

[Michael GilliganParticipant @michaelgilligan61133]

John,

This guy has a a Cowells … and explains a lot about its use:

**LINK**

http://watchmaking.weebly.com/

Highly recommended reading !!

MichaelG.

[JOHN BURNELL 1Participant @johnburnell1]

Thanks , thought it might have been the way the tool was set up,

[Bob RodgersonParticipant @bobrodgerson97362]

John, welcome to the hobby. The condition you describe is almost certain to happen whenever you turn a piece of work unless you have backed off the tool at the end of the cut as Chris has explained. You can also keep the setting but continue the cut back until the tool clears the end of the work because there is sure to be some spring in the metal that you are trying to turn.

With experience you will learn how many passes at the same depth of cut are required to take all of the spring out of the work. It also depends on how sharp the cutting tool is and how close to centre height that it is set.

Lots of practice will get you there.

[SillyOldDufferModerator @sillyoldduffer]

Worth knowing too that the tool cuts with a different edge on the backstroke. As a result, the way it removes metal isn't identical in both directions. The effect becomes more pronounced as the tool wears: the front edge wears much faster because it does most of the work.

For what it's worth (I'm self-taught), I don't retract the tool whilst removing metal just to get near the required diameter. I do retract it towards the end – as soon as finish and accuracy matter.

Learning the best way to finish is an acquired skill. Finishing with a succession of tiny cuts is (I think) less satisfactory than finishing with a single slight cut. The tool needs to cut rather than rub. As Bob said 'Lots of practice will get you there.'

Dave

[colin hawesParticipant @colinhawes85982]

My tool advice for a small lathe using HSS tools is to keep them very sharp and have much more top and front rake than recommended by text books. Tools nearly always take a cut if wound back to the starting point so simply do your measurement after that. Let it cut in both directions. The return cut will often improve the finish as it is a very small cut and the cutting point is trailing. It is also better to approach the cut with tools' cutting edge either square to the work or at a negative angle. Colin

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