Sherline lathe Questions

[Chris TickTockParticipant @christicktock]

Hi, the Sherline lathe can if fitted with a riser adapter set cope with stock up to 6 inches diameter, provided the stock isn't going to tax the little machine. My piece of aluminium was too big but I got lucky and found my 30 year old horse rasp that I thought I had lost with 5 teeth per inch so this quickly reduced the circumference to a workable limit for the lathe.

This is the first time I have fitted the riser set and using the face plate with stock bolted to it managed to get the 6 inch 25mm aluminium ready for action ..or so I thought.

The first issue with the Sherline was encountered when I tried to set up to machine the edge. With a 6 inch piece in the machine the cross slide carrying the cutter will not go far enough to allow machining with the cutter sticking out from its holder as it should. The remedy was to overhang it by far more than is recommended and by turning the cutter holder at an angle. Taking very little off it did it but I fully realise this was not that sensible.

Any ideas what to do in this situation. I guess I could machine a tool?

Moving on, this is on the face of it a silly question but can some one refresh my mind why when you machine the edge you have the cutter perpendicular to the stock and why then when machining the face do we do it at an angle. Is it to get a better finish? Note the lines on my face which in this case I kind of like but say I wanted a smooth finish?

My final question does anyone know if the taper holding the head stock should be tight or have a little slack on it that is taken up when the alum key is tightened. Both my head stock taper and the riser set taper were loose so is this as should be. When fitted all seems well.

Chris

[Chris TickTockParticipant @christicktock]

[Ady1Participant @ady1]

Looked at them a long time ago and was impressed by some of the lovely work they do

Seemed to be almost exclusively in aluminium, but good stuff

[pgk pgkParticipant @pgkpgk17461]

Posted by Chris TickTock on 18/07/2020 17:53:42:

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Moving on, this is on the face of it a silly question but can some one refresh my mind why when you machine the edge you have the cutter perpendicular to the stock and why then when machining the face do we do it at an angle. Is it to get a better finish? Note the lines on my face which in this case I kind of like but say I wanted a smooth finish?..

Chris

When machining along the length of material then however you angle the tool to the work it will cut the whole length of set tool depth sooner or later whereas across the face it's just the tip and leading/trailing edges of the tool that cuts (depending on depth) and if parallel you add drag, burnish or risk chatter.

I don't have my tool perfectly perpendicular on a long axis cut 'cos that'd be a pain to get absolutely right. Slightly 'point first' means that any shoulder I pull back from will be faced correctly but i might angle the tool further forwards, finish the cut and take away from the headstck if I wanted an undercut or angle the other way if I wanted to finish with a sloping shoulder.

there are circular inserts designed for profiling work or rounded shoulders and I'd defy anyone to set that perpendicular along it's cutting face<g>

pgk

[JasonBModerator @jasonb]

Most of the time I use the same tool set across the lathe axis at right angles to face and turn, a "right hand" tool will do both without altering it's position.

Edited By JasonB on 18/07/2020 18:33:36

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