lever or cam operated parting off tool

[Anonymous]

Neil: PM sent

Andrew

[Neil LickfoldParticipant @neillickfold44316]

Thanks Andrew, PM replied to.

[steamdaveParticipant @steamdave]

I quick search of 'More Latest Posts' found this one. I couldn't remember when/who requested the info.

Earlier today, I posted a link to a possible suitable d.i.y. cut off slide for you, Neil Lickfold:

http://downrivertools.com/downriver-tools/cross-slide-tooling-plan-sets

Dave
The Emerald Isle

[Neil LickfoldParticipant @neillickfold44316]

Thanks Dave,

At this stage I am going to buy a small slide from someone who has decided to kindly part with one that they have.I will be able to adapt it so as It becomes a rear part off tool from the back side of the cross slide. I only need to make a lever adaptor to be able to reach it all from the front and a simple plate to put a small Dickson QCTP onto it.

Neil

[MuzzerParticipant @muzzer]

If you search for "cross slide retraction" you can see various solutions to the concept of retracting the tool / cross slide between screwcutting passes. Some of them merely move the tool relative to the toolpost and others move the cross slide relative to the saddle.

I plan to make something like the device shown in photos #3 and #4 here at some point(!), for screwcutting. You could possibly use something like that to do parting off of small diameter parts. It uses a cam to move the cross slide screw in and out by a consistent distance and can be left permanently fitted to the machine.

From my own experience it seems that constancy of feedrate and a reasonable cutting speed are critical for safe and event-free parting, so any manual feed needs to allow fine and easily controllable infeed, most likely using a high reduction ratio and/or long lever. Personally I'd prefer to use power feed where at all possible.

Murray

[Neil LickfoldParticipant @neillickfold44316]

Good points Murray. The screw cut retraction units I have seen have too small a stroke for what I need. The lever I am going to adapt initially will be about a 10:1 on the current lever, but have not worked out the total ratio of lever to slide movement. I am thinking it will be 30:1 per side. It will work fine for what I want.

Another suggestion was to put a stepper and micro switch stop with auto return to the retracted position. But that won't happen unless I need to make a lot more than is anticipated. It may then be an option to just get them commercially made on a cam auto or some other simple production machine.

Thanks for the replies and input.

Neil

[Author]

Posts