Vertical shear finishing tool for the lathe. By Steve Jordan. 9:31 video:
https://www.youtube.com/watch?v=b6kckZO9ME4
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Vertical shear finishing tool for the lathe. By Steve Jordan. 9:31 video:
https://www.youtube.com/watch?v=b6kckZO9ME4
I have a couple of those Eccentric Engineering tangential tools and find they do an excellent job as a shear tool when used in reverse i.e. with a RH tool instead of running towards the headstock cut towards the tailstock and vice versa for a LH tool.
The bit could also be turned through 90 degrees to achieve the same result, I have been means to make a dedicated tool though.
Nice video and post!
I figure I am eccentric enough to make my own. So I did, but I seldom use it.
Thanks for posting!
Great info. Is the traditional cutting speed the same for this tool? Thanks.Quote:
Originally Posted by Jon
Hi Steve. Do you have any thoughts to share about the sensitivity of the finish to different speeds and feed rates? In your examples you look like you're turning at quite a low speed but moderate feed rate.Quote:
Originally Posted by Jon
Regards
Andrew
I made an indexable carbide tip version by machining the sides of the tool holder to 15 deg. There is a full description hereQuote:
Originally Posted by NortonDommi
https://www.homemadetools.net/forum/...9276#post88966
Attachment 42622 Click image for full size.
The shear tool is extremely useful for obtaining very close tolerance finishes, down to exactly on size.
One could create a formula, though a clear method escapes me. Perhaps recording of result is a better term.
Any rate, shearing differs from conventional turning that periphery and cutter are close to alignment, instead perpendicular. Spiral of chip shows that, something (barely) like a drill bit.
The lowered speed, high feed is a low temperature cut; transverse cut engages marginally wider area like deeper cut with radius tool. The finish might improve lowering feedrate more, with a diminishing return.
Job shop wise, we ground the bits on a surface grinder, stoning the leading edge. Without access to a rubber roll grinder, this worked on feed spools, like no perpendicular might.
I noticed some chatter whilst turning that you quickly averted. That suggests to me either a lack of rigidity (which doesn't seem to be the problem) or that the tool bit is no longer cutting but simply rubbing, which of course needs to be avoided. Any comments?
In my own experience these vertical shear tools don’t do a good job of turning to a square shoulder. Am I expecting too much of this tool?
I use a set of tangential tools for really fine turning and as NortonDommi noted if you take the cut to the left with a right hand ground tool bit the finish is like a polished surface. If you use a round insert an extremely good finish can also be achieved, with the added benefit of many fresh cutting surfaces.
The cutting edge is set at an angle, so you cannot expect these tools to be good for a square shoulder. These tools are only meant for very fine finishing cuts.Quote:
Originally Posted by old_toolmaker
