Help with diagonal marks left on tenon

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Charl
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Help with diagonal marks left on tenon

Post by Charl »

I've been having problems lately when cutting my tenon on the lathe. The cutter is leaving diagonal marks, as seen on the photo.
I've sharpened, honed and re-sharpened the cutter. I've made sure the cutter is not too low or too high regarding the rodstock. I've made sure that the carriage does not have any play. All I can think of at the moment, is that there is a problem with the feed. But why now only, after all these years of doing it without any problem?
Any of you tool-clever guys have an idea or help?
The lathe is a Myford ML7 and the tenon on the photo has had a rough cut, to show the diagonal lines better.
Image
caskwith
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Re: Help with diagonal marks left on tenon

Post by caskwith »

Are you using power feed to make the cut? Also lets see your cutting tool.
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sandahlpipe
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Re: Help with diagonal marks left on tenon

Post by sandahlpipe »

You could be feeding too quickly or at too low a speed.
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d.huber
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Re: Help with diagonal marks left on tenon

Post by d.huber »

I feel your pain. A few months ago I went through a phase where nothing had changed in my process (that I acknowledged) but none of my tools were producing the results I expected.

My best advice is to go back through your process step by step, relearn a few things that you think you know for sure, and start manually feeding when you cut your tenon.

For a potential quick fix, try adjusting the height of your cutting tool. For some reason all of my tools except for my facing tool cut more cleanly when they're ABOVE center.
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Charl
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Re: Help with diagonal marks left on tenon

Post by Charl »

Thanks gents, I'm back to a mirror-like cut.
I re-checked the height of the cutter, after remembering that I changed the shim a while ago.
Seems like what I thought was the perfect height, was actually a teeny weeny tad too high.
Dope!
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Tyler
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Re: Help with diagonal marks left on tenon

Post by Tyler »

In other news, where do you get the lizard skin ebonite?
LatakiaLover
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Re: Help with diagonal marks left on tenon

Post by LatakiaLover »

Andrew saves it for special, in-the-know customers.
UFOs must be real. There's no other explanation for cats.
Charl
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Re: Help with diagonal marks left on tenon

Post by Charl »

:lol: Lizard skin? Wenge, actually.
caskwith
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Re: Help with diagonal marks left on tenon

Post by caskwith »

Glad you got it sorted. When setting heights I always err on the side of too low rather than too high as rarely will that cause a big problem. Only exception is parting tools, these should be set ever so slightly too high to prevent digging in.
Charl
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Re: Help with diagonal marks left on tenon

Post by Charl »

Thanks Chris. Yip, parting tools are a different matter!
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