i'm going to buy a tangential tool holder from Eccentric Engerining. i am confused as to what size to buy. my lathe is a south bend heavy 10. i use a aloris A tool post. will be using 5/16 or 3/8 tool bits. i contacted them, and didn't understand their response. (rather than say that i am dumb, i use the excuse that i am a old man) any help as to what size to buy??
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Tangential tool holder
- Thread starter porthos
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- Nov 25, 2015
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well, what was their response?
I go for the biggest I can handle.. which is generally 1/2 on an AXA holder, unless you have the XL holders
if they only make 5/16 and 3/8, go for the 3/8
I go for the biggest I can handle.. which is generally 1/2 on an AXA holder, unless you have the XL holders
if they only make 5/16 and 3/8, go for the 3/8
Why use the largest HSS bits? Back in lantern toolpost days the tool holders for 10-12" lathes typically took 5/16" bits. When I machined a tangential tool holder for my 12" Clausing, I made it for 5/16" bits and it has worked well. I'm glad I hung onto my lantern toolpost and toolholders. There are just some operations where you can reach with an old toolholder that you can't with the tangential one.
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well we are not in lantern toolpost use these days, most of us have qctp.
Larger tools vibrate less, are more stout. Which helps lead to less chatter.
if a tool is flexing, it is chattering as it relieves its cut (away from the metal), then snaps back and digs in even deeper and faster for the moment. That then repeats. So bigger helps avoid those issues.
Obviously the rest of the rigidity needs to be there, you can't be all loosey goosey.
Larger tools vibrate less, are more stout. Which helps lead to less chatter.
if a tool is flexing, it is chattering as it relieves its cut (away from the metal), then snaps back and digs in even deeper and faster for the moment. That then repeats. So bigger helps avoid those issues.
Obviously the rest of the rigidity needs to be there, you can't be all loosey goosey.
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I have a small one,1/4 or 5/16 square bit.
I have taken to using busted center drills in it and get great results. I grind the end on some arbitrary angle that looked right and if I index it correctly I can face and turn with the same setup. The tip of the oblong face goes 45* to the center line of the axis, and is above center so the side faces cut providing the shear.
Learned this “shearing cut” off the yous toobs.
Not easy to set up, but leave a good finish.
As a bonus (my favorite feature of these) if you crash it, the tool bit just slips in the holder and nothing really gets damaged.
I like tan genitals.
I have taken to using busted center drills in it and get great results. I grind the end on some arbitrary angle that looked right and if I index it correctly I can face and turn with the same setup. The tip of the oblong face goes 45* to the center line of the axis, and is above center so the side faces cut providing the shear.
Learned this “shearing cut” off the yous toobs.
Not easy to set up, but leave a good finish.
As a bonus (my favorite feature of these) if you crash it, the tool bit just slips in the holder and nothing really gets damaged.
I like tan genitals.
I see where you're coming from with regard to rigidity and pretty much agree with much of that. e.g. - I never was successful using a cutoff tool holder in a lantern tool post. When I switched to a BXA size quick change toolpost it made a world of difference for that. I'm not convinced that a larger tangential holder would be a good choice for the OP's lathe. He's got an AXA toolpost.
Woodchucker, I see you mentioning using 3/8 and 1/2" bits in your AXA toolpost. Are either of those in a tangential toolholder? If you're using a tangential toolholder from Eccentric Engineering, then it's proof that 3/8 works in an AXA toolpost, at least in whatever size/make lathe that is. I can see the diagram on what you have to look out for with regard to size: https://www.eccentricengineering.com.au/products/diamond-tool-holder/tool-selection but the page that should open to show the tangential toolholders [and presumably their dimensions] isn't opening for me. From their description you need to check that the shank of the diamond toolholder will fit in the slot of an AXA size toolholder. Then you need to be sure that with your AXA toolholder lowered to its lowest position, the top of the cutter bit can go as low as the center height of your lathe. A little lower is fine because you can always adjust upward. The bit won't cut or it will cut with difficulty if it's lowest point is above the center height of your lathe. You need to check this even if you're considering the 5/16" size bit holder.
Woodchucker, I see you mentioning using 3/8 and 1/2" bits in your AXA toolpost. Are either of those in a tangential toolholder? If you're using a tangential toolholder from Eccentric Engineering, then it's proof that 3/8 works in an AXA toolpost, at least in whatever size/make lathe that is. I can see the diagram on what you have to look out for with regard to size: https://www.eccentricengineering.com.au/products/diamond-tool-holder/tool-selection but the page that should open to show the tangential toolholders [and presumably their dimensions] isn't opening for me. From their description you need to check that the shank of the diamond toolholder will fit in the slot of an AXA size toolholder. Then you need to be sure that with your AXA toolholder lowered to its lowest position, the top of the cutter bit can go as low as the center height of your lathe. A little lower is fine because you can always adjust upward. The bit won't cut or it will cut with difficulty if it's lowest point is above the center height of your lathe. You need to check this even if you're considering the 5/16" size bit holder.
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so you still haven't told us what Eccentric said. So it's hard to answer.
RWL, I don't have an Eccentric, I was generally referring to the biggest tool you can handle.. And yes it needs to be on centerline.
I have an older tangential tool. I don't use it much.
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- Dec 18, 2022
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Not sure if this helps; but, http://theamateurmachineshop.com/index.php/projects/13-tangential-lathe-tooling This link has good information and plans if you want to build your own tangential tooling.