The Woodturning Forum - Woodturner's Resource - How to grip a very hard workpiece with my setup

Rich Gouette

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Central Machinery 18" with 18" Rockler extension

How to grip a very hard workpiece with my setup
Sep 16^th, 2022 at 9:30am

So, I'm trying set up a piece of ebony for turning on my lathe.
Typically, my process for what I do is, mount with a spur bit, & live center.
With this wood, it's so dense, that the spur bit doesn't actually bite enough into the piece to make me comfy that it's not going to work loose.
I recently had a piece of rosewood, which ended up splitting as I was driving the spur bit into it, and I very much want to avoid doingf that to this (pricey) wood.
My only chuck is a 3 jaw...

I only need to be able to turn enough to produce a rounded end on the tailstock end of things: then I switch to my 3 jaw.

Any suggestions about how I might mount it up securely?
Do I need to invest in a 4 jaw chuck?

Thanks fellas,
Rich

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brrr I'm in Maine

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Ed Weber

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Re: How to grip a very hard workpiece with my setup
Reply #1 - Sep 16^th, 2022 at 10:43am

A crown drive or multi-point drive will usually work on hard woods like ebony.
There are many to choose from in a wide price range. Here is an example of what I'm talking about.

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Chris Brock Active Member Offline WR Rocks! Posts: 221 Phoenix Arizona USA Gender: NOVA DVR	Re: How to grip a very hard workpiece with my setup Reply #2 - Sep 16^th, 2022 at 10:45am Glue another scrap to the ebony to either take the spur drive or 3 jaw. I have done this with hot melt glue, which between centers holds well enough (for me, anyway) to round an end.
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Rich Gouette Junior Member Offline Posts: 35 04210 Maine USA Gender: Central Machinery 18" with 18" Rockler extension	Re: How to grip a very hard workpiece with my setup Reply #3 - Sep 16^th, 2022 at 10:59am ok, great ideas there.. thanks much! I'm also considering the 4 jaw check option, since I don;t have one.. Might be out of my range..we'll see Rich
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Glenn Jacobs WR Addict Offline JC L&S Posts: 2,068 North DFW, Texas Texas USA Gender: Powermatic 3520C	Re: How to grip a very hard workpiece with my setup Reply #4 - Sep 16^th, 2022 at 11:47am Questions: 1 How large is piece? width x length 2 Will 3 jaw chuck close enough to hold piece? Suggestion: saw 2 slots 90 degrees to each other to fit the spur drive in. Glenn J
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David Moeller Senior Member Offline Old chiseler Posts: 305 Linden Michigan USA Gender: LAGUNA REVO 15X24 CONOVER 15 x Infinity Long gone: Shopsmith, Myford ML8, Homebuilt bowl lathe, NOVA benchtop, Delta 46-715 and a Unimat.	Re: How to grip a very hard workpiece with my setup Reply #5 - Sep 16^th, 2022 at 12:20pm Make a jam chuck. A wood plate on your faceplate bored out to provide jam fit on the drive end.
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Ron Sardo WR Administrator WR Patron Offline Chief cook and bottle washer Posts: 9,649 Drums Pennsylvania USA PM 3520	Re: How to grip a very hard workpiece with my setup Reply #6 - Sep 16^th, 2022 at 2:01pm Take a chisel and cut an X in the center of the wood for the spur drive to fit into
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John Grace WR Addict Offline Everyone needs a good wingman... Posts: 1,277 Bel Air Maryland USA	Re: How to grip a very hard workpiece with my setup Reply #7 - Sep 18^th, 2022 at 4:06pm Take the following with an enormous grain of sale relative to your specific set-up and wood. In similar situations, I've had luck with doubl-sided mounting tape and using the tailstock until the piece has been 'trued-up'.
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Rich Gouette Junior Member Offline Posts: 35 04210 Maine USA Gender: Central Machinery 18" with 18" Rockler extension	Re: How to grip a very hard workpiece with my setup Reply #8 - Sep 19^th, 2022 at 7:43am Thanks all for the input, greatly appreciated. I just pulled the trigger on a 4 Jaw Nova chuck... Hoprfull that'll do the trick. Btw, the piece is 2"x2"x14" It's the first time I've worked with wood so high on the janka scale.. wow, is it hard stuff.. Chers, Rich
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robo_hippy

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Re: How to grip a very hard workpiece with my setup
Reply #9 - Sep 19^th, 2022 at 10:50am

There are 'steb' centers, which have a center point and many teeth on the outside for grip. Not sure how that would work. You could round off a piece of plywood on a face plate, then glue side strips around the block. Then use the tailstock to press it in. The end against the plywood needs to be square. That would work as you turn a tenon on the other end for chuck mounting.

robo hippy

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Patrick Patterson Junior Member Offline WR Rocks! Posts: 48 Cobden IL Illinois USA Gender: Grizzly G0462 and Delta 46-460	Re: How to grip a very hard workpiece with my setup Reply #10 - Sep 23^rd, 2022 at 11:53am Multimedia File Viewing and Clickable Links are available for Registered Members only!! You need to or I have been using this lately and it holds well but needs a 4 way chuck. Previously as others mentioned, I drilled a small hole in the center and cut corner to corner slots on my band was. Pat
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robo_hippy

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Re: How to grip a very hard workpiece with my setup
Reply #11 - Sep 24^th, 2022 at 10:15am

Another thought, take your 4 point spur drive and tap it into the end. Then take a bench chisel and tap it into the marks left by the spur drive. The spurs are angled, so match the angles on the chisel to the spur drive. You don't have to really hammer it in to get it started. Then turn a tenon or recess into the other end, reverse and turn.

robo hippy

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Patrick Patterson Junior Member Offline WR Rocks! Posts: 48 Cobden IL Illinois USA Gender: Grizzly G0462 and Delta 46-460	Re: How to grip a very hard workpiece with my setup Reply #12 - Sep 25^th, 2022 at 2:02am Robo Hippy, A simple and effective solution. Thanks Pat
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Paul Haus

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Re: How to grip a very hard workpiece with my setup
Reply #13 - Sep 25^th, 2022 at 5:19pm

Another option that works well: threaded block. I found a wood tap the same threads as the headstock of my lathe. I take a block of wood, bore a hole through it and thread it to match the headstock. Take the threaded block, insert a pice of grocery back between it and what you're working on (glue it on with wood glue). Thread it on, bring the tail stock up and turn away. When done, split it off with a chisel and clean up the leftovers as needed.

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Louie Powell

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Re: How to grip a very hard workpiece with my setup
Reply #14 - Sep 27^th, 2022 at 5:03am

Rich Gouette wrote on Sep 16^th, 2022 at 9:30am:

I recently had a piece of rosewood, which ended up splitting as I was driving the spur bit into it, and I very much want to avoid doingf that to this (pricey) wood.

I would be afraid to use double stick tape on ebony - tape doesn't adhere well to oily wood.

Instead, I think I would prefer a mechanical connection. Probably start by drilling a centered hole about 1/8" deep to received the center spur on the drive center and prevent splitting. I have several Steb-type drives that I think would work well, but a traditional four-blade spur center would also work. However, I would cut saw kerfs to receive the blades rather than try to drive them into very hard ebony.

Once you turn it round and cut a mounting tenon on one end, a scroll chuck should handle it well. Be sure to use tailstock support for as long as the project allows.

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Louie

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