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Bruce Wilson
09-25-2018, 1:34 PM
I've made a few bowls with a tenon on the bottom to mount in chuck but want to try it with a recess. How do you carve out the recess, especially cutting it back at an angle on the inner sides so the chuck will grab it more securely? Is there a special tool for this?

David Hill
09-25-2018, 1:53 PM
Generally I start with a blank on a faceplate. That's where I do the vast majority of the outside shaping and turning. Once that's done I usually use my square carbide to cut the recess--if I'm going to use one. Easy to set the angle for the jaws, then use it or a gouge to take out the rest of the tenon that is not going to be used. Kind of simple.

Mark Greenbaum
09-25-2018, 1:58 PM
When I cut a recess (spigot) for my Nova G3 chuck, I usually have the blank mounted between centers, and the live center does get in the way. I've found lately, it is more effective if I can pull the live center out of the way, which means I've chosen to use a wood worm screw, or a face plate for the drive side. Then I use my homemade wood gauge to mark the spigot diameter with a pencil, and proceed to cut with a parting tool to depth. I flatten out the recess, and sitch to my narrow skew to get the recess for the dovetail jaws. I make sure the recess (spigot) is flat, and not so deep that the jaws would NOT bottom out. I leave a generous amount of foot because the expansion of the jaws can break the wood if it's too narrow. Don't ask how I know. See my Box Elder Bruise on my arm in a previous post. That took 3 weeks to heal.

Neal DaMommio
09-25-2018, 2:27 PM
Mark Silay has an interesting tool he uses to make it easy. I have not tried this yet (no tool I want to destroy to create the recess tool.) but I do intend to. The link will start as he makes the cut but if you go back in the video he shows you how to make it.

https://youtu.be/KG8dulUlkLY?t=578

John Keeton
09-25-2018, 2:57 PM
Penn State sells their square nose 3/4" scraper for $16.50 each. They make great single purpose tools, and I have one ground somewhat like the one Neal posted about and used by Mark Silay. Used at an angle to the lathe bed, one doesn't need to be concerned about the tailstock being in the way and much preferable to using a parting tool.

With the $8.95 shipping, I have bought these three at a time to save shipping. You can also get a couple of fellow turners to combine on an order. No cheaper way to have those specialized tools. Not the greatest metal in the world, but the mileage on that type of tool is minimal compared to a bowl gouge. The edge lasts a long time making only one cut on each piece.

Darryl Hansen
09-25-2018, 2:58 PM
I had an old narrow scraper or maybe it was a depth gouge that I ground the side off at an angle. Works very well and allows for a dove tail recess with no problem from the live center. The end is like a scraper straight across the edge as I said at an angle.

John K Jordan
09-25-2018, 7:16 PM
If supported by the tailstock I use a special scraper I ground. I can't get a picture right now but imagine drawing a simple rectangle vertically on paper (maybe about twice as tall as wide), angle the left side back a little to match the desired dovetail angle, then rotate the rectangle maybe about 20-30 deg or so to the left. Grind that shape on the end of an old 1/2" scraper or skew (with appropriate clearance angles.) This will clear the live center support from the tailstock. I ground the shape with CBN wheel with square edges and grit down the flat side.

This is very quick to make a perfect recess. I use this whether the blank is jammed between the tailstock and something on the headstock (like 50mm jaws opened as wide as possible), or my preferred way, held in a screw chuck.

Without that scraper I've used a short parting tool but made a long wooden extension for the tailstock to give enough wotking room. The Nova live center makes this easy since I can turn a short Morse taper on the end of a stick and hold it tightly in the socket in the Nova.

If not supported by the tailstock I have cut the recess with either that scraper or (before I made it) a parting tool, holding the blank (with no tailstock support) either in a screw chuck or in a non-dovetailed recess in the top of the blank cut with a 2-1/8 or 2-1/16" Forstner bit. I drill the top recess (about 1/8 to 3/32" deep) with a drill press. The non-dovetailed recess has always held fine although I prefer to dovetail for a better grip. The dovetailed recess only needs to be about 1/16" deep in good wood (unless you are prone to get exciting catches!)

I've also cut the bottom recess on the lathe with a Forstner bit (held with a Jacob's chuck or a #2MT end mill holder) while holding the blank by the top, but I don't much like that method, one, because it's not dovetailed, and two, since the Forstner bit leaves a deeper point in the middle.

JKJ

Alex Zeller
09-25-2018, 7:51 PM
Maybe there's a reason not to but I've been using my 1/8" parting tool and eyeballing the dovetail angle. I then use my gouge to remove the center and a flat scraper to make the surface flat where the jaws will touch the wood. I haven't turned a live edge bowl so I just mount the face plate to the blank then turn the outside and the bottom. That's when I'll make the mortise.

Leo Van Der Loo
09-26-2018, 12:34 AM
I have posted and shown this picture some years ago of the tool I made to get into the recess while the Tailstock and Live center are in the way,

393962

I use the recess in pretty much all the bowl and plate/platter turnings, and have so for longer than 20 years, most often I will use scrapers to make the recess, the most import and part is the corner where the jaws are to fit, flat and clean, I do not use the dovetail shape as the jaws will hold right down against the bottom and the corner with my Oneway chuck jaws.

393963

The recess does not need to be deep to be strong, usually in the ¼ to ⅜ depth and often less than that.

Here are 2 pictures, the ash bowl’s inside being returned and held by a recess that is less than ⅛”, and the Black Walnut has been returned and held with that recess, it is here to be returned and finished.

393964 393965

Peter Blair
09-26-2018, 9:51 AM
Google Reed Grey aka Robbo Hippie he has a utube video on the subject!

Steve Eure
09-26-2018, 11:16 AM
If I'm in a hurry, I'll use a forstner bit that has the center point ground off. This way there is no indention to deal with. It makes a nice clean cut. After that I'll use a dovetail scraper to angle the dovetail for mounting in the chuck. I've also used flat nosed scrapers to make the cut.

Reed Gray
09-26-2018, 11:25 AM
Here is a link to my video about mounting things on the lathe:

https://www.youtube.com/watch?v=5KHkkws9lWA&t=6s

robo hippy

Brian Deakin
09-26-2018, 5:12 PM
You may find the link below informative

https://vimeo.com/68649135

Randy Heinemann
10-04-2018, 3:34 PM
If you have a Nova chuck, then Nova sells a dovetail chisel which will cut the recess to match the angle on their jaws. Still needs to be maintained for sharpness. I'm sure most would say it's a waste when you can grind your own on a cheap square chisel, but might be a good option if grinding isn't your thing. Don't know if the angle matches other brands of chucks/jaws or not.

John K Jordan
10-04-2018, 4:45 PM
... Don't know if the angle matches other brands of chucks/jaws or not.

I suspect the Nova scraper should work for any chuck jaws. I've found the exact dovetail angle doesn't matter much, at least in the wood species I've used. Even a non-dovetailed recess made by drilling with a Forstner bit seems to hold fine. As mentioned before, I do make the recess a little deeper when not dovetailing. I want a good dovetail for shallow recesses, say 16th inch or so. This is with good, solid wood (and probably no forces from catches allowed!)

If the Nova tool is shaped like I imagine, it could be easy to fine tune the angle by grinding just the end a bit. If no identical, I'd want the angle a little less than more acute than the jaws so they would grip tighter at the bottom of the recess than at the surface.

JKJ

Rob Price
10-08-2018, 9:16 PM
I have a 1/2” skew and I ground the cutting edge to the same angle as my dovetail jaws. I use it on its side as a negative rake scraper. I can use it for tenons or recesses.