• Congratulations to Phil Hamel winner of the April 2025 Turning Challenge (click here for details)
  • Congratulations to Steve Bonny for "A Book Holds What Time Lets Go" being selected as Turning of the Week for 28 April, 2025 (click here for details)
  • Welcome new registering member. Your username must be your real First and Last name (for example: John Doe). "Screen names" and "handles" are not allowed and your registration will be deleted if you don't use your real name. Also, do not use all caps nor all lower case.

Tenon Size Jig

Randy Anderson

Randy Anderson

Beta Tester
Beta Tester
Joined
May 25, 2019
Messages
982
Likes
1,538
Location
Eads, TN
Website
canthony.gallery
I don't use the tenon to form the foot on my bowls so 99% of the time use the same size tenon based on bowl size - 3 1/4" for large bowls or 2 1/4" for smaller ones to fit one of my two chucks. One with large jaws and the other with smaller jaws. To make it easy I simply made a small wooden block with a slot that fits a standard carpenter pencil that when placed on my tail stock collar it marks out the right sized circle for me to cut the tenon size to. Same jig just flip it over for the different sizes. Hold in place and spin the bowl. Done. Quick and easy although I find that just out of habit I can usually get it very close without the jig but better sure than remounting if not right. Likely a common method but hey, someone might not have one.

I searched first and couldn't find a similar post. Sorry if a repeat of something many already use or know.
 

Attachments

  • IMG_4757.JPG
    IMG_4757.JPG
    60.6 KB · Views: 185
  • IMG_4758.JPG
    IMG_4758.JPG
    59.6 KB · Views: 181
I just cut a scrap of oak wood - about 3 inches wide, 6 inches long, cut a 2-1/4 inch notch with a bevel to it to match dovetail of my jaws and just use that like a caliper til the wide side just slips over, then I can cut my dovetail and use the block to get a perfect angle.. so, similar.. I can usually eyeball the diameter fairly close then start checking with my measuring block..
 
Brian Gustin said:
I just cut a scrap of oak wood - about 3 inches wide, 6 inches long, cut a 2-1/4 inch notch with a bevel to it to match dovetail of my jaws and just use that like a caliper til the wide side just slips over, then I can cut my dovetail and use the block to get a perfect angle.. so, similar.. I can usually eyeball the diameter fairly close then start checking with my measuring block..
Click to expand...
Mind posting a pic?
 
Randy Anderson said:
searched first and couldn't find a similar post. Sorry if a repeat of something many already use or know.
Click to expand...
Randy certainly worth posting here. nice presentation.
It’s a concept that has been around since the ONEWAY live center came out with the non rotating bearing housing.


I cheat using the oneway center for green wood. I just cut an inch out from the threaded part by eye which is 5/8” that gives me a 2.5” tenon +/- an 1/8. i just got really good a seeing an inch. That 2.5” tenon will always dry to one that has a 2” tenon inside when turned round for remounting The dried bowl.
 
I was certain it wasn't a new idea, I'm not that smart and it's sorta obvious but since I didn't see a direct post I remembered when I first started - obvious solutions weren't so obvious.
 
Glenn Lucas has a pointer arrow type thing that is attached on the away side of his tailstock. 2 pointers, one smaller and one larger. He turns the tenon down till it likes up with the pointer. Maybe I can find the video, just saw it some where....

robo hippy
 
Here's my take on tenon/recess sizing jigs. Each one fits over the 3/4" threads on my live center and has two screws protruding through ... the inside for a tenon, the outside for a recess.
TenonRecess_01.jpgTenonRecess_02.jpgTenonRecess_03.jpgTenonRecess_04.jpg
 
I made a pair a little smaller in cross section than Randy's, one for my larger jaws and one for my smaller. I just rest the pencil on top of the jig. Each block of wood is rectangular, with one thickness corresponding to green wood and the lesser thickness for dry wood. That helps me when re-turning the tenon on the dried blank.

I glued a rare earth magnet into one side of each, which helps stabilize them on the live center, but more importantly, I can stick them to the lathe and they're always handy.
 
Axminster tools in the Uk produce this tool called a woodturnig speed sizer the tool was inspired by a blind woodturner

You could use the same principle to make a similar tool for your own jaws

www.axminstertools.com

Axminster Woodturning Speed Sizer

Based on an original idea shown to us by Chris Fisher 'The Blind Woodturner', the Speed Sizer revolutionises the job of marking jaw sizes onto a turning blank. This 135mm aluminium template makes marking out for a dovetail jaw completely safe, totally...
www.axminstertools.com www.axminstertools.com
Please view thumbnail pictures on left-hand side of web page
 
Last edited:
You can also scribe a mark on the tool rest for the center point and a scribe mark for the diameter of the tenon size you want, align the center mark to the wood blank and use the other scribed mark to align your pencil to mark the tenon. A sharpie mark will last a long time if you don't want to put a scribed mark on the tool rest.
 
Don Wattenhofer said:
That looks like an excellent gauge but I would like to suggest that you plane the gauge down to about 3/8th" to also gauge the length of the tenon.
Click to expand...
Would be probably a good thing to do, but Im too lazy to bother with that.. length of tenon is easy to eyeball, it doesn't need precision there - 'bout a quarter inch or a little over is good enough for most of my work, I may go a bit longer for bigger pieces... just finished roughing out 18 bowls over the last day and a half, can almost hit my tenon dead on without even using the gage now, just by eyeballing it.. but I always like to check just to be sure...
 
Brian Gustin said:
I just cut a scrap of oak wood - about 3 inches wide, 6 inches long, cut a 2-1/4 inch notch with a bevel to it to match dovetail of my jaws and just use that like a caliper til the wide side just slips over, then I can cut my dovetail and use the block to get a perfect angle.. so, similar.. I can usually eyeball the diameter fairly close then start checking with my measuring block..
Click to expand...
Please post pics. Thanks
 
David Friedman said:
Please post video, thank you
Click to expand...
065A9610-scaled.jpg
065A9609-300x300.jpg

It took 30 seconds to do a search and find these photos on Glenn Lucas' web site. Anybody could do it.
 
I use a ruler and a pencil. I bought the axminster sizer, but it doesn't really work on the lathe
 
Mike Johnson said:
You can also scribe a mark on the tool rest for the center point and a scribe mark for the diameter of the tenon size you want, align the center mark to the wood blank and use the other scribed mark to align your pencil to mark the tenon. A sharpie mark will last a long time if you don't want to put a scribed mark on the tool rest.
Click to expand...
I like this idea, will give it a try.
 
A couple other ideas. I make gauges out of scrap 1/4" plywood. I mark with a pencil (guessing at the diameter) then check with the gauge and adjust. If I miss on the first guess, it usually only takes one check to get it right.

Another thing I've done in the past is similar (in spirit) to the Glen Lucas pointer, but simpler. Take a block of wood and tape (or just hold) a pencil to one edge. Trim the block so when you hold it against the side of your live center, it is the right diameter for your tenon.
 
GRJensen said:
Here's my take on tenon/recess sizing jigs. Each one fits over the 3/4" threads on my live center and has two screws protruding through ... the inside for a tenon, the outside for a recess.
View attachment 38591View attachment 38592View attachment 38593View attachment 38594
Click to expand...
This looks like the best and quickest method the only thing I might change is to have them with 1 pin and marked accordingly as recess or tenon.
Dave Landers said:
I don't think Glen Lucas uses it like that. It's just an indicator - a pointer to the tenon diameter.
Click to expand...
That is a relief that he doesn't use it as a scribe but I know that I wouldn't want that clumsy thing hanging on my live center.
 
Dave Landers said:
A couple other ideas. I make gauges out of scrap 1/4" plywood. I mark with a pencil (guessing at the diameter) then check with the gauge and adjust. If I miss on the first guess, it usually only takes one check to get it right.

Another thing I've done in the past is similar (in spirit) to the Glen Lucas pointer, but simpler. Take a block of wood and tape (or just hold) a pencil to one edge. Trim the block so when you hold it against the side of your live center, it is the right diameter for your tenon.
Click to expand...
I made up a couple of blocks, one for my medium chuck and one for the large, and glued magnets into recesses. Now I put them on the live center and they stay while I fumble with the pencil. One side for dry wood, the other for green wood. The magnets also keep them stuck on the lathe when not in use.
 
You must log in or register to reply here.
Back
Top