Supernova2 Cole jaws

[John Torchick]

Back in the shop after a long time absent and relearning wood turning. Turned a piece round and turned a tenon. Put the tenon in the chuck. Hogged out the center and was going to use the Cole Jaws to finish the bottom. OK. Got it set up and the piece and CJs were wobbling out of round. Didn't even try to turn the piece! Never had a problem with the chuck and original jaws. Disappointed with the jaws. Checked and the jaws are not numbered like the small jaws that came with the chuck. I like the chuck even though I'm limited to the maximum opening of the original jaws. Now I'll need to make a jam chuck with the live center and a point to turn the bottom. Suggestions are most welcome. Thanks.

 

[Mark Jundanian]

Unlike regular jaws that are machined from a single piece of steel that is then cut into four jaws, Cole jaws are cast items, and each jaw is in theory the same.

These should fit flat on your chuck so I'm wondering if there might be some gunk on one of the jaws or chuck? Are all 8 screws snugged up?

 

[John Torchick]

Sit flat? Will check. Screws snugged up and checked again before turning on the lathe. This is the first time I have used them. They are cast...need to check for casting flashing or a high spot. Thanks for the reply and suggestions, Mark.

 

[Tom De Winter]

The castings on mine didn't sit right on the jaw slides. I had to do some scraping to get them to true up.
See my previous topic:
https://www.aawforum.org/community/index.php?threads/cole-jaw-mis-match.16865/#post-170027

 

[John Torchick]

If I need to rework the back, I could use a flat piece of MDF or something similar, double sided tape and a sheet of sandpaper. I'll also check to make sure they are not warped.

 

[hockenbery]

If you want to go the jamb Chuck route.

turn a cylinder about 3” diameter 2-3” tall ( needs to be tall enough so the rim doesn’t hit the headstock.)
It can be mounted in a Chuck or on a small faceplate. Hollow it a 1/2” or so deep and round the rim so it does not mark the finished bowl- this makes a rounded ring that will seat against the inside of your bowl.
This Cherry jamb Chuck has been serving for a couple of decades.


Before using a jamb chuck, I measure the thickness of the bottom to the face of the tenon.
I transfer this thickness to something I can hold against the live center to reassure myself that I have enough thickness to keep turning without making a funnel. I use a center caliper to keep this measurement.
You need to Mark center of the tenon( I use the original roughing center)
A folded paper towel makes a good interface between the jamb Chuck and the bowl.

to see how I use the jamb Chuck fast forward to 33 minutes
Mounting and turning a dried bowl -

View: https://www.youtube.com/watch?v=sCZWsHB4vlM

 

[Mark Jundanian]

@John Torchick , I should warn you that the buttons supplied with the Nova Cole jaws may not work well. These are cylidrical and wider than tall. When screwd down tightly to the jaw the elastic material tends to bulge out giving the side of the button an outwardly convex contour that doesn't hold well. So don't over tighten the screw that holds each button on. Nova sells an accessory set of buttons that are much better designed. These are all narrower at the bottom than top.

 

[John Torchick]

HB, good information for me and, I'm sure, for others. Noticed that there was a slight bit of wobble when you mounted the bowl in the jam chuck. Do you not play to centering the bowl a bit to eliminate the wobble or is it not a factor? I get uneasy when I get the tool close to the live center or chuck. Watched your approach and noted it was slow and very careful. Got lots of cherry. Thanks for the video!

 

[John Torchick]

@John Torchick , I should warn you that the buttons supplied with the Nova Cole jaws may not work well. These are cylidrical and wider than tall. When screwd down tightly to the jaw the elastic material tends to bulge out giving the side of the button an outwardly convex contour that doesn't hold well. So don't over tighten the screw that holds each button on. Nova sells an accessory set of buttons that are much better designed. These are all narrower at the bottom than top.

Noticed that on the first one I mounted. I used a power screwdriver to run the screw into the button and then slowly run the screw into the jaws, watching for any bulge.

 

[hockenbery]

HB, good information for me and, I'm sure, for others. Noticed that there was a slight bit of wobble when you mounted the bowl in the jam chuck. Do you not play to centering the bowl a bit to eliminate the wobble or is it not a factor? I get uneasy when I get the tool close to the live center or chuck. Watched your approach and noted it was slow and very careful. Got lots of cherry. Thanks for the video!

slight wobble is ok. When I feel it there is just the slightest flutter- so good to go.
What I do at this point is turning the foot flat with a concave.
Being slightly off center the bowl will tilt slightly but it can be noticed.

sometime the wobble can be bigger. I move the tool rest over to the rim and find the rim edge that is furthest out.
Loosen the tail stock slightly and move the rim closer to center. This is just a trial and error.
If you look at the first part of the video I take a lot of time to get the warped rims centered so that I can get the largest bowl finished bowl that is inside the warped bowl.

You don’t want to hit the live center but nothing bad happens.9
The major thing to keep’ is mind it to stay on top of the little nub.
If I try to turn on the front of the nub the gouge can get pulled under the nub and that usually breaks the nub.

deliberate is a good approach. Basics are important here.
Let the tools do the work. Slower speed here...
ABC- Tool on the tool rest, bevel on the wood, then cut.
ABC - Anchor, Bevel, Cut

 

[John Torchick]

What I do at this point is turning the foot flat with a concave.

Excellent! Will check for that. Thanks. Lots to do this morning in the shop. Hopefully, the heater will get the shop to a tolerable temperature later this morning. Would love to run a 220V line for a big heater.
Many thanks for the post, replies, suggestions and being most helpful.

 

[John Hicks]

There is an extra set of buffer feet you can get from Nova that grip the bowls a bit better (photo) Yes, the face of the plates that meet up with the chuck, are not perfectly machined. After using my cole jaws for a year or so; I went to the hold fast vacuum chuck.

 

[John Torchick]

Thanks, John. I have a chunk of HDPE rescued from the recycling bin. Came from a mechanical contractor. Might try to turn a piece to diameter and cut into lengths. Vacuum chuck isn't in the budget but a good idea.

 

[Russell Nugent]

I bought the set of buffers it made a big difference in holding. My cole jaws dont sit perfectly flat but I have used them for up to 14 inch bowls(with the extensions). Usually by the time I'm ready to finish the bottom the rim is not perfectly flat any longer anyway.
When I use the Cole jaws I bring up the tailstock, then tighten the chuck, give it a spin and see how true the bottom is running. If it's a little out I'll loose the chuck, rotate the bowl a bit, and tighten it. I may have to do that a couple of times but I can usually get it running pretty true. The tailstock doesnt come away until I've just got a little nub left.

I only use Cole jaws when I need free access to the bottom for detailing or texturing, or if I'm doing a batch of similar size bowls. If I'm only finishing a few bowls with basic bottoms I just use a jamb chuck or friction drive.
Someday I'll have a vacuum chuck but the prices and availability up here aren't nearly as good as in the states.

 

[Emiliano Achaval]

If you want to go the jamb Chuck route.

turn a cylinder about 3” diameter 2-3” tall ( needs to be tall enough so the rim doesn’t hit the headstock.)
It can be mounted in a Chuck or on a small faceplate. Hollow it a 1/2” or so deep and round the rim so it does not mark the finished bowl- this makes a rounded ring that will seat against the inside of your bowl.
This Cherry jamb Chuck has been serving for a couple of decades.
View attachment 36458

Before using a jamb chuck, I measure the thickness of the bottom to the face of the tenon.
I transfer this thickness to something I can hold against the live center to reassure myself that I have enough thickness to keep turning without making a funnel. I use a center caliper to keep this measurement.
You need to Mark center of the tenon( I use the original roughing center)
A folded paper towel makes a good interface between the jamb Chuck and the bowl.

to see how I use the jamb Chuck fast forward to 33 minutes
Mounting and turning a dried bowl -

View: https://www.youtube.com/watch?v=sCZWsHB4vlM

Al, I would call that a friction chuck. A jamb chuck would be the one that fits perfectly, so you would have to make one for each bowl. In my demos, I have to explain the reverse turning and give options, I just want to make sure I have my info right. Maybe a jamb chuck does not have to be like I described it? Stuart Batty in his demos uses a Jamb chuck, the perfect fit one. I can see using that for demos, but you can imagine for production is not just feasible. Friction chuck, jamb chuck, cole jaws, vacuum chuck, Jack Straka chuck, so many names...

 

[hockenbery]

Al, I would call that a friction chuck.

“Friction Chuck” is a better description. I use jamb Chuck to include both pressing between centers and for the turned parts that hold the work without tailstock support.

if @Bill Boehme ever writes the woodturners dictionary we can refer to it.

I don’t remember who I got the term jamb Chuck for the little block I use. Lots of other people use the term the same way I do.

I learned cutting the ring in wood from my friend Joe Dickey in the late 80s. Joe had Union Graduate and used all sorts of holding devices that let him work without a tailstock. I think you had graduate once upon a time. joes graduate had a small tailstock but was ineffective for bowls.

 

[John Torchick]

Thanks to all. I turned what was to be a bowl but reversed the sequence- I turned the inside and painted myself in a corner. I have Lyle Jamieson video but didn't want to view as it's a total of about 4 hours. Found a website, www.turnawoodbowl. that had the Reader's Digest eight minute version of turning. He started with a screw chuck in the wood, moved up the tailstock and turned the bottom with a tenon. Then, reversed to turn the inside. Going to try this sequence.

 

[Tom Gall]

Al, I would call that a friction chuck. A jamb chuck would be the one that fits perfectly, so you would have to make one for each bowl.

I totally agree. Some of the terminology we use can be confusing.

 

[Tom Gall]

I think I've commented on this before. Get rid of the buttons. Slap (screw) on four pie-shaped pieces of wood to match the plates. Think Flat Jaws. True up edges (OD) if that makes you happy. 2x material works or any other softer wood. Open jaws slightly. Turn a groove (parting tool) to closely match your bowl rim (ID or OD) and tighten or expand the jaws. Voila!, a custom jam(b) chuck. Can be dovetailed for rim curvature. Can be used dozens of times until there isn't enough wood left. Rinse and repeat.

 

[Emiliano Achaval]

“Friction Chuck” is a better description. I use jamb Chuck to include both pressing between centers and for the turned parts that hold the work without tailstock support.

if @Bill Boehme ever writes the woodturners dictionary we can refer to it.

I don’t remember who I got the term jamb Chuck for the little block I use. Lots of other people use the term the same way I do.

I learned cutting the ring in wood from my friend Joe Dickey in the late 80s. Joe had Union Graduate and used all sorts of holding devices that let him work without a tailstock. I think you had graduate once upon a time. joes graduate had a small tailstock but was ineffective for bowls.

I was using the jamb chuck word too. But, over 40 demos during this COVID era, people point out your mistakes. I think you are 100% right, I will describe a jamb chuck as the one you can use without tailstock support, the description was escaping me. I was very much impressed with Stu’s jamb chuck, but, not feasible for me on a daily basis. Thank you Al for your help. Aloha

 

[Dean Center]

If we're going to start the Woodturner's Edition of the OED, could someone explain whether it should be JAM (as in, 1) 'jamming something against something else' or 2) raspberry) or JAMB (as in, "I can never get the door to hang parallel to the door jamb")

 

[John Torchick]

Dean, I agree. Jam would be the name as applied to its use in wood turning. BTW, mine turned out OK. Turning could have been a lot better.
Nomenclature can be confusing. I have lived several places where one fish had different names. Worked in electrical at Lowes. One item was a handy box, switch box, gang box. It was the box for outlets or switches. Diagonal wire cutters were called dikes by some electricians.

 

[Bill Boehme]

If we're going to start the Woodturner's Edition of the OED, could someone explain whether it should be JAM (as in, 1) 'jamming something against something else' or 2) raspberry) or JAMB (as in, "I can never get the door to hang parallel to the door jamb")

I'll die a happy man knowing that I've helped save the English language if I can ever get Emiliano and Al to use the correct word "jam" rather than "jamb" which, as Dean points out refers to the vertical pillars on either side of a door frame. While jamb has a very specific technical definition, the word "jam" has a number of meanings besides the stuff that you smear on a slice of bread.

Could it be that what Emiliano described is a glue block and neither a jamb nor a jam chuck? There isn't enough information in his description to say with certainty. You can make a jam chuck where two pieces are pressed to fit snugly together whether you do it by hand or by using the tailstock.

And, don't even get me started about the use of "addicting" vs "addictive".

 

[Emiliano Achaval]

I'll die a happy man knowing that I've helped save the English language if I can ever get Emiliano and Al to use the correct word "jam" rather than "jamb" which, as Dean points out refers to the vertical pillars on either side of a door frame. While jamb has a very specific technical definition, the word "jam" has a number of meanings besides the stuff that you smear on a slice of bread.

Could it be that what Emiliano described is a glue block and neither a jamb nor a jam chuck? There isn't enough information in his description to say with certainty. You can make a jam chuck where two pieces are pressed to fit snugly together whether you do it by hand or by using the tailstock.

And, don't even get me started about the use of "addicting" vs "addictive".

I'm happy to see that there some confusion even between English-speaking turners. I translated some articles from the Journal to Spanish. That was really hard. Some words do not even exist in Spanish, some tools and lathe parts have different names in different countries. One of the hardest words was "sheer scrape" I'm known to use glue blocks, but not as JAM chuks, lol

 

[Bill Boehme]

I like Al's recommendation for the term "friction chuck". It's a more technically accurate description and keeps us out of a jam. The term "jam chuck" lacks the finess implied by "friction chuck". I would prefer have a perfect fit that is neither too tight nor too loose rather than brute force jamming the two pieces of wood together.

 

[hockenbery]

I like Al's recommendation for the term "friction chuck". It's a more technically accurate description and keeps us out of a jam. The term "jam chuck" lacks the finess implied by "friction chuck". I would prefer have a perfect fit that is neither too tight nor too loose rather than brute force jamming the two pieces of wood together.

@Emiliano Achaval used Friction before I did.

Also I have always tried to use “jam” however I am a big fan of Jeffersonian spelling. Jefferson is reported to have spelled particular words four different ways in the same letter - my hero in that regard.

Still need the Boehme international woodturning dictionary

 

[John Torchick]

Shear vs sheer? Here we go again.