Cole jaw adaptions - Woodworking Talk - Woodworkers Forum
 
Thread Tools Display Modes
post #1 of 18 Old 03-22-2009, 05:55 PM Thread Starter
Senior Sawdust Sweeper
 
Join Date: Jan 2009
Location: Marietta, Ga. USA
Posts: 1,472
View Gary Beasley's Photo Album My Photos
Question Cole jaw adaptions

I just had a bowl slung across the room when my scraper hung while doing the cleanup on the bottom of it. The Mini Coles' rubber bumpers weren't high enough to really get a good bite on the rounded over lip of the bowl I guess. Anybody ever deal with this? What kind of adaptions have you come up with that actually works? Seems I should have a set of rubber bumpers with a mushroom profile so it would hold down against the plate as well as pressing towards each other.
Gary Beasley is offline  
Sponsored Links
Advertisement
 
post #2 of 18 Old 03-22-2009, 06:40 PM
Senior Member
 
firehawkmph's Avatar
 
Join Date: Apr 2008
Location: Near Cleveland, Ohio
Posts: 5,022
View firehawkmph's Photo Album My Photos
Gary,
You have to be very careful when using the bowl jaws. Very light shear cuts work well. My smaller chuck has the baby bumpers you mention. You may be able to find some that are a little bit longer than standard size. My bigger vicmark chuck has rectangular polyurethane bumpers with a dovetail cut on the edges. They seem to grip very well but I still take very light cuts with a bowl gouge in a shear cut mode. The other thing you might try is to keep your tailcenter with a pointed end in place until you are just about done cutting. You will then have just a 1/4" knob to cut off. Light cuts with it also. Finish sanding and apply your finish and you should be ok.
http://www.vicmarc.com/default.asp?contentID=591

Mike Hawkins
firehawkmph is offline  
post #3 of 18 Old 03-22-2009, 08:37 PM Thread Starter
Senior Sawdust Sweeper
 
Join Date: Jan 2009
Location: Marietta, Ga. USA
Posts: 1,472
View Gary Beasley's Photo Album My Photos
Thanks Mike. I was being pretty careful with the scraper, not sure how it managed to dig in. I was just doing the cleanup cuts to make the bottom pretty so the tailstock would have been a hindrance, though I'll have to give it a try next time and see. I see the link to the vicmarc. Do you think the holes in them would be close enough in size to be used? I couldn't find anywhere on that site to order the bumpers individually. I may have to get some material and turn my own bumpers!
Gary Beasley is offline  
Sponsored Links
Advertisement
 
post #4 of 18 Old 03-22-2009, 09:09 PM
4Woodturning
 
Jeff4woodturning's Avatar
 
Join Date: Jan 2009
Location: Cedar Hill, MO.
Posts: 352
View Jeff4woodturning's Photo Album My Photos
Gary I did the same thing and i agree with Mike above need to keep tail stock in place. below is a link for other ideas for finishing bowl bottoms. i made a donut chuck with different outer sizes for bowls. finally broke down went to a vacuum chuck but still have donut chuck for back up.

http://www.cumberlandwoodturners.com...ng%20Bowls.pdf

Jeff,

"Just because your not bleeding, don't mean your turning safely"..
Jeff4woodturning is offline  
post #5 of 18 Old 03-22-2009, 09:21 PM
HLW
Senior Member
 
Join Date: Nov 2008
Location: Canton,N.C.
Posts: 174
View HLW's Photo Album My Photos
Gary, I just noticed on my latest PSI catalog that they are offering 2 1/2" "long soft jaw pins" for $24.95 per set. It's on the back page of the new catalog. I'm not sure if they'll fit other chucks or not? The item # LCJAWSJ . www.pennstateind.com. Good luck.
HLW is offline  
post #6 of 18 Old 03-23-2009, 04:16 AM
Sydney, Australia
 
Join Date: Mar 2008
Posts: 196
View hughie's Photo Album My Photos
Hi Gary,

On my home made cole jaws I have a made up a set of taller lugs/bumpers to get around a particular problem I had like yours, only in my case I did not use the smaller ones as I had no chance of holding it at all.

hughie
_______________________________________
hughie is offline  
post #7 of 18 Old 03-23-2009, 10:01 AM
Just makin chips fly
 
Join Date: Mar 2008
Location: FL an NC
Posts: 642
View The woodsman's Photo Album My Photos
Cole jaw adaptions

I think the best advice givin is keep your tail stock up against the piece.I have a tailstock extention that gives me plenty of clearance to work,plus I have a little block on the end of the center,so as not to mar the piece and you can clean it up to bout a 1/4" then back of the tail stock and finish it off.
The woodsman is offline  
post #8 of 18 Old 03-23-2009, 10:32 AM
Senior Member
 
Join Date: Sep 2007
Location: Baxter, Tennessee
Posts: 3,257
View john lucas's Photo Album My Photos
Although I agree with the tailstock and I do that whenever I can I think you need to analyze why you got the catch. Where was it, in the middle or out toward the edge. The edge can sometimes grap because it's flexing. You need to use shear cuts out on the edge and maybe even dampen the vibrations with your left hand.

How big of a cut were you taking with the scraper, in the final stages it should be very light. The handle should always be higher than the cutting edge when scraping. Were you cutting at or above center, if you get below center it can pull the tool into the work causing a catch.
john lucas is offline  
post #9 of 18 Old 03-23-2009, 05:31 PM Thread Starter
Senior Sawdust Sweeper
 
Join Date: Jan 2009
Location: Marietta, Ga. USA
Posts: 1,472
View Gary Beasley's Photo Album My Photos
John, I might have gotten the tool above center, thats the only thing I can figure that could have happened. I was at the inner 4 inches, inside the base rim smoothing the center. I think I'll try making some taller bumpers to mount to my mini cole. The pics in the PSI catalog looks like an easy thing to fabricate.
Gary Beasley is offline  
post #10 of 18 Old 03-24-2009, 09:09 PM Thread Starter
Senior Sawdust Sweeper
 
Join Date: Jan 2009
Location: Marietta, Ga. USA
Posts: 1,472
View Gary Beasley's Photo Album My Photos
Thanks to everyones input I think I've solved the problem. I went to HD and found some rubber leg tips, these marketed by Shepherd Hardware Products 5/8" (16mm), and 8 6mmx30mm allen head bolts.
At the shop I took a couple of oak pen blanks and cut them to .84" by my caliper, drilled the centers with a 1/4" bit and mounted them on the pen mandrel. I turned them down to .61" diameter and pushed them into the leg tips. Then I used the drill bit to open the tip up and used the cleanup bit to level them all dowm even. Mounted up they are more than twice as high and dovetail profiled.
See the pictures.
Attached Thumbnails
Click image for larger version

Name:	mount-to-mandrel.jpg
Views:	199
Size:	75.5 KB
ID:	7971  

Click image for larger version

Name:	inserts-in-bumpers.jpg
Views:	206
Size:	64.3 KB
ID:	7972  

Click image for larger version

Name:	making-hole.jpg
Views:	499
Size:	40.0 KB
ID:	7973  

Click image for larger version

Name:	trimming-bottom.jpg
Views:	185
Size:	45.5 KB
ID:	7974  

Click image for larger version

Name:	bumpers-mounted.jpg
Views:	389
Size:	69.3 KB
ID:	7975  


Last edited by Gary Beasley; 03-24-2009 at 09:15 PM.
Gary Beasley is offline  
post #11 of 18 Old 03-24-2009, 09:18 PM Thread Starter
Senior Sawdust Sweeper
 
Join Date: Jan 2009
Location: Marietta, Ga. USA
Posts: 1,472
View Gary Beasley's Photo Album My Photos
A few more shots.
Attached Images
  
Gary Beasley is offline  
post #12 of 18 Old 03-24-2009, 10:49 PM
Senior Member
 
firehawkmph's Avatar
 
Join Date: Apr 2008
Location: Near Cleveland, Ohio
Posts: 5,022
View firehawkmph's Photo Album My Photos
Good improv Gary,
now you're cooking with gas. Looks like it should work well. Nice looking bowl too.
Mike Hawkins
firehawkmph is offline  
post #13 of 18 Old 03-25-2009, 08:23 AM
Fighting the fight.....
 
PTownSubbie's Avatar
 
Join Date: Mar 2009
Location: Hampton Roads, VA
Posts: 231
View PTownSubbie's Photo Album My Photos
I have to agree. Nice improvement. Looks like it would hold pretty well.

Nice bowl also!!
PTownSubbie is offline  
post #14 of 18 Old 03-25-2009, 11:05 AM
Just makin chips fly
 
Join Date: Mar 2008
Location: FL an NC
Posts: 642
View The woodsman's Photo Album My Photos
cole jaw adaptions

Looks like you got it goin now,or should I say its not goin anywhere now
The woodsman is offline  
post #15 of 18 Old 03-25-2009, 06:53 PM Thread Starter
Senior Sawdust Sweeper
 
Join Date: Jan 2009
Location: Marietta, Ga. USA
Posts: 1,472
View Gary Beasley's Photo Album My Photos
Quote:
Originally Posted by firehawkmph View Post
Good improv Gary,
now you're cooking with gas. Looks like it should work well. Nice looking bowl too.
Mike Hawkins
Bowl is from ambrosia maple. Looks like a variety of spalting. Can you tell me anything about it? I know it makes great looking pens too!
Gary Beasley is offline  
post #16 of 18 Old 03-25-2009, 09:16 PM
Senior Member
 
firehawkmph's Avatar
 
Join Date: Apr 2008
Location: Near Cleveland, Ohio
Posts: 5,022
View firehawkmph's Photo Album My Photos
Gary,
Ambrosia maple, also called wormwood by some, not me, is a great wood to turn. The greenish streaks are caused by the ambrosia beetle getting into the tree. A lot of the time, spalting will be present too, and maybe some pinholes. I have turned some bowls that had so many green streaks in it, that it looked like a piece of granite. The nice thing is since it's a domestic wood, and fairly common, you can find some pieces locally if you are lucky.
Mike Hawkins
firehawkmph is offline  
post #17 of 18 Old 04-05-2009, 12:53 PM Thread Starter
Senior Sawdust Sweeper
 
Join Date: Jan 2009
Location: Marietta, Ga. USA
Posts: 1,472
View Gary Beasley's Photo Album My Photos
I had a 10 inch blank to turn (the Excelsior is a 10 inch lathe) and my 8 inch cole jaw didn't make it for grabbing the inside when it got time to finish the bottom, so I found a chunk of thick water hose and cut it to lay around the inside of the rim and chucked it to that. It held quite well on the straight sides and the chair feet dug in just right.
Gary Beasley is offline  
post #18 of 18 Old 04-11-2009, 11:52 AM Thread Starter
Senior Sawdust Sweeper
 
Join Date: Jan 2009
Location: Marietta, Ga. USA
Posts: 1,472
View Gary Beasley's Photo Album My Photos
Another update. That chunk of spalted oak firewood made for some pretty tough turning though the grain looks outtasight. I was doing the bottom cleanup with the cole and had the scraper catch three times and each time the bowl just backed up from being seated and stayed in the jaw. Not bad behavior compared to before. I'll have a picture posted in the other thread when I get through finishing it.
I tell ya, getting together with the great minds here is worthwhile. I'd have taken a lot longer to come up with a solution on my own.
Gary Beasley is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Woodworking Talk - Woodworkers Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome