I have never posted into this Wood Turners area, so I guess this is a first.  A friend asked me to cut him a 16" Longworth chuck so today I tested my drawing that I did in Fusion 360 by cutting a 12" chuck.  Looks like it came out just fine so I thought I would offer them in our Etsy shop.  You can click on the link in my signature and see the offering but I didn't want to post a link like I was pushing it, just thought you lathe guys might want to see this -

 

 

I used to turn a fair amount and still have my Oliver 8' bed lathe but it's not being used 'cause it's 3 phase and I don't have time to do any turning anyway.  So if y'all see something in the Etsy listing that doesn't look right or that I have worded incorrectly I would appreciate a heads up.  Thanks!

 

David

You have some cool stuff on the etsy. On your longworth I do not think your slots meet properly and not enough of them also. Here is a pic of mine behind the lathe. This is a 16 inch longworth.

Thanks, Gerald.  I've seen that design, too, and both seem to do about the same.  This is the design my friend gave me so that's the one I used.  I can't see all of yours but it appears to have 8 slots like the one I cut.  The shorter slot on the one I have cut is to give the center more strength.  

 

I've even seen some that appear to have way more slots than necessary, like this one -

 

And some that appear to be weak in the center -

 

If you Google Longworth chuck design you'll see the one I used makes up about half of the images and yours makes up the other half, with a few odd balls thrown in for good measure.  But that's the good thing about what I plan on doing - I can quickly redesign and change to one like yours if it's better or even offer both.

 

David

Edited February 15, 20188 yr by difalkner

That is interesting .I found it slow and cumbersome to get the thing tightened so only rarely use it now. Oh I did make up a couple handles to put in the holes instead of my fingers which made the whole process faster and easier.  Gave my one of my cole jaw sets away at club raffle and now use vacum chuck almost exclusively.

Well, the interesting thing is that after seeing that these two designs are about equal in what I have found in searches I am now wondering if the long/short slot isn't the 'old' way and the symmetrical all long slots is the improved version. 

 

After I posted earlier I put some bolts in the slots on the one I made and found that the short slots limit the travel, as you would expect, such that it won't go very small.  Now that may not be a problem because all you have to do is take those four bolts, or grippers, off and the remaining 4 will go down pretty small.  But on the one with all long slots it seems like it will go from minimum diameter to maximum without having to remove anything.

 

Of course, when you get down to 4" or so you'd probably use  different chuck anyway.  These aren't meant for hogging material but rather for finishing the bottom of a bowl or a lid and typically not running over 500 rpm. 

 

I'm going to redesign and cut one like yours to test how it works.  I may put both on our Etsy shop and let the buyers decide which they want.  If in 6 months we have sold a dozen of one over the other then that will tell me all I need to know about what people want.

 

Thanks, Gerald!

David

Very nice offerings and site layout on Etsy David.

Appreciated reading your journey in life thus far.

Hope the business does well!

David on the one I have it does like you said and goes all the way from max to min and when I tighten I alternate bolt ( tighten one some ,skip one and tighten the next) because I found that not doing that causes the bowl to be off center. If you are interested in the tightening handles I can take a pic and post.

You might want to offer a bolt and bumper option (to purchase) as well as faceplate mount to make it a one stop shop.

Edited February 16, 20188 yr by Gerald

Thanks, Gerald.  And to demonstrate that I can still be taught, I tested the 12" chuck that I made earlier and it is limited in travel due to the short slots.  I knew it would be but I just wonder if that's why there is a long slot, symmetrical version.  Anyway, someone asked if I can cut them a 10" model so I drew today that and used the long slots - I like it much better.  So thank you for making me think about it a little further.  On our Etsy shop I may offer both and see which one folks prefer, because once I have the file it won't matter to me which one I cut. 

 

Here's the 10" model that will be on Etsy shortly (fewer slots in this one because you just don't need 8 when the chuck is that small) -

 

David

OK, showing my beginner's ignorance here.  How does a Longworth chuck differ from a Cole jaw?  In this case, are the words chuck and jaw interchangeable?  Of course, I see the difference in appearance, but how do they differ in function?  I have been struggling with whether to buy a Cole jaw for my Supernova 2 chuck, as the reviews I have seen are horrible.  Is the Longworth chuck a suitable alternative? 

Not really an alternative, Tom.  The Longworth chuck is intended for light duty finishing to remove the tenon on the bottom of a bowl, for example.  And from what I have read the suggested max speed is 500 rpm.  I would say each has its place on the lathe but not interchangeable, at least for the most part.  You can see one in use here - Longworth chuck demo

 

David

 

Edit - I'm a novice at turning, as well, and when I typed above I had another chuck style in mine.  Yes, it's possible that the Cole jaws and a Longworth chuck are interchangeable.  The Longworth chuck is infinitely adjustable from min to max whereas the Cole requires you to remove the grippers, choose another hole, and remount the grippers.  Sorry for speaking before thinking - first time that's ever happened.  Ok, maybe not...

Edited February 16, 20188 yr by difalkner

Thanks for the quick reply David.  I appreciate that.  From what I have been told, each chuck manufacturer has their own version of a Cole jaw, and they aren't interchangeable.  If that was bad info, I'm sure someone will come along shortly and enlighten me.  But that Longworth chuck, as described in the video, seems more of a universal fit.  And don't apologize for letting your fingers get ahead of your thinking, it happens to the best of us.  Thanks again.

This is a great discussion!

 

The chuck I built is similar to @Gerald's. I found I had trouble trying to use the finger holes (rotating the two circles) and tightening the bumpers. I drilled several holes around the perimeters- in the edge of the circles- for Tommy Bars. 

 

I also made an assortment of "bumpers".  Rubber stoppers from the local wine/beer home brewery store work great.