Thread: disaster recovery or up grade

Looks like it's lucky you didn't suffer peripheral damages from that 'un! Nice job on the new one, too.

Any plans for an upcoming WIP on "how to remove broken screw chucks from Dead Finish"?

only one suggestion also a deeper pitch thread on the screw! I use coach bolts on my face plates and replace them every 18 month's regardless of how much work they have done! and use the chainsaw file to open up the thread. but bigger is better!

Originally Posted by Skew ChiDAMN!!

Looks like it's lucky you didn't suffer peripheral damages from that 'un! Nice job on the new one, too.

Any plans for an upcoming WIP on "how to remove broken screw chucks from Dead Finish"?

Skew probably after Easter

Neil, I am with Chuck on this one, the threads look like they are for threaded metal parts, not aggressive enough for timber.

Originally Posted by Pat

Neil, I am with Chuck on this one, the threads look like they are for threaded metal parts, not aggressive enough for timber.

Yeah I copied the Teknatool supplied thread form here 2mm pitch 2mm deep.

Hughie,
For what it is worth. Snapped one about 6 months ago - and tried to use an easy out.
Couldnt budge it at all. Had to drill all around it and used the easy out hole with punch to move
it sideways (back and forth). Didnt do much damage, but reverted to the trusty faceplate & coach screws.
I guess the good thing is that you were not injured in the process only the pride, eh. Drillit.

Originally Posted by Drillit

Hughie,
For what it is worth. Snapped one about 6 months ago - and tried to use an easy out.
Couldnt budge it at all. Had to drill all around it and used the easy out hole with punch to move
it sideways (back and forth). Didnt do much damage, but reverted to the trusty faceplate & coach screws.
I guess the good thing is that you were not injured in the process only the pride, eh. Drillit.

Bit of a cardio work out tho'

Originally Posted by Pat

Neil, I am with Chuck on this one, the threads look like they are for threaded metal parts, not aggressive enough for timber.

Pat post a pic of that monster you got.

Looks like I'd best be careful with any Dead Finish I might be
(un)lucky enough to acquire!!!

Originally Posted by nz_carver

Pat post a pic of that monster you got.

Huey, one of my screw chucks has 25mm screw. Drill a 25mm hole with a forstner bit and on very low speed, mount the bowl to the chuck.
With all you fabrication experience, you'd be able to knock one up in a few minutes.

The lump is shown with the Woodfast Screw chuck for comparison.

Hughie,

You might try one at 6 threads per inch / 4.5 metric pitch. Go in deep enough to leave just a bit of flat on top of the threads, then put the lathe in back gear and use a round file to get them deeper.

That should give you a nice course thread to bite the timber and deep enough to get a good grip.

What you have may work fine. Even if it strips out all that will happen is the blank will stop turning.

Good luck trying to screw that into hard wood like dry Red Gum.

To get a solid mounting you need to screw into a shoulder on the screw.

Cheers

Tim

Huey, one of my screw chucks has 25mm screw. Drill a 25mm hole with a forstner bit and on very low speed, mount the bowl to the chuck.
With all you fabrication experience, you'd be able to knock one up in a few minutes.

Pat thats some screw chuck I have planned to make another around 25mm dia. Unfortunately my lath ain't so accurate as to make a screw on type. I will have to use one of my chucks to use it on the wood lathe.

You might try one at 6 threads per inch / 4.5 metric pitch. Go in deep enough to leave just a bit of flat on top of the threads, then put the lathe in back gear and use a round file to get them deeper.

Paul as mentioned to Pat I plan a larger one,. I was looking at 8tpi but I have to check what my old lathes specs are . I am considering this sort of thread form ___|\___ not quite so pronounced and coming to a point..

Tim the Timber Turner

Good luck trying to screw that into hard wood like dry Red Gum.
To get a solid mounting you need to screw into a shoulder on the screw.

Tim I'll be using the Teknatool system or idea where the job butts up against the chuck jaws. I also have a series of 3 mm stainless discs of various diameters that fit over the screw chuck to give a wider area of support.

Originally Posted by hughie

Paul as mentioned to Pat I plan a larger one,. I was looking at 8tpi but I have to check what my old lathes specs are . I am considering this sort of thread form ___|\___ not quite so pronounced and coming to a point..

I think 8 tpi would be fine for the hard timber available there. Much of what I turn is spalted or soft so a deep and coarse thread works better.

I think the thread form you describe above is called a buttress and works very well in the one direction.