Home made Pin Chuck

**DaveTTC** · 2nd May 2014, 04:57 PM

Well I been at it again, playing around. My chuck jaws are absolutely off centre. Not happy Jan!!!

The need to mark the jaws is very apparent. I have decided on custom chucking for multiple use. I have put a screw in the jam chuck next to the No. 1 jaw in line with the key hole. May be a little hard to see below, had to go out side to take the pic because of the lighting. Still not much better lol. Oh and because of this screw I have decided to make my tenons a little larger than optimal. I have ground the head off the screw and just left a smooth shank sticking out. I thought of a nail but did not like the idea of it comeing out at 3000 rpm

Now I needed to take it down to size to suit the forstner bit. Lets try one of my plugs ... the the short side of the tenon has a centre point to work off

Jamb that up agains the chuck using the tail stock and I have an instant guide .... no measuring or making mistakes .... can do a visual without stopping the lathe (I'll just add that the end of the jamb chuck needs to be trued up before trying to use the plug and care taken to put it on central and keep the required pressure)

Moments later

What I decided to do was make another 'pin chuck' of sorts. I did not want the hastle of having to make sure the pin stays in place or worry about it coming out so this is my prototype. Not sure that I would spin it without something on it as the timber may give may. Also was chasing a way to clamp the chuck while I drill it.

Next was to turn some custom pins ... could have used steel but did not feel like cutting heads off of bolts. The idea with the holes is for them to be exact leaving a slot where the dowel can protrude under force but when stopped the pins need to be flush with the tenon. The dowels are about 1.5mm smaller than the holes drilled.

Little oversight on my part. When I drilled the holes above I lined up the first one, clamped the two fences in place and drilled the hole. Great line nice and square .... I was happy. Being that the chuck is round all I had to do was rotate it round to each position and drill again.

Oh Yeah .... the jaws are not closing to centre. The holes were out. One was perfect two were out. I ended up re-drilling the two holes that were not breaking through enough with another drill one size up. This worked but still .... should not have to compensate like that.

Next was to try it out. I have a blank with a hole cut in it so lets slide it on and give it a whirl .... and polish it while we are at it

Worked like charm. Steel pins being heavier would likely grip better, a nurled pin likely even better.

My only concern with a steal pin would be if it broke through the chuck and worse yet through the job being turned. Even with timber dowel I am not game to run the chuck without something on it.

Hope some may get inspired

Dave the turning cowboy

turning wood into art

**Hermit** · 2nd May 2014, 05:49 PM

Very Ineresting - Laugh-In.JPG

Hmmm. I saw the title and expected something more like this. The pin/roller sits on a flat surface, forcing it outwards by rolling across the flat surface when the piece is rotated.:
Pin Chuck - peterchild_com_ukslashchucksslashpinchuck_htm.JPG

Are your pins really forced outward by rotational force?

**Hermit** · 2nd May 2014, 06:20 PM

Three pins set up something like this might work better though, so that the outer edge of the pins is flush or minutely proud of the outer surface of the chuck body.:

Pin Chuck Design.JPG

**DaveTTC** · 2nd May 2014, 06:25 PM

Yes they move out. The pins are about 1.5mm smaller than the hole maybe a bit more. That means they can protrude more than the amount the hole drilled sticks outside the size of the chuck. The grip is good enough to stand up to chisel and sanding forces. The pieces going on slide on easy ... no forcing yet when it spins it grips.

I have another design I will be working on soon that leaves this one for dead, I just need a sure fire way to release it when I work it out.

Dave the turning cowboy

turning wood into art

**Hermit** · 2nd May 2014, 06:28 PM

Originally Posted by DaveTTC

Yes they move out. The pins are about 1.5mm smaller than the hole maybe a bit more. That means they can protrude more than the amount the hole drilled sticks outside the size of the chuck. The grip is good enough to stand up to chisel and sanding forces. The pieces going on slide on easy ... no forcing yet when it spins it grips.

I have another design I will be working on soon that leaves this one for dead, I just need a sure fire way to release it when I work it out.

Dave the turning cowboy

turning wood into art

They'd only move out by centrifugal force, though, wouldn't they? Is that enough? I'd be careful with that one, personally.

Not trying to rain on your parade, mate.

Just speaking out of concern - I'd hate to hear that you've been hit in the head by a chunk of flying wood.

**DaveTTC** · 2nd May 2014, 06:36 PM

Yeah centrifugal force, very similar to the pin chuck with a flat spot but I guess you can rotate that to get more of a mechanical lock too.

To come flying off the piece would have to come loose to start with, I have had one that moved a bit on my former set up and on this one one moved about 5 mm along the length and stopped. Before it comes off (if it was going to) I would just put the side of my chisel up against the base.

Thanks for the concern, always nice to have a reader and feedback

Dave the turning cowboy

turning wood into art

**Hermit** · 2nd May 2014, 06:44 PM

Originally Posted by DaveTTC

Yeah centrifugal force, very similar to the pin chuck with a flat spot but I guess you can rotate that to get more of a mechanical lock too.

To come flying off the piece would have to come loose to start with, I have had one that moved a bit on my former set up and on this one one moved about 5 mm along the length and stopped. Before it comes off (if it was going to) I would just put the side of my chisel up against the base.

Thanks for the concern, always nice to have a reader and feedback

Dave the turning cowboy

turning wood into art

No worries, mate. If you can achieve a mechanical lock as well with your second design, it'll be much more secure and safer to use.
It's great to see you thinking and coming up with new ideas, by the way. If you come up with something that looks marketable, though, don't tell us or otherwise publish it publicly until you protect your idea.

I'm speaking from experience - I designed a simple circuit for cutting off an electric fuel pump in the case of a rollover years ago. Sold one batch, then they copied it and installed it on a whole fleet of buses.

**DaveTTC** · 2nd May 2014, 07:30 PM

Yeah, its inevitable that it will get ripped off no matter what you do I think.

I could get onto the boys at vicmarc and see if they want to do one. Not sure if they would reward e for my design

Dave the turning cowboy

turning wood into art

**DaveTTC** · 2nd May 2014, 07:32 PM

The one I have made above, made in steel would be awesome. The great thing with this design is you never have it jam.

Dave the turning cowboy

turning wood into art

**Hermit** · 2nd May 2014, 07:44 PM

Originally Posted by DaveTTC

The one I have made above, made in steel would be awesome. The great thing with this design is you never have it jam.

Dave the turning cowboy

turning wood into art

I don't have one myself, the pic I posted was from the web, but I can see how they could jam.

**DaveTTC** · 4th May 2014, 05:38 PM

Steve .... just did my custom chuck Mk III

emailed it to you, see what you think

Dave the turning cowboy

turning wood into art

**Hermit** · 4th May 2014, 08:45 PM

Originally Posted by DaveTTC

Steve .... just did my custom chuck Mk III
emailed it to you, see what you think
Dave the turning cowboy
turning wood into art

Looking good. This one shows more promise I reckon.

**Tim the Timber Turner** · 4th May 2014, 10:02 PM

Originally Posted by DaveTTC

The great thing with this design is you never have it jam.

Hi Dave

You got it in one mate, pin chucks never jam.

Every time you stop the lathe and start it up again the works locates on a different part of the chuck.

This means the work runs slightly out of true.

Pin chucks rate very highly on my list of useless gadgets for a wood lathe.

There are much better and safer ways of holding wood on a lathe.

Good on you for thinking outside of the square

but I suspect your idea is too far away from the square.

If you were thinking of making for sale, or publishing plans for your idea, can I suggest you research product liability insurance.

Sorry to rain on your party mate.

Cheers

Tim

**DaveTTC** · 4th May 2014, 10:08 PM

no worries tim,

as the pins all protrude the same amount on 4 sides i find i can rotate the work and start the lathe again with hi accuracy. i agree, a single pin does not do it.

This is so much more accurate than a scroll chuck that must have the jaws marked for re-alignment.

I think even you might be impressed by my latest design

I am interested in this product liability insurance idea though

Dave the turning cowboy

turning wood into art

**Tim the Timber Turner** · 4th May 2014, 10:12 PM

With regard to protecting your idea, unless you have heaps of financial resources to defend a patent, no matter how good the idea, its not worth the effort or the outlay of trying to protect it.

Again sorry to rain on you party.

Cheers

Tim

Thread: Home made Pin Chuck

Thread Tools

Search Thread

Home made Pin Chuck

Similar Threads

Home made sash clamps made from cheap pine short cuts

Home made chuck for holding wooden spoons

Home made Jig

Home made ice box

ET never made it home...

Tags for this Thread

Posting Permissions