Adjustable 4 jaw selfcentering chuck

[conetip]

Does anybody have an adjustable 4 jaw selfcentering chuck like the Taig Type?

I made this one adjustable through the 3 pin holes.I drilled them through,taped m6x1 (std m6) and put some plastic pads in the bottom of each.The scroll was taken off the chuck to do the work.I bored out the scroll id by .006 inch diameter bigger,it also deburs the holes after tapping.
The reason for the plastic pads is to have some spring to stop the 3 set screws from coming loose.It also allows to open and close when using the same diameter so it does not need to be readjusted on a repeat size.

 

[conetip]

why am I getting two pictures showing? any help is appreciated.

 

[conetip]

Is anyone interested in this simple mod to these chucks to make them adjustable ?
If so , I will take some pictures when I mod the next chuck.

 

[rhncue]

Is anyone interested in this simple mod to these chucks to make them adjustable ?
If so , I will take some pictures when I mod the next chuck.

Yes, I would.

Dick

 

[fiolledapool]

Is anyone interested in this simple mod to these chucks to make them adjustable ?
If so , I will take some pictures when I mod the next chuck.

hi,

is this chuck for fit in your metal lathe?
What threated?

 

[fiolledapool]

Is anyone interested in this simple mod to these chucks to make them adjustable ?
If so , I will take some pictures when I mod the next chuck.

hi,

is this chuck for fit in your metal lathe?
What thread?

 

[conetip]

Here are the pictures.
Dissassemble,then drill the holes through.I used a 4.8mm drill down the existing holes through to the centre.
I set the scroll up in the lathe to tap as it is easy to hold and I need to bore the ID afterwards anyway.
After tapping M6 , I indicate the scroll true,then bore the ID out to be .005-.006 inch bigger .It also deburs the tapped holes.You don't have to tap through, but I do as it is easier.
Then I clean it and get it ready for assembly.
Next I make some plastic pads.I use a soft plastic, PVC .They are 2mm thick and fit into the bottom of the tapped holes.Best to use a soft plastic so that there is something keeping the set screws from coming loose.Delrin is really too hard, but Nylon would work.
I get M6 set screws and machine the front face flat to push against the plastic pads.
Assemble the scroll back onto the chuck and replace the circlip.
Then I place a pad down each of the holes and the set screws after.
I show a picture of the plastic pad near the bottom of the tapped hole.
You could drill new holes and tap to what ever you want ,and have 4 sets of pads. But as they rarely align to the jaws,I don't see the advantage over 3 holes.
It is easy to dial in when you know how to dial the 3 sets,bit like a buck chuck or griptrue.The 3 jaw in the picture is a griptrue from Prattburnard.

When reassembled and on the lathe, I place a ring in the back of the jaws to enable the retrueing of the chuck jaws. I use a DTI on the outside of the scroll indicate to true.At that point I bore out the jaws.
After this , if the chuck is not zero with the work piece, I know that there is upto .006 inch with the DTI available to zero with.

I hope this helps out those that want to make their Taig Type chucks with a small amount of adjustment to get the job running true.
As this relies on moving the scroll, care should be taken not to try and correct more than .004 to .006 DTI of run out.

 

[conetip]

hi,

is this chuck for fit in your metal lathe?
What thread?

This will work on the Taig chucks. 3 jaw and 4 jaw.
All my chucks have the 1-9/16 - 32tpi thread.