chucks

[buster]

What is the best way to hold the stummel in the lathe for drilling and shaping ? Which type of chuck is what I mean, a three jaw four jaw i don't know. Also once its in there whats the best way to center it. How well do four jaw self centering chucks work ?

[kbadkar]

A four jaw chuck, with two jaws removed. Use the tall (tower) jaws. The self-centering chucks do exactly what their name implies. If you sqaure your block well, you don't have to worry about center alignment problems on the drilling axises.

[Frank]

Also once its in there whats the best way to center it. How well do four jaw self centering chucks work ?

You might want to scribe centre lines on the faces of the chuck jaws.

[Tano]

Hi Buster,
I thought maybe a picture might make things more clear.

[JHowell]

Tano, it might be a good idea to make a backing plate for your 4-jaw instead of counting on the threaded rod in the 3-jaw as an adaptor. It's an admirable piece of field expediency, and I'm sure it works -- I can't tell if you turned the threads off the part in the 3-jaw -- but I think reducing the length of your rotating assembly yields less vibration, better accuracy, and more safety. That's just me, though, you're probably a tool and die maker.

[sethile]

I prefer a four jaw independent with two jaws removed and in my case I've modified the remaining jaws with extensions and locating pins to facilitate alignment between the tobacco chamber and the draft hole. I have always had a heck of a time getting blocks perfectly square, and on occasion, it's been handy to be able to locate my drilling off center. If I'm chucking a block it's easier and more accurate for me to get the block somewhat square as opposed to perfectly square, then lay out my drilling, center punch where the chamber and draft hole intersect, and location for my mortise angle if it's different, such as for most of my bent pipes. I also center punch for the drill bit. Then I can just chuck up the block according to the locating pins and align it for drilling by using two chuck keys (one for each jaw) and moving the entire block captured in the chuck until I've aligned the drill to my punch marks for drilling.

My rig is a home brew version of the chuck J.T. Cooke and several others use, pictured here with a pipe test stummel:



Unless I'm also doing some turning I'm most often drilling freehand (after shaping) these days, but I still find the above rig very handy for traditional shapes, and anything requiring any turning on the lathe.

Ken Lamb and Trent Rudat both make something similar. The one pictured on Trent's site looks like a self centering version (scroll chuck), but I bet he would make an independent one too:

http://www.lambpipes.com/pipemakingtools.htm
http://www.briarpipetooling.com/