question about my chuck

[Niels]

Hello,
i got a question about a chuck i have.
i bought a Record Power ML305 Lathe not so long ago and they recommended a SC2 chuck to go with it. The chuck has a minimum width for the material of 35mm. Now i wanna buy a collet chuck for penturning but i need te make square blanks i use round first. I was wondering if people know homemade solutions to make a square blank of say 22 mm fit in a chuck which is basically to big. Otherwise i have to buy a new chuck for it and the numbers are running up.

It's just to know for on the side cause i can buy round blanks off course but it's good to be able to not be stuck to that.

Thnanks already

Niels

 

[jttheclockman]

Turn between centers. I do it all the time. I use a steb center like this in the head stock and a live center in the tail stock. Just need to find centers on blank which is easy if you do the cross hatch diagonal markings on the ends. Then use an awl to punch a center hole and good to go.

https://www.packardwoodworks.com/lathes-acc-cent-steb.html

 

[monophoto]

Niels:

I think your Dutch accent may be causing your question to be hard to understand, but I think what you are saying is that the recommended tenon diameter with the SC2 chuck is 35mm, and your objective is to hold a square blank that is 22mm on each side while turning to round for later mounting in a collet chuck. So the question is how can a billet with a 22mm square cross section be mounted in a chuck that is designed to receive a 35mm round tenon.

This is a common challenge, and there are many ways to solve it. Some of the options that come to mind include:

1. Don't use the SC2 chuck. Instead, mount the 22mm square blank between centers to turn it to round and create a tenon that matches your desired collet. This is probably the simplest approach and is quite safe..

2. As seen from the tailstock end, the SC2 chuck looks like the sketch. Note that the optimum 35mm dimension is the inside diameter of the circle formed by the jaws of the chuck when the chuck is closed down to the point where the four quadrants of the jaws are spaced about 2-3mm apart. When you grip a tenon of this diameter, the jaws will be in contact with the surface of the tenon around the entire circumference of the tenon, and therefore provide maximum gripping strength. (You can mount a larger tenon, but then the jaws will be in contact only at four points and therefore the grip won't be as strong.) But experienced turners are also known to grip square billets as illustrated by the shaded square shown superimposed on the sketch. I don't have an SC2 chuck so I can't measure the maximum size of a square billet that can be mounted in this fashion, but obviously it will be with the jaws expanded to their maximum extent. This approach can be a bit more risky than mounting between centers, so it would be prudent to use tail stock support to assure that the square billet remains centered.

3. The third option is to buy another set of jaws for the SC2 chuck. Record Power make 'pen jaws' (catalog 62305) that are designed for pen makers. These jaws grip opposing corners of a square billet for drilling, but can also be used to grip a billet while it is being turned to round.

 

[howsitwork]

Another option is to turn a plug of solid timber to fit your 35 mm diameter chuck , then hollow it so your 22 mm square JUST fits in the hollow you've made. You can then either fill around it with hit melt glue , or glue it in with CA . Hold it between centres whilst the glue sets.

Another option is to ACCURATELY cross cut a slightly larger , say 45mm plug having hollowed it deeply first . The cross cuts will allow your jaws to compress the plug onto your blank. I suggest holding the pieces with an elastic band as it's easier , while you put the blank in and put it in the chuck.

Ive done all of these and they work .

 

[farmer]

Always between centers
Only time I chuck up a piece of wood is to do work on the end of the piece wood for inlays or drilling or boring.

No grippers needed