36" Column on a Lathe

[Samuel Brooks]

2 Questions,

Design Issue of Columns
Technical Issue how to mount on the lathe.

I need to make 4 columns 36" long with an outside diameter of about 4-1/4" inches. It would take too much wood to do a glue up so I was thinking about making it a segmented column out of (8) 2" pieces cut on 45 degree angles and glued. My stock is Rift Sawn Red Oak 4/4. They did not have any 5/4 of the Rift Sawn. I wanted a straight grain look for the columns.

Also I need to joint in side pannels to the columns. I am planning on using a 3/8" dado in the side of the finished column but it might be eaiser to use biscuts. I am also going to use 3 corner blocks on each column, like what you would see when a table is built. The project is going to be an altar so stress will not be an issue at all.

I need some advice if the above sounds right, plus how do I go about mounting it on the lathe after I have everything glued up.

I have a stock Jet 1442VS with the stock components, i.e. face plate, spur and live center. Will I need a chuck to accomplish this? I have been thinking about the Barracuda2 (http://http:/www.pennstateind.com/store/csc3000c.html) Chuck which might make this process easier.

Comments will be appreciated.

Sam

[Don Baer]

I'd just srew a faceplate to one end and use a live center on the other. In terms of the Dado, I'd just make a jig like Jim Becker did for his shaker table and use a router. Do it while it's still mounted on the lathe.

[Don Baer]

Sam,
Here's a link to the router jig Jim made.

http://www.sawmillcreek.org/showthread.php?t=32449&page=2

You'd have to make it a little differant but I'm sure you'll get the Idea.

[Samuel Brooks]

Thanks for the link, that is what I was thinking of for the dado.

How would I attach the faceplate to the end of the column since it will be hollow?

Sam

[Don Baer]

Glue a sacraficial plate to the end and screw it into the facte plate.

[Bill Grumbine]

Hi Sam

I would suggest that you turn this between centers rather than screw it to a faceplate. Faceplates are great for holding work securely, but if you have any error at all with the end of the piece being out of square relative to the long axis, it is going to be multiplied considerably as you go down the length to the other end.

If it were me doing it, I would install a faceplate on the headstock, with a waste block fixed to it, and turn the waste block to a cone, or a cone with a rabbet in it sized to fit the inside of your glued up stock. Make the stock a little bit longer than what you need for your finished length, and screw it into the waste block if you want something a little more positive for the driving force. A similar cone on the tailstock will hold that end. Turn it round and rout it out just as described in previous posts.

Of course, you can use a faceplate if you don't mind fiddling around with the screws to adjust it, of if you get it dead on square.

Good luck with it!

Bill

[Steve Clardy]

Make you some false ends.
These are nothing pretty, just something to get the job done.

[Charlie Plesums]

I just did a couple mahogany columns over 4 feet long, tapered from 8 to 6 inches. I did a segmented glue up of 12 segments, 15 degree angles, with 3/4 inch stock. As I cut the segments, I moved one end 1/2 inch away from the fence to build the taper, and glued with a bunch of hose clamps.

A friend in my wood working club had a segmented column explode, so he recommended leaving a clamp on somewhere while turning. Instead I cut a plywood dummy top and bottom , with a screw into each of the 12 segments. I used a faceplate and live center since I didn't want to have any outward pressure on the inside of the column. The time you spend finding the exact center and balancing the piece is a worthwhile investment - don't rush that step.

After I did them for a lot less money, I got a quote to do them commercially for about $1400 for the pair. Darn.

[Samuel Brooks]

After you built the columns, how did you joint them to your project? Since they are hollow, I will not be able to use things like M&T.

[Charlie Plesums]

A segmented column, hollow, is not a major structural support... it is decorative. The commercial columns I got the quote for say "no" load at all.

On the ones I did, the design called for a final bead. Rather than having to cut that much wood away from the entire column, I made the bead out of a flat board (yes, the end grain shows, but it was acceptable to the client). I put a small indentation/inset in one side so any imperfections of the column end wouldn't show, sort of like using the column as a tenon 1/8 inch long. The customer glued and nailed the bead to the end of the column. The other side of the bead had a slight shoulder (~1/16") to lift the bead off the square base. Same for the cap.