Built a few columns

[mreza Salav]

The past couple of weeks (among other things) I was busy building a few columns for the new house trim work.
I purchased the carved caps and the bases from Osborne wood and built the fluted columns out of hard maple. The cap and the base are solid (not hollow) but the columns I made hollow from 12 segments. The glue-up was a bit challenging (to say the least). I have used dominos to help with alignment of the pieces. The first glue-up I did 6 pieces at once: the first few photos show the pieces and the dry fit, and the glue-up:

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soon I realized this was a big mistake and the final result was less than perfect and even though my wife said it looked fine to her I decided to start from scratch and make 4 new ones, this time glueing pieces 2 at a time, then make a half circle with 3 paired pieces. I realized I need a few more clamps than just the band clamps. The photos should show the construction process.

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The fluted column is 6' tall and with the cap and the base they are just over 7'. They have a very slight taper (7.5" wide at the base and 7.25" at the top).
To cut the pieces to length since I couldn't cut them on my home made milling setup and don't have a large enough cross-cut saw to cut through 7.5", I made a shallow cut with the router on the "lathe", then made the rough cut on my miter saw by rotating the column a few times and then cleaned the rest with a flush trim router.

[mreza Salav]

I use ten 2" (3/8") to connect the caps and bases to the column. Used the bushings on my Jessme dowel jig to make another jig to drill the holes. Here is the final result:

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[Kent A Bathurst]

Impressive.

Just so I understand - the box with the router - that functioned as a lathe to smooth the columns into round, before the fluting?

If I got that bit right - how long did it take to pass the router back-and-forth to make the tapered round profile?

[mreza Salav]

Yes, that box was built to round the column and make the flutes. I used a 1/2" spiral bit and one pass (along the length) was enough to bring it to the height I needed, each pass taking about 1/4"-3/8" of the perimieter. It took about 2 hours to round each column and about 1 hour to make the flutes (although the first one was much slower).

[Chris Padilla]

Sweet!!! I love it!! I assume you purchased the tops and bottoms to your columns?

[mreza Salav]

Sweet!!! I love it!! I assume you purchased the tops and bottoms to your columns?

Yes, as I said in the first post they were purchased from Osborne wood (I don't have a CNC unfortunately ).

[Sam Layton]

All I can say is, WOW. Your columns are impressive. You did an outstanding job. Good thing you have a good assortment of clamps. How are you going to finish them? Will you put finish on the inside of the column to seal the wood?

Good job, Sam

[Dave Richards]

Very nice columns.

I noted your comment about clamping the pieces for gluing. Are you familiar with the "birdsmouth" method used by spar builders to create hollow spars for boats? The process involves making a V-groove on one edge of each stave. This provides a nest for the neighboring stave to rest in. After applying glue to all the V-grooves, you put one end of the column together and slide your hands down the length. The staves will all snap into place and will stay there. I made a few spars that way and used zip ties to clamp them up. The typical birdsmouth spar uses 8 staves but the angle can be adjusted easily to allow as many staves as you wish. I made a calculator that allows you to enter the number of staves, the finished outside diameter and desired wall thickness. It returns the width and thickness of the staves. Tapered spars or columns are easily done be tapering the square edge of each stave.

[Scott Austin]

What excellent work, love the router/lathe. To do the taper did you just move the "axle" up off center on the top ?

[Vince Shriver]

I'll second Sam's comment: wow!

[Bruce Page]

Beautiful! Your clamp collection is almost as impressive as your work!

[Al Launier]

Very impressive indeed!

[Al Launier]

Very nice columns.

I noted your comment about clamping the pieces for gluing. Are you familiar with the "birdsmouth" method used by spar builders to create hollow spars for boats? The process involves making a V-groove on one edge of each stave. This provides a nest for the neighboring stave to rest in. After applying glue to all the V-grooves, you put one end of the column together and slide your hands down the length. The staves will all snap into place and will stay there. I made a few spars that way and used zip ties to clamp them up. The typical birdsmouth spar uses 8 staves but the angle can be adjusted easily to allow as many staves as you wish. I made a calculator that allows you to enter the number of staves, the finished outside diameter and desired wall thickness. It returns the width and thickness of the staves. Tapered spars or columns are easily done be tapering the square edge of each stave.

Dave, any pictures, or reference source, to further explain this process?

[mreza Salav]

Thanks to all.

Dave, I am familiar with that system but unless I use a router bit like this
http://www.mlcswoodworking.com/shops...ed_glue_anchor

making the grooves still is prone to error. The problem is the height of these bits were not large enough for the stock (8/4) I wanted to use.
In a 12 sided shell even a 0.1 degree error in the bevel cuts will result in 2.4 degree of error (there are two cuts per joint) and 2.4 degree will show like a sore thumb at the time of glue up.
What I ended up doing was to make two half columns and then run each on the jointer to get a perfect joint at the end.

[Dave Richards]

Dave, any pictures, or reference source, to further explain this process?

Made a quick sketch, Al. Eight and 12 staves.



Lee Valley sells router bits to do this but I just make them on the tablesaw. I haven't had any errors when I've made them.