help with segmented project

[Brent Grooms]

I am planning my first segmented piece, and I need some advice.

I am planning on making a +/- 20in tall x 5 1/2in ID cylinder and I need to figure out how thin my wall can be before I will get flex issues. This also affects my segment size.

I have not found any guides or calculators that are of help with this. Anyone have any practical advise?

I am anticipating doing this using a faceplate with a large cone in the tailstock as support while turning the OD.

[Malcolm Tibbetts]

Brent, you haven't given enough information for me to even attempt an answer. Are you talking about stacked ring construction or "stave" construction? Factors such as wood species, # of segments per ring, height of the rings, etc, all will have an effect. What do you mean by "flex issues"? In general, I would not expect a well done segmented piece to "flex" more than a piece turned from a solid block of wood.

[Richard Madison]

You will probably need to use a steady rest when turning the I.D. of a piece that tall.

[Tim Boger]

I am planning my first segmented piece, and I need some advice.

I am planning on making a +/- 20in tall x 5 1/2in ID cylinder and I need to figure out how thin my wall can be before I will get flex issues. This also affects my segment size.

I have not found any guides or calculators that are of help with this. Anyone have any practical advise?

I am anticipating doing this using a faceplate with a large cone in the tailstock as support while turning the OD.


Brent .... keep in mind that the super thin wall are often produced to demonstrate the skill of the turner as compared to any other reason of real value. Except perhaps weight when making ornaments and such.

Is there any reason you can't leave the wall thickness at or near 3/8 to 1/2" to encourage less flex while working the piece?

Certainly a steady rest would be almost mandatory, check out:

http://www.woodennicol.com/

Just a thought .... no doubt opinions will vary.

Love to see it when done!

Tim

[Brent Grooms]

Right now, I have it layed out to be 12 segments per ring, approx.20 rings @ 1in thick. I am planning on making it out of a combination of maple cherry and walnut.

My plan was to start with a faceplate/sacrificial block glued to the base of the piece (solid) then add 1-2 rings at a time, cleaning up the ID first then the OD as I went. Once fully assembled, make any necessary clean-up cuts on the OD, sand and prepare to finish.

I spent some time today experimenting with the segment orientation to see what was going to give me a "basket weave" appearance without going too crazy on the segments. I think I can get the look I am after by alternating the wood types.

I have the lengths and angles, and now with a guide for the thickness (I am going to keep things in the 1/2 - 3/8 range) I am going to try to make some test pieces up for glueup this weekend and see what happens..