Shopsmith Forums

The next project here is a book pedestal for my wife’s family bible. This piece has no drawings so I am winging it as far as design, which is not my usual procedure but it should be fun. For starters I am making the central pedestal which will be a turning and as long as the SS will allow. It will again be in the ArtDeco theme. It will be two long alder cones with the points dying into a mahogany sphere at the center. The sphere will have a ring at the center of paduak and Maple with a thin layer of ebony on the top and bottom of the ring. My plan is to glue it all up as a post and then turn the whole thing. The base and the top part the book sits on I will make once I have an idea how the pedestal looks. To start with it will be two long blocks of alder and the central block of mahogany sandwiched in the middle. The question is how small of a point I can bring the cones down to where they intersect the sphere in the middle without losing the integrity of the piece. My plan at this point is to run a dowel (1/2” ?) down the center of the mahogany block and into the upper and lower pieces of alder to keep it from flying apart.I started on the central ring today.
Paul

what sort of clamp did you use to get started ? I made a picture frame clam from a old ratchet strap and some small pieces of wood years ago hat works good on square glue ups .

How small do you want the cone points to be? If you’re really pushing it, something like a 3/8” high-strength steel rod, epoxied into a center bore, should give adequate strength. I’d bore all three pedestal components through. Then the rod itself would be serve as an alignment pin for glueup. Depending on how you plan to attach the top, you could either turn between centers, or leave the steel rod proud and chuck directly onto it.

I’d also turn the down the small ends of the cones last, and do it at very low speed — that pedestal geometry is going to want to whip like crazy. Come think of it, turning the components individually and then assembling them onto the steel rod might be more practical. You could even use threaded rod, and simply bolt the assembly together.

Thanks Dennis. I had not thought of individual components and then bolting it together. That might work much better. It will also solve the height problem. I wanted the center pedestal to be a little longer than I was going to get out of the SS lathe. I don’t think running rod completely down the center will work due the length of the hole. I can probably get away with drilling as far as I can and then epoxing in some allthread in the ends of the cones and coupling nuts ito the sphere. This will also cure the whipping problem which has been nagging me. The sphere will be easier to turn as a separate item also.
Paul

This 3/8x18" bit should make it easy enough to bore through-holes in the individual segments -- you just cut off the square part of the shank to use it in a regular chuck. I'd be curious to see how straight it cuts in end grain.

https://www.mcmaster.com/#standard-drill-bits/=1a2ydzc

It occurred to me that if I turn it in three parts I will have more than enough horizontal room on the lathe to be able to turn a tenon on both ends of the cones which will allow me to drill a hole in the sphere and the bases and glue them together. It will also solve another problem by allowing me to use the router jig I have for the lathe which will allow me to produce perfect cones.
Paul

masonsailor2 wrote:It occurred to me that if I turn it in three parts I will have more than enough horizontal room on the lathe to be able to turn a tenon on both ends of the cones which will allow me to drill a hole in the sphere and the bases and glue them together. It will also solve another problem by allowing me to use the router jig I have for the lathe which will allow me to produce perfect cones.
Paul

That sounds good -- the only reason to put steel in it is if you need to reinforce very slender cone ends. And I'm sure you're a better judge of that than I.

Well this has been so far the most complicated glue up and project I have tried. I have attempted to think it through from one step to the end and let’s hope it works !
Paul

About a 5" sphere?

What are the blocks outside of the mahogany for? Mounting blocks?

Now tell us about the plywood on the face plates.

The blocks on the ends will give me some clearance between the faceplate/ live center and the sphere in the initial turning. After the shere is roughed out I will cut off the ends left between it and the faceplate and live center. At that point I will sandwich it between two cup centers ( the plywood mounted on the faceplates) so I can turn the axis of the sphere at will and complete the turning. I still have to turn the cups.
Paul