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joe greiner
7th Jan 2011, 11:00 PM
My interpretation in Cherry of a popular toy, finished with EEE Ultrashine and paste wax, buffed on the lathe.

The jacks are about 6 1/2" x 6 1/2" x 6 1/2" (165mm x 165mm x 165mm) with partially-hollow stems. The stems are secured on the legs of 3-piece burrs of interlocked dowels, also of cherry.

The ball is about 6 1/4" (160mm), hollow, of 252 segments (253 if the central pole is included, or 254 if its ends are counted separately.

The entire set came from a log about 9.5" diameter x about 12" long, cut into squares (to assist alignment of the leg miters), and the remnants were further cut to make the dowels and the segments.

C&C welcome.

Cheers,
Joe

Ad de Crom
8th Jan 2011, 07:34 AM
Joe, an incredible creation, I admire your skills and patience, especially for the segmented ball.
Wonderful !!!
A really good start for the new year.
Ad :2tsup:

artme
8th Jan 2011, 07:37 AM
Wonderful work Joe!! Our friend from the Netherlands has said it all!!

jimbur
8th Jan 2011, 08:58 AM
I know it's greedy Joe, but have you any pictures of the gluing up?
Beautiful work.
Cheers,
Jim

Ed Reiss
8th Jan 2011, 01:03 PM
Verrrrry interesting Joe...you get an A++ :2tsup:

Gil Jones
8th Jan 2011, 05:10 PM
Hey Joe,
Very good segmenting and turning too. I have seen the "jacks" a month or so ago and the "sphere" at our Jan 04 club meeting, so i can say the whole lot is amazing :2tsup::2tsup:
Bravo, well done.
Gil

joe greiner
8th Jan 2011, 11:09 PM
I know it's greedy Joe, but have you any pictures of the gluing up?
Beautiful work.
Cheers,
Jim
Not greedy at all, Jim.

I have about 100 pictures of the whole process, all hi-res. I'll select a few for reduction and remarks, and post later.

Thank you all for your assessments.

Cheers,
Joe

Sawdust Maker
9th Jan 2011, 10:39 AM
Nice work
I'd be interested in the glue up and a little WIP as well. thanks (yeah I know I'm asking a lot) :U

joe greiner
10th Jan 2011, 11:31 PM
Construction of the jacks is probably more meaningful than the segmented ball. And I took some liberties in the ball construction which need further experiments and corrections before I'm ready to claim improvements.

The jacks almost invite multi-axis turning. But there would always be some weak grain directions, and a horrendous amount of waste chips. In my construction, all the legs are long grain, and the 3-piece burr provides adequate strength across the intersection.

In hindsight, it would have been better to turn a half-sphere at the leg intersections for more perfect miters, using the sphere center as a work point, instead of the tangent point between the fillet and the sphere. [01088 & 02090]. (The spherical center is tenuously defined by small triangles just beyond the fillet, as shown in mockups [03232] I turned before proceeding with final design. Using the tangent is like shooting with a Derringer in contrast to a rifle.) I sorted the pre-forms by width at the central end in hope of mating each group. [04094]. The red letters indicate proposed ball-end legs; the blue letters indicate pointed ends because of cracks or other deficiencies.

The square blanks facilitated cutting the miters [05096 & 06097]. I used hot-melt glue to secure the drilled blanks to a dowel for turning [07105]. I turned, sanded, polished and waxed all the ball-end legs first, so that in case of error I could use one for a point-end leg vs. the other way around. Two such errors occurred. I made a tiny parting tool from a broken street-sweeper bristle and a small vice-grip pliers [08110], which was an interesting development in itself. Then I made all the point-end legs similarly. I used cardboard templates for both shapes.

I glued the 3-piece burrs with CA and sawdust [09117 & 10118]. I ground away the excess for clearance at the joint. I had a few minor misadventures in gluing the legs; the miters tend to fight one another when pressed together. The most effective way was to glue each joint all at once, with rubber bands as "clamps." For the point-end "clamp jaws," I cut castellations in salvaged toothpaste-tube caps [11124]. I used 30-minute epoxy here. The masking tape protected most of the leg from any glue drips. The numerals on each leg match the best-fit dry assembly. The wax finish facilitated chipping away excess glue after it hardened.

Cheers,
Joe

jimbur
11th Jan 2011, 10:55 AM
Thanks Joe. Absolutely fascinating. What do the following have in common - elastic bands, toothpaste tube tops and street sweeper bristles?
thanks again,
Cheers,
Jim