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X" sq stock will yield Y dia. Sphere chart - Printable Version

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X" sq stock will yield Y dia. Sphere chart - whatline - 11-12-2017

Can anyone point me toward a chart that shows say 2.5" x 2.5" sq. stock should give me a ????? Sphere. I'm turning globe/ finial ornaments and I'm pretty sure the globe I ended up with... About 1.25" dia could have been larger if my technique was better. Thanks


RE: X" sq stock will yield Y dia. Sphere chart - Arlin Eastman - 11-12-2017

(11-12-2017, 06:51 PM)whatline Wrote: Can anyone point me toward a chart that shows say 2.5" x 2.5" sq. stock should give me a ????? Sphere. I'm turning globe/ finial ornaments and I'm pretty sure the globe I ended up with... About 1.25" dia could have been larger if my technique was better. Thanks

2.5x2.5 should give you a 2.5x2.5 globe but it depends on if it really is square and if you put it between centers right.  I usually come up with 1/8" less.

I do not know how everyone else does it but I will put in a 2x2x3.5 and knock off the edges to make it round.  I then take the measurement of the width with either a dial caliper or outside caliper and then hold it up to the piece I am turning.  I take my dial caliper and take it from the end of piece and mark the other end of the caliper and then you have both of your dimensions.

I then part about 1/3 way thru the outside of the inside mark and then make two more pencil marks.

I go off of the end 1/2" and 1/2" on the top of both sides and round them off there and then finish off the piece.

Hope this makes sense.


RE: X" sq stock will yield Y dia. Sphere chart - whatline - 11-12-2017

Thanks Arlin. I've used that same principle. Mine end up more egg shaped than I'd like? I'm going to split the widths more times and see how that works


RE: X" sq stock will yield Y dia. Sphere chart - Arlin Eastman - 11-13-2017

(11-12-2017, 09:44 PM)whatline Wrote: Thanks Arlin. I've used that same principle. Mine end up more egg shaped than I'd like? I'm going to split the widths more times and see how that works

Twice or even three times would do it.  One at 1/2" another at 1" and the last at 1.5.  Also do not fret if it looks egg shaped since you can out the tapered part at the top with the hook and the bottom with the finial.  Perfect in now always great or an attention grabber.


RE: X" sq stock will yield Y dia. Sphere chart - iclark - 11-14-2017

(11-12-2017, 09:44 PM)whatline Wrote: Thanks Arlin. I've used that same principle. Mine end up more egg shaped than I'd like? I'm going to split the widths more times and see how that works

In case you make the same kind of mistakes as I do, remember to cut the mark on the small side of the line.

I am not saying that well.

If you mark a blank for a 4" sphere with 0 towards the headstock, Then the 1/2", 1", and 1-1/2" sizings are on the headstock side of the lines. The 2" sizing is centered on the line. The 2-1/2", 3", and 3-1/2" sizings are on the tailstock side of the lines.

I hope that that makes sense.


RE: X" sq stock will yield Y dia. Sphere chart - MichaelMouse - 11-14-2017

(11-12-2017, 09:19 PM)Arlin Eastman Wrote: 2.5x2.5 should give you a 2.5x2.5 globe but it depends on if it really is square and if you put it between centers right.  I usually come up with 1/8" less.

Well, a sphere needs 9only one dimension to describe it.  I get the same as you, 1/8 less than full.  I use a beading tool (straight chisel) or Bedan to round over, cutting first left then right.  

The term sphere reminds me of my dad's old expressive saying.  He referred to someone as "spherically stupid".  Same no matter how you looked at him.


RE: X" sq stock will yield Y dia. Sphere chart - Woodshop - 11-15-2017

(11-12-2017, 06:51 PM)whatline Wrote: Can anyone point me toward a chart that shows say 2.5" x 2.5" sq. stock should give me a ????? Sphere. I'm turning globe/ finial ornaments and I'm pretty sure the globe I ended up with... About 1.25" dia could have been larger if my technique was better. Thanks

sounds like you need a gauge. you can make a simple one by drilling a hole the size sphere you want in a board,  saw it leaving 1/2 the shape. a piece of steel works better. but harder to come by in a woodshop. or even a steal pipe cut off square.