ATTN: JOHN HAGGERTY

[myxpykalix]

Hi John...I saw some pics on the camp shopbot links that bill just posted with the caption
"bowl-turning-hub-2" and there were some bowls there.
Are you somehow turning bowls on your shopbot? Thats what i don't like about flikr is some of these photos need descriptions to explain what we are seeing.
Can you get me some more detail about what your set up is there? More pictures?
I had to give up traditional turning because of the arthritis in my neck and shoulders and would be interested in this process.
thanks

[oddcoach]

Hi Jack
I needed a simple way to keep center registration when i flipped the bowl. I just used what was already invented to do that. My lathe chuck, it came with 3 thread bushings for different thread sizes. one of them was blank on the inside. I used that one and made a fixture to bolt it to the ShopBot table. i recessed that into the table for 2 reasons to give me some more z height and i can leave it setup and still be able to cut full sheets of plywood
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I can take the chuck off when not in use

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I used the ShopBot to make a bunch of dovetailed faceplates that i screwed to the blanks

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I use he faceplate to cut the bottom side then put a dovetailed recess in the bottom of the bowl

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then I can turn it over and cut the inside without loosing center.
then I put it on the manual lathe for some touchups and sanding
this setup will allow me to make a bowl 48" n diameter

[cabnet636]

now that is a great idea!

jim

[wberminio]

John
I haven't used my lathe in years.I've turn many bowls in the past.

I really like your method!
Can you tell us what software you are using?

Great work!

Erminio

[myxpykalix]

So the faceplate holds the lathe chuck and you tighten it so that the blank doesn't spin correct? So the next logical question is how do you make your toolpath to create the bowl?

[myxpykalix]

oh i forgot to ask...how do you make the toolpath for the inside of the bowl also?

Also as long as we are kind of on the subject...
would there be any advantage to turning the indexer face up to hold the bowl blank while it turned?
My thinking was this might be another use for independant axis control but then again while i write this and think about it, this can be achieved with the indexer in its current configuration.....
However you couldn't make the diameter of bowl like John is making in that config.

But then again...(is this guy rambling or what?)
I wonder about what has to be basically a circular stepdown toolpath to create his bowls..?

[oddcoach]

Hi Guys
I use PYTHA to create the models and desk proto for the toolpaths. it lets you use a spiral configuration. you could use millwizard or partworks 3d you are going to clean it up on the lathe anyway. hope this helps
John

[myxpykalix]

John..i'm still a bit confused, not knowing that program.
How do you create the profile and the part? Do you take a vector profile and extrude it 360 to make a round bowl object, then toolpath that object?
If so what type of toolpath is created? What i mean, is the carriage circling the bowl blank and progressively cutting deeper as it goes?

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[oddcoach]

Hi Jack
you need a 3d cad program to generate the model. you draw a curve the the one you showed. the use a revolve function then you have your model. you are correct the router goes around in circles. now that i think about it you could use Bill Young's extruder program to create you toolpaths then you just need a flat dxf