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humble artizan
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Discussion Starter · #1 ·
I'm wondering what the max size is for practical use on a Jet 1640 lathe. I would like 5 or 6 inches but I'm having trouble finding them in that size.. the object is cookie/candy jars with the bark left on..
 

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That might be a but big. I haven't seem them that big but if you found them, I would think you would have to start much smaller and move up in size.

I would for see a problem with the drill chuck in the tail stock spinning. With that much force and torque coming from the headstock and piece of wood, it would spin the bit with the wood. You would really need to lock it in there and go really slow.

You could get a smaller, say 3" bit and cut the rest out with a chisel.

Do you want to cut out the end grain or make a natural edge bowl? What kind of wood?
 

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I don't know how big you can find but I am sure that they would be very expensive. Why not just use s bowl gouge?

Jack
 

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humble artizan
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Discussion Starter · #5 ·
I don't know how big you can find but I am sure that they would be very expensive. Why not just use s bowl gouge?

Jack
Time factor.. I have some very nice bowl gouges but would like to bore the jars out as large as possible, first.. the largest I see in a quality Forstner is about 3.5 inches

Darkmoor is a business and this will be production work
 

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Time factor.. I have some very nice bowl gouges but would like to bore the jars out as large as possible, first.. the largest I see in a quality Forstner is about 3.5 inches

Darkmoor is a business and this will be production work
Have you considered metal-work style boring bars or fly cutters?

They'd require a starter hole and multiple passes, but would probably be faster than using a hand-held gouge.

Or maybe one of the many articulated-arm hollowing systems?
 

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You're going to spend almost as much time backing out that bit, clearing the waste, and letting the bit cool; not to mention that you'll probably have to do this at a much slower speed than you would if you just turned it.
 

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humble artizan
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Discussion Starter · #9 ·
Good info, thanks guys.. maybe a combo of Forstners followed by a bowl gouge.. bigjoe, the plan is to use 8 to 10 inch diameter sections of tree trunks with the bark left on, and end bored, for 'bark on" cookie jars, for retail sale. Have much redwood, honey locust, birch, alder curing

Also larger "bark on" redwood planters after we get the smaller process worked out
 

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The gouge is really fast if you cut across the grain. Drill a hole 2" or so to get rid of as much of the end grain as you can down to about the depth you need to do. Then cut from the center out with a bowl gouge. I prefer to go a little deep and then cut out at an angle so I'm cutting across the grain at an angle.
The flute should be about 45 degrees or about 10:30. Make a bunch of cuts leaving the edge just a little thicker than you need. Go down about 1 1/2" or so and then cut straight down from the lip and thin this area to the final dimension. Don't go back, this area is done. Cut another inch or so and then cut down trying to blend the previous stop line. Shear scraping works well for this if your gouge technique isn't that good.
When you have about 3" left you an just go ahead and hollow it all the way and then do the last finishing cuts.
Guys who thin really large and thin pieces like lamp shades often use a really thick straight coring cutter to core out a cone shape. This makes it go faster but probably isn't necessary for what your doing.
 

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Alan Sweet
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Quest ..

I think that we are talking a maximum thickness of 5-6". Is that right?

If so maybe just use a Forster Bit say up to 2".

The use carbide square insert tools to widen hole say 1/4-3/8" at a time. Come straight in from the end grain. Should not take too long.

You really have to be tight at the chuck. Seems that the size of the hole would be limited by strength of the wood, how thin, does it have checks, how dry?

I have made hollow columns that 4" long and 5" diameter in such manner.

Alan
 

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humble artizan
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Discussion Starter · #14 ·
I think that we are talking a maximum thickness of 5-6". Is that right?

If so maybe just use a Forster Bit say up to 2".

The use carbide square insert tools to widen hole say 1/4-3/8" at a time. Come straight in from the end grain. Should not take too long.

You really have to be tight at the chuck. Seems that the size of the hole would be limited by strength of the wood, how thin, does it have checks, how dry?

I have made hollow columns that 4" long and 5" diameter in such manner.

Alan

You got it, just trying to speed up the process a bit.. makes sense to me, thanks

Will be relatively thick walls, solid dry woods, birch, sequoia, alder, maple, etc
 

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