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Old 05-02-2018, 08:33 PM
jbiddle jbiddle is offline
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Location: Canton, MI
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Default milling a slab and using butterflies

So, one of my takeaways from the Aspire camp was from one of Gary's presentations; the forces on a bit are mostly side-loaded (sorry Gary, I probably hacked that up). I'm making a table and I want to mill this piece of 3' x 4' waterfall bubinga up on both faces and add butterflies to control the checks. My old thinking would be to hold this part by the live edge side and cut from open grain to open grain.

Am I right in now wanting to hold the piece along the end grain and cutting from live edge to live edge?

Is my 2-1/2" spoilboard bit the right choice (board is fairly flat but slightly cupped) or should I use a 1/2" end mill?

Should I add butterflies to both faces to control movement?

How thick should I make the butterflies?

Where in the process are the butterflies added?

Thanks in advance, Jim
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Old 05-02-2018, 11:18 PM
Erik Land Erik Land is offline
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Wow Jim, what a great piece of Bubinga,

I think your going to have to hold down the side of your board you have pictured from the cut ends. The live edges are undercut and if you try and clamp them you wont be able to surfac all the way to the edge.

Id think tour 3kw spindle would spin the 2 1/2 cutter fine. Cutting with the grain will be much easier to have any cutter marks hide.

Once you surface a side cut your dovetails in. You might want several files at different angles to work with your cracks. Make the pockets origin in the center of the dovetail so you cnc move your cutter to where you want the dovetail and zero the X & Y there. Makes placing the pocket easy. I usually cut my pockets 3/8 deep but that depends on the thickness of the board Im working with. DONT forget to when flip your board over to mill the second side. And yes, I would dovetail both sides.

Erik Land
Dorena Oregon

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Old 05-02-2018, 11:40 PM
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Gary Campbell Gary Campbell is offline
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Make 2 surfacing rectangles, each a little over half the width, with a bit width overlap in the center. Start from the outside (live edge) cutting climb direction, with the grain, and work to the center. Repeat, live edge to center, climb mill, on the other half.
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