[60rock]

Hello,

Let me clarify, this is a "through" pocket. Perhaps it would be better called an extrusion.

I want to get input regarding deep pocket milling. For instance, let's say I have a 3 inch 1018 plate, that needs a 12" by 12" pocket milled out of the middle.

Now, instead of cutting the entire pocket, is there a proficient way to only cut around the edges of pocket and have the remnant drop through?

Waterjet or laser is not an option-"they" want it done "in-house."

Thanks!

[mariojl]

Sure there is a way: and IMO is by plunge cutting. Of course you'll have to be carefull or you'll brake the tool. Let's say you're using a .75" end mill, ( means 4 diameters of cutting length); cut almost all around, leaving some ribs in all 4 corners of about 0.5 x 0.5 " uncut. Then clamp the central part securing it to the table, ( it must have spaces underneath) so it wont fall, and finally cut the 4 ribs. Otherwise this heavy block, weighting aprox. 35 lbs. will move and pinch your tool and for sure it'll be broken. Hope this is clear enough and help you.
Mario

[txcncman]

My way has been usually to drill some through holes in the middle and bolt to a fixture plate so nothing falls. Another way might be to relieve enough material around the perimeter, up to two times the cutter diameter, but leave tabs for the final cut through.

[BAMCNC.COM]

Drill the center holes, mount the "scrap" to a fixture or table. Then profile the scrap with "conventional" milling. Then profile the finished part with "Climb" milling.

If you can do tabs, then do that with a ~1/4" endmill, ~.020" thick tabs, then cut through the tabs with a 1/16" endmill, it won't even bother the scrap piece so you never have to mount it.

Really depends on ur cad/cam which is easiest to do.

[60rock]

Thank you!