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Doug Goncz
 
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Default Basics on Depth of Cuts

From: ( Doug Goncz ) (Me)



You can adjust DOC, RPM, and IPM


Ok, let me lay this out:

RPM: Revs Per Minute, spindle speed, limit by machine design
HP: HorsePower, the amount needed to remove CIM, limit the HP rating of your
machine
FPM: Feet Per Minute, cutting speed, limit for your material, above which chips
weld, tools burn, and other bad things happen
IPM: Inches Per MInute, feed speed, limit the feed motor, or how fast you can
spin the handle
DOC: Depth Of Cut, in inches, which can be just one dimensional, or two. If two
dimensional, it has units of square inches
Lathe or mill.
CD: Cutter diameter, on a mill or drill press. On a lathe, the average diameter
of the material being removed, like turning bar stock to 3.999 inches with
0.010 DOC, would be damn near 4 inches. (4.0055)
M: Machinability rating. HP/CIM, which is the factor you multiply your proposed
CIM by to convert it to the HP required to make that cut.

For milling mild steel, about 1. For reaming steel, maybe 1.5. For grinding
steel, maybe 2 or even 3 or 4. For milling aluminum, I am actually not sure.
Would it be or 1? For milling magnesium, 1.

Machinability rating is work of fracture times area fractured per second. Small
chips have more surface area. Work of fracture is roughly Young's modulus times
% elongation required to fracture. Tested on Instron tensile tester at NVCC,
mild steel, and aluminum.


So:
FPM * 4 / CD = RPM;

DOC * IPM * M HP limit and
FPM * 4 / CD RPM limit and
FPM FPM limit and
RPM RPM limit and maybe

HP * IPM force limit on tooling

Yes, I am using some symbols twice. But hey, we use FPM and IPM so we can refer
to cutting speed and feed speed by just saying their unit names, which helps
keep everything correct. They are the same type of "thing". They are both
speeds: they are distance / time.


I had a great idea for a simulator: show the three DOC, RPM, and IPM selections
on a 3D surface, which may be colored or warped. Then play a synthesized sound
file telling the user what it'll sound like to make a certain cut that way. Or,
play this:

"Crack! Beep, beep, beep..." (broken tool) or

"Hmmmmm.... pop! Whoosh! Cough, cough, cough...." (stalled motor on fire) or

"I can't believe you ran the cutter into the TABLE! YOU'RE FIRED! .... I'd
like to apply for unemployment ...... Not eligible!?.....Yo, buddy, spare
change?"



Yours,

Doug Goncz
Replikon Research (via aol.com)

Nuclear weapons are just Pu's way of ensuring that plenty of Pu will be
available for The Next Big Experiment, outlined in a post to
sci.physics.research at Google Groups under "supercritical"