PICTURES -- Full circle milled MANUALLY with "Egyptian Pyramid CNC"

ditto, it's making my head hurt...

Change the name of this idea to "Jeopardy CNC" - it's an answer looking for a question.

Ned Simmons

Hey Ig,

Iffin you ever get a real cnc, what're you gonna w/ all that free time you will gain from built-in circular interpolation??? Not to mention the loss of exercise from not cranking all them handles anymore.

Btw, as long as non-circular curves are analytic (ie, have underlying algebra ), macros are very efficient ways to generate those curves. In any increment/resolution you desire, up to machine resolution.

lets see 20,000 dollars for a cnc or 2000 for a good used bridgeport mill to do the same job, hmm what to do ,what to do

See how much work a Bridgeport can do for you while you are doing something else! It's an apples to apples kinda thing.

Cheers Trevor Jones

=========== Very interesting. Shows what can be done with some innovation and imagination.

Unka' George [George McDuffee] ============ Merchants have no country. The mere spot they stand on does not constitute so strong an attachment as that from which they draw their gains.

Thomas Jefferson (1743-1826), U.S. president. Letter, 17 March 1814.

I never really did consider "the pile" to be a sophisticated construction method.

Eddie in Detroit

Method could be applied to simple, one-off cam paths. Here's an illustrated discussion on manually milling a bolt locking cam in a rifle receiver.

David Merrill

Correction: make that a discussion of a 'cocking cam' (cams back the firing pin when bolt is opened). Could also be applied to bolt locking/extraction cam.

David Merrill

That was a very interesting discussion actually, thanks.

i

An excellent link David.

Wes

kinda like starting a fire by rubbing two sticks togher, interesting to watch, but I'd rather do it another way.

:^)

How long did it take? i hope less than building a pyramid! (o: JS

It took about 20 minutes. Felt like a long time.

i

I remember doing this back in the 80's with my TANDY PC-5 that I programmed in BASIC. CNC wasn't that readily available for one-sies and two-sies and I'd finish plunge milling the circle or contour/profile before the programmers could punch a tape. I got a pretty good raise for it too. Nowdays, modern DRO's will calculate this stuff for you by inputting a few parameters. Nice thing about the DRO's, they calc each plunge and all you have to do is crank to X0 Y0 and plunge, hit a key and crank to X0 Y0 and plunge, keep repeating. Easier than cranking to Xn.nnnn and Yn.nnnn Of course these DRO's are way more expensive than a laptop or pocket PC,....... even a PDA would work. Good job, Ignoramus3045. Kudos for thinking outside the box. Keep it up and I'm sure you'll be posting here with more innovative stuff in the future!

Bart

Ig:

That's pretty cool. Back in the 70's I had a book that had columns of numbers indicating the movements in X and Y to do circles or corner radii. You just multiplied the standard radius (1" I believe), to achieve the radius you wanted. Since I work with a CAM system & CNC's now, I don't really have much of a use for this sort of thing, but as a mental exercise I tried to see if I could reproduce something similar in a spreadsheet. I have zero knowledge of Pearl and know next to nothing about spreadsheets, but I dug up an old Excel 2000 program I had and gave it a try. The following is the bare bones result.

================================================ Radius 2"

ANGLE X Y

0 2.000 0.000 10 1.970 0.347 20 1.879 0.684 30 1.732 1.000 40 1.532 1.286 50 1.286 1.532 60 1.000 1.732 70 0.684 1.879 80 0.347 1.970 90 0.000 2.000 ===================================================

When the radius or degrees change the X,Y columns recalculate. I used

10 degree increments and one quadrant as simply a proof of the process. A real program would have nice labels, changeable degree increments, full circle capability, and other details that I didn't bother with. I would assume ellipses, parabolas, hyperbolas, and other formula derived curves could be done as well.

>

Yes, I think that this is "it". The only two other things that I did, was converting it to dial positions and outputting warnings when one of the axes was changing directions (to account for backlash).

i