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

Pictures are here (very high resolution, enlarge them to see the detail). My Troyke rotary table was NOT used -- only X-Y dials.
http://igor.chudov.com/projects/My-Bridgeport-Mill/Z-00-Egyptian-Style-CNC/
Here are pictures of a full circle milled with a manual mill, using my laptop Perl script that tells me how to move dials and when to adjust for backlash when reversing feed direction. I call it "Egyptian Pyramid CNC".
The name is a tribute to ancient Egyptians, who built enormous, sophisticated and lasting structures using only primitive tools and manual labor. Here, I made a circle using only dials and manual operation only, taking directions from my laptop.
The laptop is Linux only, no viruses here.
i
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Well, then, you shoulda run the spindle offa a foot treadle. :)
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On Tue, 12 Jun 2007 01:08:28 -0400, Proctologically Violatedฉฎ

Maybe I need to get some slaves...
i
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They're always on back order these days.
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John Husvar wrote:

No, the problem is that it takes some 9 months + a decade of training to get them to be useful and after all that you only get perhaps 5 years of useful work out of them. Cheaper to just hire illegal day laborers...
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That's slick.
-Carl
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Thanks... Besides, this method lets me make any curve, not just a circle, a circle is just the simplest illustration.
i
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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.
http://www.homegunsmith.com/cgi-bin/ib3/ikonboard.cgi?s ช76d269bd36ab615170a5c513767ddb;act=ST;f=8;t588
David Merrill
wrote:

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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

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An excellent link David.
Wes
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http://www.homegunsmith.com/cgi-bin/ib3/ikonboard.cgi?s ช76d269bd36ab615170a5c513767ddb;act=ST;f=8;t588
That was a very interesting discussion actually, thanks.
i

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[snip]
I was going to say with dro backlash comp isn't needed but I just remembered you don't have a dro yet.
Backlash on a bp screw tends to be highest in the center of each table's range. My X screw is pretty nice but my Y screw is pretty nackered from a oiling issue that previous owner didn't notice or correct. Not a real big issue since I have a dro and don't count turns.
Wes
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That's right, I do not have a DRO yet. Also, since I am reading numbers off a laptop, backlash comp is handy as it obviates the need to start with a new set of numbers once the direction is reversed.

I have 0.05" backlash on the X screw. It can be adjusted, but the manual says that it is a "normal" value.
i
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For a fun thing to do after you get your dro, zero readout with handle at 0, crank handles .200" and look at dro. If the dro steps .200 in lockstep you got a good screw.
Two things matter with screws, backlash and pitch accuracy. Also bearing end play. Make that three. No make that two, end play shows up in backlash.
Wes
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I do not need a DRO for it, I can do it now with a dial indicator.
i
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Ignoramus3045 wrote:

Very good. But just how long did it take to do that one circle. :-) ...lew...
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Approximately 20 minutes. If I could get a helper to read the numbers aloud, it would probably go down to 10 minutes. I may change the script to read the numbers to me using GNU Festival. It is not really difficult, I use it for my talking artificial intelligence robot Splotchy:
http://www.algebra.com/cgi-bin/chat.mpl
I am not sure yet where to take this script exactly. But I may add some sort of a "read aloud" function. It would need some obvious capability such as rewind and replay etc, it is not simple.
i
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Ignoramus27221 wrote:

And 180 passes as you told somewhere else. 6.6 seconds per pass. Tell that shit someone else!
Nick
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Now you need to write a script that will read CAD/CAM generated G code and give you handwheel movements out! :-)

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I think that it is, seriously, a great idea. It is the sort of a thing that I want to try out before considering any "CNC conversions".
My own feeling is that for most of my personal needs, I will not need this "milling to a script" type of approach very often, and a rotary table along with various positioning tools ought to serve me fine. But for those less frequent instances, when something complicated needs to be done, "milling by script" might work. Plus, it is fun, as it lets me do what I like, which is computer programming.
i
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