Self-Reproduction of a Universal Machine Tool

I am impressed by the range of DG's skills and don't think it's an unreasonable shift. I'd pick it up again but with EPA regulations chemistry isn't a home project any more.

Have you considered pancake motors milled from circuit board material for actuators? Maybe with those and interferometric or other remote position sensors a mother machine with intelligence could make and control daughter copies of its mechanical design. Perhaps it could carve the parts from bar and rod stock with a die grinder.

Reply to
Jim Wilkins
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Yes, I asked the site's adminitrator, Tony Griffiths, to separate out the universal machines with a header "Combination Machines", at

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and the Hommel is listed there, abou t75% into the page as you scroll down. It is a candidate for self- reproduction, and so are all the other universal machines listed there. I gaze at those photos for hours thinking of configuring the subject machine to make a part of itself. Ideally, I'd have a zillion dollars and one of each of those universal machines to evaluate. Practically, I have the Super Shop only, and Autocad Inventor LT 2009, the demo edition. Big gap. :)

Doug

Reply to
DGoncz.703.475.7456

You know, I have a lot of experience with Kollmorgen pancake motors. I've disassembled and modified them for the MOEPED. And I knew you could mill PC traces from stock, but I'd rejected computer control because there's such a large gap between the scale on which reproduction is done: great heavy lumps of cast iron, versus lithographed integrated circuits. My vision is for machine tools operated manually to reproduce after the fashion of those outlawed in Samuel Butler's 1879 novel "Erewhon". So we're talking about auxilioprodutive, subtractive, universal, self-reproducing machine tool, making "one-off" copies of themselves.

A single pancake rotor made subtractively is a fine achievement and adds depth to the universality of such a machine, but...well...how do you wind a one-off armature? By hand, of course. That is included in the scope of the term auxilioproductive. But then where do the armature pieces come from? Ay, there's the rub!

Efficient motors usually use stamped and varnished armature pieces stacked and then wound. Such pieces must be stamped to minimize the hysteresis induced by machining. So we'd need to mill a copper board to be a rotor, but then mill out hundreds of armature bits and live with a little less efficiency. Chemical milling of such pieces is strain-free, but the resultant torrent of chemical waste is entirely antithetical to the zero-impact soul of the effort. I don't see a compromise; do any of you here see one?

Doug

Reply to
DGoncz.703.475.7456

...

EDM?

Reply to
Winston

I thought of another one.

The mechanical part is two or more robot arms with the elbow upward like a backhoe. The wrist is a hollow rotating flange you attach tools or grabbers to.

Arms like this can be made from aluminum bar stock with brass tubing bearings.

There is one or more upright posts or blocks on the base that serves as the zero reference and a work support, so to cut off a bar one arm holds the bar against the posts while the other one saws it, pulling straight inward so flex doesn't change the cut line. This way it can saw out all its links, tubing and shafts.

It drills pivot holes with a Dremel and carbide ball cutter. First it roughs out the center of the hole, ignoring its positional errors, then it spirals out, taking lighter cuts to reduce deflection. Finally it asks you to ream the hole and insert a brass bushing that it cut from tubing.

Pivot shafts are held by snap rings. It saws their grooves by holding the shaft against the rest and rotating the wrist.

The actuators are water hydraulics. The cylinders are sawed fron tubing, the pistons and ends are carved from thin brass sheet, stacked and soldered. This gives the O ring grooves smooth sides. You also solder the closed end on to avoid threads. The mother contains the water pump and controls until you figure out how it can make its own power source..

The wrist could be driven by purchased bevel gears on shafts it cuts to length. It might be able to make a worm and a worm wheel with square threads.

Initially the position feedback could be fishline winding off spools with encoders. A later version could use sonar or optics controlled by the mother machine with only a reflector etc on the daughters.

Using rod and soldered brass tubing reduces the turning to a minimum. As far as possible the machining is only sawing stock to length and drilling relatively rough holes. The mother machine learns to compensate for play in the joints somewhat but the big help is resting the work against a stop and using partially self-guiding cutters such as saw blades.

You buy all the small hardware and standard metal shapes, and you assemble the parts after it makes them. Assume that wire and all electronics are too complicated to make and buy them.

Reply to
Jim Wilkins

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