What to do with lots of little motors?

[Evodyne]

Guys,

I frequent surplus places, always in search of "The Next Great Deal". I'm at one yesterday and there is a tote with at least 100+ little servo motors. These are small-maybe NEMA 17, DC brushed (four brushes/motor), with encoders. Motor shafts appear to be a bit more than 1/8" diameter. They are, I believe, Japanese, and are tagged "Minertia". No specs or part numbers at this time.

If I buy these (probably won't do better than $300/lot) I need a plan to recoup my investment. I doubt they have any reasonable CNC application, due to their small size. But I could be wrong-the owner says they are powerful for their size. And I have no use for them myself, really. But that little inner voice is saying "buy them". Every time I DON'T listen to that voice I regret it later.

I'm looking for ideas from you guys for unique things to do with these. Little hobby ideas? Buy 'em for the encoders? Motors for indexers/smaller tooling? Micro CNC? Robots? HELP!!!!

Lance

[spalm]

I don’t know about listening to that little voice. It used to get me into trouble when the bars closed.

[Boilermakr]

Hmm...

What about engraving keychains and dog tags like the machines at the front of the pet store supercenters?

The tool indexing would be really cool too. Could they be used to make part grippers for automatic part removal?

[Verfur]

how about a gaint plotter ?

[turmite]

How about a small footprint 5 axis articulated head router? I know you're thinking bout it!

Mike

[Evodyne]

Spalm, that's the OTHER voice: I NEVER listen to him-been burned too many times!

Boliermakr, I'm sure thse would be perfect for parts grippers-they are small, so could easily be embedded. Indexers too if one used enough gear reduction. For something not needing much power, like the X-Y for a small engraver, these ought to be perfect. Something that a guy could build with round rail and slides where defelection wouldn't be a problem because the loads are light.

Verfur, damn typos! Would that be a giant plotter, or a paint plotter? If anything, maybe small plotters...

Mike, "How about a small footprint 5 axis articulated head router? I know you're thinking bout it!" He he he-I'm doing MORE than thinking. Selling off some spare parts now and going to buy some harmonic drives! Given the absolutely amazing tourque multiplication, ANY small motor could drive these.

Thanks for the ideas so far guys-keep them coming!

Guys in general-I guess to flesh out my first post: the question is do I buy these or not? I don't want to build a million small doohickies myself. But the right idea-say a small engraver, etc, might generate some interest in these. I'd only need to sell these for $5-$6 each to recoup my investment and make a buck or two. Sitting on them does me no good, and unless I have some belief that I can sell them, I'll probably have to pass

[lucas]

Lance,

get the partnumber, I have a bigger Minertia myself and found the specs.

You could check their price on Ebay and sell them there, Ebay has several for the moment. You probably considered this?

They could be used for what you call micro cnc, one application where torque is not really the major factor is PCB drilling.
Disadvantage of servo's is the complicated driver, I am looking into it and it doesn't look like something easy for the DIY-er.

Luc.

[Boilermakr]

For $5-$6 ea., I'd be interested in 5 or 6 of them, perhaps more.

I'm thinking robotic, cnc airbrush! It would have to be a custom machine, but it wouldn't need a lot of torque or speed. R/C car bodies, boat hulls, and heli canopies would be prime candidates as well as computer cases.

Etching glass ojects also comes to mind. Sure, it can done with stencils and a steady hand, but I would prefer more complicated designs and greater control!

[Evodyne]

lucas,

I’ve got two that I believe are the same as those in the big batch. If they are not then those in the batch are a bit bigger. The ones I have are indeed Minertia types, mini series. They were made by Yaskawa Electric Corporation. The balance of the nameplate is this:

TO1L-ST33
P/N 410611703-C-EC29145
VC/N281328
93 02

Found the following specs (and I looked before but DIDN’T, doh!) for the T01L Mini Series:

Stall Torque: 33.3 oz-in
Rated Torque: 13.9 oz-in
Torque Constant: 8.1 oz-in/Amp
Winding resistance: 3.67 Ohm
Armature Inductance: 0.8 mH
Peak Current: 4.5 Amp
Voltage Constant: 6.0 Volt/1000rpm
Visc. Damping Coef: 0.71 oz-in/1000rpm
Friction Torque: 1.61 oz-in
Breakaway Torque: 1.71 oz-in
Mech. Time Constant: 2.8 ms
Elec. Time Constant: 0.2 ms
Power Rate: 3.6 kW/sec
Thermal Resistance 4.60 deg C/Watt
Therm. Time const: 10 minutes
Max. Armature Temp: 155 deg C
Rated Speed: 2000 rpm
Max. Safe Speed: 4500 rpm
Max No Load Speed: 6000 rpm
Cooling Required: none

Don’t know about the encoder resolutions yet-I need to “play” with them. I do know the ones on the motors I have are single ended A & B (as opposed to differential with NOT-A & NOT-B as well).

Yeah, ebay would be an option, but I get tired of eBay in the sense that you could be offering a $10,000 part for $100 and people still only want to pay $25. It's frustrating. I've done much better selling CNC related stuff here. Of course I price things reasonably (I think) and have cut people deals depending on their situation. But for these, at a low price per unit or at a skid/bath price, maybe. Gotta see how little I can get them for too-my $300 price was a guess based on past dealing with my buddy.

Lance

[Evodyne]

Boilermakr,

Interesting! How big of a work envelope (travel) would you need? I've got a wide assortment of ground rod/slides that are too light for a mill or router. I just picked them up at lunchtime with thoughts of listing them at the 'zone this evening!

Lance

[Boilermakr]

Most of the r/c bodies for the 4x4 rucks I run are about 16" long, everything else is shorter. I think some of the heli canopies are in that size range too. The boat hulls would be the trickiest. I have a 1/4 scale tunnel hull that is waiting for paint and it's 48" long and 22" wide. That is a large r/c boat though. The next longest hulls would be 1meter long r/c sailboat hulls, but I can flip them and work from a constant zero point on the table since the arm will be moving, not the table. Final details on a large hull would be "connected" by a handheld airbrush, then sprayed with clearcoat via HVLP or the robotic airbrush.

The tricky part would be automating the valve on a double-acting airbrush, but I have a couple of ideas in my head with a linked-cam arrangement that would need two linear actuators. I think it would be 5-axis plus the two linear actuators to control spray volume and pattern width. I could go to 6-axis and use another indexing table to rotate the work 180deg for the longer pieces, but then my guarding and the over all size and footprint of the machine almost doubles. It would be cool though.

I invision the work piece sitting on a large downdraft spraybooth table to pull the overspray and fumes down and out from the work unit. I have a large shaded-pole blower already that I'm going to use in a down-draft spray spooth for painting with latex-based paints. The booth will be 42" or 54" wide to accomodate the longer hulls. Lacquers will still have to be sprayed outdoors by hand because they are too flammable to use even with a shaded pole blower.

[Evodyne]

Boilermakr,

That would be fairly involved, woudn't it? But definately cool. How would you handle changing colors-multiple airbrushes? Neat. Have you seen anyone do this before? Everything I've seen has been 2D (cake decorators and even the wall traversing graffitti robot). Hey-you could be the first!

Lance