(For anyone who doesn’t get the reference, search “Romanes eunt domus” on YouTube.)
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there was a youtube video of a maslow type machine that used spray paint cans to paint random art on a building at some sort of fair. the owner said running out of paint and clogging were major issues, funny you should bring it up! lol.
Painting it once isn’t that much trouble, if you had to do it 100 times it would pay to automate it.
I see Monty Python, i press like 
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I was wondering that since four cables are used, you could prevent rotational (or control rotation) of the sled. If so, would the math be simplified enough that you could fix the location of the spools on the sled? I always thought for quadrilateral arrangement, trying to calculate the sled rotation was the mathematical issue that triangular kinematics solved. Is this correct?
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This is why I was questioning what Bar mean with 4 cables. He said 4 cables, not 4 motors. I’m pretty sure I remember watching a video of how they designed the Maslow where they discarded using bottom motors because they complicated things without adding much benefit.
I had just assumed it would be four motors. I agree that it would complicate things, but I tend to think there could be benefit if the issues are overcome.
I was thinking four motors with all four working on a triangular type system
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Anyone here good with gears?
Look at the drawing below. I am not sure I drew the sproket correctly.
it has two gears around the motor gear. Here are my questions:
What is the diameter of the 25" chain when wrapped around the 10T sprocket?EDITED TO ADD ONLINE CALCULATORS SAY 0.8090.
I want the chain to feed to the center line of the motor sprocket.EDITED TO ADD 0.4045 IS CORRECT DISTNACE INSTEAD OF 0.43" THAT DRAWING SHOWS.
What is the center to center distance from the top sprocket to the middle motor sprocket? so the chain feeds around smoothly. Not sure how much tolerance is normally used? I’m guessing 0.8090 is too tight?
How much chain wrap should one have? Right now it is about 270 degrees worth. What is the minimum amount of chain wrap one should have 180 degrees? EDITED TO ADD. I GOOGLED IT, 180 IS FINE, SO THE BOTTOM SPROCKET WILL BE MOVED SO THERE IS LESS WRAP.
I am worried the chain will kink and get stuck between the motor and lower gear.
Do i even need the top gear? Seems like forcing the chain to center line takes out a lot of fuzzy math. the system becomes truely triangular. The motor is pointed to the center and the end points in the top left/right corners are simple pivot points (no chain wrap calculations. )
Once I get these questions answered I can get some parts laser cut to try out.
I like your concept. I assume it will be on a “ring” mount of some sorts?
yes it will be very similar to the standard ring, just thicker and stronger.
My other concern is the motors are going to contribute to the chain sag. They are currently just held on with two ball bearings and tension. Exactly like the exsisting ring kit.
I’m thinking of adding a 3rd bearing to the outside diameter to combat this, Kind of like you might see on a 3d printer with a eccentric nut to allow for some adjustment.
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The default software had chain wrap compensation calculations. I am assuming if I set the chain wrap diameter to zero it will negate those calculations. Not even sure how to do that. can it be done in the software some where?
Have you considered the weight of the chains on the spool, and the spooling assembly? Looks like it would tend to pull the motors down, off of the centerline to the bit.
I am not worried about the weight because the bottom spring bar will be bolted to the sled.
i am worried about how much spring tension there is, which will cause the problems you mentioned, pulling down the assembly. Especially in the bottom corners where chain tension is lowest and the spring tension is highest. That is why I am using a 25 ft tape measure spring, the tension tends to be more uniform, I’m guessing than a 12’ one. Hoping maybe this can be compensated for by chain sag equation in the software?
Another thought. Somewhere back in these threads I saw where they were using a double stacked Lazy Susan type of steel ring with bearings. Perhaps if the motor assembly‘s were attached at 90° to the Lazy Susan ring then the whole sled assembly would be guided off of your centering idler sprocket on each motor.
Yes I have made a sled out of lazy susans and they would prevent any chain sag do to their stiff construction. However they are expensive relatively speaking. if the above works, the laser cut parts are less than $20 lazy susans are $20 each or $40 total, plus the labor is more.