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Idea on printer mod to contour painter. Answered

I've been thinking about this for some time now. Over the years I've accumulated a lot of computer related junk and it's time to do something with it. I would like to take an ordinary ink jet printer and convert it into an automated painter, to be more precise it would be a HVLP spray painter for painting motorcycles, cars, houses, etc. Now the question is where do I start?


For bikes etc. an inkjety is really too small and fragile, however an old A3 plotter could well give you some good results...

Also a big old plotter would be cheap and heavy a fairly sturdy rig on it.

. Yeah. What he said. . Examining the workings of an ink-jet printer may give you some ideas, but for something like painting a car, it's just too small and probably too fragile.

True. I need to understand the workings first. I think I will start with an old Alps MD-1300. Thanks and please follow all comments, maybe you'll be inspired too.




This could take awhile...
Between an ink jet printer or two, maybe you could paint models, with an air brush. A rotating stage would help. Beyond that...

The questions are how much movement do you need, on how many axes of motion. (BTW axes is the plural of axis.)

To paint a flat sign, you need at least two axes, across and up-and-down. Set the paint gun at a fixed distance and have an electric valve turn the air on and off. To use a brush or to paint something simple that's not flat like the underside of a bowl, you'd also have to go in-and-out. That's three axes you're already up to.

Now we're up to something complex, a tea cup. We need to get under the rim and inside the handle, with our sign painter mounted over the table looking down into the inside of the cup, the gun nozzle at the end of an arm pointing downward. Imagine your hand holding the gun with your arm sticking straight out. You need a wrist motion. You'll need to bend the wrist up-and-down and side-to-side. It might be nice to rotate the wrist (twist your forearm) but not necessary, with the two wrist motions and the arm movements you'll get the same effect. Well, now we're up to five axes of motion.

Okay, let's get to that motorcycle! You'd need a nice large frame, slightly bigger than the side profile of the bike, then mount the arm to go up-and-down and across, the arm goes in and out, and the nozzle will twist left-to-right and up-and-down. You've painted the first side! Now for the next... Wait, the bike needs to be turned. The automatic system needs it rotated, maybe if it was on a platform that rotated. A sixth axis? Nah, use an indexer. Like a ratchet as it clicks, each time an indexer is indexed it rotates a fixed number of degrees, just needs a few on/off signals from the controller to do it. Still, something to consider.

Needless to say, it is hard to put a house on a rotating platform for painting. So something different needs to be done. You need robotics. Specifically you need a robot arm on a mobile base. No massive frame needed, as for a CNC router or mill. You're just positioning a nozzle for spraying, no contact involved. How many axes do you need? Well, how many do you have? Your upper arm at the shoulder does up-and-down and sideways, your elbow does another, plus two wrist bends, so that's five. Your body may do a lot of twisting while painting but really, if your arms were long enough you wouldn't have to. Your feet may move you around the floor, looks like two axes, but in operation positioning the base will be a separate task from painting, set base then paint, so you really only need five axes for painting. For a house you'd need a really long arm, but actually the smart thing would be building an elevation adjuster in the base that'll raise up the arm assembly into place before painting.

So, as you asked, where do you start? Umm, here, from the looks of things. You need to learn robotics. Look around the site, there's plenty about robotics and related controls. Might take awhile, but then the site isn't planning on going anywhere so you're good.

And save that inkjet printer, might need the odd screw or a small roller. Besides it's summer, need something to keep the garage door open for the breeze. ;-)

Thanks! This is very helpful and precise information. For the sake of this project lets stick to motorcycle automated painting. I'm a rider and and enjoy my motorcycles but I'm never happy with stock. I'm not a painter and I'm not sure how detailed you can paint with an airbrush. The tins are removable (fenders, tank, etc..) which makes painting somewhat easier. The following link also provides information on the mechanics I need to take into consideration ( http://www.bnhmachines.com/BNH1000.htmhttp://www.bnhmachines.com/BNH1000.htm ).

I was thinking the printer is only limited by the frame size. On a MD-1300 the head goes side to side and the paper feed goes backward and forward. So, I assume one could change the paper feed roller to a mechanism for moving the print head. I think that may be my begining experiment.

Thanks also go out to killerjackalope and NachoMahma for you helpful comments.