Ideas for special pump, peristaltic maybe?

[The Artful Bodger]

I would think that using air pressure would be easiest, and solenoid operated valves next to the spray nozzles.

My notion for operating the airbrush is to use a fixed position cam/ramp that the button will ride on as the Z axis moves down. This will avoid having to modify the software or electrics/electronics.

[Dan Dubeau]

Just stick a paintbrush in the z holder, and a cup of paint to dip in on the table somewhere. Program in a bunch of lines for brush strokes, with a few paint dips in between every once in a while . It will either have that artsy hand painted look, or look like a toddler did it lol.

[The Artful Bodger]

Just stick a paintbrush in the z holder, and a cup of paint to dip in on the table somewhere. Program in a bunch of lines for brush strokes, with a few paint dips in between every once in a while . It will either have that artsy hand painted look, or look like a toddler did it lol.

Not a bad idea, in fact I have seen someone online who has done that! At this time all options are on the table.

[genea]

How big are these signs?

There are at least two possible problems with peristaltic pumps for painting signs. It's true, the output of a peristaltic pump can be precisely averaged over a period of time, but over a short period the output will be uneven. It's the nature of the pumping mechanism. On top of that, they're driven by motors that are hard to start and stop with precision. If you're using one to load a brush with paint it might be OK. If you're painting directly to the sigh face the paint could be uneven. You'd need to experiment to know how well it will work.

Most commercial fluid dispensers use regulated air to move the piston in a syringe or barrel a controlled distance or at a controlled rate. Others use a stepper motor driven screw to move the piston.

If I was doing this, I'd look for something like this EFD1000XL controller from EFD / Nordson: https://www.ebay.com/itm/18526077414...h5hOF#shpCntId

[boslab]

Not what you asked but how about an autopippete, slurp and squirt into the engraved letter ( done it with a syringe a bit, blunt needle)
you can go peristaltic, there are tiny ones on the nebuliser of an ICP spectrometer, the tube through the rollers is less than 1mm.
mark

[Hawkeye]

Might be worth looking at these for ideas.

Smart Edge Roller 3-in Inner-Fed Paint Roller https://www.lowes.com/pd/Wagner-Smar...Roller/4513828

Wagner PaintStick EZ Roller Inner-Fed Paint Roller https://www.lowes.com/pd/Wagner-Wagn...ler/5002909541

[The Artful Bodger]

Thanks for the information and suggestions which all add to the options before me. Right now the courier should be here with an airbrush in a day or so.....

[Black Forest]

You also could use an airless paint sprayer. That would be very efficient. Just how many signs are you going to need to paint? That would dictate how much of an investment would be warranted to me.

[The Artful Bodger]

I only have a couple of roadside signs on the horizon but I expect there would be a bit more demand if I could easily turn out a good produce.

There have been airless paint sprayers in my past and they might be OK for doing the background etc but text would be difficult.

[Noitoen]

Check out these guys

[The Artful Bodger]

Check out these guys

Yes, I have found that and others and tomorrow I will be waiting at the door for an airbrush to arrive!

Those Czech guys have made a very tidy airbrush mount and their site shows a three colour version.

[Black Forest]

What type of signs are you making? Are they metal with the lettering just painted on or are they wood with routered letters and then the letters get painted?

[The Artful Bodger]

Right now I am making a couple of 8x4 ft wooden signs, painted with painted text. The ones I have made so far I just used the CNC table to draw the outline of the text which we then hand coloured.

[Black Forest]

I am sure you are aware of the method of engraving the letters on the router, then spray painting over the engraved letters with not much attention to over spray and finally with and vibrating/oscillating sander clean up the surface. The paint remains in the engraving just fine. It seems to me it would be much faster and much less finagling around with a better result.

[The Artful Bodger]

Yes, I am aware of the engraving and paint process and it would surely be an easy enough as it has been when I have done it.

There is always a lot of finangling in my workshop!