Automated mini paint booth that does the painting for you!
In order more accurately control the flow of paint I have installed a Digiten 12V solenoid. I am controlling it via an Uno and a 9v power supply. I think the real question is how well will it hold up with paint running through it vs. water which was it's original intention!
I built a quick looking enclosure for the sprayer out of a plastic storage bin that I had laying around so now I can start to test with paints, and not have it make a huge mess. I ran a test today with the following:
|Sprayer Setup||4 nozzles approx. 1.5" apart|
|Paint||Cheap Walmart Red Acrylic 1:1 paint/water|
|Total Run Time||10 - 15 sec|
|Fluid Used||2-3 oz|
|Test Subject||Good ole toilet paper roll|
|Avg Distance Between||7-8 inches|
Surprisingly much better than expected. Nozzles had a pretty good misting spray; however pretty wide angle so quite a bit of wasted paint. Also the paint was a bit spotty meaning it wasn't atomizing enough, so maybe smaller orifice, more pressure. Could have eliminated 2 of the sprayers. Need the ability to cut of the fluid rather and just the air. I do have a valve on the fluid line but I can access it from outside the container.
Go Forward To do:
I picked up a 1/5 hp compressor from Harbor Freight to test the sprayer with a constant pressure. I had to use like 4 different connections to get the dang thing from 1/8 npt connector to the existing connector I had installed (as you will see in the video). I was running at pretty low PSI (15-30). Overall I would say it is successful, it goes through quite a bit of liquid though (~10oz per minute) definitely lots of paint, on par with house paint sprayer. While spraying I put my hand about 8 inches from the nozzles and it felt like a pretty even distribution of spray, but my hand was dripping within seconds, which I am guessing will become and issue.
I also test it with 2% milk.....yes milk. From what I could gather 2% milk is similar consistency to paint-ready-to-spray and it made for a much cleaner test. I filtered the milk with 100 mesh filter, just to try and avoid clogging. It did ok, there was some dripping and it wasn't as consistent of spray as water but it still looked usable.
Overall I would say the testing was successful enough to move onto actually trying to paint an object. I plan to use diluted acrylic paint. I will it with basic shaped object plastic object and see how it goes.
I replaced the tube connecting with a male and female quick connect, and I replaced the air-in with a male compressor fitting. After a bit of tweaking I was able to get the spray coming out of all misters without any major leaks. The initial test was done with a bike pump hence the sporadic spray so next I will test it with a consistent air in from a compressor. Overall I am pretty impressed with the spray under low pressure (20 psi) I think if I can run it at 30-40 psi it will be a very nice consistent mist. I am thinking I may run into issues when I try to run anything else but water through this system...only one way to figure out......
Leaks at both the hose and shrader valve. I thought I could get away with the sloppy silicon glue seals but the container won't hold pressure. I am going to be upgrading today and replacing the shrader air valve with a 1/4" compressor male coupler and using barbed to thread connectors for the tube. Add a couple nuts and rubber washers and it should make a nice seal.
Current Objective: build a simple pressurized multi-nozzle sprayer setup to determine feasibility of spraying an assortment of different liquids through multiple nozzles with some consistency. Then attempt to cover an object with liquid (maybe paint) to determine overall feasibility of the project.
Went forward with a slightly different plan for the prototype. I decided to use something with a screw top so I could easily access the inside of the container. I am going forward with a PVC container, shrader air valve from old bike tube, 4 - 2gph mister nozzles, 1/4" hose with stiffening wire,
First I am going to start by making a very simple spray paint style can with multiple nozzles and an outside pressure system. I want to see if an air-paint mixture throughout the entire system will work. Originally I was thinking I would make something similar to an airbrush however I think it is overkill since I really don't need that precision and control. So I am going to essentially try to recreate an aerosol can with a compressor, sturdy paint container, and multiple exit nozzles.
1. Pressurize paint mixture and spray through multiple nozzles. (current)
2. Iterate/modify to try and get consistent spray out of each nozzles. Options to vary:
-Main orifice diameter, nozzle diameter, paint viscosity, pressure->paint sequence, and more.