08-14-2009 Vangobot 2 discussing paint delivery system
I am trying to get away from air and valves. This is plunger similar to a screw valve controlled by a reversible motor. Knowing the RPM’s of the motor threads per inch of the screw and the volume of the chamber we could totally meter the amount of paint we extrude down to ml’s. No more worries about viscosity the paint will all move at the same rate because we are just decreasing the volume of the chamber.
The benefit of the reversible motor is that after we dispense the desired amount of paint we flip the motor in rev for a half a rev and the paint is going to suck back up into the chamber once that vacuum is created we don’t need to worry about any drips.
When paint runs out we raise the plunger to the top unscrew the motor/plunger assemblby slide it up a couple of inches and pour in new paint from a mixing cup.
08-21-2009 Vangobot 2 screw piston paint delivery system elements
08-21-2009 Vangobot 2 screw piston paint delivery system elements
08-21-2009 Vangobot 2 screw piston paint delivery system elements
08-24-2009
Interesting. I remember reading something about offsets for arcs in the emc manual It had to do with tool placement similar to inside, outside & centerline when tracing.
Here are the brush diameters at the heel of the ferrule dose not to take into account spread at the toe.
Brushes sizes:
3/8
5/16
1/4
3/16
1/8
1/16
Like you said though we should do some actual measurements :-0
Luke Kelly wrote:
OK no problem. I still want to send you some test code — will use single colors and just do fills.
Although there is probably an SVG to G-code bug lingering the other problem I saw particularly with the large brush underpainting from this week is that the brush mechanics don’t follow the polylines in the curves as close as I thought they might. What this translates to … is determining how close strokes must be in each brush size to get coverage.
What we’ll find, I believe, is that I need to adaptively shape the SVG stroke width when calculating curves. In other words, when the brush is following a curve the shape of the brush changes and I need to anticipate that. I believe I can do it by changing the brush size adaptively in the SVG– when following a curve shorten the width of the stroke so that the strokes are closer together in the curves but wider apart in the straights.
Bottom line this goes back to what I was saying about benchmarking our brushes and determining if a stroke size X is suitable for canvas size Y and brush size Z. To this point I’ve been totally guessing.
In landscape painting #1 the strokes were way to close. In the pear painting they were better and in the winch painting they were too far apart. It’s not bad for them to be too close other than making the run-time longer than necessary.
Luckily all of the code optimization will apply directly to any new machines we build.
On Aug 13, 2009, at 8:16 AM,Doug Marx wrote:
Just blew another pinch valve.(Periodically the hose that was pinched in the valves would fail with a shotgun like explosion and a Pollock like spray of paint over who or what ever was near.) White again and we are out of white…. Seems to be some correlation between the paint pot being empty and the hoses blowing. Burst was in the exact in same place.
I’ll shut her down and start working on a new paint delivery system.
08-24-2009 Vangobot 2; paint piston with motor
I have to make a coupler and it is done. I think you are on to some thing with zerks for refills.
08-27-2009 Paint mixer 2
Motor mounts couplings shafts cut to length ready to turn.
08-27-2009 paint mixer 2
Endcaps retaining rings motor mount spacers all done. All the external components are done.
If the gods are with us here’s the way I see it playing out.
Friday: finish internals
1 day for carousel
1 day for electronics
1 day for fitting
That means depending on delivery we could be ready to roll end of next week.