Open Sourcing the Pegasus

[doobie]

Was playing around trying to work on my GUI last night and created a nice looking calibration feature for the Z axis. It works for me, but might be a little confusing. I'll try to make a video to get some suggestions. I enabled some flexibility in adjustments beyond what FSL provides. They have a fixed 5micro per step, I enabled it so that you can adjust that slightly by using how many steps per MM (200=5 microns). In the process of trying to develop it and using some "precision" measurement tools I found that I am not controlling the Z axis well. And possibly this is why I destroyed my PDMS layer. I need to make some modifications to how I move the stepper so that I take into account the acceleration and deceleration of the stepper and build plate. I need to found info on doing this and coded it up, but haven't had time to try it out. I need to figure out how to fix my VAT as I don't have a warm enough location and probably won't for at least a month or two (likely the stable temp will be between 40 and 60). I also need to clean it a bit better because it is very messy even after wiping it down with IPA.

I also know my calibration on the x/y galvo isn't really correct either, that one will take a bit more effort, but I think I should be able to get prints with what I have regardless of that calibration.

I've been unable to get my GUI to work while printing, but I have a command line method for running the galvo. I'm pondering attempting to enable FSL software on my BBB to see if I can do anything with it. It would greatly speed up comparisons/debug if I could.

[fred_dot_u]

I had read that cleaning the PDMS type vat results in cloudiness and possibly other problems.

If your ambient temperature is a problem, have you considered to start up your cooking oven at the lowest temperature, placing the vat inside after powering the oven off? Obviously, you'd want to do so after the oven reached a reasonable temperature to avoid damaging the vat. Once the oven has warmed and then cooled to a reasonable level, it would retain enough warmth to combat cold, I would expect. I'd try that as long as my wife was not home, of course!

[doobie]

My original Z axis code was off by 20micron, oops! That is A LOT! And I think why I destroyed my vat and possibly why I was smushing the print. My new updated code is off by 1 micron; better, and maybe within a margin of error of my measuring tools. I was basically moving up and down 1cm at a time and measuring how much it really moved. I need to order material to redo my vat and then I'll probably try another print.

[doobie]

I'm having issues with github, but if I can work through it by the weekend I plan on releasing my first code stream to it. I have one change I want to make to the code to maybe make things work better. Right now I fill my buffer with about 8000 points before sending it to the printer, I think I want to change it to just doing each line from the gcode. It'll make it smoother and it'll look more like the FSL's print code.

[doobie]

Ugg, software isn't working today. This is what I get for getting busy and letting things sit. I have no idea why it would work worse today than it did last time...but that's software. Laser isn't running properly. Ends up being spotty looking and periodically stays on when it should turn off.

[doobie]

Ok, fixed things up and pushed all my latest code out to the githib repo. https://github.com/doobie42/pegasus3dprinter/

I don't recommend using the FSL BBB, grab a different one. Don't plug the 24v supply into the BBB. Put tape or glue in it so you don't do it.

[doobie]

I need to get around to recoating my VAT and I'll hopefully be able to get printing again. That is unless my last attempt got resin on the vat bottom and I cannot remove it or I goofed and scratch it; I didn't realize how touchy this all way for finger prints/dust/scratches.

[doobie]

Anyone good at mathematics? I need to come up with a formula to go from the X/Y MM position to the galvo position? I'll basically have at least 25 points defined, similar as the FSL3D calibration, which I'll use to transform from Xmm x Ymm to Xpos x Ypos. It's definitely not linear, close to linear in the center, but not as you move to the edges.

[fred_dot_u]

Do you have a diagram to better explain your objective? I enjoy math, trig, geometry, the whole package, but the word problems can be challenging. If it is what I think you mean, it's very much trigonometry and relatively simple math as a result. I have a machinist friend who has effectively memorized a good number of such functions and can almost do the math in his head. The drawing to represent the goal is the key.

[doobie]

I don't have a diagram, but if you have the FSL3d Calibration page it has 25 points, imagine each of those 25 points has an X,Y associated with it. The values are roughly ~325 per mm.

so maybe something like this:

0,0 330,5 655,10 980,5 1120,0
0,320 335,315 650,310 985,315 1115,320
....
etc
Not sure how well this will come out.

But each dot is about 45mm apart, so depending on where you are it'll transform into the above matrix, so 135,0 would be 980,5, 90,45 would be 335,315.