- LittleRP 2 Beta
- Fun-to-Do Deep Black resin
- ViewSonic PJD7820HD with
- See-Me-CNC Universal Flex Vat with 5 mil FEP sheeting
Quick recap: which (I think) was mostly due to the Z Lift being too fast. After that, things started coming out more cleanly, but had severe light bleed.
The exposure time was twice what it should be FTD resins are crazy sensitive.
Subsequent test prints revealed a fairly serious light imbalance with my projector. I created a new test print model to test how severe things are and where. Feel free to use it. You may have to scale it down by 10% or so.
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The one on the left is my first attempt. As you can see, about a third of it failed to build, even the base grid. I then made a mask, which resulted in the right one. It improved, but it wasn't quite enough. There's still a fair amount unformed and peeling.
Here's my situation in trying get this thing working:
1. I don't have the means to purchase and make the whole UV sensor set up I have to do this with trial and error, creating masks in GIMP.
2. I'm wondering if I may have screwed in the lamp slightly off kilter when I moved the color wheel. It didn't exactly have a LEGO tight fit in there.
3. I'm thinking sticking is still a problem. When the second test grid was printing, it was peeling up awfully hard. Got kinda loud at random points. One idea suggested by goopyplastic was using a different Flex Vat. The sheeting on SMCNC model is drum-head tight, where as HTL's model has more slack, which should allow for easier peeling.
4. When I printed with the mask I made, I also doubled the exposure time (500ms -> 1000ms). I think this contributed to the extreme sticking, but there was also some little squares of cured resin stuck to the vat. They didn't cover the whole underexposed area, but they were there. I've made a new mask that covers more and is significantly darker than the last. Since the weak areas were still underexposed, I'm wondering if I should increase the exposure time more.
5. I'm questioning the settings of the projector. With the way it was originally, just the ambient light was curing the new FTD resin (wound up with a cured sheet the size of the whole build area), so I had to turn down the brightness and up the contrast by quite a bit. I'm wondering if more light for less time would work better than less light for more time. Again, I'm fighting/avoiding light bleed here.
6. I have done nothing to the GCode. I've seen people on here writing things in for timing, speed, distance and whatever else. Is there something I could do that would help any of this?
7. Even the fully printed pegs on the test grid still had a ribbed surface. Goopyplastic said something about the high tension Flex Vat causing lines on the prints, but I'm not sure if that's what he meant. If that's not it, then it might have something to do with the reactivity of the resin changing, or the exposure settings, or the Z Lift speed... I don't really know.
I've also been looking at the new NanoDLP host software. It seems to have many advantages over CreativeWorkshop, including it still being free and updating.
The spread sheet for the LRP2 said it was an option (among other things), but it's made to work with Raspberry Pi, while I'm still working with Audrino. I don't know if it could work with Audrino, I don't know enough to convert or patch it in if I had to, and I do not have the money to throw at a Raspberry Pi set up.
TL;DR: My prints are still sticking to the vat, the lighting is grossly uneven, I'm having a hard time judging what to do with making the masks, and there's just so many variables to work with that all interact with one another.
I am at a loss for what direction to go in, and it seems like it's been taking a long time for people to get back to me.
I need some help and advice. I've had this thing for almost a year and I have yet to get a usable print out of it.