Build Your Own SLA/SLS

I'm attempting my first print, just the calibration grid for now and i've noticed the projector displayed the next slice too fast before the arm had gotten back into place. I think it has something to do with the lift and sequence time in creation workshop but i'm not sure how much to change it by.

I'd love some help setting up my littlerp for 25 micron in general, i'm a newbie to all of this, I have a acer x152h in the forward position and im using makerjuice waxcast. Used the old information videos on Vimeo as a guide but changed what I thought was right for my projector.

Settings:

Yeah you'll need to bump up the lift and sequence time. I would take your vat out and do a dry run. Keep increasing the time until you get to a point where it starts projecting about a second or two after the Z arm has stopped.

Might as well update here rather than making a new thread, some success and some failure but better than I expected.

I can't seem to attach a file as it says it's too large, oh well. Of the 6 calibration grid pegs it printed 5 of them. One at the corner only printed the base and the two next to it along the short edge are jagged vertically, like they were thicker layers.

What might be causing one side to print well but the other not to? I can only think the build plate being unlevel but it seems right to me.

Also how can I check for certain I'm printing at 25 micron?

Z Bottom speed and Z Lift Speed are pretty important. You want a slow Z bottom speed to ensure your bottom layers stick to the platform (If its too fast it will rip the build off the platform) Same with Z Lift Speed, too fast is not good. I would start with 50 mm/m bottom speed and 60 mm/m lift speed, once you start having successful prints you can slowly increase if you want. Keep in mind you will have to adjust Lift Sequence again after you make that adjustment.

Prints at the corner of the build plate don't cure as fast as parts in the center (Most of the projectors light is focused in the center). Also because of how projector lenses work, you generally have slight distortion in the the corner of your prints, this is why you may of seen people mention avoid printing on the corners. Those two things could be why the corner print failed. Increase exposure time slightly as see if that helps.

Slice thickness is what micron you are printing in the Z axis. 0.025 for 25 micron, 0.050 for 50 micron and so on.

I don't know what purpose you need 25 micron for but I would encourage you start at ether 50 or 75 micron. These thicknesses are easier to print and work with until you get the printer dialed in.

With the larger print cross sections you can do with flex vats, slow is a good thing, 50 up and 200 back is a good choice.

Thank you both, my print quality is improving gradually as I tinker. The reason I was originally interested in 25 micron is not about why, but why not? My sculpts I thought would be detailed enough to take advantage of it and I bought a projector capable of it though seeing someone else recently post at 50 micron shows how well it captures detail.

One thing I noticed is the scale is off and by quite a bit. A 1cm cube comes out at 1cm high, and about 7/7.5mm (I don't have callipers yet) X and Y.

I increased X and Y scale in creation workshop by 25% which seems a lot but that made it 9mm, almost there and I can increase it more but it feels like I'm just eyeballing it, is there a proper way to fix this issue?

I had a post all written up about how the settings changing did nothing, that I had a pile of failed prints etc but before I posted I decided to do one last "am I an idiot check".

It turns out I'm an idiot.

I wasn't clicking the apply button. I'd gotten used to clicking it in the slicing config but not the machine config, whoops. I'm getting good, properly scaled prints now, I do have odd lines running through a couple of layers but I think I've derailed this thread enough and I'll make a new thread, thanks for your help.