Build Your Own SLA/SLS

I just completed my first print. Looks like i've still got a long way to go! Any suggestions on how to fix these artifacts? Or at least pinpointing the problem, I think it is either z-wobble or undercuring. Thanks!

Definitely looks like Z wobble to me. Your aspect ratio of the projector is also very off... Marvin's looking a little thin!

Definitely build plate wobble, undercuring wouldnt do that.

Can we have a look at your Z axis?

And yeah, like Pomeroy said, Your aspect ratio is off on your projector, marvin should be more round.

Haha, yeah I laughed at skinny Marvin when I saw the finished print! I'll work on that after this wobble is gone
Here is an album of my z-axis
I was considering putting on a flexible coupler, and I designed a sturdier anti backlash nut that I'm going to print tonight.
Any advice?

Ah, you have a DropLit! I would check your slide rather than your "leadscrew" (And I use that in the loosest sense of the term). See if you can wobble your z stage by hand, and if you can, try tightening the wheels.

It's z-wobble and platform wobble. The Droplits that I've seen are rather structurally unstable.

Thanks for the replies, I haven't had time fix the printer yet. I can see the build plate move side to side as it goes up and down. The wheels on the slide are tight, maybe too tight. The eccentric bushings are loosening every now and then too.

I will probably just rebuild the whole thing with aluminum extrusion after I get the hang of this. Or maybe just completely redo the z-axis with a leadscrew or ballscrew.

I got a good print! I took the flexible coupling off of my Prusa and put it on this printer. The z-banding is gone. I adjusted the XandY by measuring the projection on the vat. Marvin is still just a little too skinny. To adjust x and y do am I supposed to measure the projection on the vat? or print a calibration obejct, like a cylinder, and measure that?

Take a look at to see how to get your projector setup.

Thank you, I'll get started on that