Build Your Own SLA/SLS

I've been trying to build a DLP 3d printer for a while - I got suck on the z axis and how to get it working correctly. So I took a break for a while.

I just came back to the DLP tonight. It occurred to me that I could use my mendelmax 1.5 for the z-axis. The mendelmax wasn't getting used (I have a MH3000 as my primary printer). So, I took off the extruder, Y axis, and X axis carriage.

My plan is to print an X-carriage with a mirror image so I can mount in upside down on the X axis (flat side down). Mount a build plate to the Carriage. Place a vat under. and project the image up through the bottom.

Do you think the z-axis is strong enough? What problems should I look out for?

(I'd buy a littleRP, but I can't wait that long. BTW- nice job on the littleRP if your reading this.)

I think the Z Axis of the MendalMax 1.5 should work fine. I have a Mendalmax 2.0. Post more pix of your setup as you make progress.

It occurred to me as I was trying to figure out a release mechanism (tilt), that the Mendelmax has two Z-axis stepper motors. Currently both are linked and contain support bars for the X-axis.

I was wondering if anyone has ever tried to do two z-axis attached to the build platform. Basically you would have the platform attached to each side (with pivots). And you would simply move one side up before the other to get it peel up and avoid the vacuum.

Any thoughts on the idea?

I've finally got 2 hours to work on the printer. Given my schedule, I decided to build quickly with what I had lying around.

I had to modify the lens of my Toshiba projector. I printed out a 3mm spacer to put in the projector. I used the customizable cylinder on thingiverse (I can't draw), printed it out, sanded it into a square, and drilled the holes. It decreased the throw distance to about 10 inches.

I figured out how to mount the projector to a piece of plywood. Then mounted that to a 2x4 table I build. I ended up cutting a hole in the bottom of the piece of wood on the mendelmax 1.5 and then cut a hole in the table. It worked out pretty well.

I had a little trouble with the vat. I thought I would just sit it on the mendelmax frame, but it was to low. So I ended up cutting a couple of oak boards as spacers. I used some roofing rubber to give a little give to the vat to prevent it from breaking if the build platform goes to far. I'm just going to use clamps to hold the vat to the frame/oak board supports.

I printed out a mendelmax extruder platform I found on thingiverse with 4 bearings. (I had one with 3 bearings that was cracked). I also ended up printing a spacer under the platform to give me clearance of the sides of my vat. To get the spacer, I ended up using the thingiverse platform, and I scaled the Z axis to be huge in Cura (the X and the Y were not scaled). When I printed the part, I just stopped the print when it hit the height I needed. I also managed to get a piece of aluminum for the stage. I ended up epoxy'ing the platform, spacer, and aluminum together to get the final build platform.

I'll finish the coating on the vat soon. I have two vats, so I'll use Sylgard 184 on one, and the other one I'll try to get some release liner silicone coating.

more pics

I still have one problem. How do I move the (2) z-axis independently. I want to move one up then the other, but I can't figure out how to do it.

I'm assuming I need to use gcode. But I'm not sure where to put it. Do I put it in Marlin? Do I put it in Creation workshop?

I found this "
;********** Lift Sequence ********
G4 P500
G1 E-2.8 F1200 ;pre position cam
G1 E-2.2 F100 ;release motion
G4 P700 ;wait for 700ms
G1 Z($LayerThickness * $ZDir) F$ZLiftRate ;lift Z
G1 E-5 F1200 ;tilt back up
G4 P50
;<Delay> %d$BlankTime
;********** Lift Sequence **********
"
But how do I use it?

Any help would be great.

thanks,
Pie.

You might want to look at the mUVe firmware posted by Dean Piper. It's a modified version of Marlin that can move the 2 axis's independantly or in unison for the peel sequence. I beleive he's using a special gcode/mcode command to set parameters and perform the lift and peel.