Designing and building my own SLA printer

Hey guys, I am currently designing my own SLA 3D printer. For now, many of the parts have been already ordered and the prototype should be assembled in a month or so. The frame is built with T-slot extrusions and laser cutted aluminum parts. The laser will move on a carrier with a Hbot gantry. The build platform will be easily removable from the Z-moving carrier for part removal. I will be using Arduino Mega R2560 R3, Ramps 1.4 and a full display control LCD. The esthetic panels will be powedercoated aluminum sheet metal. The UV shield should be made of clear PC. All the moving parts will be mounted on linear ball bearings on hardened shafts. The Z axis will be a 12mm ballscrew for no backlash. I will be doing my tests with MakerJuice resin.

Here are the main specs of the printer as it is right now :
Build volume : 8.2'' x 6.7'' x 8.75''
Exterior dimensions = 13.11'' x 15.00'' x 18.1''
Laser = 405nm, 150mW
Full control with LCD display

I finally managed to modify the Marlin firmware for a SLA printer. I got rid of all extruder/hot bed functions which are useless for my printer. I also added the logo on the welcome screen and the main menu screen. All the machined parts are ordered and should be here in a week or so. I will add more pictures soon with the prototype assembly.



Edited 1 time(s). Last edit at 03/19/2014 07:00PM by PierreYves.Pepin.

This is awesome. Keep us updated, and feel free to create a wiki page. Or, if you are doing documentation somewhere else, link to it and someone may be nice enough to transfer it to the wiki.

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Sure I can make documentation on how to modify different parts of the interface like welcome screen, main menu screen, logos (with bitmap code) and disable some features and also how to create new functions in the menus. It won't be for now because I have a lot of things on my mind (still fulfilling pledges for my Kickstarter campaign : [www.kickstarter.com]) but once I have enough time, I will make the modified firmware public and make a documentation on how to make these changes. Please note that I will be exhibiting my 3D printer at the Bay Area Maker Faire!

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PierreYves.Pepin
once I have enough time, I will make the modified firmware public and make a documentation on how to make these changes. Please note that I will be exhibiting my 3D printer at the Bay Area Maker Faire!

That's great. I may be there this year, I hope I see your printer.

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Help improve the RepRap wiki! Just click "Edit" in the top-right corner of the page and start typing. Anyone can edit the wiki!

Hey guys! Here's an update. I've started assembling the printer and everything is working fine for now. I just wanted to give you a little teaser about the progress. I should start doing my tests with laser/electronics on next week. All the parts of this printer are aluminum machined parts so the frame is very robust and the mechanism very precise. I'd say that the whole assembly is quite light for now (about 15 pounds).

Here is another update. I've made some tests and I am able to drive the laser with a relay and a servo output. The Hbot gantry is also working good even If there is some play between the bearings and shaft (shaft are not as precise as I expected). That results in the mecanism being a bit loud. I will try to fix these issues soon. I should receive the glass for the bottom of the resin tank tomorrow so I will be able to start printing some test parts. I will keep you guys updated.

Today I did my first test with a gcode program and some resin. Since the bottom of the resin tank is not ready yet, I used a spare glass with only a thin layer of resin on it. The result is amazing and the contour lines are perfectly straight. Next step is to manage to print a 3D part.



I have a question though, is it possible to use the output from the stepper driver to power the laser? I have an adjustable regulator for the 5V of the laser. Right now I use a servo output with a relay to power on the laser.

Thanks

Edited 1 time(s). Last edit at 04/07/2014 03:33PM by PierreYves.Pepin.

... I'm driving my lasers by switching the power through MOSFET's - when the laser is ON, then every motor-step of the X or Y-axis will give a pulse of some microseconds (adjustable for power) ...

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Viktor
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Thanks for your input. I've managed to fix that issue by modifying the Marlin firmware. I changed number of the E0_DIR_PIN from 28 to 4 (My servo output) in the pins.h file. With that change, my laser is turned on whenever the extruder extrudes filament and turned off when the extruder retracts. I think it is the easiest way for me to do this trick. I should be printing a 3D part as soon as I get my resin tank ready. Right now, I have waiting for the SYLGARD184 coating to dry completely. I will keep you guys updated!

Just noticed another problem, it seemed to work so far but I just notified that once any axis is moving, the laser turns on again. Is there any reason why the E0_DIR_PIN is reactived/reseted every time an axis is moving?

Anyone? Still looking to find a fix for my issue.

What was your initial solution before u used the stepper driver output solution?

I first tried to use the servo outputs by entering the servo's pin instead of the step pins of the extruder. It would not work because of a bad timing. The laser didn't turn on and off at the good time.

Good thing is that I managed to build a circuit that would convert the pulses from the RAMPS 1.4 to DC signal. I can now drive my laser perfectly and the timing is good as well. Here is a few prints I made with it for now.

Wow! awesome! What's the printing time for the yoda?

The yoda took 3 hours to print. I know it's quite slow. Right now, I can't go any faster that 20 mm/s because I get layer's misalignment. The next iteration will have new stepper as the ones I use now are rated for maximum torque @ 2.5A (which is not supplied by the drivers). I also think that the mechanic resistance caused by low quality linear parts doesn't help neither. They were supposed to be ''precision linear parts'' from China but they ended being ''poor quality parts''. I will use linear parts from USA on the next revision of the printer so maybe I can get speed like 150-180mm/s and get decent print times. I still have a lot of adjustments to do on the printer/Slic3r settings to get even more precise parts. I'll keep you guys updated.

HI could you put a video on here showing the printer working they look spot on, )))

wow, awesome quality on the prints!

Hey,
how is the project going on? I am planning to built a sla printer, also and watch out for inspiration. Your project seems to be most promising. Do you have mor info about your mirrors and how you power them and so on?

Bye
Boris

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PierreYves.Pepin
Sure I can make documentation on how to modify different parts of the interface like welcome screen, main menu screen, logos (with bitmap code) and disable some features and also how to create new functions in the menus.

I would really love to have a chat about modifying the menu and main screen items...
It seems as though I cant get rid of the heated bed image at all, and the 3rd extruder pic is annoying me!

Also, I'd love to make a graphic of the cube shape of my printer, with a pixel that 'rep'resents (see what I did there) the nozzle position...
The coding I will be able to work out for that, but I'm simply looking for an outline of where to start.
I have already changed the welcome screen, but couldn't find any reference to the main screen stuff...

Thanks

Look for ideas and help here: [www.buildyourownsla.com]

Very nice print!
Do you use LaserShark?

Salut Pierre Yves, can you follow up on your printer? im also wanting to make a laser sla.