Kind of* back on-topic*, see why in a minute... Idea: Make a printer with two tanks. One resin and one IPA. The printer raises the part out of the resin then the tanks moves on a rail and the platform goes back down but this time int IPA tank and the platform move 1mm or 2mm up and down quickly. The up goes the platform and a third "tank" filled with air is used or rather it is filled with UV light and a drier fan.
You could also manually swap the three tans. I think you could use glass built plates. You need a dozen or more of them and periodically you chemically clean them in a fourth tank. This is why I suggest to people to buy the "Ender" as a first printer. It's cheap and easy. A printer with a complex robotic parts like tanks on rails would best be done using LinuxCNC and Hal then with Merlin. Especially if using a few dozen glass plates. These could be loaded from a hopper and the clean post process parts could be robotically unloaded, still attached to the glass. The mechanics is not horribly hard, I'm 3D printing both a CNC mill conversion and a self-drive car controller. And SLA printer is not much different I think a DIY full robotic workflow with LinuxCNC controller might be done for under $1K (and 4,000 hours of free engineering time.) On Thu, Jun 4, 2020 at 3:18 PM Bruce Layne <linux...@thinkingdevices.com> wrote: > On 6/4/20 4:50 PM, Chris Albertson wrote: > > One more question. How do you post-process the printed parts? Do you > use > > a separate UV lamp or sunlight. Same with cleaning? Just use a bucket of > > alcohol? I know they make SLA post-processing equipment, ultrasonic > > cleaners, and UV booths. > > > I'm still experimenting with post processing. I'm fairly new at resin > printing so probably not the best source of information. I want to be > able to run limited production so I want to simplify the process as much > as possible and automate it as much as I can. > > For cleaning the printed parts, I'm having the best results with > isopropyl alcohol. I spray it on and scrub gently with my gloved hand > and then spray the part again and let the IPA rinse drip off and allow > the part to air dry. I had seen some encouraging videos and posts > online from people getting good results with a detergent such as Simple > Green in an ultrasonic cleaner so I bought a larger ultrasonic cleaner. > The first parts out of the cleaner looked very good but every part after > that was progressively worse. The part surfaces were increasingly > cloudy and there was some gritty orange precipitate in the bottom of the > ultrasonic tank that would settle on the parts. I don't want to drain > the ultrasonic tank each time or I'd be better served by spraying IPA on > the parts. Some resins apparently don't like aqueous cleaning. At the > very least, the cleaned parts should be allowed to dry overnight before > the UV post cure. > > I thought I'd be clever and UV post cure the parts in the final rinse > tank. I was planning to ultrasonically wash the parts, rinse the parts > in a tank of deionized water, then do a final rinse in another tank of > DI water that's agitated with a submersed pump. After a minute of > agitated rinsing, an Arduino would turn on the UV light in the lid of > the rinse tank to UV cure the part underwater. I did some research and > others were UV curing under water. I tried it and the results were OK > but not great. Then I read where some resin manufacturer stated that > the UV post cure should not be done under water and the parts should be > thoroughly dry before they are post cured. > > I'm still experimenting. I bought several different resins to test but > have only tried two resins. I need to do a lot more experimenting but > I've been busy designing and printing parts on the FDM printers lately. > > The cost of the MSLA 3D printers is low, and the print resolution and > part strength is high, so resin printers are going to be gaining > popularity and these post processing issues will become much less hassle > and mystery. I've looked at some post processing equipment and read > reviews and so far I'm underwhelmed. Someone needs to make a Resin > Printing Best Practices video or PDF. If it exists, I haven't seen it. > There are some useful tips but much of the information is contradictory. > > I need to make a fixture to gently scrape the parts off the build plate > in a controlled manner. That can be a treacherous process, fraught with > peril. Maybe I'll devise something that washes the parts on the build > plate by spraying everything with IPA to clean the build plate at the > same time, then scrape the clean parts off the clean build plate to > avoid gumming up the scraper mechanism. That would be better than slimy > gooey parts flying across the room, or gouging a resin covered scraper > 10mm into my hand. > > I bought an inexpensive but very nice 30W UV lamp, Amazon ASIN > B07XCQ5C58. It does a good job of post curing the parts. I've seen > where people build curing boxes with UV LEDs and line the box with > mirrors, not realizing that glass blocks most of the UV. They'd have > better results with polished stainless steel as a front surface mirror. > > > > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > -- Chris Albertson Redondo Beach, California _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
