adam619
December 17, 2016, 10:12pm
1
Hi guys, I’m trying to sort out differences between “Daylight Polymer Printing” (DPP) and “Digital Light Projection” (DLP). http://photocentric3d.com/ (DPP) http://uniz3d.com/tech-specs (DLP) Both appear to use an LCD, so is the difference just wavelength and intensity (with DLP using higher intensity)? Which is better? Does either require UV post curing? Which is faster? UNIZ Slash speed spec: 1000 cc/hr (50% infill solid structures) Up to 200mm/hr (hollow and thin-wall structures) PhotoCentric LCHD speed spec: 18-25 sec layer or 2-1.44cm/h 18-25 sec layer or 0.78-0.56in/h - Adam
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Well, the first thing is that if it uses LCD it is not DLP. DLP is a patent from Texas Instruments and it refers to an array of micro-mirrors that by tilting “turn on and off” each pixel of the image and is found in projectors. From the specs of the Uniz and having a Photocentric myself, I would actually say that the difference between the two machines is the LCD screen. In the Photocentric it is a commercially available screen, standard backlight. For the Uniz Slash I would say it is a purpose built one, without the colour filters and with a blue instead of white backlight. By doing this they can tune the backlight to what they need (intensity and wavelength) and speed up the process. The Slash resin is most likely proprietary, like the Photocentric, because it works at 405nm, which is a violet-blue and still in the visible range. Both machines and pretty much every resin machine will produce parts that need post-curing and I guess that sunlight will work better than UV LEDs. I use nail UV lamps, which have a larger spectrum and produce light at a useful wavelength. The price range of the two is quite similar and specs make the scale tip towards the Uniz Slash (which is not available yet, hence cheaper for now). Later on it might be a more even comparison, but the cost of the resin might have a strong impact. Photocentric resins are good and cheap, the others I don’t know…
Hi Adam, I’ve been looking at both of these too. As far as I can tell they are very similar, using blue LED’s and LCD’s to cure resin at about 460nM. Uniz is also producing a separate 405nM LED array for the Slash that would make at least some UV curing resins usable. Both use flex vats, maybe different films though. Speed would come down to the output of the LED’s, although Uniz claim their water cooling allows faster printing than otherwise. I know the Slash uses a purpose made LED array rather than the backlight of an LED screen (so brighter/faster). Not sure about the Photocentric printers.
I’ll be interested to see some reviews of the Slash once they start being delivered.
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DLP uses UV light DPP does not
I’m following these as well. Once the Slash hits the street, it would be so cool to talk to someone who has used both. Specs aside, I’m curious how they will compare in terms of build quality and support. And a hands-on opinion about which simply works better would be amazing.
I “invested” in a slash printer on Kickstarter over a year ago and was supposed to have received it last December. Not only is Uniz 7 months late (and counting) but they have quit posting updates on Kickstarter and they are not answering the questions being left by backers. I hate to be a pessimist but based upon their lack of updates / responses to the 500+ backers who funded the development of the Slash printer, I am not optimistic about ever seeing my printer. If you are still looking for a resin printer I would suggest you staying far, far away from Uniz and buy a printer that really exists from a reputable company.
I personally don’t think Slash is going to hit the streets. They are 7 months late (and counting) and Uniz has quit posting updates on Kickstarter and they are not answering questions from the 500+ backers who pumped more than $500,000 into the company as of April 2016. I really hope I am wrong but I don’t expect to ever see a printer from them or my money back.
Hi Adam. The light source DDP or DLP usually does not influense of printing speed. It is just about kind of material usage. For different wave length. The printing speed mainly depends on mechanical process of slicing between the cycles of each photo polymerization.
So you have to compare volume printing of the same model for each printer. - Eugene
