Qidi Tech Shadow 5.5S $250 SLA Printer

[Gandalf_Sr]

There is so much online in the way of awesome designs for things like knobs for test equipment but when I print on my Qidi Tech FDM (Fusion Deposition Modelling) 3D printer, the surface finish results leave a lot to be desired - I'm not knocking Qidi, I think it's a great brand, but I want the results such that most people could not tell at a glance that one knob was 'real' and the other printed and, unless you get into kluges like acetone chambers which sort of melt the surface of the FDM print, FDM prints are always going to have visible layers.

So, in a video happy hour chat with a long-lost nerd buddy in the UK last weekend, he told me he had an FDM and an SLA (Stereo Lithography Apparatus) printer which made me go look at what's now available...

SLA printers use resin that's cured by UV light and the printer 'pulls' the model out of a bath of resin on a moving Z-axis build plate. It used to be that the resin was $100 per liter and the machines were $1,000s, now the resin is $22 and SLA printers with a typical max print size of 115 x 65 x 150 mm can be got for around $250.  The major breakthrough seems to be that the print is achieved by shining UV LEDs through an LCD panel into the resin to cure each layer, it takes between 2 and 8 seconds per layer (depending on the resin and how powerful the UV LEDs are) so it takes 1-2 hours to print per Z-axis inch but, unlike FDM, the entire SLA layer is done at one time so printing 4 things takes the same time as one.  The panel doesn't last forever but Qidi claims 2,000 prints per panel and a new panel is currently $45, there's also something called an FEP screen which is a thin transparent film that sits between the resin and the LCD and that needs to be replaced more often.

Anyway, now I have this Qidi Tech Shadow 5.5S SLA printer on order. After reading a load of reviews on the $250 price range printers, this one stands out for:
- Quality of parts like the CNC aluminum frame and resin tank (one brand has plastic resin tanks that crack and cost $45 for 2 new tanks)
- Ships with ChiTuBox slicer software which is highly rated in online reviews
- Great support from OEM (as long as you're happy to do that via email - Qidi fixed an issue with my FDM printer and sent me new parts for free)
- Availability of spare parts at reasonable prices
- The LCD resolution is 0.045 mm and the mechanical Z axis can move in increments as small as 0.00125 mm although practical layer thicknesses are typically in the range 0.01 - 0.02 mm.

3D printers are not appliances (although there are some really expensive ones that are marketed as such), cheap ones are better treated as a complicated machine that needs to be understood, carefully setup, and maintained with TLC (Tender Loving Care).

Anyway, the results from SLA machines are (I hope) the quality level I'm seeking.  I can still see usage for the FDM printer but it would be for things like the clip for my mailbox or the toilet roll holder. 

Although I'm an EE, I taught myself FreeCAD vn 0.16 and find it good enough for my needs, I use it so infrequently that I have to go back and remind myself how stuff works like lofting. I use it most for making 3D models for components that I create in Diptrace, my EDA tool of choice. My friends rave about Fusion 360 but I taught myself FreeCAD and it does the job.

I'll report back when I get the new SLA printer set up and show some examples of FDM vs SLA.

[Mechatrommer]

The major breakthrough seems to be that the print is achieved by shining UV LEDs through an LCD panel into the resin to cure each layer, it takes between 2 and 8 seconds per layer (depending on the resin and how powerful the UV LEDs are) so it takes 1-2 hours to print per Z-axis inch but, unlike FDM, the entire SLA layer is done at one time so printing 4 things takes the same time as one.

watched youtube reviews on how good the resolution is.. apart from that, the bolded line is another good point, so this unit is worth investigating... it should be faster to print more like mass production small prints such as small enclosures etc. i agree FDM has another use, so these 2 tech will complement each other, not obsoleting each other. the $300-400 tag SLA is for such small build, i'm continuing my 500 x 800mm bed x 1400mm height FDM build, for bigger print, FDM is still the only way since i suspect we'll not be seeing super large UV LCD anytime soon, even if we have, the price should be insane. fwiw.

this explains this new tech MSLA type printer...