I backed the Kickstarter campaign for the Pegasus Touch SLA printer, which I got for $2,250. At that price, and given the samples they were showing, I thought it might be a good deal. Of course, with Kickstarter, you never know. And I’ve been seeing grumbles on the forum from other people who have received their printers (or perhaps not).
I received my box a few weeks ago and finally had a chance to set it up this past weekend. The packaging was good, and there were no issues with broken parts. The box included the printer, a 1/2 liter bottle of clear resin, and the power supply. That’s it. No manual.
I downloaded the manual and software and setup the machine on my desk. My desk isn’t near an Ethernet jack, so my desktop computer is connected via Wifi. No problem, the manual indicated that I could print without a network connection, using a USB thumb drive. So I fired up the machine. A splash screen appeared, and then the screen went blank after about 10 seconds, and just stayed that way. Even after 10 minutes, it was still blank.
OK, perhaps that meant I needed to update the firmware first. But how to do it. I checked the manual again, and the manual said that “Ethernet is the preferred interface but USB PC connection (requires microUSB cable, not supplied) and WiFi (requires dongle, not supplied) are also supported.” So, I connected the USB cable, and after some fiddling to get the drivers installed properly on Windows, the machine showed up in my devices list. And now RetinaCreate (their software package for talking to the printer) told me that the printer’s firmware needed to be updated. However, I couldn’t find a way to update it.
Finally, I moved the machine to another location where I could plug it into an Ethernet wall jack. It booted, and I was able to update the firmware. It turns out the manual isn’t correct, and you need a hard-wired Ethernet connection, at least to get started. I haven’t tried it without, so I’m not sure what does and doesn’t work. However, I was able to print—yay!
I loaded a model into RetinaCreate that I’ve been working on for a while to stress test the printer. This is a small caboose in HOn3, and it’s just under 7 cm long. You can find more details in my previous blog posts:
Here is what I got after 5 hours (using 50 micron layers):
You can click on the image to see a larger version. Below I’ll describe more about what I learned. But first, here is what the 3D model looks like in Solidworks:
And finally, here is what I had in RetinaCreate:
In case you caught that I had clear resin, the picture above is after spray painting the model with light gray, which makes it a lot easier to see what the surface looks like. Also, I hand-modified some of the supports after using the automatic support generation feature.
What I learned
First, I learned that this printer has a lot of potential for creating small models. Until I printed this model, I wasn’t sure it would live up to the task. Sure, the printed part will need some sanding to smooth out the curved surfaces, but so do models from Shapeways.
I also learned a lot about working with SLA printers, which is very different from working with FFF printers. The model is printed upside down, and that meant that uncured resin got trapped in various parts where I didn’t want any resin. As an example, look at the floorboards at the end of the caboose. In the printed model, they didn’t turn out very well. A lot of resin got trapped under (or above when printing) the floorboards, so there was a lot of goopy resin still in there when I took it out of the printer. The floorboards also didn’t cure very well. That may mean I need more support, or it could be a result of the goopy resin above.
As it turns out, the orientation I used was completely wrong. I’d always wondered why SLA printers tended to print parts at strange angles. Well, now I know—it’s to allow the uncured resin to drain out of the part as it prints, so you don’t end up with partially cured goop. Using clear resin probably doesn’t help, as any trapped resin can still receive some light. I really want to get some tinted resin to see what difference that will make, because the laser doesn’t travel very far into opaque resins.
After printing this part, I discovered that RetinaCreate has a button called Find Optimal Rotation that only appears when you have the object selected. I had not noticed that. Here is what it looks like when I use that option:
That’s a very different. I’m not convinced this is the optimal angle, but I’m going to give it a try.