As a 3D print user myself, the setup and getting the Polar 3D printer out of the box and up and running quickly with ease is one of the most critical things. And I have to say using your printer so far it absolutely has been one of the easiest out-of-the-box. As a piece of hardware, it's a beautiful machine. I'm impressed with it.
This is part 2 of an in-depth, hands-on review of the Polar 3D Printer by Tom and Tracy Hazzard, of Hazzard Design. They discuss Printing in Circles with William Steele of Polar 3D. Based in Orange County, California, husband and wife design experts Tom and Tracy Hazzard have spent more than 20 years living and designing together. Collectively they have designed and developed over 200+ retail products that generate more than $500 million dollars in revenue. They hold over 35 utility and design patents with an 86% commercialization rate – double the USPTO-reported national average.
Tracy Hazzard: Something minimal is always actually harder to design. People don’t realize how much harder to design and invent something simple is actually harder than something complex.
Bill Steele: So what's interesting about that is when we first started we designed a printer that we kind of seeded into about 100 schools prior to releasing this latest generation device. We basically gave them the printer and solicited their feedback about what they liked and what they didn't like.
For example, we included the Raspberry Pi 2 on the board, our current machine, we have the camera on board, we have the slicing on board. Those were all the result of feedback from teachers that said, as an example, a student would plug in their computer into the printer, they would start to print and then the bell would ring for the next class. Well, they couldn’t take their computer with them. That was not to be an acceptable model and it led us to develop the entire cloud-based platform that we have now to support the printer so that a school could, for example, manage multiple students using multiple printers. And a student can design a part, they can print it to, I’ll call it, a print queue and then the teacher can select which printer to print that object to. Again all of that is the result of the feedback that teachers gave us on what their actual workflow is.
We designed the machine around their feedback and workflow.
Tom Hazzard: Since I’ve used your cloud-based system, I could tell it's really meant for students and that's fine. But is the cloud-based slicing the only way now to slice a print and send it to the printer? Or, is there an offline way G-code can be created and sent to the printer?
Bill Steele: Again, because we have to support every environment from a school's perspective, we also have to support what their infrastructure allows. Some schools require that a PC be tied to the printer and that it is not on the network. So you can use a standard desktop software.
A great example package is something called Simplify3D and their package is kind of printer neutral package. To print to any 3D printer, you just connect that to the printer via a USB cable. There are other features built into the printer itself where you don't even need the cloud. For example when you first take it out of the box and turn it on, it will automatically stand up its own WiFi hotspot. And I do this all the time at tradeshows. I'll ask a volunteer for their phone and I will connect to the printer with their phone using just the local WiFi hotspot.
I’ll upload a file and hit print and the printer because all the slicing is on board the printer, we don't actually need a PC involved.
Tracy Hazzard: You know that’s one of the things that impressed me the most though is that because your printer is – it came in the smallest box I’ve seen yet, and yet still capable of printing some of our largest prints. And it’s so easy and small that you could take it to do demos and to teach in other locations. So I think that's an ideal…
Bill Steele: Again, that's based on feedback from teachers. One school might not have a large budget and instead of having the printer in a lab or in the library or something like that, we added the handle, we made the machine completely portable because of those requests. Where they said, I'd like to take this printer from classroom to classroom depending on which class needs it, you know.
We even have schools that allow their students to check out the printer and take it home with them. So we had to make the machine incredibly rugged. Our original machine was actually made out of wood and then later on we moved to acrylic and then later on after that to aluminum. We even found that the aluminum wasn't rugged enough for some of the scenarios, so the current generation is made up of very thick steel, it takes quite a bit of tooling to actually make the machine. But you know as you can tell, it's an incredibly rugged machine.
Built Like a Tank
Tom Hazzard: It's definitely built like a tank, it's a small machine, but it is built like a tank, no question. So, Bill, I have to apologize because as I went through your website and the instructions that came with the printer and I couldn't find any information on printing in a standalone way. And I have Simplify3D, we use it with other printers and I couldn't find any profiles to use Simplify3D. So I'll want to get that and do some more testing before we finish writing our review of the printer.
Bill Steele: We have profiles actually out in the support forum. You can actually just type in Simplify3D and it should bring up my profile right in there.
Tom Hazzard: So if I create a G-code file with another slicing software, and I connect to the printer via its own WiFi, I can send a file to it and it will just start printing?
Bill Steele: You can’t send the G-code through WiFi directly, but you can actually connect your WiFi and send a model to the printer and it'll slice it on board the printer, okay.
Tom Hazzard: Okay.
Bill Steele: And that's just through the local pages. But the USB port allows you to use the external software, so Simplify, Repetier or Cura, any of those packages will work just fine with the printer by connecting to it.
Tom Hazzard: Okay, very good.
Bill Steele: And then you're just using just like you would do any other 3D printer out there, your desktop software connected to the printer printing over that.
Calibrating the Build Plate
Tom Hazzard: We have actually several printer reviews going on at the same time, yours actually looks like going to be the first to get published. But with every other printer, it takes quite a while to calibrate the build plate. I was really impressed at how easy it was to just take your build plate, set it on there and there is really nothing to do.
It seemed in the print process it sort of senses the build plate and makes sure it's where it thinks it is and starts printing.
Bill Steele: Yes, that's another benefit of using Polar coordinates where the standard Cartesian printers are moving the head in multiple axes. The polar coordinate printer doesn't have to do that. We move the bed in two axes, but when you take it apart and when you look at it, you realize that it's not actually moving it in two axes, it only moves it along the radius and then rotates it along the angle. Well, the benefit of that is we only have two linear rails to deal with and as long as we as builders of the machine build those rails parallel to each other, no error can be introduced into the build plates because the build plate will always rotate around that central radius.
Tom Hazzard: You've taken care of maintaining I guess consistency and relative positioning in the hardware you've manufactured rather than leaving it up to the user to make sure it's right all the time and periodically fix it?
Bill Steele: Right, exactly. We still do have a calibration process, but what we're doing is we're calibrating, for example, the Z-height, the vertical height. A user might decide that they want to use painters tape or they're going to use a glue that’s thicker than our normal hairspray for various materials, you know various reasons. And in those cases they need to recalibrate the Z-height so it knows where to start. Certain materials react differently – so you have to have that.
The other one that we have is calibration for the X-axis where basically you’re aligning the nozzle with the center of the build plate. We'd literally use just one single sensor in the entire printer that senses both the Z-axis and the X-axis, which is the radius, to actually get it to that center point. And that's built into the printer.
It's a very simple calibration script that's built into the printer.
Tom Hazzard: We’ve made several test prints and, and actually the quality that the print produces is quite good. I mean, we had a few mistakes we made along the way and that's pretty typical, but the service quality of the prints and everything is quite good. There's one question I have, though, it seems that the very center of the build plate seems to be an area where some, I guess, surprises have occurred for us. And I was tending to move parts away from the center of the build plate to avoid that, is that typical, do you see that?
Bill Steele: Yes, there are a couple of issues that you can run into in the very center of the build plate, because we're using Polar coordinates that's our pivot point that we rotate everything around. If your part is smaller than the radius of the printer, you can actually simply center the part on the radius and you will avoid any of the – what we call the singularity, the singularity at the very center of the build plate. That's a lot more efficient to print mechanically anyway, if you move it off center because if I put a square in the middle of the build plate, the build plate has to rotate 360 degrees to cover all of the area of that square. But if I move it towards the edge of the build plate, the motor only has to rotate the build plate a few degrees to cover the entire area of it.
So mathematically and mechanically it’s a lot more efficient to move it off of the center.
The other thing that you'll see there is that I mentioned the X-axis calibration, if you don't have that X-axis calibration perfectly tuned to the very center, then you could actually wind up with either an overlap or a gap in the very middle, because the nozzle either reached too far or didn’t reach the center of the build plate. And again that calibration process is a very simple fix for that just to recalibrate that. But yes, because for example if you're drawing a straight line to the very middle of the build plate, it will move along the radius and then have to rotate the build plate 180 degrees and then move away. Because of that dwell time where it kind of rotated around a little bit, you will have a small artifact left over there.
Tracy Hazzard: Yes. That’s what we’re noticing. It's like a little rough spot.
END OF PART 2