Polygon Robotics - Polygon 2060
Posted: Fri Oct 07, 2016 5:31 pm
Before I start, despite the name the only thing i have to do with this printer is I backed it on KickStarter, and I was aware of the designer.
WARNING as of this writing documentation is still incomplete, and all that exists for what is documented is a video with no voice over.
The claimed build area is 10 inches diameter, the arms will certainly get there, but my guess is in practice it will be closer to 8 or 9 inches.
The Kit itself is very complete, it consists of everything you need for the build minus the electronics and heated bed if you want one. I built mine with an E3D V6 Lite, Duet 0.85 and a heated bed.
Outside of the extrusions, the acrylic black panels around the top and the plexiglass enclosure pieces, the majority of the other parts are made of laser cut Delrin. I've machined Delrin before, and many of the nice properties that it has there transfer over to building things out of layers of it held together with machine screws. There are almost no nuts in the entire build almost everything is build by tapping the Delrin with the provided screws. The Delrin holds up stunningly well to repeated reinsertion of the screws.
The printer itself has a novel linear bearing design, basically the extrusions are the rails and delrin pieces inside the slots constrain unwanted movement, you can see the assembly of them in the videos on the polygonrobotics page. I was somewhat dubious how well this would work, but it turns out very well, the only real criticism I can make of it is the relatively large number of adjustment points that have to be fiddled with to get the tolerances correct.
Because the bearings are inside the rails, the enclosure is incredibly simple, the plexiglass pieces are simple placed in the slots in the frame rails under a small amount of tension, two of the sides have two pieces of plexiglass that overlap slightly, so the bottom one can be slid up as a door.
The arms use magnetic joints and IME so far work well with a caveat (see later)
The Design is very clever, bordering on the over designed in places, the hotend mount for example is probably the most rigid I've ever seen, but your not going to be swapping it out quickly.
The only real problems I've had with the kit have been minor.
I had an issue with one of the magnetic joints becoming disconnected when moving around the outside of the build area, I could see no mechanical interference, and it occurred even after dropping my speeds/acceleration and jerk values to unbelievably low levels. I believe what was happening is that there was enough friction between the magnet and the ball that is literally rolled out of the magnet. I put a dab of lithium grease on the balls and it appears to have resolved the issue.
It's not a quiet printer, not that it's excessively loud, but with the enclosure pieces in place they act like a big sounding boards.
I broke one of the acrylic panels for the top, this was my fault I was trying to test fit something in the electronics bay and flexed it too far, Billy has promised to send me a replacement free of charge.
Overall I'm very impressed, there is little to no slop in the mechanics of the machine, the platform feels as rigid as any delta I've used even towards the edge of the build platform and that shows in the print quality.
The first print I pulled off the machine, all I did was guess at the ESteps value and it is probably the best first print I've pulled off any machine, other than some minor over extrusion which was entirely my fault, it was pretty much flawless, no ringing, perfect layer alignment.
I haven't spent a huge amount of time on the printer yet, but I have printed a couple of 6 inch diameter ABS parts with the enclosure on the printer and there was no warping. I was a bit concerned about heat in the electronics section, but it seems to stabalize with the Duet CPU around 60C which is well within it's tolerances.
The printer is an incomplete kit, there are no electronics provided, and no heated bed, these were both intentional decisions made to dissuade inexperienced builders from backing the initial KickStarter run of kits. I have no idea if Billy intends to continue production outside the initial run, but there is a place on his website to sign up to be informed when additional kits are available.WARNING as of this writing documentation is still incomplete, and all that exists for what is documented is a video with no voice over.
The claimed build area is 10 inches diameter, the arms will certainly get there, but my guess is in practice it will be closer to 8 or 9 inches.
The Kit itself is very complete, it consists of everything you need for the build minus the electronics and heated bed if you want one. I built mine with an E3D V6 Lite, Duet 0.85 and a heated bed.
Outside of the extrusions, the acrylic black panels around the top and the plexiglass enclosure pieces, the majority of the other parts are made of laser cut Delrin. I've machined Delrin before, and many of the nice properties that it has there transfer over to building things out of layers of it held together with machine screws. There are almost no nuts in the entire build almost everything is build by tapping the Delrin with the provided screws. The Delrin holds up stunningly well to repeated reinsertion of the screws.
The printer itself has a novel linear bearing design, basically the extrusions are the rails and delrin pieces inside the slots constrain unwanted movement, you can see the assembly of them in the videos on the polygonrobotics page. I was somewhat dubious how well this would work, but it turns out very well, the only real criticism I can make of it is the relatively large number of adjustment points that have to be fiddled with to get the tolerances correct.
Because the bearings are inside the rails, the enclosure is incredibly simple, the plexiglass pieces are simple placed in the slots in the frame rails under a small amount of tension, two of the sides have two pieces of plexiglass that overlap slightly, so the bottom one can be slid up as a door.
The arms use magnetic joints and IME so far work well with a caveat (see later)
The Design is very clever, bordering on the over designed in places, the hotend mount for example is probably the most rigid I've ever seen, but your not going to be swapping it out quickly.
The only real problems I've had with the kit have been minor.
I had an issue with one of the magnetic joints becoming disconnected when moving around the outside of the build area, I could see no mechanical interference, and it occurred even after dropping my speeds/acceleration and jerk values to unbelievably low levels. I believe what was happening is that there was enough friction between the magnet and the ball that is literally rolled out of the magnet. I put a dab of lithium grease on the balls and it appears to have resolved the issue.
It's not a quiet printer, not that it's excessively loud, but with the enclosure pieces in place they act like a big sounding boards.
I broke one of the acrylic panels for the top, this was my fault I was trying to test fit something in the electronics bay and flexed it too far, Billy has promised to send me a replacement free of charge.
Overall I'm very impressed, there is little to no slop in the mechanics of the machine, the platform feels as rigid as any delta I've used even towards the edge of the build platform and that shows in the print quality.
The first print I pulled off the machine, all I did was guess at the ESteps value and it is probably the best first print I've pulled off any machine, other than some minor over extrusion which was entirely my fault, it was pretty much flawless, no ringing, perfect layer alignment.
I haven't spent a huge amount of time on the printer yet, but I have printed a couple of 6 inch diameter ABS parts with the enclosure on the printer and there was no warping. I was a bit concerned about heat in the electronics section, but it seems to stabalize with the Duet CPU around 60C which is well within it's tolerances.