With the summer heat here in the East, staying inside in air conditioning was a more comfortable option. And, with the arrival of my Printrbot LC+ last week, building this long awaited kit was the perfect indoor activity.
So how did it go? Well, total build time so far 5 hours (to what you see in the pictures). It is not yet ready to fire up but close. The heated build platform is off at the glass cutter for a custom fit — more on that later. For now, let me reflect on the good, the not so good, and some (yes) bad.
The kit had all of the parts as listed on the manifest, including some extras here and there. The laser cut plywood is stiff and nicely done. I had no fit issues per se with the plywood pieces. The electronics are well executed and the board is clean and has a nice layout. I bought an extra one earlier for use on another reprap project. You get a pound of black 3mm ABS filament to get started and an extra brass nozzle. It even comes with the USB cable. Linear bearings and smooth rod are nice but the use of threaded rod for the z-screw is a throwback to the old reprap days. By now Acme screw rod should be the norm here.
The motors and other electrical parts come with pre-wired connectors so that part is plug and play. However, no cable management materials come with the kit, so I used my own spiral wrap to dress the runs.
Not So Good
Documentation for the build needs a lot of help. For the LC+ what you basically have is a 2D layout of the laser cut wood parts that are more or less in spatial relation, but no 3D views of any assembly other than the extruder, which is common for all the models. What you do get are (IMHO) tedious assembly videos that are specific to the LC+ without any printed documentation and mostly one (above view) camera angle. Mr. Drumm sometimes contradicts himself or gets chatty with really unnecessary explanations. There are times when I just gave up watching and fast forwarded to some frame with a sufficient view that helped to show the result. The folks at the H-1 project (www.seemecnc.com) have an incredible step-by-step build book that Mr. Drumm should emulate for future sales from his store. Could my kid build this? Yes, he’s an aerospace engineer. Could your 12 year old build this? Probably not without some serious help. While I understand the response from the Kickstarter campaign was over the top, one of the first persons I’d get under some contract for help would be a CAD draftsperson to craft detailed documentation.
The z-axis uses two motors – one to drive each threaded rod. I’m wondering just how well this will work, because if one motor skips due to friction, the tilt of the x-axis will be affected. As it is now, it appears that there is some warping from side to side, so that may be something to address when I try to run it.
To insure positive engagement of the x-axis endstop, I turned the screw around so that the head was facing the switch. Not sure this is in the video or not, but if you use the threaded end the alignment is off enough that it misses the edge of the switch lever. Since this should be a once and done adjustment, I don’t see this as a big deal.
The Bad
Yes, there is some bad to share. Most of the printed plastic parts left a lot to be desired. The biggest problem was they were so undersized they couldn’t be used. The other problem was that on the down-facing surface, there was a noticeable flare where the plastic melted, suggesting to me a too hot build surface. This was most evident in the drive gear for the extruder. The result is that unless you remove the flare, the mesh of the extruder gears is very poor.
The extruder body itself was also undersized. Thus you could not easily place the hot end into the hole without first reaming it out. In the large extruder gear, the head of the hobbed bolt could not be fit into the opening. I was able to use the bed mounts and the Z-axis motor to screw adapters, but I reprinted on other equipment all of the other plastic parts. Comparing the sizes didn’t need calipers, as it was readily evident to visual inspection.
The heated bed didn’t come with a glass cover (which was expected) but there were no clips to hold down the sandwich of glass and platform as shown in the web catalog shot. In my case, I’m having the glass made with the corners cut at 45 degree angles away from the mounting screws so that the cover will allow for a bed leveling design I’m adding. Although it is mentioned that you can cover the heated platform with painters tape or Kapton tape, the glass surface has the advantage in being very flat and uniform. A local shop made mine for $8.
Conclusions?
For now, I’m waiting to get the glass for the heated build platform, and complete the assembly and confirm my electronics hookup. Of course, you will end up with a PC power supply on the loose, but that is the nature of this unit. Is it worth $699 at the store? Well, stay tuned, as a review of a Solidoodle 2 is coming next week or so. Although it has a smaller build envelope (6″ cube) it comes fully assembled and tested.
These days the numerous offerings of 3D printers for home use is very reminiscent of the early days of personal computers when models were showing up everywhere — VIC20 anyone?
UPDATE: I’ve given it the “smoke test” and after powering up, it connected to pronterface and all axes work and the hot end works correctly! Still waiting for that custom glass piece for the bed! ;-( Build video coming soon!
UPDATE #2: Glass piece came but now a big problem – the heated bed is defective! Somehow it is a dead short, and every time I turn it on from pronterface the next thing to happen is the power supply goes down from overload. I have a very sensitive ohmmeter and it says “dead short.” So, thankfully I had another 8×8 mendel prusa heat bed in the shop. I used this instead for the one that came with the kit and all is well! I contacted printrbot by email asking for a replacement but no response so far… The next thing is to actually try a print!
UPDATE #3: Someone from printrbot finally responded to my inquiry and at their request, I sent the heated bed plate back to them for testing on July 19. Well, two weeks later (8/4) still nothing heard… I did just send an email asking for an update on my board. Compared to Makerbot (where I find the response is almost immediate), the customer service here so far leaves something to be desired….
UPDATE #4: After some fun with the glass company and a replacement heated bed, the unit is done! But due to my work obligations, vacations and such, I’ve shelved this project because my 3D Systems Cube(tm) is now on the way. So, maybe I’ll get the time to actually fire this up again and test a real part on it. I’ll get a report out then!
CO2 laser cutters have been around for a while, but they are either very expensive or just (like low-end imports) not well designed. A new offering that is probably the most consumer friendly device I’ve seen in this area is called the “Glowforge.” The basic unit comes with a 40W CO2 laser, continuous autofocus, a 12″ x 20″ bed and internal object recognition cameras that work to identify the materials and alignment.
Renaissance Engineer 
You must be logged in to post a comment.