At the recent World Maker Faire in New York, I bought my first 3D printer. It is a Printrbot Simple. I chose that particular machine because it is available assembled (I didn’t want to deal with a kit), inexpensive ($399 assembled), and has an active user forum (I figured that would be a more reliable source of help than the typical email support provided a tiny, fast-growing 3D printer company).
No doubt a lot of other consumers are buying the Printrbot Simple for exactly the same reasons. I’m afraid the majority of them are headed for disappointment, and many will be returning their machines.
In buying an assembled printer, I assumed that setting it up would be simple—something like setting up a desktop printer: plug it in, download a driver, and I would ready to start printing things.
That was a bad assumption. It took me more than 4 hours to get it running (and I probably have a much stronger 3D-printing background than the average purchaser).
The bulk of this blog post (and it’s a long one) details my struggles in setting up my “ready to print” Printrbot. I’m including a lot of detail here because I hope others who set up a Printrbot Simple can save themselves some grief by reading about the problems I had, and how I solved them.
Were my expectations too high? I suppose they were—but so are the expectations of thousands of other potential customers with even less background than I had. If Printrbot hopes to get (and keep) these consumers as customers, they need to make sure new users don’t have problems like those I had. I hope Printrbot is paying attention (although I have no basis for that hope). Most of the problems I encountered could have been avoided by making some simple corrections to the documentation.
The remainder of the post describes my frustrations in setting up the Printrbot Simple. If you aren’t considering this machine, there is no need for you to read on. But if you are getting a Simple, or if you have one and are trying to set it up, I hope you will find this helpful.
A promising start, and then… When I got home from the Maker Faire, I unboxed my Printrbot Simple. Everything looked fine. The package included a sheet of paper that told me to download the setup instructions from the Printrbot site, and I did that. The “Prinrbot Getting Started Guide” looked clear, with lots of screenshots to help out. So far, so good. I read through the instructions to get a sense of where I was headed.
Then I noticed a small square block (around 1” x 1” x 3/8”) of clear plastic sitting on the build surface. After a moment’s thought, I decided it had to be a test print done at the factory. It would need to be removed before I could print anything else. (Would an inexperienced user know this? It is not mentioned in the instructions.) I tried to pull it off, but it wouldn’t budge. I tried a kitchen knife (which merely chipped away at it) and a paint scraper (which had no effect).
Hmmm. I didn’t want to try anything that would damage the machine. I noticed the roughness of the blue build surface and recognized it as a layer of masking tape (which I had read about in descriptions of 3D printers but had never encountered directly). Perhaps I could peel up the masking tape, and the plastic block would come too. I carefully peeled up the tape, but the plastic block stayed put. The tape simply ripped off where it disappeared under the block. I could see that I would need a way to apply some brute force (but without damaging anything). I found a pair of parallel-jaw pliers (these were Craftsman RoboGrips, but anything with parallel jaws would have worked) and I applied some twisting torque to the plastic block. It finally came away, and nothing else was hurt.
Removing the sample print required a lot of force
I understood what I needed to do, and had the courage to apply the necessary force. But what would an inexperienced parent do, faced with setting up this Printrbot on a kid’s birthday? It might not end well.
There is one more step to take before setting up the software: removing the “shipping plate.” This is not mentioned in the instructions. You will only find out about it by reading a message in small print that has been laser-engraved into the shipping plate, which is a piece of plywood that looks a lot like various other plywood pieces that make up the Printrbot frame.
The shipping plate can be removed by cutting the three wire ties (zip ties) that hold it in place. (Important: do not cut any other wire ties!) Cutting the wire ties is difficult, because they are in an awkward spot that prevents the use of ordinary scissors. I ended up using side-cutting pliers. (How many ordinary consumers getting into 3D printing own a pair of side-cutting pliers? Come on, Printrbot, try to make this easy!)
Cutting zip ties to remove the shipping plate.
If you fail to notice the instructions on the shipping plate (as I did) you will be rewarded with ominous grinding noises when you try to operate the printer. Fortunately, in my case, no damage was done to the machine.
Setting up the software. The directions told me to download Repetier (the software that connects to the printer) and a USB driver. I did that, and started the setup process.
The first step is to plug in the power and the USB cable. The printer’s green LED should light up. (You may have trouble finding the tiny USB connector on the printer. Keep looking. It is just below the white connector with six wires emerging from it.)
Then I started typing various parameters into Repetier. At first, things went smoothly, but soon I ran into trouble. In retrospect I can see that I had actually loaded three different programs: Repetier (which deals directly with the printer and is used for specifying temperatures and filament parameters), Slic3r (which specifies how the 3D object will be decomposed into horizontal slices, and how the head will move when building the object), and Skeinforge (an immensely powerful but awesomely complex alternative to Slic3r).
Repetier, Slic3r, and Skeinforge are separate open-source software products whose development is controlled by volunteer organizations with no connection to Printrbot. When downloaded, they contain generic settings that are inappropriate for the Printrbot Simple (for example, the size of the build area and the size of the filament are wrong). It is important to put the right settings in, or printing will go wrong.
The Printrbot guide’s directions for Repetier were fine; but once I got into Slic3r I had trouble. Clicking the Configure button for Slic3r launches a “wizard” (not mentioned in the Printrbot material) which proceeds to ask a bunch of questions. Most of the answers can be found in the guide, but you have to search. I ended up cancelling out of the wizard and following the directions in the guide, which were adequate though not very clear.
I would suggest using the Wizard, which is much easier. Here are the answers you will need:
- Firmware G-code flavor: accept the default (“RepRap (Marlin/Sprinter/Reptier)”)
- Bed size: x: 100 y:100
- Nozzle diameter: 0.4
- Filament diameter: 1.75 (The Wizard warns that “good precision is required, so use a caliper and do multiple measurements along the filament, then computer the average”. Like most users, I don’t have a caliper. If this is really required—and I don’t think it is— Printrbot should include it.)
- Extrusion temperature: 200
- Bed temperature: 0
These values should get you started, with one important exception. The Printrbot Simple doesn’t have a heated build platform, so the bed temperature is always 0. For some reason, the Wizard leaves the temperature value for the “First layer” (the plastic that will go directly on the build platform) at 5 degrees. You want it to be 0, the same value as “Other layers”.
I’m not positive it is necessary to fix this value, but I think so (and it can’t hurt). You can fix it this way: in the Slic3r tab of Repetier, click Configure. The Slic3r window should open. Select the Filament Settings tab. At the left, click on Filament. In the window at the right, change the setting for “Bed: First Layer” to zero. Save the setting by clicking on the little square floppy disk icon at upper left.
Testing the print mechanism. Having entered and checked the software settings, I was ready to see if all the motors were working. I checked to be sure the power and the USB cable were plugged in and the printer’s green LED was lit.
I clicked the Connect button at the upper left in Repetier. Within a few seconds, it turned green and its label changed to Disconnect, indicating that a connection had been established. Then I selected the Manual Control tab. At this point, I expected to be able to make the Printrbot extruder move up and down by clicking the +Z (up) and –Z (down) buttons. But I did that and nothing happened. (Dozens of other users have experienced the same thing, judging by the questions on the Web). The only change was an increase in the Command Waiting count at the bottom of the screen This seems to be a bug in the Repetier software, and it cost me more than an hour of on-line searching and testing suggested solutions.
Fortunately, the fix is simple: at the bottom of the Manual Control tab is an OK button. (If you are running a laptop with a relatively small screen, you will have to scroll down to see it.) Click the OK button, and the Printrbot will execute the pending commands. After that, all your clicks will take effect immediately. You won’t need to click OK again.
At this point, I was able to test the various X, Y, and Z movements by clicking the arrows on the Manual Control tab, and they all worked.
When you do this, make sure the “zero” position of the z (vertical) axis is correct. The extruder will go directly there if you click on the house-shaped Z button (Z home). Try it at several different positions on the build surface. A business card should barely be able to slide in under the extruder.
My Z home position (which is controlled by a limit switch on the back of the machine) was set a millimeter or so too low, which meant the motor tried to drive the extruder into the build platform. Not good! This issue is not mentioned in the Printrbot guide, but I found I was able to adjust the limit-switch screw with a Philips screwdriver to fix the problem.
Setting the X and Y home position is also essential (and the Printrbot guide doesn’t mention it either). In principle, the Printrbot Simple should be able to determine its home position by itself, based on its limit switches. I couldn’t figure out how to make it do that, but here’s a method that does work. Click on the X home and Y home buttons (which will return the machine to what the software thinks is its home position) and then turn off the printer (which you do by unplugging its power cord). With the power off, pull the extruder out from the body of the machine as far as it goes, then push the build surface to the right as far as it goes. When you plug it back in, the software will be able to move the build platform correctly. You will need to do this each time you turn on the printer, or the software won’t know where it is printing and you run the risk that part of the object you are printing won’t fit on the build surface.
Loading filament. The filament-loading process is not well described in the Printrbot guide. The “extruder latch” mentioned (and pictured) in the guide is not present on my printer. Instead, there is a small wooden block with a hole for the filament that fits into an opening above the filament feed gear (the “hobbed bolt” referred to in the guide). The wooden guide block (which is not mentioned in the Printrbot guide) must be pried up and threaded onto the filament before the filament is initially fed into the hobbed bolt.
Prying off the filament guide
Start by raising the extruder 20mm or so, by clicking on the upward Z arrow. This leaves some space for the dribble of plastic that will emerge when it heats up. The extruder must reach its working temperature (200 degrees) before the filament can be fed into it. There is a button to heat up the extruder in the Manual Control tab. Once heating begins, you can watch the temperature values change until they reach 200, at which point you can load the filament. The tip of the filament should be trimmed at an angle (scissors will do for this) before it is fed into the extruder. Make sure the guide block is threaded onto the filament, but don’t press it into place yet.
Threading filament through the guide and down to the hobbed bolt
Feed the filament tip down into the gap in front of the hobbed bolt and click on the Extrude button. This is a downward-pointing arrow near the bottom of the Manual Control tab. Click Extrude several times until the filament is caught by the hobbed bolt and moves downward into the extruder. Once the filament is captured by the bolt, press the guide block back into place, with the filament passing through its guide hole. Click Extrude a few more times until a uniform string of plastic flows out of the tip of the extruder. You are now ready download, slice, and print a test file. (There are instructions for this in the Printrbot guide. I didn’t test them, since I already had some files on my machine from previous 3D printing experiences.)
Summing up. I bought my assembled Printrbot Simple expecting a relatively easy setup process. After all, I thought, I had struggled with a fussy RepRap printer for several months and learned its secrets. I didn’t expect any trouble.
In fact, the whole setup experience was disappointing. Altogether, it took me at least four hours to get my Printrbot Simple working. If I hadn’t already had a good bit of experience with another 3D printer, it could have taken much, much longer.
The Printrbot documentation was wrong in many respects, and it failed to even mention several crucial steps, such as removing the sample print block, removing the shipping plate, dealing with the filament guide, checking the height of the extruder relative to the build surface, and setting the X and Y home values. This is just unacceptable for a product that is meant to be ready to use by consumers purchasing their first 3D printer. Unless Printrbot gets its act together quickly, it is going to severely damage its reputation among consumers, it will be inundated by returns from people who failed to get their machines to work, and it will hurt the reputation of 3D printing generally.
Come on, Printrbot! You can do much better than this.
Tools I needed to set up my Printrbot Simple:
- Parallel-jaw pliers (to remove the test print)
- Side-cutting pliers (to remove the shipping plate—tin snips would do, or maybe toenail clippers)
- Phillips screwdriver (to adjust the vertical limit-switch screw)
- Scissors (to cut the filament at an angle)
- Masking tape (to cover the build surface as needed)
- Tweezers (to remove hardened dribbles of plastic dripping from the extruder)
- Ideally, I would also have had a digital caliper to measure the filament diameter precisely. Eventually, I’ll probably have to buy one.
