The CEL RBX01 Robox 3D Printer was graciously provided to me to review. Hobby King is known for their remote controlled parts such as airplanes, cars and all other sorts of things. They’ve stepped up their game by selling 3D printers and filament.
Some quick specs to get you started:
Build Volume – 210 x 150 x 100mm
Technology – FDM/FFF
Filament – Chipped/1.75mm
Extruders – 2 (needle value)
Heated Build Plate – Yes
Automatic Bed Level – Yes
Automatic Nozzle Height – Yes
Enclosure – Lockable Fully Enclosed
The height is actually quite low for a 3D printer in this price range, but what makes it extra expensive is that the printing area is completely enclosed in a chamber-like fashion. Furthermore, it has a dual extruder with one material input. This may be slightly confusing for some, but the CEL Robot is one of the only machines in the market that uses a dual extruder system using only only material. It does this by using a needle valve system where the nozzles will tilt out of the way of each other as it deposits material out of each respective nozzle.
You may be asking the importance of this. This is because the CEL Robot has a .3 mm diameter nozzle with a .8 mm diameter nozzle. The advantage of this is that you can print incredibly fast draft prints with the larger diameter nozzle, while still being able to print incredibly fine prints with the .3 mm nozzle (or of course a combination of the two). This is an incredibly innovative concept that Hobby King has put into their CEL Robox, and no one else has done this yet on the market. Having said that, they are bringing out a dual material upgrade and is currently in production. This is a probably a good thing. The upgrade to dual material capability will be pretty cool.
If you’re looking for a great 3D printer in a classroom environment, there may be some features of this printer that draw you toward it. For example, the closure comes down easily, and while the print is in progress it will lock in place. This is one of the few machines that has such a physical lock that can’t be opened while the print is in progress. As the bed moves forward when the print is finished, it will press down on the lever and lock the enclosure. As the bed starts to move backwards during the printing process, the door locks in place and you can’t open it. It’s worth pointing out that if you for whatever reason need to defeat the lock, you can simply insert a card to push the tab out of the way. Of course this is something you wouldn’t want to show your school kids, but it’s great in case you need to get in for whatever reason.
The Robox also comes with its own range of filaments, and each filament has chips in them. You might be thinking that they’re going the way of an inkjet printer in which you can only use ink cartridges with a certain type of chip in them, but this isn’t quite the case. The reason for these chips is to tell the software the type of filament, how much is left and also how much you’ve used thus far. The Robox best takes 1.75mm PLA, but you can also use copper filament as well. Running this through the machine didn’t have any issues. As long as you take into account that the print head on the machine is quite special and delicate that if you damage you can’t just rip it open and clean it, you can run other materials through the system successfully. However, that’s not what I recommend for a machine like this. As mentioned above, I recommend this machine for school presentations or experimentation due to the fact that it’s reliable, it works and has automatic calibration built into it. If the filament jams, the machine will pause. Not many machines even today have this feature.
Interaction and Software
In terms of inputs on the machine, you’ll notice that there are zero interfaces on the machine itself which to some may be a huge turnoff. However, this isn’t really needed. There’s a button on the side for when you change filament, but apart from that you have to do everything from the software – the Automaker Slicing Software. This software is designed to be friendly and easy to use for beginners. The new Automaker Software is much improved, using Cura or Slic3r as the backend slicing engine. There weren’t any issues with slicing speed. Rafts and supports pulled away quite nicely, and I had no real issues with slicing speed. Although I did find that the estimate for time in material took a very long time to chew through when it was doing the fine detail estimates, just taking a long time to spit out the number. What you will need to do is upload files via the included USB cable, and it will cache into the machine. Once it’s done you can disconnect the cable and let the printer keep printer. But if you want to do anything else – apart from pressing the button on the side to make it pause – you’ll have to do it via the software. This means that if you disconnect your computer, the machine will keep printer, but there’s no other way to access teperature or time information without connecting it back to your computer.
The auto arrange function in the software in itself is slightly buggy and will say that prints are outside of the build volume, but it is quite useful in organizing how you want your final print to be laid out. This made me realize even more that 100 mm in height for build volume is a bit limiting. I actually had to scale my prints down slightly since the overall height was just a tad over 100 mm. While it’s not a terrible thing, it’s a little frustrating because the Fabricator Mini is only $175 US and I could still get a print volume as big as 80 x 80 x 80 mm. The quality may not be as good, but for beginners it would be the best choice. The CEL RBX01 Robox 3D Printer on the other hand is close to $1,100.
The CEL Robox has a heated bed and heats up to 125 degrees celsius and is one of the few 3D printers that can print ABS pretty well without warping the material. It actually has a print surface which slides out quite easily by moving latches out of the way and pulling it free. The plate is a very thin fiberglass-like print surface with a sandy side and a glossy side depending on what you want to achieve. If you want something that’s going to stick better, use the sandy side. If you want something with more of a glossy touch, put the glossy side of the plate up. This works surprisingly well, and I didn’t have any issues with adhesion although I did get a tiny bit of warping with ABS prints.
One of the cons of the machine is that with the print bed, when you put it into the machine with the sandy side up you’ll notice that even though it’s locked in place, it can still move. It moves left to right about 2-3 mm. The first print that I did on the CEL Robox turned out a little bit different from the original model design. This wasn’t the printer failing, but rather due to the bed being lose. It’s kind of like having a well-designed car and having the steering wheel attached to a string. However, I’m almost positive that this is a batch issue and that my particular model happened to be like this – not all CEL Robox printers have a plate like this, especially since the other ones I reviewed didn’t have this issue. In order to fix this, I just placed pieces of card near the latches and it worked fine. This held the bed in place and stopped the bed from moving. Yet it’s still a bit disappointing.
Before each print, the Robox will wipe its nose by extruding a bit of plastic into a patch in order to clean itself. It’s in the form of a little cup, and it works really well. Make sure to put the cup back in with the bed. Sometimes it may stay attached to the nozzle, but for the majority of the time it’s not the case, and this has never happened to me with PLA, only ABS.
Automatic Tracking and Calibration
Another big selling point is the automatic calibration function. Before every single print, the CEL Robox 3D Printer will touch its head to various points on the bed and then use software compensation to automatically level itself in order to get a perfect first layer every print. This is phenomenal for ease of use for a first-time user. For anyone who has used something like the i3 design machine in which you have 4 thumb screws, leveling those beds by hand is incredibly tedious and difficult, and they change over time. So you may get a print that works great one week, but then the following week no longer sticks because it’s no longer level. The Robox does calibration automatically before every single print, so you have no options. This is definitely my favorite part about the printer.
I mentioned above that the filament sold by Hobby King does come with a chip, telling you how much filament is left, the temperature and how much you’ve used. Yet if you don’t use filament that has a chip in it, the printer will still be able to check if there’s a jam, a feed issue, or detect if the filament has run out. This is huge in terms of making sure your prints stay reliable and making sure that you don’t damage your printer leaving it unattended, whereas it could be boiling away for hours and having PLA burnt up in your nozzle causing you to replace it. This has happened to me in the past more times than I could count.
Let’s look at the print quality since the price point argues that you should be to get pretty good prints out of it. We’ve already shown that it can be reliable, but we still don’t know how good of prints we can get. We can print down to 20 micros, but I’ve only tested it don to 100. I must say that the prints are incredibly nice and very smooth. I ended up printing a test egg with the c copper PLA material, and it turned out great. The thread was clean, I didn’t need any support material, and it printed really nicely.
In terms of the rough prints, they were much faster, but the quality won’t be near as good. However, I kind of like how the prints came out because it gave them more of an authentic feel. It looked as if they were made out of wire. Even if you don’t want this feature and want something more detailed, you can always choose to go back to more detailed prints. .8 mm nozzle prints are significantly faster, but keep in mind that finesse and detail will be lost. There may be a bit of stringing as well. I haven’t fine-tuned the nozzle openings yet, and the results I received were by default. By doing a bit of calibration, I could probably get a little bit better prints.
We also need to go back to the fact that machines never stay stagnant. When I first got this model of the CEL Robox 3D Printer and fired up with the software, I was promoted to upgrade the firmware. I was able to compare two different prints from the previous software and the upgraded software, and the newer model didn’t have a melted top like the first one. They did quite a good job of improving it, and it gives me a sense of security knowing that Hobby King is constantly upgrading their products and materials for their consumers.
Overall, I was quite impressed with the printing quality, as not many 3D printers can print such a thin piece of material with such detail. I’m actually pretty impressed with the fine nozzle. I finally was able to test some ABS prints. My prints were fortunately produced without warping using Grey ABS filament. Both the .8 mm nozzle and the .3 mm produced great results, but the .3 mm nozzle definitely produced much better results. There was no warping at all, and the finished product was dead flat. This wouldn’t be possible without a raft since the bed heats up to 125 degrees. This is one of the secret sources in the CEL Robox Printer for being able to print ABS material. Just make sure that the print bed is super tight, and shim it up completely so it can’t move. That’s the only flaw that I found, and I’m hoping it’s a batch issue. Otherwise, the mechanics are completely fantastic.
For people who have other 3D printers and are looking at the CEL Robox, the print head is very, very special. The nozzles do tilt out of the way, they have needle valves and they are not user serviceable at all. If something happens to go wrong with the nozzles such as clogging up because of dust or you break them using a 3rd party filament that doesn’t configure well with the settings, you won’t be able to fix them at home. This is one of the biggest issues I can foresee, unless you’re willing to replace a broken head. If a head gets broken, you will not be able to fix it yourself. This is not a machine that you can abuse. It’s rather a 3D printer designed to print parts and be as reliable as possible while giving you great quality, and it wasn’t really designed for anything else. Again, it was designed for schools and classrooms in order to ensure safety, and you can even network 10 or 20 printers together up to one PC while having one person manning the machine. With the Robox you won’t have to worry about bed leveling issues. All the user will have to do is design the model and replace cartridges, making the Cel Robox 3D Printer incredibly value in this sense while being well-designed for its price point.