3D printing with Exa3DCube Pro
Yes, I bought a 3D printer for me! You can find it here:
Nice pictures, good reviews… But as it usually happens, there is a dark side (but not without the bright one)! And I want to discuss about it (but not only — I will give many pieces of advice). So, let’s start…
- DHL shipping is included in the price. From my point of view this is not bad — I love the speed of the guys from DHL! But I promised the dark side… OK, here you go — before leaving Hong-Kong and reaching Republic of Moldova in less than 3 days it stayed there for… 1 week! Also, because seller was overloaded, printer was sent not immediately after placing the order (I bought it on Thursday and the printer was handed to DHL on Monday). In the end, considering all the days, it wasn’t the expected express shipping…
- Description. It contains nice images, but they do not reflect all the aspects… Cables. There are all the cables? I wasn’t thinking about that till I started assembling the printer. On the photos in the description you have no cables, except for the one from the fan. Connect all the cables and you get a very messy device… Really, it looks ugly! Had to fix it with a lot of black tape. Thanks to my big desk I had enough space to place all this mess! Another thing is the main table on which is standing the printer — it’s not actually this shape. You can see on the photos the display installed in the corner of the printer. Actually, there is no corner at all (check out the photo below)! Last thing to mention here — roll holder is not mentioned (but provided, which is nice!). It’s ugly and primitive, but it’s way better than without it at all;
- Materials. Frames are really good! No questions about them. But the rest… Non-metal parts are made of acrylic. And all of it is covered, you need to clean it yourself. It is not a problem with the parts not assembled, I am not that lazy. But what to do with the parts already assembled? I decided not to touch them, I am OK with the look. But that’s not all — some parts are made of black acrylic, others are transparent! Bad, bad choice…
- Heat bed. In the description it is not mentioned if it is really a heat bed. The only way to guess it is the fact of mentioning the «Hot table tape 20M». If we started talking about the heat bed… Don’t use the tape! Yes, it does it’s job of fixing the printed part on the bed, but too well. It is hard to take the finished thing from the bed! A better idea is the dry glue (check the image below). But the experiments showed that the dry glue is also way too strong… So I tried the liquid glue (silicate if I am not wrong, check the second image below). You have to pour it enough, but the result is nice — the printed thing stay well on table during the printing and at the same time it is easy to take it from the table when finished! It is even better to mix these 2 methods — first layer put silicate glue and above it the dry one. It’s firm but simple to take out. Important moment — pay attention to the sliders of the bed! In my case they were on the wrong side (third picture below). And one more thing — take care to level the heat bed as even as possible! UPDATE 12.05.2016: Better use cold bed and the tape (with heating after printing). And put a radiator on the bed’s IRF! It is getting freaking HOT during the work and may kill your printing!
- Power supply. Actually, it’s good! Does the job perfectly.
- Electronic components. Pretty much no questions, it works as expected. Arduino Mega is a Chinese clone (it’s clear by the fact that it is using CH340 chip for USB communication). You also get an All-in-one Card Reader + SD card 1GB. Don’t repeat my mistake and try to search for the manual in the box or Internet — it’s actually on the SD card… (shame on me!) Instructions are not full but pretty much covers the necessary basics. Regarding the LCD screen — had to enlarge the hole for the rotary encoder button.
- Firmware. Oh… It seems I made some stupid mistakes during the assembling and couldn’t get the printer to boot. In the end I decided to load the Marlin. It booted the printer successfully, but default configuration was not adapted for Exa3DCube. Had to spend some time to finally get the right values in the Configuration.h. If you will want to repeat my path — here is my configuration: http://pastebin.com/BkD8bF6u
- Extruder motor. Oh… Pain in the a**. Really. Constant problems with feeding. Reasons — gear position and grip; roll getting hard to pull. Let’s analyze each of this problems. First one is painful — it is really hard to set it up nicely, have to constantly monitor and adjust. This problem leads to the second one — roll can’t be pulled easily. This happens especially with new rolls, with filament getting out of roll and getting stuck at some degree. Damn annoying to constantly monitor the printing! Still thinking on how to solve this issue… UPDATE 31.12.15: Seems that I found the source — spring is not strong enough. This can be easily identified by the fact that filament is scratched and its pieces remains on the gear. In order to fix this I just put a screw in the hole on the left, which in turn increased the pressure on the filament. No more scratching, filament is extruded/retracted without a hitch!
- Extruder itself. Does it job really well, nothing bad to say. But I have some advice for you — don’t even think to get rid of the fan! You MUST use it! The reason is simple — if you won’t use it, the filament will clog in the tube and you will have to clean it up (very unpleasant job)!
- Plastic cooling. There is NO fan for cooling the plastic during the printing. Yeah, that sucks! So, I had to improvise. On the left of the heater there is a hole. I used it to install a 80 mm fan. But compared to the 40 mm fan you can connect it to the RAMPS, in order to be able to control it (I enabled it in the configuration I gave). Connect the wires to the Heater 2 section (and check the air flow direction — it must be oriented down!). Works nicely and quiet enough. Yeah, it’s not cooling the exact spot of printing, but the practice shows it’s much better than nothing!
- Illumination. None in the box, but would be nice to have. I used some simple 12 quadro-LED square and fixed it using the 2 fans installed. Power comes from the power supply, thanks to 12V support. For convenience, as in case with 40 mm fan, I used a switch to be able to turn on and off the LED as desired.
- Endstops. Bad, BAD idea to use buckles for them! Especially for Z axis! So, don’t be lazy and find some spare M2 screws and nuts and fix endstops in a proper way. Thank me later!
- Z axis. In my case it’s not high enough. Had to search for 2 nuts of the right size.
- Control software and slicing. On the SD card you can find Repetier and Cura. I preferred MatterControl (downloaded from the WWW. They have a version for Linux too), I got used to it. It can perfectly control the printer through the USB, but, of course it is way better to load the G-Code to the SD card and print autonomously. You never know what can happen on your computer… And yeah, I hope you know the rule — never remove files from SD card till it’s not full? This simple rule will make your SD card live much longer. Here are my printing settings at the moment of writing the article (they permanently get adjusted for better results): http://pastebin.com/cGqagPRW
- Belts. They are used for X and Y axis. With X situation is simple — just tighten and you are done. With Y axis it is more complicated… On the upper side, there the motor is installed there is not enough tension, whatever you try. So I printed something like this: http://www.thingiverse.com/thing:1191949 It really helped, but it will be hard to install it, you will have to push it to the bed table and «vandalize» a little bit the Y axis endstop in oder for it to «react» earlier.
- Use some tape underneath the main table of the printer so it won’t scratch your desk.
- Motors. They are getting BLAZING hot during the printing, still thinking how to cool them down… If your printer is idle it doesn’t help to disable steppers from the menu — better shut off the printer completely. UPDATE 12.05.2016: So I solved the problem — bought eight medium-sized radiators and attached them to the motors with thermal-conductive glue.
- Buckles. Use them as many as necessary to clean up the mess with the cables (I also used black tape a lot for this purpose, as I mentioned earlier)
- To be continued/updated…