Two months ago I posted my review of the Anet A8 and I thought it’d be a good idea to give an update after a couple months of use.
I’m not going to advocate letting your printer run unattended, this is something you should decide based on experience and should be based on trust that things won’t go horribly wrong. I have let mine run unattended without it starting on fire but I still try to avoid it.
The first safety step is to be careful of bad advice, there is a lot of it out there. Always look at things with a critical eye, especially if it’s accompanied by “should be fine” or something similar. Even be critical of my advice, I will try to only pass on things I have good confidence in but I am fallible and not an expert.
Safe wiring is a must, reading through various forums and Facebook groups I’ve seen plenty of wiring and connectors overheat and badly melt away. A common cause is not doing properly connecting wiring. The Anet comes with some screw terminals that are perfect for spade or ring connectors but doesn’t provide connectors so a common practice is to just stick the wire under the screw and tighten so it holds them in place. This can work but also can also start a fire if not done well and has burnt up many Anet connectors and circuit boards. Get a crimper, learn how to use it, and use the appropriate sized spade or ring connectors.
Never tin stranded wires that will be used in a clamp fitting, whether this is a screw terminal or crimped connection. This actually causes less contact with the the connector and can result in arcing and fire. Similarly don’t solder a crimped connection, you are just compromising the quality of the crimp.
The Anet A8’s board (and many other budget 3D printers) circuit boards are often barely up to spec for the actual current load or in some cases under spec which can manifest in burnt up connectors or circuit boards. You should install a beefy external mosfet for the heated bed at least, and since they are fairly inexpensive do the hot end too. You can read more about how and why to do this on the 3D Print Wiki here.
Finally in the safety category the connector for the heated bed is not rated for the current going through it. It will start discoloring or worse, keep an eye on it or just remove it and solder the wires in directly. Also keep a close eye on the wiring to the heated bed as it’s subjected to a lot of stress through movement.
Things you can improve with printed parts
This is another area where you need to be careful and critical of advice. You don’t need “z-wobble fixes” that fix the Z-axis smooth rods to the Z-axis threaded rod. The reason is that it kinematically over constrain the Z-axis and cause Z-wobble not fix it.
Wiring drag chains are super common but almost never are designed in a way that actually relieves bend stress on the wires and often creating a bigger chance of wire fatigue than none at all. This not to say you shouldn’t use them, they can be done right (basically the bend loop needs to be fairly large) and do look pretty cool but they aren’t some silver bullet.
Belt tensioning is important on the A8 and having proper tension can have a significant effect on print quality. There are plenty of designs available on sites like Thingiverse and My Mini Factory so I’ll let you chose your favorite or experiment. One word of caution with the Y-axis is to not over tension as the frame is just acrylic and not that strong and will break if you over tighten things. People do tend to over-tighten and then compensate by printing these huge support structures… I’ve had good luck not over tightening things.
As I mentioned in my original review I mentioned the Z-axis endstop fix, totally worth it and makes things way easier to setup. The only other real printer upgrade I’m running is using a glass build surface, I won’t go too into detail as I’m designing some improved parts for it and it’ll be a subject for another post but there are certainly plenty of guides that will show you how online if you can’t wait.
Parts you should keep on hand
I’ve learned the hard way there are some spares you should keep on hand, this is probably not a definitive list just the things I’ve run into so far.
Nozzles: I’ve had one clog, and one complete failure. For a clog I had a little success with removing the nozzle, buying a dollar store baking pan and heating it up to soften the filament and using a needle or tooth pick to help out any bits that won’t drain out. This worked ok, not sure it was worth it though. Replacement nozzles are readily available fairly quickly from places like Amazon and on Amazon Prime but they are super cheap on sites like AliExpress. My advice, stock up on them for like 60 cents each on AliExpress and and if you need one before they arrive Amazon is an option just expect to pay closer to $2 each.
Thermistors: This is the same thing as nozzles, can be found easily on Amazon but way cheaper from far east distributers and if you have a thermistor go out the machine will be out of commission till you replace it. While you are at it some Kapton (polyimide film) will be handy for this repair.
Threaded tube: I’m not sure what the correct name for this is, but this is what I’m talking about. I haven’t broken one of these myself yet but it can be as it attaches the heat block to the extruder and you need to tighten the nozzle while on the machine and heated up so a slip of the tool could snap it. I have some on the way for just in case.
I still think it can be a good deal if you are willing to deal with it’s faults and recognize that this isn’t a machine you set up and use. You set it up and constantly maintain and adjust it to keep it happy. That is not to say a more expensive machine necessarily eliminates all this, but can certainly reduce it.
I’ll leave you with this slightly hypnotic timelapse printing a simple crystal I found on MyMiniFactory. This is a slightly unique model in that it’s printed in what’s called Spiral or Vase mode where it prints the bottom and then does a single constant perimeter till it’s done. It’s a fast way to print models that can support it and very little plastic is used.