Anet A8 lightweight and unobtrusive X-axis cable chain by juh

Last crawled date: 3 years ago

Changelog:
Update 2021-03-01: Steve (faultedlogic) made a remix for current A8 models with plastic bearing blocks.
Update 4 (2018-06-17): added countersunk hole for chain fence
Update 3 (2018-06-11): updated left motor mounts for different type of end switch
Update 2 (2018-02-24): added chain fence
Update 1 (2018-02-10): added info on possible z-axis problems
This is a lightweight x-axis cable chain mount solution for the Anet A8. Compared with other solutions,
its chain links are placed upright, thus allowing for a less obtrusive position behind the left z-axis,
it needs less material (filament) and prints faster,
it needs fewer chain elements (23),
although placed behind the z-axis, it is still compatible with the Anet A8 exoskeleton by aeropic.
(However, you might lose a bit of z-build space, see Update 1 below) <-- now obsolete, see update 2
Note: My Anet is from December 2017, please take a close look at the pictures to check if your x-axis motor mount matches.
The left-side X-motor chain mount comes in two versions,
a short and basic one (X-motor_mount.stl) for minimalists like me,
a longer one (X-motor_mount_with_tunnel.stl) with an additional tunnel leading the cables to the backside and with an additional screw fix from behind for extra stability.
In addition to the left and right mounts, you'll need:
23 Cable chain elements from Anet A8 Y Cable Chain by sukhoi27 (download .stl file]).
two screws to remount the x-axis endstop-switch
for the longer left-side version: one screw ca. 3mm x 7mm for fixing the left mount from the backside for additional stability
This is my first published design after ca. 1 month of owning the Anet A8 and learning FreeCAD, and I'm terribly proud of it. Please comment and/or show your makes.
Update 1 (2018-02-10):
As I usually don't print that high I forgot to mention, but depending on your setup you might lose a bit of build height (but see update 2, below). My test results:
If you get your chain to coil nicely in a perfect U-shape or if you move it out of harm's way manually while going up, you could actually go as high as z=240mm (see fourth image, I used the manual method here). Just make sure that the cables at the left don't get caught between the x-axis motor mount and the left side of the lcd back panel.
If your chain doesn't coil perfectly in a U-shape, it could bump into the bottom of the lcd back panel at ca. z=160 (see update 2, below, for a solution). Not sure if maybe movement on the x-axis would actually prevent that from happening, as the problem mostly occurs in the right part of the x-axis. If your object doesn't use the full x-width, printing in the left half of the build plate should eliminate the problem entirely. However, I just wouldn't leave my printer unattended at these kinds of heights, but, hey, an A8 you should never leave unattended for long anyway, so...
If you're using the Anet A8 exoskeleton, the chain might also touch the right hand rod from ca. z=140 upward, but I don't expect that to be a problem if your chain is not too rigid. Also, at the very top the rod mounts will cost you 1-2 cm.
Update 2 (2018-02-24):
I've been musing about the z>160mm problem for chains that don't coil perfectly like mine (see update 1 above). I considered several approaches, but ended up with the most simple one: a fence which keeps the chain from bending back to the area where it could bump into the lcd back panel. For the moment, I added a standalone solution to be installed permanently beside the carriage chain mount (chain fence (standalone) v3.stl). In order to keep friction to a minimum, you'll need to thoroughly sand the faces of the fence which touch the chain. Maybe you'll even have to sand the corners of some of your right hand chain elements, if they are very sharp. After installing the fence, test it first by manually moving the carriage from left to right, to see if there is absolutely no friction left, before using it in action.
Against my own expectations, I could not observe any negative friction effects on the quality of my prints during my tests in the last week. Nevertheless, I plan on adding another clip-on solution, which allows you to use the fence only for higher prints on demand.
Update 3 (2018-06-18):Lethos1560 reported problems due to a different kind of x-axis end switch provided with his A8. This version of the switch has a longer lever which will collide with the motor mount, preventing the switch from being triggered. I updated both versions of the left motor mount with a second set of mounting holes for the end switch. Position 'A' is for the (as it seems) usual kind, position 'B' for end switches with longer levers. See images for type 'B' (extra image) and type 'A' (all other images) switches.
Update 4 (2018-06-17):Supernova_6969 pointed out that my original design of the chain fence needs a longer screw than the default one and posted a remix with a countersunk hole. Following his comment I updated my design accordingly using his measurements. Thanks again to Supernova_6969!
PS: If you've wondered about changes in the title of this thing, it's just my attempts at search engine optimization.
https://youtu.be/TKg5vBGrwKg
All my Anet A8 designs:
Anet A8 lightweight and unobtrusive X-axis cable chain
Anet A8 slim and robust x-axis tensioner
Anet A8 power supply cover with LCD power meter and switch