Introduction: Anet A8 Bowen Style Upgrade
A fairly simple method to convert your Anet A8 direct drive to a Bowden style extruder.
Step 1: Bowden Type Extruder Upgrade With Reasonable Parts and No Changes to Software
All you need are these 2 kits and some left over screws from building your Anet A8.
I went for pre-made parts (for durability) but there are printable parts on thingiverse too.
Which were created by Mafiatorte
Step 2: Once You Have the Kits...
Take apart your extruder assembly. Be sure to save all the parts in case you want a direct drive again later. This is a reversible modification.
The Extruder stepper is then mounted on the top of the frame using the bracket from the kit.
I used one of the existing screws from the frame itself and then drilled a new hole to have 2 screws holding the bracket down. I used one of the spare 3m screws and nuts that are used on the rest of the frame assembly.
Once the bracket is mounted to the frame mount the stepper motor and extruder setup to the bracket as shown.
I used both fittings from the bowden tube kit as the one that shipped with the extruder kit did not seem to hold the tube well. Attach the fitting to the extruder part before assembling the extruder parts and motor onto the frame. The drive gear on the stepper motor will need to be shifted back a bit so it is centered on the free wheel (use the smallest Allen wrench from the A8 assembly kit to unscrew the small Allen screws just enough to let it move). Also note, the spring from the kit is quite strong so take your time and be careful. I attached the gold part first and then the spring and the blue part.
Step 3: Once You Have the Stepper Motor Attached to the Frame...
You can attach the 2nd bowden tube connector to top of the bottom 1/2 of the old extruder assembly.
Make sure there is a snug connection between the connector, the threaded tube that the hot end connects to and the nozzle. If any of these connections are loose you'll get melted filament leaking all over. Usually you can get everything moderately tight except the nozzle (leave that only finger tight) then preheat for PLA and finish tightening down the nozzle. (There are good guides for this on you tube if you have issues with it.) Careful the hot end gets hot and will heat up any tool you use too. I always make sure to hold the hot end (the boxy thing) with a C wrench so it does not move while I tighten the nozzle. Having the fan duct out of the way helps for this process.
So, I basically re-used everything from the original direct drive assembly except the top part of the spring clamp system. It also needed two 3m nuts since the threaded stepper motor was no longer there to attach the heatsink to.
I also drilled a small hole in the top right of the front plate of the carriage so I could zip tie the cables to reduce the chance of them wandering.
When you cut the PTFE Tube to length be sure it is more than long enough to reach the furthest position of the extruder from the mounted stepper motor. I also needed to play with the tube to get it so it did not try to snag as it moved around.
This makes the X axis a lot lighter with out the motor on it but mostly for me this made clearing jammed hot ends so much easier as I no longer have to disassemble the whole direct drive system to clear out a jam and then re-level the bed etc etc. I can just unscrew the lower tube connector and usually that gives me the access I need to clear the Jam.
Be aware that you will probably need to set your retraction quite a bit higher than before since there is more flex in the system between the extruder motor and the head. I ended up being happy with 10mm at 60mm/sec but you'll need to tune for your own system as always.
Step 4: Don't Forget!
Keep your left over parts in a safe place! You can always put the direct drive back together if you find you prefer it or if you want to print exotic filaments that require a direct drive setup.
Good luck and have fun with your new setup!