This is an all-in-one upgrade kit to get a bowden extruder for your anet a8. My target was to use as many parts as possible from the original kit, so most parts used for the upgrade are spare or original parts from the kit or parts you could print by yourself.
In addition you will need to M10 Push Fittings and some teflon tube which is available as a kit at Banggood:
The only other parts I added are some M3 and M4 nuts and washers.
The mounting adapter was taken from 3Dator´s Bowden Extruder
The motor block was customized from Lancervo21´s Anet A8 Bowden update
All screw threads were generated with Poor man´s openscad screw library
Print the pneumatic_adapter with 100% infill as this has to be pretty solid. The other parts were printed at 50% but less may be good as well.
The adapter has to be rotated by 180° before printing.
Print all the Parts and make sure the all holes have the correct size. You may need to use a drill to make them wider, especially the one the filament will pass through.
After that, attach the push-in Fittings as shown in the pictures below.
Disassemble the extruder, you will have to take it completly apart for the conversion. After that, begin with the reassembly as shown in the pictures.
For attaching the fan to the hotend I left out the heatsink as I don´t see it´s purpose anymore. As a spacer between the fan and the aluminium block my Anet A8 extruder lamp could be used. This is not the perfect solution but it does the job. As an alternative you could also use some nuts as spacers.
Make sure everything fits very tight
Now we will start to assemble the extruder Motor.
All needed parts
How the mounting adapter is positioned
Add an additional M4 nut to the screw as spacer
assembly of the feeder block
should look like this
make sure the pinion gear is aligned correctly, put away the black part after that
now attach the feeder block to the motor. I originally wanted to use fitting screws but I could not find any so I used two washers
now attach the black part and mount the spring between both parts.
Congrats, you´re almost done.
As I could not find an appropriate spot to mount the motor on the printer frame, I mounted the whole printer on a piece of wood and put the motor next to it.
Now you just have to attach the teflon tube and connect the motor to the mainboard again.
You may have noticed that the color of the adapter changed during assembly. The reason is pretty simple, the gray part was printed with 50% infill like the other but broke at one point during assembly so I had to print it again.