Prusa I3 Auto levelling bowden carriage

Since I first heard about about auto levelling the bed I wanted it on my Prusa I3. I also wanted to convert it to a bowden carriage to speed up my prints a little. This is the result.
http://www.youtube.com/watch?v=0vTvOp6-MhM




The servo used is a Tower Pro micro servo 9g SG90, easily found on ebay for cheap. I am using 2 40mm fans for cooling but they are optional and can be disabled in the source code.

BOM:
*REQUIRED*
1x SG90 9g servo
1x microswitch
2x m3x15 screws and nuts for microswitch
2x m3x10 screws and nuts for servo
2x m3x40 screws to mount carriage
2x m3x40 or m4x40 screws and nuts to mount hotend (provided STL's are m4)

*OPTIONAL*
2x 40mm fans (optional)
6x m3x20 screws and nuts for fans
1x bowden coupling (this is supplied with bowden version of hotend. only required if your using the non-bowden version)

I used the bowden version hotend, but I added support for the normal version too. All you need to do is change the "bowden_hotend" variable to false and change the "bowden_thread" variable to suit your coupling.

The files can be found here: https://github.com/N3MIS15/3dprinting
To get the auto levelling working I highly suggest watching ZennmasterM's guides on converting his makerfarm I3 which can be found here: http://www.youtube.com/watch?v=awsI9bMndJA&list=PLU2kePyB_WAZlCnA-fMbLDbGeFXTffiP9. I could never explain any better than he did.

Cheers,
David

 

I have tried a couple intergrated designs the past and neither of them could cool the print enough for bridging (IMO) hence the overkill duel 40mm fan design. This is also my first foray in openscad, so nothing to extravagant .

 

Doing a test print now.

*EDIT: Clearances are tight but it all seems to fit. With the front fan enabled all wiring will need to be routed out the hole next to the servo, so I have made that a little larger. Changes are on github.

 

I stopped my test print once it reached the new mount, so no pics of that. I am going to try to add nut traps behind the heatsink fan because at the moment its near impossible to get a spanner on them.. A new print will follow.

 

Source is on github as per usual.

The nut traps worked a treat and I am officially out of 40mm fans :lol:

EDIT* BTW this picture is the non-bowden version (I am awaiting a 1/8 BSP tap to get this going on my other i3 printer) the only difference is it adds 4mm extra to allow the bowden hole to be tapped.

EDIT2* quick edit so you can see the difference between the original and the heatsink fan version...https://www.dropbox.com/s/jqw5jkg9bah223c/2014-03-14 22.00.25.jpg