I designed this to mount an E3D v6 hotend on my PrintrBot Simple (2014 model). It should work with the previous models of Simple as well, but I don't have a way to verify this. It should also be able to accept other groove-mounted hotends as well. The pegs/holes are a little bit out of alignment with the wood peices on my Simple, but it does fit and is quite sturdy.

I would recommend >50% infill with 2 or more perimeters. Getting the hotend into the mount was kind of tough... Put a long M3 screw through the hole at the back of the mounting slot, then use zip-ties to pull the hotend in towards the screw. Once the hotend was seated I didn't need anything to hold it in place.

Attribution - Non-Commercial - Creative Commons

E3D, v6, E3Dv6, hotend, hotend, groove, mount