Ive updated the original X-Carriage I designed, and have included a mount for dual bowden extruders. The extruder mount also contains a belt grab, in order to control the carriage.
Adjustments include tweaking hole sizes a bit, along with circumscribed polygon size tweaks.
This X Carriage is designed to run on a 2020 v slot. 6 mm space built into the design. 7 mm holes for eccentric spacers included for fine tuning. Depth of bearing holes should allow for a full caphead bolt to counter sink. Accessory holes are laid out in a 20x40 pattern, and allow for an M5 bolt, with M5 nuts recessed.
The dual extruder mount: wow, this was a challenge. This is my second "thing", and being pretty non-design savvy, took me quite a few hours to like it. After a few test prints, and some minor modifications, I am finally happy with the fitment, and ease of belt entry. The extruders I have (sorry, dont know the brand), have a 6mm slot, oppose to some others on hand that only had a 4mm slot. This model has the 6, but if you need the 4, I have that on hand as well, just need to clean the stl up a bit. The 3 screws needed for attaching the cap to the mount are M3's, roughly 30mm long TOTAL. Thats including the caphead. M3 nuts are recessed into the back of the mount.
Printed all three of these in ABS at 100% infill. Took roughly 9 hours, and I am VERY happy with how they have turned out.
I hope someone else will find this useful.