This project is still under development. The primary part of the project is the profiled top designed to create a flat platform that fits on top of the Robo 3D R1+. There are two .stl files for the top profile, one of which is blank, or flat, the other of which is grid which contains a grid of hexagonal recesses that fit a #8 hex nut.

Two of the top pieces would be required to span the entire top of the printer. The top piece can be rotated 180 degrees, and two can be bolted together. There are four 1/8" diameter x 1/4" deep holes for alignment pins, and two 1/4" holes that run the length of the piece with 3/4" recesses on the exterior side to accomodate flat washers and hex nuts (to bolt two top pieces together with a piece of allthread).

There is geometry that will align the top to the top of the printer, and a notch for the filament guide, which must be in the middle of the slot on top of the printer.

The following is required for each spool held (if two top pieces are used two spools can be held):

2 - Bearing Brackets
2 - Cross Bars
4 - Bearing Bushings (one for each bearing)
4 - skateboard bearings (two for each bearing bracket)
4 - #8-32 x 5/8" Flat Head Machine Screws
4 - #8-32 x 3/8" Flat Head Machine Screws
4 - #8-32 x 1/2" Flat Head Machine Screws
12 - #8-32 Hex Nuts

The crossbars should be bolted to the bearing brackets, and then to the top. The cross bars allow the position of the bearing brackets to be positioned on the top piece. A bushing can be installed in each bearing, which can then be installed in the brackets.

Update 2021-12-15:
After putting two of these on a single printer I realized I was unable to look through the slot on the top of the printer to feed the filament into the extruder when changing spools. As a result, I made the following updates:

• added a slot to be able to facilitate feeding filament into the extruder when changing spools
• added some smoothing to the interior curve matching the top of the printer

Aside from improving visibililty when trying to feed filament into the extruder, this also had the nice side effect of a significant reduction in print time (about 10 - 15%). I have also included the .skp files for the top pieces.