RoboVac Accessibility Door Threshold Ramp (1" Height-Scalable, Multi-Width)

Our home has a number of ~1" (25-28mm) tall doorway thresholds throughout our first floor that makes in nearly impossible for our robo-vac to traverse the whole floor of the house w/o getting stuck on one of the thresholds. 

This has also been something of a tripping hazard over the years and I finally decided to solution-the heck out of it. ;-)

This design has 4 main components that can be used in a number of combinations to creation threshold ramps as narrow as 20" and as wide as pretty much how many "B Parts" you feel like printing for your need.

1. Part A - Right-side curved edge, 6.375" (160mm) wide

2. Part B - Right-side center panel, 9.575" (220mm) wide, or 10.825" (270mm) wide

3. Part C - Left-side center panel, 9.575" (220mm) wide, or 10.825" (270mm) wide

4. Part D - Left-side curved edge, 6.375" (160mm) wide

The center panels come in two variants: 220mm and 270mm width that can be mixed and matched for fitting to your specific width.

There are also two back-edge variants:

1. Chamfered, which provides a 6mm chamfered edge to accommodate a clean fit the a square-edge threshold and provide gap for cable runs. 

2. Quarter-Round, which provides a ~14mm cutback to accommodate 1/2" quarter round molding. (which I have all over my home).

I included a pair of 3mf files with my plate layouts for printing the 220mm variant (ABCD parts on two 300mm x 300mm plates) which covers a 30" wide door threshold quite nicely.

ALSO: I've tested this at as short as 20mm and tall as 32mm height and it scales vertically without issue. YMMV for scaling the depth; the clearances on the dovetail keys may not hold up.

I print at 0.20mm layer height, 15% Gyroid infill, with 3 perimeters for strength. Use either corner circle-pads or ~5mm contact brim to keep those corners held-down, they like to curl up.

ASA Wood or Light Brown filament works great for matching to hardwood flooring. Something that can handle getting stomped on.

I've found 3M double-sided duct-tape works great for securing them and can easily be pried up with a flat plaster blade. Your adhesive of choice for gluing the parts together, I like to use clear Gorilla general purpose glue for a bit of flex, but cyano-glue should work well too.