Parametric ramp for robot vacuums, wheel chairs etc.

llllThis ramp has a single dovetail joint so you can puzzle it together to a size of your choice. 

To change dimensions you need to log into Onshape (free) and change parameters.

Link to model:

https://cad.onshape.com/documents/bd8154f80e7bb20c6e09589d/w/d352418493684a6d6ce65e2a/e/f3b8e97481db3d6b01a3cefe?renderMode=0&uiState=657b530bf7259650f0019017

At the bottom of the Onshape document there is a tab for centerpiece and a tab for end pieces. The variables ramp_height, ramp_depth and dovetail_tolerance must be the same for both the centerpiece and end piece. 

For centerpiece you can change module_width to the width of your liking. For end pieces it is called end_width. 

The ramp in the pictures is not printed to be used with this door in this house, therefore it is not wide enough. The picture is for illustration.

If you have trouble with changing parameters, leave a comment, and I will see if I can help.

As it is now:

Centerpieces = 200mm wide

End Pieces = 50mm wide each. 

Ramp height = 30mm

Ramp depth = 130mm (incline of 13 degrees)

Dovetail margin is as standard set to 2mm, as it is used, it will be divided so, the margin is about 1mm around. on my print they fit perfectly with the value as is (PETG).

There is also a 1mm fillet at the thin floor-end. 

The pictures shows a ramp of 3 center pieces and both end pieces, a total of 70cm ramp width. Since it is parametric, and you can print as many center pieces as you want, you can also make it as wide as you want.

To make the ramp fit your needs, divide the width so you get equally large center pieces, and divide the rest so the end pieces are also the same size. It looks the best. 

The way this is designed, you can make it as wide as you want, and as steep and deep as your printer allows. If you want a really narrow one, just print the end pieces and put them together. Very flexible!

I printed with 
 

6 walls 
6 top layers
6 bottom layers 
20% infill 
0.2mm layer height. 

Due to the nature of 3d printing, you will get layer lines on the top surface if printed as is. Normally not wanted, but here it is helpful as the surface is slightly rugged, and helps with traction. If you want a more smooth surface, flip it upside down when printing.