Customizable Threshold Ramps

I want to roll my office chair over the threshold between the office and the next room. Threshold ramps are commercially available, but I wanted a custom size. In Thingiverse's customizer you can set the height of the ramp, the length of the threshold, and by setting the width of the ramp how steep the slope is.

In Thingiverse's customizer the **parts** pop-up to get STLs for your left, middle, and right.

In the finished photo, you can see I used 2 lefts, 8 middles, and 2 rights.

Measure your threshold. Subtract Width, since that will be the amount of the threshold touched by the half-round endcaps.
Call that number *ThesholdMiddleLength*
divide *ThesholdMiddleLength* by (the usable dimension of your printer minus twenty (to allow for the printing skirt and the connecting knob between the pieces)) then round that number up to the nearest integer. That's the number of copies of the middle piece you'll need, **Num**. Now do *ThesholdMiddleLength* divided by **Num** = that is w