When I first bought a 3D-Printer from MakerBot around mid-year, I printed things like key chains and smart-phone covers to get a feel for it.
On relevant platforms such as Thingiverse, it is easy to find all kinds of 3D-models to re-print. Looking around the site, I found the “Cupholder” for wheelchairs. I thought this was a cool idea. Unfortunately, my 3D-design capabilities were not enough to refine the Cupholder to meet my requirements, specifically, my wheelchair. To date, relatively few items designed for wheelchairs are available on Thingiverse.
So I began experimenting with some basic shapes, and it dawned on me pretty quickly that I could print two wheel chocks that would help me ride up small steps in my power wheelchair. The ramps should be large enough to allow you to ride up a decent-sized step, yet small enough and light enough to fit into the back pocket of the wheelchair.
The first attempt promptly failed, as the chocks were too steep. With the help of my buddy, Benni from Kickerverleih 5meter.de, we optimized the shape, reduced the steepness, added a non-slip surface for the wheels, and experimented with stability.
The result was the following rampOf course, there is still room for improvement. For example, I cannot reach the ramps in the back pocket and set them down by myself. But that was not really the idea. I find asking for help acceptable. Theoretically, it is possible to correctly position the ramps by yourself using an all purpose grabber.
Please keep in mind that we are dealing with a prototype here. Every copy and re-print is at your own risk!
What can be improved
- Rubber surface for the bottom of the ramps to prevent sliding during descent
- Infill should be set at 20% as to prevent the ramp from breaking
Once the prototype has matured, plastics companies such as Mertl or Tischlern could be approached to see if they would produce a small series of real ramps.
The 3D-printer is the most expensive item of this venture:
- Current price of MakerBot Replicator 2 is approx. USD 2000.
- A 50-dollar spool of plastic will produce approx. 2-3 ramps.
- Printing time is approx. 26 (!) hours, assuming all goes well.
- You can download the 3D-model of our ramp at Thingiverse.
If you do not own a 3D-printer, you can search for printers in your area at 3dhubs.com and, at your own risk, make a copy of or make improvements to the model. It would be great if the results were shared among everyone else. Just post the links in the Comments section.
Please do NOT apply for a patent!
It was suggested in facebook-comments that I should patent this product. I don’t think that is a good idea. This project is just an idea for all those interested in craftsmanship.
Some of my friends on Facebook-, twitter- and Google+– suggested building the ramp on the LEGO principle. The ramps could be assembled with 100 “Roof Tile 3X4/25°“- and 100 “2×4“-pieces and be customized to fit individual steps.
But that would be quite the job every time you wanted to use the ramps :-)
Price point at approx. 50 €
Of course, using wood or aluminum to build the ramps is another option. However, they will usually be heavier. But I will be happy if you prove me wrong!