Adaptable Wheelchair for Handicapped Dogs

UPDATE: We have changed the design to a one-piece chest-plate with an additional bracket to mount a third wheel for stability. The model files differ from the shown pictures.

A few months ago we discovered Luisa, a handicapped puppy who was born without forelegs on the website of an animal protection organisation (www.pro-tier.de) and decided to build a 3D-printed wheelchair for her. In the meantime we finished the wheelchair and have adopted Luisa. This project is open-source and we want to give everybody the opportunity to help a handicapped animal with this instructable and the 3D-Files we uploaded with it.

The Wheelchair comes in two sizes (The bigger size consists of several parts, so that it can be printed on smaller printers as well) and is adjustable in every possible aspect (width, height,camber,...).

All printed parts were printed by my company (www.multec.de) on our biggest 3d printer (Multirap M420). Of course the files can be printed on any printer, as long as the print area is big enough.

Step 1: What You Need

Here's what you need to build a wheelchair:

- a 3D printer for the 3D printed parts

- aluminum tubes 18x1,5 mm (lengths depend on the size of the dog, you better just buy ~3 meters and saw/cut it at home to the correct dimensions)

- tube connectors (e.g. from KIPP http://www.kippwerk.de, 4x K0485.18, 4x K0487.18, 2x K0472.1818, 4xK0486.18, 4xK0488.18_a, 12x K0494.018150)

- wheels: We chose wheels with a diameter of 250mm, these are usually used for bicycle trailers or buggies. Cost ~30 euro a pair. Make sure to buy tires with tube, because they absorb shock energy and tire pressure can be adjusted to different underground conditions.

- optional: a Third (smaller) wheel to help the dog as long as he is not used to balance the chair.

- an axle to connect the wheels to the wheelchair. We used a simple threaded rod. What you specifically need depends on your selected wheels. Depending on your choice you might as well need an additional printed adapter to connect the axle to the aluminum tubes

- A soft inlay (e.g. Foam) to make the wheelchair more comfortable for the dog

- Fasteners/belts (2x) to make sure the dog doesn't fall out of his wheelchair.

- bolts and nuts (M5, M4 in different lenghts)

We spent around 130€ for all needed parts.

Step 2: Print!

Print the attached files.Make sure to enable support-structures for overhanging areas. Since the parts are pretty big, i would recommend you to use 'fast' printer settings (big layer heights) and a heated printing bead to prevent warping problems. Also, I used PLA-Filament instead of ABS, because there are less problems with warping. Make sure that you don't run out of filament while printing.

UPDATE: We have changed the design to a one-piece chest-plate with an additional bracket to mount a third wheel for stability. The model files differ from the shown pictures.

Step 3: Assemble!

Assemble the parts according to the pictures above

Step 4: Adjust!

Adjust the assembled chair, so that it fits well. Adjust camber angle, caster angle , ground clearance, width, heights and lenght

Step 5: Train!

Let your dog train with the wheelchair. The following is the most important part of this instruction:
Do not force the dog to use the wheelchair, make the training as comfortable as possible (read: use dog treats). Though giving a new level of freedom, the wheelchair might be a strange object to the dog at first. Let him get used to it slowly and he will learn to use and like it.

If you have any questions or need assistance building a wheelchair, feel free to contact me.

In case you want to read more about Luisa, you can follow her on facebook: https://www.facebook.com/luisas.tagebuch or on http://luisas-blog.de/