Presstext

Jana is een enthousiaste jonge vrouw die afhankelijk is van haar trouwe viervoeter. Omdat haar hond haar overal begeleidt, zou Jana haar graag belonen voor het geleverde werk. Ze zou dit graag doen door tennisballetjes te smijten, beter gekend als het klassieke "à porte".

Dit wordt echter bemoeilijkt door het feit dat Jana een beperkte spierfunctie heeft, waardoor het voor haar onmogelijk is om een bal voorwaarts -en vooral- ver weg te gooien. Deze gebreken staan dus een speelse interactie tussen Jana en haar viervoeter in de weg.

Het idee dat wij hebben uitgewerkt is geïnspireerd op een professionele base-/tennisbalwerper. Bij dit systeem worden er twee wielen aan het draaien gebracht met behulp van één elektromotor en een tandwieloverbrenging. De tennisbal wordt vervolgens doorheen deze wielen geperst en versneld; de tennisbal vliegt enkele meters door de lucht.

Aangezien Jana in een rolstoel zit, moet ons ontwerp hieraan aangepast zijn: een makkelijke aan- en afname is wenselijk. Een extra eis is ook om -met wat marge- doorheen deurgaten te kunnen manoeuvreren.

De uiteindelijke tennisbalwerper voldoet aan al deze eisen en kan de bal een 15-tal meter ver schieten. Zowel Jana als haar hond zijn unaniem enthousiast!

Jana is an enthusiastic young women who depends on her dog. Because her dog accompanies and helps her all the time, Jana would like to reward her for the work she does. She’d like to do this by throwing tennis balls, also known as the classic “fetch”.

But this isn’t an easy task for Jana because she has a limited muscle function, because of this she isn’t able to throw a ball far or even forward. Because of these limitations it’s harder to have a playful interaction with dog.

The idea that we developed is inspired on a professional baseball/tennis ball thrower. In this system there are two wheels which are made to spin by one electromotor and two gears. The tennis ball is then pushed through these wheels and accelerated; the ball is then airborne for several meters.

Since Jana is in a wheelchair, she has to be able to attatch and detach the launcher in an easy way. An extra demand is that she should be able to pass through doors easily.

The final tennis ball launcher meets all these requirements and is able to launch a ball 15 meters far. Both Jana and her dog are unanimously enthusiastic!

Group picture

Visit 4 to Jana

The previous attachment system did work but the result was too wide. Jana couldn't ride trough the door. So we tought about another solution. We came to a system where the machine is suspended from the armrest.
We do this by attatchin a alluminium loop on top of the machine and because a part of the machine is under the armrest we gain a few centimeters.

In the final prototype we'd like to attatch a screw at the top so Jana can fixate the machine.

To detach the machine Jana first has to loosen the screw and then by lowering her wheelchair on the same system that was used in the previous test.

We also tested if she was able to drive through a door.

We also tested the latest version of the machine itself. Jana aswell as her dog were happy with the result.

DIMENSIONS CASE

Today we decided our final dimensions after Jana's visit.
The case will be divided in two halves: one for the wheels and gears, one for the motor, battery and other electrical components...

Dimensions:

We will form a mold in PU foam and vacuum form it in PS (white, 2 mm thick to have a sturdy case)

PROTOTYPE #23

After we got all our parts, we started to build our final prototype.

To test if everything works fine, we builded a test arrangement.

For our final prototype, we used:

- 2 C-profiles

- 2 wooden wheels (diam 100 mm)

- 2 gears (diam 145 mm)

- 45 mm between wheels

- 12VDC motor, 35W (heavier than previous motors)

- 1 Fader to regulate speed of wheels

- 4 copper gliding bearings

- some bolts to keep everything together

Conclusion:

Expected positive feedback: The system works and the ball shoots further.

Unexpected positive feedback: /

Expected negative feedback: /

Unexpected negative feedback: - Battery is low after 5 minutes, motor asks too many ampères and goes off quickly.

- Fader is too weak and can't resist the high ampères flowing through.

Makeabilityscore : 2 (4 hours work)

Visit 3 to Jana

We tested the attachment system with a rough prototype that presents the size. The system defenitly works, we will only need to attach the final device on the right height to go under and over it with the wheelchair. 

The bolts in the prototype are not the right size yet, that's why the prototype is hanging so loose, hat problem will be solved in the final product. 

DIMENSIONS WHEELCHAIR

Our client Jana, momently has a Permobil C300 to learn how to ride it in awaiting of her Permobil C500 Lowrider. This wheelchair has a similar wheel base and attachment rail, so we decided to design our product for this wheelchair.

We took some measures to see how large our tennisball thrower can be.
The Permobil can move vertically about 13,5 cm, so we can use this for the attachment system.

We also measured the door width and the width of the wheelchair to see how wide we can go so Jana can still pass with the tennisball thrower attached.