PROTOTYPE #16

The position of the screws is amended

CONCLUSION:

Expected positif feedback: It went a little bit further.

Unexpected positif feedback: The noise of motor is nice for the dog

Expected negatif feedback: The ball still doesn't go 15m.

Unexpected negatif feedback: /

Makeability score: 2

PROTOTYPE #15

- Visit 2 to Jana- We have added two screw to prevent that the wheels don't expel again.

CONCLUSION:

Expected positif feedback: It went a little bit further.

Unexpected positif feedback: The noise of motor is nice for the dog

Expected negatif feedback: The ball still doesn't go 15m.

Unexpected negatif feedback: The screws do contacts the wheel /

Makeability score: 2

Aspect 5: Noise

-          The sound of the prototype was good for the dog, when he heard it, he became excited and he knew that a ball was coming, so it’s not too loud.

Aspect 4: Attachments

-          She found it a good idea to work with the T-gutter on the side of the Permobil to attach the shooter. But then, it should be detachable, because the wheelchair may never be bigger on the sides to be able to pass through doors.

-          She would look for someone with a Permobil wheelchair and look where she would put and attach the product.
Our next meeting will normally be with another person with a permobil too. 

Aspect 3: Launching tube

-          Because Jana has difficulties to put her arm high and far backwards, the launching tube may not be that high. It’s a point we should explore around. 

Aspect 2: weight of the prototype

-          Jana is able to carry the prototype, but she won’t be able to pick it up or do big movements with it.
The prototype is now made of wood, so by a different material choice, the product will weigh much less. Now, we also use two motors, by reducing it to one that’s connected with both wheels, we also take a big weight of the product.

Aspect 1: Weight of the battery

The weight of the battery was very good, it’s easy for her to pick it up or disconnect it to reload the battery. 

Visit 2 to Jana

-          We tested the prototype with the wheel-system at Jana’s place. Jana was happy to see our prototype, especially the DIY-solutions (PVC, wood rests…) were seen as a strong point of the product. The shooter still only shoots for 10 metres, she said it would be cool if it shoots further, but like it is now, it shoots already further, higher and in the right direction then when she throws the ball with her throwing stick.

Because her new wheelchair won’t arrive for 2-3 months, we couldn’t really measure or test the perfect spot to attach the tennis ball shooter. In the following posts, you can read some aspects we learned during our visit.

PROTOTYPE #14

During the previous test, one of wheel was expelled, so they had to be replaced by others.

CONCLUSION:

Expected positif feedback: It went a little bit further.

Unexpected positif feedback: /

Expected negatif feedback: The ball still doesn't go 15m.

Unexpected negatif feedback: /

Makeability score: 2

PROTOTYPE #13

To make the launcher autonomous we went to buy a battery pack (12V 1,3Ah). The wheels are able to turn for about an hour. That is more than enough for this application. Jana will never go over the hour a day to throw tennis balls with her dog.
 

With this battery the wheels turns faster but the ball doesn't go much further.

CONCLUSION:
Expected positif feedback: It went a little bit further.

Unexpected positif feedback: /

Expected negatif feedback: The ball still doesn't go 15m.

Unexpected negatif feedback: One of the wheels came lose during one of the tests.

Makeability score: 2

Specifications benchmark

• Diam. 195 mm
• Spacing 35-45 mm
• Advice from maker: 
• I've used 'FIRST CIM 12V 5280 RPM' motors, but would recommend them only if ou can't find anything better (100-200W, 3500-5000 rpm under load and long shaft). They are just too powerfull for this application and draw quite a lot of current. Currently I use LiPos, but eventually I want to have two UPS batteries connected in parallel. Wheels are custom made from MDF. They're twice heavier than wheels used in professional machines, so I'd recommend using original ones if you can get them. The wheels have to be well balanced otherwise the cause quite violent vibrations. 

Feedback from Jana

Contact with Jana learned us:

• Good System
• Don't use the battery of the wheelchair
• Enough power left to drive? 
• Garanty of the wheelchair falls away
• Can the ball go further? In the following movie it goes further with the same system: 

PROTOTYPE #12

The last adaptation is the launching strip in front of the wheels, this makes the ball go higher and therefore also further. 

CONCLUSION:

Expected positive feedback:
De ball is launched.

Unexpected positive feedback:
The ball goes further then expected. 

Expected negative feedback:
The ball still doesn't go very far. 

Unexpected negative feedback:
/


Makeability score: 2

PROTOTYPE #11

To have more resistance on the wheels, we attached rubber bandages around it. The effect was not super, but the ball went further then without the bandages.
In this prototype, we also used the launching tube, wich also helped to launch the ball further.

CONCLUSION

Expected positive feedback:
De ball is launched and goes further then without tape of launch tube.

Unexpected positive feedback:
/

Expected negative feedback:
The wheels don't turn completely equal. The tube is not steady enough. It has to have a better atachment.

Unexpected negative feedback:
We expected more power.

Makeability score: 2

PROTOTYPE #10

To get more surface of the wheels touching the ball, we made thicker wheels and gave them a curve on the sides. The size of the before sanding was diam . 83 mm. If we launch the ball, we notice it doesn't go further then the small wheels. Even a bit shorter. But maybe, that's because we didn't use a launch tube. 

CONCLUSION

Expected positive feedback:
De ball is launched.

Unexpected positive feedback:
/

Expected negative feedback:
The wheels don't turn completely equal.

Unexpected negative feedback:
The ball doesn't go further then with the thicker wheels. We expected more power of it.

Makeability score: 2

PROTOTYPE #9

The launch tube is still attached to the prototype. We changed the sandpaper wheels into rubber wheels.
This is the best prototype up to now. The ball goes further and higher than the first wheel-system-prototype.

CONCLUSION

Expected positive feedback:
The ball goes higher and further then before. And the ball isn't affected.

Unexpected positive feedback:
/

Expected negative feedback:
The launch tube isn't steady enough to launch the ball in the best way every time.

Unexpected negative feedback:
/

Makeability score: 2

PROTOTYPE #8

We kept the sandpapered wheels from the prototype before. But now, we worked on the aspect of the direction and the way the ball gets into the wheels by making a launch tube. The tube has to be exactly in the center.

CONCLUSION

Expected positive feedback:

It goes further and higher then all the prototypes before. 

Unexpected positive feedback:

/

Expected negative feedback:

The ball gets affected by the sandpaper.

Unexpected negative feedback:

The tube isn't steady enough to launch it good everytime.

Makeability score: 2

PROTOTYPE #7

Because the tennisball got affected by the sandpaper, we searched for something new to make the wheels addhesive. We attached balloons on the wheels for the next test. As you can see on the picture below, the balloon didn't last very long.

CONCLUSION

Expected positive feedback:
The ball goes higher and further then without the balloons. And the ball isn't affected.

Unexpected positive feedback:
/

Expected negative feedback:
/

Unexpected negative feedback:
The ball doesn't go as far as the prototype with the sandpaper.
The balloon breaks after a few launches.

Makeability score: 2

PROTOTYPE#6b

The prototypes launched the balls horizontal. Now we put the prototypes in an angle, so the ball can fly higher.

CONCLUSION

Expected positive feedback:
The ball goes higher and further then before.

Unexpected positive feedback:
/

Expected negative feedback:
The ball gets still affected by the sandpaper.

Unexpected negative feedback:
/

Makeability score: 2

PROTOTYPE #6a

To make the wheels more adhesive, we put sandpaper on it. If we launch the ball now, the difference is quite big. The ball goes further but tennisball gets affected by launching it with sandpaper, as you can see on the picture.

CONCLUSION

Expected positive feedback:
The wheels have more effect on the ball.

Unexpected positive feedback:
The ball goes further then we thought he would.

Expected negative feedback:
/

Unexpected negative feedback:
The ball gets affected by the sandpaper.

Makeability score: 2

PROTOTYPE #5

We made the wheels bigger (diam. 40mm) and launched it again. The ball went further then before, but still not far enough. We think the wood is to slippery to have enough effect on the ball.

CONCLUSION

Expected positive feedback:
It goes further then with the smaller wheels.

Unexpected positive feedback:
/

Expected negative feedback:
Still not far enough.

Unexpected negative feedback:
The wood is to slippery to have enough effect on the ball.

Makeability score: 2

PROTOTYPE #4b

We made sure the tape was firm enough to stay on the wheel with another tape on top of it. This made the wheels a little big bigger to. 

CONCLUSION

Expected positive feedback:
The ball was launched and the tape stayed on the wheel.

Unexpected positive feedback:
/

Expected negative feedback:
Not enough power to launch very far. That's probably because the wheels aren't close enough to eachother.

Unexpected negative feedback:
/

Makeability score: 2

PROTOTYPE #4a

This prototype is based on the system of benchmark #11. It's a good system to attach to a wheelchair because it's compact and quite lightweighted. Because the wheelchair works on 12 V, we used the same motors to build this system. That's because we connect and use the batteries of the wheelchair to launch the ball.

The wheels are made of wood (diam. 35mm). The distance between the wheels is the size of a tennisball (6.7 cm).

Because the tape came loose, we didn't manage to launch a ball with it yet. 

CONCLUSION

Expected positive feedback:
/

Unexpected positive feedback:
/

Expected negative feedback:
/

Unexpected negative feedback:
The tape comes loose.

Makeability score: 2

PROTOTYPE #3

We used Benchmark #13 to develop this prototype. The swing is pulled by a cord and released to launch the ball. 

By testing this prototype, we realised it doesn't work, the ball simply doesn't come out of the thrower. 

CONCLUSION

Expected positive feedback:

/

Unexpected positive feedback: 

/

Expected negative feedback:

Not enough power to launch very far.

Unexpected negative feedback:

The ball doesn't even come out of the thrower.

Makeability score: 4 (quite easy to make)