Our team was invited to an local festival called Fluff festival. For that event, our robot had to be marshmallow themed So we decided to make a marshmallow cannon robot. To make the robot we took off the gear collector off our competition robot and used lawn sprinkler valve to control the airflow,black iron pipe to store air before shooting, pvc pipes to create cannons that shoot marshmallows and some pneumatic. Toilet paper was used to make a good seal against the walls of the pvc pipe because without it the air would escape through the marshmallows. We coded it used pneumatic in Java. The marshmallows went pretty far. About 8 feet
We later used it at an event at a local college but instead of marshmallows, we used candy instead. At both events, the kids were given nets to catch the marshmallows or candy.
It was a success! We had a lot of fun building it. The children at the events had a lot of fun. The adults would join it too.
To expand on firecrafty’s response, PVC is NOT a good choice for use with compressed gasses. I’m on mobile right now so don’t feel like going into a long paragraph about (my thumbs can’t take it), but here is a link to a post made a number of years ago regarding this subject.
So many people build air canons using PVC. What are some suggested replacements?
If you look at their setup, I would not have much for concern on the PVC. They have black pipe on the pressure side of the valve and a marshmallow as the only thing holding back pressure. I understand the concern with PVC, in this application i dont fault them for their choice.
Now it would also be good to know system pressures prior to passing judgement. We run a specialty CPVC rated for use in high pressure sprinkler systems for our t-shirt cannon barrel and cartidges. We are okay with this because we run at 12 PSI. We also have several purpose built failure points. As far as I can see, this team used a marshmallow and toilet paper for their failsafe.
The other thing to think about is … “That it’s all fun and games, until someone loses an eye.” ::ouch::
Be careful about shooting candy at people. I’m guessing that the candies might injure an eye.
Maybe put the candy into small soft bags (along with tissue paper to take up space) that become small pillows, and minimize the chance of injury?
PS: I know that Christmas parades and other parades frequently toss candy into crowds, but … when the jury hears that you shot yours out of a cannon :eek: :rolleyes: , it will be time to get out your checkbooks.
We were very careful. We blocked off an area for the robot. That way the kids can’t get hurt. We also used very soft candy and avoided hard candy such as lollipops or gum balls. We made sure everything was safe. Also the candy did not shoot straight into a crowd. It was more like a curve up.
The only way a child can get hurt from the robot is if they were looking to the cannon which was impossible for the child to do since we blocked off the area the robot was in. So the robot was very safe