Author Archives: onurolgac

Catapult Day 3

Figured out I could use a higher and more sturdy hinge, welded it on top and used the bar I found on Wednesday to make the thin rod go through. Since there were small angles when I welded both times, they added up and I ended up with a slightly off mechanism. But this did not affect throwing since you could fix it as you were aiming.

I decided that the piece that stopped the bar -that was also fixed to the ground- didn’t have to be a fixed single piece. I screwed the bottom piece onto the wood platform and fixed it 2 clamps. And with a small cap (that was spray painted later on) from the kitchen the catapult was ready for testing.

I was glad to see that my colleagues were more than happy to try it and play around with it before people even started to show up. We played around with pretzels and a game to see who would be the first to get a rock inside a plastic cup later in the evening.

 

And the final bonus cat photo:

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Catapult Day 2

Tim suggested we work on a 2nd mechanism on top of the 1st layer so that we can launch stuff with more momentum and control. I started off with a small hinge that would balance the long bar on top. Had some trouble with the drill and broke off the first piece, then struggled aligning the holes on each side.

After the 3rd try I had a small hinge that works with a proper piece that has aligned holes and is loose enough to move.

At this point I had a basic mechanism that works, but I doubted that the small hinge would be enough, so before leaving I found 2 small parts and a thin rod to mimic the first level I already developed that was working.

My plan is to make a hole through the bar and let it rotate on the thin rod and create the hinge out of a larger piece. The last part would be to find a solution for the stopping mechanism that is connected to the ground.

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Last but not least, second day bonus cat photo:

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Catapult Day 1

I started out with the idea of having a bot that would hop after an initial kick, a mechanism similar to a hole punch since I remember trying to make those things hop as a kid. When we started out with the first day and I started looking for bits and pieces to use, I stumbled upon a bunch of stuff that would be perfect to a build a catapult with.

After outlining what the structure would look like and how it would function, I cut 2 small pieces of steel rod to stabilize the spring from both ends, one to be hammered onto the wooden plate and the other to be welded onto the upper piece. I welded the main piece onto a small pipe that would go over another piece of cut rod so that it would rotate freely allowing it to gain momentum from the spring and travel the distance necessary.

Then I drilled a small 10mm hole into the wooden plate in order to place the bottom piece for the spring, hammered it in and fixed the 2 L shaped pieces that would keep the structure together with a rod going through them.

After everything was put together I did a small test to see if the spring kicked back hard enough to reach a certain momentum. This was the result:

From here I probably need to find a way to properly stabilize the rods together with the spring, maybe work on some parts that will help things sit properly on the piece to have more accuracy and do some target practice to see how it’s performing.

Also, bonus cat photo for internet karma:

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