After last week’s experiments and tests it was time to scale it up and build the real thing. This playing card gun was an awesome build and the testing is was quite enjoyable to say the least.
I had seen Mark Rober’s video so I used his design as a starting point to build my machine but of course I gave my own twist to it. I don’t own the tools he used and I made mine a little smaller and (in my opinion) less complex. But the concept stayed the same:
There is one motor with a wheel on it that pushes one card at a time from a stack of cards toward the other motor. The other motor is the launcher motor which has a larger wheel on it and spins real fast (like 10 to 25k fast). This wheel touches two high speed bearings. When a card is pressed in between it the wheel gives the card both forward as wel as rotary motion. Giving the cards speeds of 200 Km/h and higher.
As of now I have only turned it up to about 60% of what it can do because that is about when it starts feeling unsafe..
When I saw the mythbusters episode where they shot cards years ago I wanted to try that myself. Then when Mark Rober build his playing card machine gun a couple of months ago I knew what I had to do.. Make my own version of a playing card gun.
I wanted to give this project the best chance of succeeding so before I started the actual build I made a little test setup and tried a lot of things; 3 different types of cards, different positions to hit the card and if the pinciple of shooting a card with a spinning wheel works.
I learned a ton doing these little tests:
O-rings strech out a lot when spinning at 15k rpm
Regular bearings cannot handle speeds like this
A bouncy test jig with a wheel spinning at more than 15k rpm is really scary
And the vibration of the testjig made the wheel inefficient.
In this weeks video I’m showing my process of building the test rig and doing the tests. In the video next week I’m building the actual playing card gun and spoiler alert: it is way way better than the test rig…
