This week, [Chris] tips the scales but ultimately fails. He’s on the road, hacking through the Great White North and improvising from a poorly-lit echo chamber that happens to have a vise.
Knowing nothing about firearms (do you believe that?), he decided to build a BB cannon out of pure scrap. Several kinds of sparks fly, starting with a Hitachi drill-as-lathe and ending with a tiny cupcake sparkler. [Chris] proceeds to bore out some redi-rod by eyeballing it and offers helpful tips for course correction should you attempt same. Having centered the cavity, he drills out a tiny hole for a fuse.
His first fuse is of the crushed up match head paste variety. It burns kind of slowly and does not launch the BB. Naturally, Plan B is to make napalm glue to adhere Pyrodex pistol powder to paper. As you might imagine, it worked quite well. The wadding was singed, but still no joy. After packing her full of propellant, it still didn’t explode and merely burned out the blowhole. So, what gives? Insufficient barrel length? Should have used bamboo instead of redi-rod? Didn’t want it badly enough? Give us your fodder below.
Continue reading “Fail of the Week: [Chris] vs. The Gorn”
It turns out that old newsprint can be a bit explosive; at least when it’s combined with the proper ingredients. [Markus Bindhammer] worked out a way to make solid rocket propellant from newspaper. Judging from the test footage after the break the home made engines work great!
There isn’t a long list of ingredients. In addition to newspaper you’ll need some potassium chlorate (KClO3) which serves as an oxidizer, white wood glue, and PVC pipe. The KClO3 is ground with a mortar and pestle, then run through a sieve before being combined with the wood glue. This combination is painted on the newspaper which is then rolled up with a glass rod at the center. This is allowed to harden before going into the PVC. The excess is trimmed and the whole thing is baked in a convection oven at 105 C for two hours.
If this process doesn’t suit you maybe cooking up a batch of sugar-based propellant is worth a try?
Continue reading “Rocket propellant manufactured from old newspaper”
[KoD] and [Navic] are building solid propellant motors using sugar and potassium nitrate. They cook up the two ingredients along with water and a bonding agent. They find that corn syrup is particularly good for bonding and that cooking the strange brew is more of an artform than science. Either way, the video after the break is proof of the dangers involved in this hobby. Testing the engine thrust with a bathroom scale ends badly for the scale.
There is something satisfying about the ingenuity that goes into the materials. For a casing they’re using PVC pipe, and forming a cone to focus the thrust by using a what amounts to plumber’s epoxy putty. The capping agent for the finished motor is ground up kitty litter.
This is an interesting read, but for now we’re going to stick to water rockets.
Continue reading “Homemade solid propellant rocket motors”