I took this photo while testing my solar hot air balloon. It's much bigger than it looks from this angle. It's filled with air by hand then the sun heats it up and it rises. It's made by cutting off a 30ft * 12ft piece of 0.3 mil painter's plastic drop cloth ($30/300ft), folding it in half and sealing the remaining edges with clear packaging tape. The pillow shaped balloon then has one corner cut off and a cardboard mouth/ring put in for filling and the tether. The dark coloration is from air-float charcoal ($15 1lb) put inside and shook around till it coated the surfaces. These types of "free balloons" can lift a good fraction of a pound to over 60,000ft. But until I can understand and fulfill the FAR 101 regulatory requirements fully these are just brief handheld tests below local structure heights.

I learned how to make this type of balloon from the excellent documentation at Danny Bowman's Bovine Aerospace website and youtube videos.

The cardboard ring holding the balloon mouth open for inflation can be folded down onto itself a couple times to close the mouth and prevent wind from deflating the balloon. This folded cardboard block also provides a good place to wrap and knot the tether to the balloon. It's also fairly air-tight so a long flat tube casually rolled up as a pressure release valve might be necessary for non-tethered flight.

First lay out 30ft of the unfolded sheet. Then unfold it sideways and fold it vertically to make it two joined overlapping 15ft long sheets. Weight it down with random soft objects. Then go around the remaining 3 edges taping them together.

Now that I've figured out construction and everything works I'll move on to making a proper large envelope with normal diamond-like gores joined with strapping tape to distribute the load.

4-whistle.stl - whistles are the hello world of 3d modeling for 3d printing so I thought I'd try my hand to test my new printer. This '4 whistle' is 4 whistles all sharing the same mouth piece. 2 of of the same length and 2 are shorter or longer. So there are 2 whistles at the same tone beating against each other in sync and then two whistles at slightly different frequencies out of phase going in and out of beating interference.

It is not loud. Just blow softly. It sounds sort of like an old english police whistle.

20% infill and no supports at 0.2mm layers. ~1 hour. (Printables Page)

3.5 cups bread flour, 1.25 cups water, 4 tsp salt, 1 tsp yeast, two periods of kneading a handful of hours apart. Boiled in salt water, washed, then added to broth. The broth is 4 tsp won-ton powder, 4 cups of water, a dash of sherry wine, 2 drops sesame oil, 1 tsp (lots!) of white pepper, 5 cilantro strands wrapped into a knot and soaked/removed, 1 jalapeano pepper split soaked and removed, 6 finely diced garlic gloves, and green onions garnish. The meat is pressure+slow cooked pulled pork in soy sauce/ginger/garlic/hoison sauce.

A 5 gallon bucket with holes in the bottom and sides and an towel attached with zip ties and folded underneath makes for a decent improvised zamboni for smoothing out the surface of rough ice out on the rink I maintain(ed) on the lake this year.