We have to be impressed by [amazingdiyprojects] who completely totaled their manned multi-copter build, which has been spanning over eight videos. He explained the crash in video number eight and is right back at it, learning from the recent mistakes.
When you get right down to it, this is as dangerous as this seems. However, a giant multicopter is probably the easiest flying machine for a hobbyist to build. It’s an inefficient brute-force approach, but it sure beats trying to build a helicopter from scratch. This machine is a phenomenally un-aerodynamic chair on a frame that has a lot in common with the lunar rover; with engines on it. Simple.
There are a lot of approaches to this. One of the crazier ones is this contraption with a silly amount of electric motors. [amazingdiyprojects] went with eight gasoline engines. We’re really interested in his method for controlling the rpm of each engine and dealing with the non-linearity of the response from a IC engine throttle. Then feeding that all back into what is probably the exact same electronics from a regular diy drone.
Honestly, we’re surprised it worked, and we can’t wait for him to finish it so we can see him zooming around in his danger chair. Videos after the break.
Thanks [jeepman32] for the tip!
Continue reading “Manned Multicopter Project Undaunted By Crash”
[misterdob] wanted to spice up his Halloween decor, so he built these flaming concrete jack -o’-lanterns to decorate his walkway. He started with the classic plastic jack-o’-lanterns that trick-or-treaters have been using to collect candy for years. [misterdob] filled the plastic pumpkins halfway with concrete mix, then dropped in metal coffee cans. He then filled the pumpkins up to the top with concrete, shaking them up a bit to avoid air pockets.
Once the concrete had set, [misterdob] cut away the plastic revealing nearly perfect concrete duplicates. He used acid stain to color his creations – though it looks like he missed a spot or two.
We have to disagree with [misterdob’s] choice of fuels. In fact, we think he was out of his gourd when he picked gasoline for his flaming pumpkins. Seriously though, gasoline is a horrible choice for a fire pot like this for a multitude of reasons. Gas has a particularly foul odor and its fumes are explosive. If a Halloween prankster were to try kicking one of the pumpkins over, not only would they have a broken foot, they’d also be covered in burning gas.
Thankfully, the folks on [misterdob’s] Reddit thread had better fuel suggestions – citronella torch cans with lamp oil and wicks, kerosene, or gel fuel would be better suited for these hot pumpkins.
If you still don’t believe how dangerous gas and its fumes can be, check out this video of a bonfire gone wrong (language warning).
[S Heath] is a Coleman lantern collector. Coleman lanterns can run from a variety of fuels, however they seem to run best with white gas, or Coleman fuel. Store bought Coleman fuel can cost upwards of $10USD/gallon. To keep the prices down, [S Heath] has created a still in his back yard to purify pump gas. We just want to take a second to say that this is not only one of those hacks that we wouldn’t want you to try at home, it’s also one that we wouldn’t try at home ourselves. Heating gasoline up past 120 degrees Celsius in a (mostly) closed container sounds like a recipe for disaster. [S Heath] has pulled it off though.
The still is a relatively standard setup. An electric hot plate is used to heat a metal tank. A column filled with broken glass (increased surface area for reflux) rises out of the tank. The vaporized liquid that does make it to the top of the column travels through a condenser – a pipe cooled with a water jacket. The purified gas then drips out for collection. The heart the system is a PID controller. A K-type thermocouple enters the still at the top of the reflux column. This thermocouple gives feedback to a PID controller at the Still’s control panel. The controller keeps the system at a set temperature, ensuring consistent operation. From 4000 mL of ethanol free pump gas, [S Heath] was able to generate 3100 mL of purified gas, and 500 mL of useless “dregs”. The missing 400 mL is mostly butane dissolved in the pump gas, which is expelled as fumes during the distillation process.
Continue reading “Boil Off Some White Gas in the Back Yard”
[MacGyver] [Lou Wozniak] is on a mission to build an internal combustion engine using only hardware store parts. What you see above is his third attempt at it. Depending on your hardware store this may have ventured outside of what they sell because [Lou] switched over to using gasoline. But the first two attempts were powered by a propane torch fuel canister.
Unfortunately it still isn’t running. But the demo below makes us think that he’s really close. Timing is always touchy and that seems to be what is causing the problems. He makes use of a lot of plumbing fixtures. At the right you can see the parts (including a peanut butter jar) which make his carburetor with a valve pointing straight up as the choke. The fuel and air mixture moves down through the pipe to the cylinder and valve assembly where it is ignited by the black grill igniter module. His custom cut plywood gear moves with the fly-wheel. It triggers his improvised spark plug by using a bit of wire to pull on the leaf switch.
We feel like he’s so close to getting this up and running. If you have any advice on where he might be going wrong [Lou] welcomes your input.
Continue reading “Building an internal combustion engine from hardware store parts”