Homemade backpack flamethrower
Brady writes “What you see is a homemade backpack flamethrower. I initially got interested after finding this page showing another guy’s plans on making one. I tried twice to make the main tank out of PVC, but for some reason the PVC just did not want to hold more than 50 PSI without leaking (the first one actually exploded at about 75 PSI). So I went the more expensive but safer route by using a metal tank. Also, with a metal tank you can use gasoline ($2.50/gallon) instead of denatured alcohol ($10/gallon) as the combustible liquid because gasoline eats PVC, so if I went the PVC route I’d have to use denatured alcohol.” Link.

Seems like a fun project to replicate “…a windmill with a diameter of just 10cm which works by flexing piezoelectric crystals as it rotates, causing them to generate a current. A ‘gentle breeze’ of 16km/h is enough to generate the 7.5mW necessary to power a small electronic sensor. Such windmills are designed to solve the problem of powering Wi-Fi kit in remote locations. Geologists, for instance, can monitor seismic activity using wireless-enabled sensors located across large geographical areas.” [
Hans has a good how to on making a $45 hot air pencil for desoldering “Many types of surface mount capacitors will delaminate when soldered with a regular soldering iron, the main problem being the thermal shock and uneven distribution of heat across the component. Using a Hot Air Pencil solves this problem, by carefully raising the temperature of a component these thermal shocks can be avoided. So, I needed at least a simple Hot Air Pencil. Checking my favorite catalogs I found several, but the cheapest being $600! Need being the mother of inventions, and refusing to pay the price, I started looking for a way to make my own Hot Air Pencil.”
Greg from
“Up until recently, Mac users didn’t have a similar Sleep mode which required no power. When Apple announced new PowerBooks in October 2005, it also introduced Safe Sleep to Mac OS X, an extention to Sleep mode that allows for hibernation without power.” The article details how to put other Macs to deep sleep with a clever hack – the comments also have a lot of useful information. [