Gas powered go karts are awesome fun – fast and noisy will put a smile on the face of any driver. But the undeniable torque available from an electric motor gives two advantages: insane acceleration and kick-ass hill climbing ability.

A quick instructables from a couple years back has info on retrofitting your gas-powered go-kart to run with a motor, battery and electronics. Turn it into a silent speed machine!

Motor:
Type: Series Wound DC Motor
Max Current: 300A
Cont. Current: 100A
Voltage: 36
Max HP: 15
Cont. HP: 5
Length: 14″
Diameter: 7″
Weight: 30Lbs

Controller:
Alltrax Series Wound Brushed DC Motor Controller
Max Current: 300A
Cont. Current: 100A
Max Voltage: 50V
Min Voltage: 20V
Throttle Type: 0-5k

Batteries:
Lithium Phosphate 42V/33AH system
Capacity (WH): 1.3KWH
Voltage: 42V
Capacity (AH): 32AH
Max Current: 800A
Cont. Current: 400A
Weight: 28Lbs

How does electric stack up to gas? The Mythbusters built and raced an electric go-kart against a gas powered one. The electric components (motor, batteries) doubled the weight of the cart, but even with that, the acceleration easily beat that of the gas version. With some tweaks, they felt they’d be able to have gotten the top speed up to that of the gas engine, too.

A user video of a converted racing go-kart shows the speed capabilities:

I’m a fan of projects that you can do at your work desk – print on the office printer, cut out with scissors and an exacto, and glue/tape together. The Dirkon paper pinhole camera might be the pinnacle of this type of project. This thing is cool – it’s a fully functional pinhole camera that looks like a papercraft SLR. It uses standard 35mm film, and actually advances the film. It has a makeshift “shutter release.” Maybe best of all, it looks super cool – the assembled version is a great decoration for your camera shelf or desktop. It’s been around for a while; I put one together a few years back myself.

The original instructions are in Czech, but have been translated with assembly tips. There are a couple sections that leave some questions, but use some intuition and it all comes together.

If you plan to use this for photography, you’ll need to use cardstock when printing it out – double-check that it doesn’t let light through (if so, line the inside to eliminate all light). Otherwise, standard xerox paper will be just fine.

Here’s the main page with writeup, notes and tips: Dirkon Pinhole Camera

This is the PDF to print out.

And while at it, check out the Rubikon 2, another print-and-fold camera that is an evolution of the Dirkon.

The pinhole.cz site also has some great information about determining exposure time for pinhole cameras.

Finally, get inspired by checking out Flickr pics of other Dirkons and the photos they create.

PDF of the Dirkon

The folks at diyphotography.net have a good post with seven easy DIY projects that will help beef up your photo studio. Beauty dish, dual speedlight mount, ring flash, softbox, snoot, suction cup mounts (very clever), and a PVC light stand. All of them are useful tools.

I like the beauty dish project as an easy, cheap way to get that softbox look. These things can range in price from the $50 range to a well over $200. The version described here will cost next to nothing, especially if you source the supplies at the local thrift store.  Here’s a good example of what a beauty dish does for lighting:

(no, that’s not me – it’s just an example I found online)

Do you want to launch a softball 50-60 feet without having to get down and dirty cutting wood, metal, and using power tools? Here’s an easy way to build a fairly sizeable trebuchet out of cardboard and a few other basic materials.

For this project, the components are glued together and assembled with bolts for the axles. A few small pieces of PVC are used to create axle bearings–this could be improved by using skateboard ball bearings instead (side note: it’s crazy that you can now get a single skate bearing for 99 cents). Also, a commenter makes a great point that adding wheels will allow the trebuchet to rock as the counterweight falls, which allows the counterweight to follow a much more efficient linear path and increases the capabilities of the machine.

Glued corrugated cardboard develops a decent amount of strength while remaining fairly lightweight. And as anyone that watched Punkin Chunkin knows, lower weight means faster speeds. Keeping the throwing arm as light as possible is key for massive launches.

Follow all the steps on the Instructable here: Cardboard Trebuchet. Also, I lied about the power tools part. You may need a drill to create the opening for your axle. No big deal.

And if you want something a little more desktop sized (plus kill some time at work), check out the Paper Trebuchet instructable too.

After spending a bone-chilling week in NYC, freezing my hands every time I had to answer a phone call, I started looking for a solution to using this wonderful iPhone while not losing any digits to frostbite.

Turns out, there’s a simple solution: conductive thread.

The iPhone’s touchscreen is capacitative, where the slight electrical charge in our skin interacts with a slight electrical charge behind the glass screen. This point of interference is registered and processed. Wearing gloves insulates that electrical transfer from happening.

By adding conductive thread to the fingertip of your glove, the electrical interference is once again able to take place. Here are the super simple steps from Instructables.com

Supplies
You will need:
A glove.
A needle.
12″ (30cm) of conductive thread. (TIP: If you don’t want to buy a whole spool, you can buy a few feet much more affordably from SparkFun with the Lilypad Bobbin.)

• Sew a few stitches in the finger of your glove.
On the outside try to make the stitches pretty close so it only touches the screen in a smallish area (about 1/4″ or 6mm in diameter.)  This will help your finger touches be more accurate.

Tip: Don’t make it too small!  The iPhone, for example, will ignore small touch areas.  If it doesn’t seem to work very well, try increasing the size of the stitches on the outside.
On the inside of the finger, it’s actually good for it to be messy.
3-5 stitches should be enough.

• Leave some extra inside the glove.
You want to make sure the thread touches your finger or your hand on the inside, so leave some extra.  Leave danging thread on your knots, etc.  You might even tack a bit to the lining of the glove

• Repeat on other fingers (optional)
If you use other fingers or thumbs to use your screen repeat the step on them too.

That’s it! Not as accurate as glove-less iPhoning, but much warmer. Now, to figure out how to stop clumsily dropping my phone when I’m wearing winter gloves..

Pizza: One of my favorite things to make. There are so many challenging variables in creating a perfect pizza, many that are nearly impossible to control completely. Oven temperatures, yeast activity, ambient humidity, protein content in the flour, etc. As hard as it is, even a failed pizza tastes pretty amazing. But when the variables all line up, it’s a truly magical experience.

I’ve worked in pizzerias in high school and college, taken pizza classes, and spent countless hours reading books and websites in search of the perfect pizza. And still, after many years of learning and experimenting and eating lots of great pies, I am still working to master many specific parts of the process. Currently, I’m working on using wild yeast for a rich flavorful sourdough. The first attempt worked out great–made the best batch of pizza I’ve ever made, but the second time the dough lacked the elasticity and strength to hold itself together well, and pulled apart easily while being shaped. Regardless, we cooked on the grill and the pies turned out very tasty.

Two resources that I’ve found that have been a good guide: the A16 Pizzeria cookbook (my favorite pizzeria in San Francisco), and S. John Ross’ Sourdough Bread: How To Begin website. And I just upgraded to a KitchenAid mixer finally, with 575 watts of dough-kneading power under the hood. I hope to have a solid grasp on the sourdough by the Spring. And then its back to the garden to grow those tomatoes…

Here’s a photo recap of four years of tasty pizzas I’ve cooked and enjoyed.

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Steadycam test 2 – before and after from Nathan Carrick on Vimeo.

Shaky footage can be one of the biggest killers when shooting video. As cameras get smaller, and zoom ability gets more powerful, the effect of shake is multiplied greatly. This can still be fine for everyday, “snapshot” use – but to capture footage for any semi-serious use, you need to brace your camera against the jitters.

A way to retain mobility while combating shake is to move the center of gravity of the camera to a point that is not in line with the lens. This is the basic idea behind the steadicam, a mounting rig that is used by many professional camera operators. Typically, a counterweight is affixed to the camera at a certain distance via a mounting bracket. The length of the bracket and the heft of the counterweight are set for the specific style of shooting that you want to do. The displaced center of gravity helps nullify the small jitters from shaking the lens, and the added mass of the setup also helps keep the motion more fluid and less herky-jerky.

Normally, you’ll see high-end steadicams that have a nearly frictionless joint (gimbal) that allows the camera to remain steady as the rig twists, turns, and tilts. But satisfying results can be had with a simple unit that uses just the counterweight alone.

Johnny Chung Lee has a start-to-finish writeup on his site steadycam.org on how to build a $14 steadycam with everyday items. The gist: two short lengths of steel pipe are combined in a sideways T, one side for a handle, the vertical piece to hold the camera at top and the counterweight below. A small weight is affixed on the bottom, the camera is connected to the top with a modified endcap that has a mounting bolt in it, and voila: DIY steadicam.

DOIT reader Nathan Carrick sent me some photos and videos of his assembly of this project, and a before/after video of the results (the inspiration for this post). I’m impressed – you can see how this improves the quality and creates a smoother looking result.

Nathan's PVC endcap for the DIY Steadycam. The 1/4" mounting bolt on top is the standard size all cameras use.

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Waiting for a delayed flights is a regular activity for most people, so when airports take it upon themselves to have interesting installations, I say “Hell yeah, this ain’t so bad after all.”

Case in point: SFO’s Tornado Machine. Tall enough for a grownup to stand inside of, the machine creates a very cool vortex of mist spiraling seven feet high. The effect is completely mesmerizing – I stared at it for two hours straight, and suddenly it was time to board my flight. Here’s a quick video I took of it.

Tornado machine at SFO from Mike Senese on Vimeo.

Gotta have your own? I felt the same way, and found a write up on how to build one for your home (with accompanying PDF information). This is a smaller size unit (about 3′ tall) but some modification wouldn’t be too hard.

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“You’ve gotta see it to believe it” means less and less as we take each step into a digitally manipulatable future that is nearly impossible to distinguish from the real thing.

Need to film a visit to Vegas? NYC? Moscow? Green screen it! As evidenced by the above demo reel, we’re now at a point where the television and movie images that look and feel so very real are as fake as science fiction. Even as someone who works in the entertainment industry, I’m blown away, and maybe even saddened a little by these illusions be revealed to me – I truly thought Hiro from Heroes was IN Times Square. But it is a testament to the acting abilities and the special effects capabilities that we have available today.

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Jump into your weekend with some DIY projects. Here are a few of my favorite ones that I’ve posted here. Remember to take pics and send them to me too.

How to Build a Temporary Wood-fired Brick Pizza Oven with Cheap, Easy to Find Materials
(and Make Your Own Wooden Pizza Peel (Paddle))

Near-Space DIY Aerial Photography for $150

How to Make A Digital Pinhole Camera – Fast, Cheap and Easy

Arduino RC Controlled Lawnmower Project

Build a Six-Wheel-Drive ATV for Go Anywhere Fun

Build Your Own Camera Gyro-Stabilizer With a Spare Hard Drive

DIY Electronic Drum Pads for Less Than $30

Bike Repairs Made Easy With the DIY Bike Repair Stand
Then Tune Up Your Bike: Adjusting the Derailleurs