Double-acting PVC hydraulic cylinder and control valve

The pressure in your typical garden hose is nominally around 40 psi or so, so my first hydraulic cylinder should be able to develop about 125 pounds of force if it had really good seals. This is a proof of concept so I didn’t bother with o-rings or anything, so it leaks like crazy and thus is unable to develop quite those kinds of pressures, although it is quite strong. Moving from a 2″ to a 3″ hydraulic cylinder would bring this up to about 282 pounds of force, not too shabby for garden hose power!

The hydraulic cylinder is made of standard PVC pipe (2″ for the cylinder and 1.5″ for the ram), although I had to use my lathe to turn down a 1.5″ pipe cap to fit inside the outer cylinder. The control valve is made of 1/2″ CPVC fittings and tubing, with the exception of the spool which is a length of 1/2″ solid PVC rod. I had to turn down the spool on my lathe to the appropriate profile and also had to drill out the valve to fit it. The fit is fairly poor but it shows that the concept definitely works. Eventually I am hoping to be able to have all the custom parts injection molded to get the unit cost down cheap enough that it would make a good toy for DIY doodlers and budding engineers everywhere.

What’s fosscon? From the fosscon crew:

Fosscon 2012 is a free and open source software conference, and will
include six general-interest talks, and workshops on topics including
development, community building, hackerspace activities, and more.
Learn about 3D printing, security, and protecting your privacy.
Network with the local tech community and discover new technologies.

(fosscon.org)

Whoa, workshops?! That’s right! Some of which will be conducted by Hive76! We’ve actually been given an entire ROOM for the conference, so be sure to stop by when you’re there!

The workshops that we’ll be running cover Intro to soldering, Intro to Arduino, Build Your Own Flat Panel Speakers, and several workshops on Building Your Own Simple Square Wave Synthesizers.Several? Yeah, Sean will cover using 555 timers, MSP430s, and also Arduinos!

The costs for these workshops will vary from $10-$30 to cover instruction and also cost of materials used.

Make sure to register for fosscon! Seating is limited! If you’d like to financially support fosscon (you should, it’s awesome!), it will only cost you $25 and you get some nice swag! Otherwise, fosscon is a free-as-in-beer event, but you still have to register!

Why be so public about something so secret? Because this tile uses a layout technique that lets you build charlie-plexed LED arrays quickly and cheaply — and that’s something worth sharing.

Charlie Tile Circuit

You need to flip the tile over in order to see what’s special about it. Here’s a quick list of features that make the assembly what it is:

• The back of the tile has six “column” conductors and six “row” conductors.
• These column and row conductors are connected along the diagonal of the row/column array.  At all other points in the matrix, the row and column conductors are isolated via a layer of masking tape.
• LEDs above the diagonal have their cathode connected to the conductive row immediately above the LED.  LEDs on or below the diagonal have their cathode connected to the conductive row immediately below the LED.
• All LEDs have their anode connected to the column that is to their immediate left.

The resulting circuit allows you to individually address any of the thirty LEDs in this 5×6 matrix using only six lines from a micro-controller.

It turns out that this assembly technique is pretty quick.  It’s also physically robust.  Best of all, it’s cost effective — copper tape is relatively inexpensive and masking tape is downright cheap.  To get some perspective on how this compares to other assembly techniques cost-wise, go price a custom printed  4.5″ x 5.25″ circuit board.

This technique can be used to assemble arbitrarily large tiles.  In fact, the larger the tile, the more effective the technique is with regard to saving time and money.  And, as a fortunate coincidence, most peg-boards happen have 5mm holes — so that means you buy the peg-board at the hardware store and jam LEDs in there perfectly w/o any drilling whatsoever — so just buy the panel, tape it up, jam in the LEDs, solder the leads and enjoy the show …

Tuesday – DIY Music Night

Wednesday – Open House

Thursday – Game Night Featuring Tetris Arm Wrestling Tournament

Friday – PTW Gala demonstration (offsite)

Events at Hive76 Monday through Thursday start at 7pm and 

ARE OPEN TO THE PUBLIC.

Friday Gala Ticketing information available here.

She ain't pretty, but she flies great

I’m a noob when it comes to RC helicopters. I got a Syma S107 for about $30 a year or two ago and it is incredibly stable while being ridiculously bulletproof. I can fly it into walls, and I’ve never replaced a part. If it’s laying on its side on the floor, I can often get it to right itself by just gunning the throttle. (Do I recommend it? No. Do I do it? Sometimes.) A wire fatigued off the board once but that was the only thing I’ve had to fix. It’s a hell of a bargain and it’s treated me great, but being so stable and easy to fly, it has some inherent performance limitations. So I decided to step up a few levels.

I heard about the Blade mCP X helicopter, the first “real” helicopter of its size that came stock with 3-axis attitude-holding stabilization electronics. It weighs maybe double what my S107 does but its performance is amazing. It can do inverted flight, flips, all sorts of crazy stuff. That is, when supplied with an appropriately-skilled pilot, which I certainly am not. But I can fly it in my backyard in 30 mph winds, and this little beast can take it — pretty impressive for something that weighs the same as a good quality 9V battery. Being such a noob, I crash constantly, but I can usually patch things up without needing to buy replacement parts. Here is the list of mods I’ve performed on my helo so far, mostly out of necessity:

• Grommet mod – tightens up the swash, reduces vibration (not my idea). Works great
• Tail boom from mCP X2 – comes with a more aggressive tail rotor which helps with yaw authority
• Created a simple tool to speed up resetting the main gear after crashes – just remove the battery and push this drilled-out rod over the gear hub to click it back in place, no need to remove the canopy or landing gear. I keep it zip-tied to my transmitter since I crash a lot
• Lengthened tail boom – added perhaps 1/2″, seems to help with yaw authority
• Added magnetic breakaway tail boom mount – after a crash the tail boom pops off instead of breaking, can be reset by simply moving it back in place and letting the magnets lock it down. Works very well, but be careful because if you have too much slack then with the right kind of crash the tail motor wires can get wrapped around the head. I’m sure I’ll keep experimenting with this one
• Masking tape holding my canopy together? Classy
• Hot glue holding my landing gear together? Not perfect by any means, but it keeps me flying until I buy a spare

Aluminum piece presses into the helo frame like a stock tail boom, but has an embedded magnet. Tail boom is hot-glued to a piece of bamboo skewer that fits into the channel, and has a magnet glued to it using CA and baking soda. Rubberbands or o-rings might be better

New Printer, right next to sawdustgenerator

Here at Hive76, my desk sits right next to the wood working station. Normally, this isn’t an issue because my computer uses passive heat management, so there is no risk of getting dust clogged up in the fans. But I recently bought a new printer and want to keep it nice and clean. I initially thought of buying a dust cover, but serendipitously completely forgot to even look for them before I left the store. So, necessity being the mother of invention that it is, I was stuck in the space, not wanting to hop back in the car for a silly little dust cover, when I realized that I had a useless cardboard box that I was about to discard that was almost the exact dimensions of the printer itself. Duh! The box it came in! I cut one side off of the box, taped the corners down, left the hole from the missing flap for the wires coming out of the back of the printer, and voila! A free dust cover. I suppose if the color ever bothers me I can just spray paint it a solid color. This solution is actually better than a real cover because now I can stack papers and other lite objects on top when the printer isn’t in use and not have to worry about them sliding or rolling off because of the somewhat round top of the printer.

A few simple cuts

How convenient

Here’s a hack that managed to make me happier than it probably should have … I was in a phone conference recently and was having trouble juggling my phone while typing on my computer.  I really couldn’t leave the meeting and was getting a little irked with the situation … and then I happened to spot a 3×5 index card.  A few quick folds and I had a perfectly good phone stand … irk be gone.

I’m not sure why this was such a kick — maybe the fact that it was so simple and stable combined with the fact that I conceived and executed the entire idea while participating in a meeting.  Plus, it really was a big improvement in my overall comfort at the moment.

At any rate, if you’re interested in making something similar, I present the following instructional video: