20101127

Moving heavy equipment with your mind

This book was written in 1922 by an artillery school, and includes lots of info on hoisting and moving huge, heavy, delicate machinery, like cannons or machine tools or overturned/stuck vehicles. The book covers knots, leverage principles, and some of the basic tools that can be created to help the task.

Mostly you will be using manpower and simple leverage multipliers of all kinds, along with some good thinking about what you're doing. Thus the 'mind' part. Unfortunately they don't cover pure telekinesis in this volume; I'm still looking out for that book.

http://www.archive.org/details/mechanicalmaneuv00coasrich

20101126

Rotary to linear motion with wooden gears



OBJECTIVE
Build a robust, accurate rotary-to-linear motion transfer box within a weekend, without spending any money.

PLAN
Some projects need an element that moves in a straight line, but this is not always as easy as getting rotary motion straight from a motor, pedals, or crank.

To accomplish this, I read online about mechanical linkages and selected a hypocycloid linkage. It has a very elegant and simple design, with a long linear travel for a small size. Rotary input (like a hand crank or drill) applied to the central shaft is converted to straight line motion across the diameter of the ring gear. The linear motion will be as long as the ring gear is wide.

BUILD
I hand-cut two plywood gears on the bandsaw and built a frame to run them in. The ring or internal gear has 32 teeth, the round gear has 16 teeth. Using powers of two ensures both good support from the spirit world, and harmony with the geek nature.

My gears were cut from a paper pattern generated with the free online gear calculator at http://woodgears.ca/gear_cutting/template.html , which I printed out and glued right to the plywood.

According to the site's gear-making recommendations, this is sometimes a problem with laser printers -- though not with inkjets, since they have tighter registration requirements. I used a laser printer and measured the gear patterns in several places to ensure that the laser printer didn't stretch the image in any direction.

All parts were cut by hand on a bandsaw, trimmed by hand (very little) with a wood file, and finished and lubed with paste wax. 1/2" bolts and washers were used throughout.

FITTING
Since the gears are hand cut, and since this is the first time I have made gears like this, there are small variances despite the saw being quite accurate and maneuverable. The dimensions aren't exactly perfect -- they are very close, however, and well within working tolerances.

I clamped all the various layers and spacers together, rotated the movement by hand and tested the path, tuning with a small hammer to tap the pieces into their best fit.

I aligned the teeth to find a combination that gave smooth travel without binding.
I rubbed some wax into the teeth to ease their meshing up during the initial tests.

Then I chucked up a drill on the main shaft and gave a test run, repeating my tuning process and eventually screwing all the layers together when I was satisfied. I then ran it for a few minutes to work in the gears.

The time spent aligning the parts by hand provided a much better end result -- this was time well spent. I haven't finalized this as a working tool, just a prototype, so it's not painted. But it is sanded smooth and finished on all 6 sides, square, and generally nicely worked.

RESULTS
The gearbox is quite stable, and it goes way faster than I would need. I estimate the main shaft got going at 200-240rpm, at the drill's fastest speed in high gear.

This was a successful project and consumed about 10 hours of time to plan and complete. (This includes the time spent taking the laser printer completely apart due to paper slippage problems, servicing the paper feed rollers, and reassembling it.)

WHAT I LEARNED
This project was purposefully set up with very rough measurements throughout. I used it to improve my skills at eyeballing, guessing correctly without actually measuring anything, and improvising solutions precisely the first time.

I used a divider to copy one measurement --I needed to rebuild the center arm, but with a 1mm increase in length between the main shaft hole and the gear hole.

Everything else was strictly eyeballed, even measuring the center of the main axis hole was an eyeball measurement. This was probably not the best or easiest choice. But that was the point, to do something using basic hand techniques, and have the project come out working as planned despite the lack of laser cutters, CNC tools, or even exact measurements.

Don't be afraid to extend the boundaries of your ability and sharpen your techniques for making good guesses and improvising in your projects. It improves your work when you have more practice at deciding confidently off the cuff, and fixing as you go.

FUTURE REFINEMENTS
* Add an adjustable counterweight to the main shaft to counter a minor wobble.
- Apply a more attractive, durable finish like battleship grey spray paint.
- Consider making parts in metal or acrylic. Heavier = more stable.
- Add proper bearings for smoother and faster travel. These could be shop built or salvaged.
- Add a better driver, like a crank or built-in electric motor.

20101123

Homemade UV LASERs


This week we decided to build lasers. Not just any laser, but one that puts out 100KW pulses of Ultraviolet light. Okay, the pulses only last 1-2ns and it's hard to burn things with it, but it's still pretty cool. It's pretty easy to make from junk, and it uses Nitrogen right out of the atmosphere to lase. Check out the video:

23B TEA Laser


Arclight

20101107

Venus de Cthulhu

Modified this otherwise unremarkable found-statue:




sorry for the sideways pics, maybe you can turn your monitor.

Tool Blocks and Holders

Pliers holder

This plier holder declutters several drawers of jewelry tools. I used a torch to forge and bend the scrap of rebar. I forged the center bar thinner to allow the smaller pliers with sprung handles to rest nicely alongside their larger cousins.

Handmade fids and awls (plus 2 bought ones)

I made up a few sets of hardwood tool blocks for my ever-growing collection of needle files, assorted bits, awls, and knot-tying fids. They get the tools sorted and visible, as well as helping protect sharp points and delicate files from getting the blood of the unfortunate on them, which rusts the metal.


Sandblasted dinosaurs were added for visual interest.

Salvaged pallet wood with nice nail stains and character.


Open Access Control v1.00

Open Access Control v1.00 system prototype

The Open Access Control system is an electronic alarm and door access system currently in development by Arclight at the 23b Shop. It is open-source and open-hardware, meaning you can get in on the fun and build one yourself.

It is currently being tested for duty as a burglar alarm, door chime, and people tracking system. It logs door access data in syslog format, sends the data via ethernet, and has on-board memory as well for data, command, and user storage. Its real-time clock ensures accurate data logs.

A numeric keypad is attached for entering commands -- for example, make the door open , set to chime on open, stay unlocked for x minutes, lock and allow exit only, deny access to a user, add a user, learn an RFID fob, and so forth. More keypads can be added.

Inexpensive RFID readers allow the system to be deployed without compromising the building's doors, windows, or walls to mount a keypad at the entrance, though this could be done as well.

The strike is a standard electromagnetic building strike; there's no sense messing with such a great and overbuilt piece of hardware.

Homebrewed circuit boards allow fast prototyping

The system is built around an Arduino Duemilanova board with an Ethernet shield and custom hardware for the in/out devices. The boards were designed and built at the shop. Laser-printed PCB images and Fab-In-A-Box transfer resists were used to generate prototypes quickly and easily. An inexpensive ID card laminator applied the resists to the board material. A fast accurate etch was obtained by wiping ferric chloride onto the prepared board, which was a novel method that seemed to work more quickly than tank etching with the same chemical, with much less cleanup and chems used.

The power supply board

Users can build their own unit from scratch, or possibly obtain partial, full, or assembled kits by contacting the shop.

Hardware files and Arduino code are available here:
http://blog.shop.23b.org/2010/10/open-access-control-v100-board.html

Users would be able to write code to support other functions of their own devising, like releasing poison gas, activating lasers or tranquilizer dart projectors. Of particular interest are the 'talking sentry', 'MOTD', and time-aware Mini-Bake Oven modules, all in various stages of development.