November 5, 2007
The hunt for the great white solenoid
I'm working on a physical prototype that requires a device that I can send power to, and have it make a sort of punching motion. Luckily for me there is just such a device. It is called a linear actuator, or solenoid.
Devices such as these are EVERYWHERE. There are dozens of them in your car for example. When you push a button, and your door locks click open or closed, that my friend is the work of the solenoid. They are in our cars, our hot water heaters, our thermostats, our doorbells, our security systems, and just about everywhere.
Unless you need to just buy one...
In the case that you just want to buy some solenoids your options are extremely limited.
Essentially, for the everyman, here is what you get...
I know... wow.
This device consists of a magnetic coil with a plunger. The catch is... that's it. You can stick in the plunger, apply voltage, and wham, the plunger moves forward. If you want it to do anything else, for example return to the starting position, you have to do all the engineering yourself. If you have a highly equipped metal shop, no sweat, but who has that?
I've found several companies that produce more complex solenoids, but they do not usually sell to people like me, who need 5-10 units. They want to sell me 1000 units at about $18 each.
This is by far, the most frustrating thing about doing physical design; simply finding the right materials. Sometimes things just don't exist, and sometimes they do, but you don't get to play with them, but at the end of the day you still need to finish that prototype, and the duct-tape solution you've rigged up is not going to cut it. I've spent several weeks working on this prototype, and the vast majority of time has been searching for the right solenoid, or trying to figure out a way to modify the one I have such that it does not require blow-torches, or look like that breakfast making contraption in beginning of Pee-wee's Big Adventure.
All of this has given me a lot of respect for artists who do large scale installations. They really must spend a lot of time just looking for the right materials. In art and design, I have to wonder how much the ability to find these materials separates those who end up being mediocre to those who end up being renown.
Posted by whazlewo at November 5, 2007 10:12 PM