Don's Pages and my Music

Tuesday, July 27, 2010

Some of my wooden machines

Some of my wooden machines


    Wooden engine
    My wooden double action reciprocating air engine



I have heard it said that every self respecting machinist has, at one point or anoher, built a steam engine. Although I'm not a machinist, I felt lacking in this sort of aspect, because I was already in my late teens by the time I built my first electric motor.

I had built numerous reciprocating engines out of legos before, some with two cylinders, each double acting. Legos is ideally suited for this sort of task. Building one out of wood seemed a logical next step. The engine I built was a single cylinder double acting engine. The valves is a specially carved out piece of hardwood sliding in an enclosure with other holes cut in it. Its nearest the camera in the picture, and actuated by the crankshaft in the middle. The main piston is the large thing in the back, which attaches to the large wheel.

For fun, I added some auxilary pulleys for stepping the rotational energy up or down, but the engine was never powerful enough to actually power anything - in large part due to blowby in the main cylinder. There is no seals in the piston, and it has to run freely even with low precision and wood warpage. It was very sensitive though - I could run it on 400 pascal, or about 4 cm of head when measured with water. It could only run on air - steam would have quickly swelled it and completely jammed it up.

I have since written a more detailed page about this air engine on my woodworking website.


    Blackberry key pressing machine
    Blackberry key pressing machine
Another machine I built for work back in 2001. We had a "software problem" on the devices, that only seemed to happen on some devices. Investigating this, I suspected that typing on the keyboard caused some contacts behind it to eventually become intermittent. So I built this machine to "exercise" the keyboards on some units continuously to try to reproduce the problem. The machine pictured here is actually the second machine I built, this one being able to exercise two devices at the same time. The wooden disc over the keyboard changes its angle to press the keys along its edge. The disk is moved side to side by another motor, so that all parts of the keyboard get exercised.

As it turned out, if exercised long enough, every unit would eventually turn into a "bad unit". It was too late to fix the hardware design by that point, but the machine did allow us to better study the problem, and test a software workaround for it.

This isn't the only wooden machine I built for testing products at RIM. One of my other machines was the pager rotating machine


    Wooden track tractor
    A little track vehicle with wood tracks
I have often built little wired remote controlled vehicles. By this I mean vehicles without any electronics in them, just a big umbilical cord running back to a control panel of switches. No batteries or electronics required.

The neatest of these vehicles I ever built is the above wooden tractor. The tracks are block chains all made of wood. Each chain is independently powered by a VW bug wiper motor (perfect size and format for the job). This vehicle worked amazingly well, and thanks to most of the weight on one end, it turned very easily, and could climb even very soft and unstable surfaces, such as a pile of planer shavings. I was amazed by how well the chains worked, and by how much abuse they could take.

I have since written a more detailed page about this tracked vehicle on my woodworking website.

To my Woodworking website

Back to Matthias Wandel's Home page

Go there...
http://www.sentex.net/~mwandel/built/wooden_machines.html

Don

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