Sunday, 08-02-2004

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15mm sleeving, 10mm latex tube, end pieces.... here we go! Relaxed air muscle Charged air muscle

The end pieces are 10mm aluminium tube and flatened at one end in a vice. One end piece has a 3mm piece of aluminium tube going through it to provide air. The end pieces are filled with Poly Glue.

The left piccy above shows some large cable ties... they didn't grip the tube well enough and leaked badly.

Using 2 smaller cable ties to hold the end pieces works very well... the tube comes off the pump first!


Lego ready air muscle. Relaxed air muscle supporting 2850 grammes. Charged air muscle lifting 2850 grammes.

The holes in the end pieces were drilled (4.5mm bit) and then hand filed to give a snug fit for a Lego Tachnic axle. Lego Technic axle/pin holes are 4.9mm (source: Dacta 1030,1032,1034 inventory sheet).

I was quite suprised that the air muscle could support the weight (2850g)... I was even more suprised that the muscle could lift the weight, the pictues above are of the very first test!
The ends of the air muscle have a 3 long Technic axle through the hole, one is wedged in the Workmate jaws and the other end is in the vice.

I haven't yet tested any heavier weight.


8.3g of muscle! relaxed height... 325mm (approx) lifted height... 367mm (approx)

The air muscle weighs in at 8.3 grammes, and with a current lift of 2850g, the air muscle is still capable of lifting more than 340 times it's own wieght. Very respectable using push on hosing and a lego pump :)

Letting the air out from the first test was a bit scary, letting the air out a bit at a time kept it intact... I don't want to do destruction testing just yet, I'm still getting used to the idea that these little air muscles I made work at all!

The test weight was lifted approimately 42mm... this muscle will make a good muscle design for J5's body control.


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This page is part of a diary of the design and build of my Lego Mindstorms robot J5 (based on Johnny Five from the film short Circuit.)
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