we used a type of rubber band that was more resistant to wearing out, but yes, we do need to recalibrate it every month or so. I also explored using a design similar to yours, but just found the physical pressure indicator more user friendly (color-based) and the gear to be more robust than a sliding mechanism.
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Pretty much the whole point of me making this is to make VEX create a intended-use pressure sensor with a similar setup to that. However, I just canât see anyone being able to make a pressure-hose based bourdon tube that is consistent or readable by a sensor. Thatâs the simplicity in the piston: it can be calibrated with rubber bands to be sensitive to specific pressures.
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While I think that is a very clever idea, sanding down the wall thickness on a piece of pneumatic tubing seems to be a pretty clear violation of <R20> (No modifications to electronic or pneumatic components are allowed).
While the rule number may change from year-to-year, I forsee exactly zero chance of RECF allowing modifications to pneumatic components in future years (for safety and liability reasons).
If you can find a way to do this WITHOUT modifying the tubing, it might work.
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A coil of tubing would probably partially unwind when pressurized. If you can visually see the tubing, no need for a sensor.
I just had an idea- if you were to use a dual action piston you could have a pressure regulator pulling it down, so at a low pressure the piston would unextend without the use of bands, which are the main source of inconsistency.
That is a clever idea. The only reason it might not work is that a pressure regulator will not only ADD air from the reservoir if pressure is too low, it will also VENT air to atmosphere if the pressure is too high.
If there is a way to use a double-acting cylinder and seal the âreturnâ side, you might be able to create an air spring in that wayâŚ
Can you shut off the flow metering elbow on the return side of the cylinder enough to avoid leakage?
the pressure sensor is directly connected to our pressure cylinders, which is how we avoid the problems you mentioned. Since pressure regulators output a relatively steady pressure, it wouldnât be useful to connect the pressure gauge downstream of one of those things.
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Nope. You are probably using it wrong. Pressure regulator will regulate pressure down to a set PSI. We use a system like this on our robot right now, which we pressurize both sides of the cylinder at once.