Posted on December 9th, 2012 2 comments
Just spent an hour or two looking for low cost pressure switches to use on the CEB Press. I would like to add them as a way to add reliable sensing of end cylinder stopping points. This avoids the need for external sensors to determine when to stop primary and secondary movements. I will still need sensors to know when the primary cylinder should stop growing the compression chamber as well as one to know when the secondary cylinder should stop for a compression stage. However, with just 2 sensors instead of 6, it should be a fair bit simpler to use physical switches instead of the unreliable hall effect sensors.
The sensor I found to use is this one. It is $32 adjustable from 1000-3000 psi and rated for maximum 6000 psi overload.
There is one at the surplus center here, but the one they sent me was used and broken, there is no datasheet that exactly matches what they sell and there are only 3 left in stock which means that they aren't going to be able to be used by many more people. I'd rather find a solution that can be easily replicated.
2 Responses to “CEB Press Hydraulic Pressure Switch”
hey z, will the main cylinder stop compressing when it reaches a certain pressure? does that mean the brick heights would vary? or do the blocks get trimmed as they are pushed out? will blocks just be put on their side so height is not an issue? im a little fuzzy. definitely sounds great to have uniform compression.
Yeah, that was the idea. Brick heights will vary based on the soil type, but as long as you keep putting the same amount of the same kind of soil in, I’ve tended to get the same sized bricks out. I also plan to put them on their side, so height isn’t an issue.
That said, uniform height despite changing soil properties sounds nice, but is not achievable with this method alone. Perhaps some combination would be good. A distance sensor to ensure that the brick has reached an acceptable height combined with a pressure sensor to ensure that the brick has received enough pressure, might be the ideal.