Good grief. I can't believe I wrote that. Ugh. It was late.

The MP uses the same pump as the AV with the bypass valve which regulates the 9bar. No problem there. I guess the relief channel from the paddle is because it is very hard to create a reliable low flow rate with 9 bar. You could use a small nozzle but it will tend to clog. If you bypass it, pressure drops and one can use a larger orifice.

The strada uses the gear pump and the feedback sensor.

I don't think you can use a gear pump without a sensor - or at least a substantial bypass that relieves excess pressure. In the latter case I'd still be worried of over pressure.

If it were me I'd copy the strada sensor setup. If only as a 10 bar cutoff. If the sensor is conditioned I'd think an Atmel ATtiny would suffice.

Given Dick's analysis I would think it is a rather low reward exercise to convert a AV to an MP. It is probably cheaper to buy a used one.

A better exercise is to mimick a strada. Apart from the look is a paddle a strada is a GS/3 with EP control. One can use a massively better quality potentiometer (e.g. A NOS military pot), and get a much better ROI.

Dick is 90% of the way there, and has the added advantage of AV control.

A low profile, small footprint 1 group strada EP. I dig it.

Edit: the more I cogitate over this the more I like it. The GS3 MP has a very substantial compromise to allow the use of the 9 bar pump. A very elaborate valve (with bypass), giving up the AV ability, expensive O rings, etc. Meanwhile a gear pump, a sensor and a controller can make a far better solution. An added needle valve (or an expensive proportional valve Yay!) would extent the capabilities of the system even more.

Split follow-on discussion to Flow/pressure profiling for the La Marzocco GS/3 at Dick's request. Please let me know via PM any posts not associated with the new topic were dragged along.

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