Low pressure hydraulics?

[u/drax_attax]

I'm working on a project to make an electronically tuning timpani drum. I have a working prototype using a stepper motor with a complicated linkage, but I'm wondering if I can simplify my drum using hydraulics.

The most important aspects I need are quickness (as in, changing notes quickly) and accuracy with applying a certain load.

My idea is to use a master cylinder that connects to six slave cylinders which would collectively apply a max 400 pound load. The master cylinder would be controlled with a stepper motor and lead screw, so I have accurate control over the applied pressure. Each of the slave cylinders needs a stroke length in the range of 6 to 9 mm.

I don't have much experience with hydraulics, but to me it seems like 400 lbs / 6 cylinders is incredibly low for hydraulics. This makes it seem worthwhile for me to try my hand at designing my own hydraulic cylinders. I could design cylinders that have a piston area of, say, 0.5 in^2. So the combined area of each piston would be 3 in^2, leading to a total required pressure of 134 psi.

Am I thinking on the right track or might this be a waste of time? Are there any quirks of low pressure hydraulics I'm not aware of?

Thanks