I designed and built different FSR "mounts" in order to be able to use FSR for automatic bed leveling with my Rostock Mini.
I came up with three designs of which I'm right now using the last one (V3).
Even if version V2 has a small heightening I could not really get the bare FSR trigger correctly.
I ended up using version V3 together with those small rubber feet you get with a lot of electronic devices (see picture)
Version V3 has holes to mechanically mount it to the printer but those big paper clips also do a very good job here.
I maybe add something on top to keep the printing bed from going up on one side while the printing head is pushing it down on the other side but up to now this was not needed.
Unfortunately, I could not get any firmware to work with complete auto bed leveling on my Rostock Mini but measuring the average z-height using G29 in Repetier firmware works like a charm with this construction.