I have a Felder saw/shaper combo with sliding table. It is a really nice machine and the precision, specially when working with larger boards is avesome. However the position of the on/off switches for shaper and saw are strangely placed and are difficult to reach. For both safety and convenience I have thought of building an swich stand similar to those on high end panel saws.
I'm afraid I have no experience with any European combo machine, but there is an effective solution for simpler table saws used in many shops in the U.S. (and other places). A wooden frame is built that hangs from hinges from the bottom of the front rail, and extends almost to the floor and completely across the front of the saw. This frame has an actuator that is positioned over the off switch (usually a push button switch somewhere near the top left of the frame). Bumping the frame, with either hand, a knee, a foot, or even a push stick, anywhere on the frame, and from anywhere at the front, or left or right side of the saw, actuates the off switch. The stiles and rails of your frame need to be laid out to not impede access to any of the critical controls, including the blade height adjustment wheel, the blade tilt wheel, the mobile base controls, the On switch, etc., of the individual saw.
You might also ask for ideas on the Turning forum, as many turners with large lathes have them equipped with a power switch (and speed control) on a pedestal that swings around to various positions conveniently accessible to the turner when turning spindles or hollowing bowls or hollow forms. Some of these are provided by the lathe manufacturer, but others are DIY.
But I'd think you'd be best off asking Felder. Their reputation is very good and that may even have a ready-made add-on that will solve your issue. They used to have a US rep who was a contributor here in WC; forget his name, however.
In my opinion you need to join the "Felder's owner's Group in you don't already belong. Lots of help and information on that site. They can steer you to all the right parts to make a "pendent switch" for your machine. That is what I did almost 20 years ago and glad I did. A lot of the guy with Felder saw have made and installed them.
Here's a picture of my pendent switch I put together with the help of the guy on the Felder forum. The switch hangs on the side rail and slides up and down the length of the slider and clamps in place where you want it.
Many years ago there was an active Yahoo run Felder forum. It was shut down but a new Hammer/felder forum showed up some years ago but now it seems to be dead also.... Are the old messages accessible?
I want to build a pendant switch as Richad made, however I am considering placing the switch on a a moveable arm some 50 cm (20 inch) above the saw/shaper table.
Like said, if you own Felder equipment you should join their group. This is the linK (https://groups.yahoo.com/neo/groups/felder-woodworking) You have to ask to join.
My saw is about 20 years old. By now Felder may have come up with their own accessory, I don't know. But adding the pendent switch was easy. And I'm not the sharpest chisel in the box.
My saw is 10 years younger than yours. Perhaps Felder made it more complicated. I understand eloctronics just a tiny bit, basics only, so it seemed too complicated to me. We are not looking at the same machine and 'difficulty" is an objective matter, so being wrong is not an issue here. I am glad you were able to modify your machine.
I've been a member of FOG since I bought my machine.
What is unsafe about an off switch that you can reach with your foot? The off switch that came with my SawStop is easily reached with my thigh or knee, and it it were a bit longer, I could also reach it with my right foot while standing to the left side of the saw. Note that the switches I am describing are off switches only. The only way to activate an on-switch for my saw is with a push of the finger on the shielded on-button (very similar to the one in the Felder picture in this thread). I agree, any switch that could inadvertently turn on the saw is unsafe, and should never be implemented. Even the foot switch I have for my scroll saw and Dremel has a guard so you must intentionally insert your foot into the switch to turn it on. I wouldn't even install it on my drill press.