keyboard sustain pedal

[jaapie]

I may start playing keys with a friend's band soon, and I need a sustain pedal to use with my keyboard. It seems like a pretty simple pedal, so I'd much rather build one myself than order one (especially since I've got an extra boss enclosure lying around that seems like it'd work pretty well). I haven't been able to find much info on the construction of such a pedal, though, so i was hoping someone here could point me in the right direction. I figured that i could just wire a momentary switch (like the one that was in the boss pedal) across the two conductors of the 1/4" jack, so that when the switch is pressed they'd be shorted together, closing whatever circuit does the footswitch stuff. I tried plugging a short guitar cable into the footswitch input and shorting it to test my theory, which didn't seem to work. I'm taking that to mean that my assumption was wrong, so I'm coming to you guys for help. What should I do?

[ashcat_lt]

Should work exactly the way you've described.  Some strange keyboards might be set up for "normally closed" sustain pedals, but you should get some change when you short those leads.  Are you sure you're not missing a parameter on somewhere on your keyboard that tells it to ignore the sustain pedal?

Here's a fun little project.

[SonicVI]

Some sustain pedals work by closing an open switch and some work by opening a closed switch.  It depends on the keyboard. Try it both ways.  Some keyboard can automatically detect at power-up which kind of pedal is being used.  With the guitar cable inserted in the jack try turning the keyboard's power off and back on.     What brand of keyboard is it btw?

[sean k]

In relation to my Boss looper I went and checked the Boss switches and expression pedals and as above the switches were pretty much just that, at least for my needs, and the expression pedals were just a 10kB rheostat.

[raulgrell]

Try a stereo cable, sometimes these units come with two pedals, one for sustain, the other for... whatever the second one is usually for...

Basically, you may be shorting the wrong one...