Sewing machine pedal who wants to become wah when it grows up

[bancika]

I finally got sewing machine pedal. Unlike ones I've seen here, this one's made of plastic. As I've said here before, I'd like to try building wah from it. Like bad horsie, it has spring, which is nice thing. It feels very well. Instead of pot, I'll use optical circuit with LED and LDR.
The main concern at the moment is switching. There isn't place for standard stomp switch, and I'd like to build it switchless anyway.
Do you have any idea for switchless operation? I've seen bad horsie schematic and I'd like to try something little less complicated if possible.
How hard would be to detect if foot is near (for instance 5cm from the top). It would be cool way to switch it that way...

Any input about this project would be great

Here are few photos of pedal

[Roobin]

Heres an idea i was gonna have a go at, but decided it would just be easier to buy.

How about one or two small momentary switch embedded in the top of the wah, so they protrude a bit, but switch when you put your foot on them. May not be the most reliable/easiest thing, but an idea for starters...

[Seljer]

magnet + reed switch -> controlling an electronic bypass circuit?
with something to delay the switching in between like the morleys?

[choklitlove]

i think the easiest and most efficient way would be to make an external box with the switch in it.  connect them with a cable.

just my 2 cents, lol, imho, 

[bancika]

Roobin, I was thinking the same but the problem with that approach is - what if you don't press it well. It's not the most reliable switch.
chiklitlove, I'll that for a last resort, switch in an external box doesn't fit it switchless concept
Seljer, how could I do that, I don't know much about reeds?
Tnx all

[birt]

attach a piece of metal to the underside of the rocker right next to the spring. put another spring under it but in a way that it just isn't high enough to touch the piece of metal. then wire both spring and metal in the ground path of a relay coil. as soon as you push down the rocker just a tiny tiny bit, it touches the spring and the relay switches.


*bows*

:p

[Roobin]

Another idea I had (i'm full of useless junk), similar to the first, is perhpas a momentary switch under the heel bit (you could make it delayed off, if  you want), so that after a certian time, it switches off.

Heel switch + spring = possible switchless wah?

BTW for those who want to spring load your vox or 'baby, I came up with somethign really odd, but fun. You know that bungee elastic, that's 5mm dia, well make a loop of that. Now twist it, so you have two loops (8 shaped). Now put one on top of the other, making a single loop. Now put that over the heel areas of your wah. Adjust to suit. Not quite sure what practical application it has (apart form playing The Audience is Listening like a maniac!)

Bancika, about the 2 switch idea - maybe one at heel area, one at toe is (both on the top of the wah) and you would only have to switch one or the other.

[Roobin]

Another idea (I'm on a roll!)

Looking at the pic, I'm assumign the front portion is completely light free, but accessible. What you could do (although it may not be electronically simple) is to put a LED/LDR combo, or light transistor (what are they called), which switches precises when it is closer thatn when the heel is down (ie not being used). As soon as the foot goes forward, the resistance decreases or tranny switches, and thus activates the circuit. You'd need to regulate the power supply though, to get a constant LED brightness.

How hard would be to detect if foot is near (for instance 5cm from the top). It would be cool way to switch it that way...

Proximity switch...seen a few ideas around. A new filter based on that idea, strapped to ya finger. Also ZVex has something alogn similar lines...could be expensive though.

[bancika]

attach a piece of metal to the underside of the rocker right next to the spring. put another spring under it but in a way that it just isn't high enough to touch the piece of metal. then wire both spring and metal in the ground path of a relay coil. as soon as you push down the rocker just a tiny tiny bit, it touches the spring and the relay switches.

that's exactly what I was thinking about
What about delayed OFF switching, anyone know how to do that?

[Roobin]

Capacitor?

[bancika]

I think I'll try with morley switching system, it doesn't look too hard like the first time. I'll make separate board with switching system and in/out buffers so I can try different swapping wah circuits. First will be colorsound inductorless, I can't find inductors here so it's good circuit to start with.
I'll post any progress