Anybody ever make this ribbon controller?

[mth5044]

http://www.wiseguysynth.com/larry/ribbon/ribbon.htm

The construction with the velvet looks to the hardest part, the rest (like wood carving and stuff) is just for show and not really necessary.

I was thinking about giving it a try. could be cool to control effects or oscillators.

[Paul Perry (Frostwave)]

I haven't built it, but I have been searching for suitable resistive material.
the common 'conductive' rubber used for electronic workbenches isn't nearly conductive enough.
And the conductive foam used to store chips in is OK but, it doesn't last mechanically.
I think the original Moog unit had a resistive wire (possibly spiral wound to increase the resistance, i can't remember) with a contact strip above it, you put pressure on the upper strip & the contact point acted like a wiper on a pot.
Note that if you put a couple of pressure sensors under the ends of the base, you could (if very agile) get an extra variable out.

Which last point makes me think.. if you had a pressure sensor under each end, and you pressed vertically, you would have enough information to say where along the board you were pressing.

[~arph]

Old VHS tapes ?

[frequencycentral]

Old VHS tapes ?

Yeah I did that once, was that the Synthstick? I've still got some conductive sticky tape from that experiment - I remember measuing the ohmage of every VHS tape in the house! Happy days!

[~arph]

Ah yes, the synthstick it was.. Tim Escobedo I believe 

EDIT: linky..

http://www.geocities.com/tpe123/folkurban/synthstick/synthstick.html

[mth5044]

I haven't built it, but I have been searching for suitable resistive material.
the common 'conductive' rubber used for electronic workbenches isn't nearly conductive enough.
And the conductive foam used to store chips in is OK but, it doesn't last mechanically.
I think the original Moog unit had a resistive wire (possibly spiral wound to increase the resistance, i can't remember) with a contact strip above it, you put pressure on the upper strip & the contact point acted like a wiper on a pot.
Note that if you put a couple of pressure sensors under the ends of the base, you could (if very agile) get an extra variable out.

Which last point makes me think.. if you had a pressure sensor under each end, and you pressed vertically, you would have enough information to say where along the board you were pressing.

This is an excellent idea. I want to get the basics understood first by building one with just one variable, then I'd venture out to what you are saying. Sound really cool.

As for the VHS tape, I've seen that, but between finding VHS tape that works, and that plastic stuff for the top, the materials in the link I mentioned are a bit more ready, even though it may cost a bit more. Plus I would assume that the synthstick is cool for fooling around, but for practical reasons I doubt that it would hold up for very long? I could be wrong, but the ribbon controller that is showed in the link looks like it could last a long time.

[flo]

Presure sensitive resistor is perhaps interesting to use. In Dutch for about $10:
http://shop.conrad.nl/elektronica-meetapparatuur/componenten/sensoren/druk-sensoren/503368.html
Translation:
Pressure sensor FSR-400
Pressure sensors can be compared to foil-switches. They change resistance in reaction to applied pressure. Pressure of 10 g till 10 kg on the sensor changes the resistance from 2M Ω to 3k Ω.

[nelson]

What about Soft pots?


http://www.trossenrobotics.com/store/p/5832-SoftPot-Membrane-Potentiometer-500mm.aspx

[mth5044]

What about Soft pots?


http://www.trossenrobotics.com/store/p/5832-SoftPot-Membrane-Potentiometer-500mm.aspx

I have a small one, I think it was supposed to be like.. 0 to 10k resistance. It goes from 9k-10k now, all up and down the strip, so I guess they aren't very reliable. Also, I hear they don't last very long. It doesn't look very linear on that video, slow on the bottom end and really fast on the top. That wouldn't be too good for making notes, but maybe the other ribbon controllers are that way too?

I've never seen one quite that big though. It would be about as much as it would to make my own out of the materials from the first link.

Thanks for the link, I'll definitly keep it in consideration.

Does anyone else have any input on the ribbon controller from my first link? Like posibilities of failure?