Thread: Servo Controller Help!

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Hey Everyone....I scored my first Craigslist Halloween thing today! I got this unbelievable Organ for $25 and it mostly works!....It was converted at some time to electric air power instead of the manual bellows....I messed with it most of the day and after figuring out what the stops did, I tore out everything that blocked the reed holes so it would be loud! I decided this thing has way too much character to go the route of speakers and an MP3 player...I figured out a tune that uses 8 keys so I'd like to mount servos under the keys to pull down those 8 keys...I tested how hard it was to press those keys and I'm guessing the servo that moves a bucky jaw should move the keys....I've never done anything with servos so first of all, what controller would control 8 servos that's easy to program and is also stand alone....I don't want to control this with a PC...Also what servo would you recommend?....Thanks for taking the time.....ZR

I've decided to go with air instead...Something I understand and probably more rugged in the end....ZR

Did you mean air cylinders, or just solenoid valves feeding the organ? If you meant air cylinders, it might be easier/cheaper to use solenoids. Some white-goods solenoids are quite strong, and you could probably find them surplus pretty easily.

As for the controller, check out DC Props. It looks like they've got a 'key banger' programmable board, as well as a MIDI controlled board. Other alternatives would be using a Prop-1 type of board, but you'd need to program that in BASIC (program the delays between each note, program how long each note is, etc).

- Hook

Originally Posted by Hooked_on_Scares

Did you mean air cylinders, or just solenoid valves feeding the organ? If you meant air cylinders, it might be easier/cheaper to use solenoids. Some white-goods solenoids are quite strong, and you could probably find them surplus pretty easily.
- Hook

Hello!...I got these cylinders - 9 Bimba 5/16" Bore Single Acting Air Cylinder, 0071.5 - eBay (item 200066610312 end time Jul-25-09 20:52:18 PDT)

and this valve bank - Bank of Numatics Solenoids w/Manifolds, Valves & Cbls< - eBay (item 370147313579 end time Jul-25-09 20:54:13 PDT)

I'm looking at a Gilderfluke minibrick8 for control....It would power the 24 volt solenoids and I've got a few 24 volt power supplies laying around....I think there is enough room under the keys to mount the cylinders...My idea is to put small eyebolts under the keys with a small solid piece of wire like on the servos attached from the eyebolt down to a metal piece that will be like a see saw...When the cylinder pushes up against the opposite end, it will pull that end down bringing the key down with it....I'm hoping that works because if it ends up not having enough room, I'll have to go a cable route which would be much more complex....

I'm really curious how your using just solenoids to cause movement?....I thought they only opened up the valve for liquid or air....I'd be obliged if you'd shed more on this....Thanks!...ZR

Solenoids are electromagnets that pull on something. They're used in contactors (very high current relays), valves, or just by themselves, to pull on an external linkage. So, what you presently think of as a solenoid is really a solenoid valve.

Here's some surplus solenoids from a place near me.

- Hook

Thanks Hooked On Scares for the info.....That's very interesting for sure....It looks very appealing space wise but the reviews people wrote say there isn't much of a duty cycle without heating up....I imagine there are industrial solenoids that would do the job at a higher price of course....After thinking about it, I think the air cylinder route would be the most robust and should outlast servos or solenoids but much more work to install....I'll keep those solenoids in mind when I build my own version of the "Spookytown" miniature village out of foam though....That would definitely be the ticket to move small foam pieces around...Thanks for the "enlightenment"....ZR