[sdiy] Kinda OT: electro-mechanical instruments/ solenoids

[Ken Stone]

The problem with this diagram as shown is you will find the movement of the
solenoid too short to be practical.
The reverse "C" hammer/damper is okay, though you will probably need to move
the solenoid to the right, and have a pivot point even further to the right
than that. 

H------S--P

where H= hammer, S =  solenoid and P = pivot.

Ken

>Excellent notes, thank you. I want it to be played from a (midi or CV) 
>keyboard so that when a keyboard key is released, the corresponding 
>xylophone bar is muted. I have an idea that looks like this:
>
>
>                            +-------------+
>                            +-----------+ I
>                          DDDDD         I I
>                           DDD          I I
>                                        I I
>+------------------------------+       I I
>+-- Xylophone bar -------------+       I I
>                                        I I
>                                        I I
>                    BB                  I I
>                   BBBB/\/\/\/\+--------+ I
>                    BB         +---++-----+
>                                   II
>                                   II
>                                   II
>                                   II
>                                +------+
>                                I      I
>                                I      I
>                                I      I
>                 Solenoid  -->  I      I
>                                I      I
>                                I      I
>                                I      I
>                                +------+
>
>Where
>1) DDD is a dampening material - cotton pad or rubber
>2) BBB is a "heavy" bead mounted on a spring
>3) Key on -> solenoid extends upwards, hits a full stop a few 
>millimetres under xylo bar, bead hits xylo bar due to inertia, spring 
>pulls the bead back
>4) Key off -> solenoid retracts down, cotton pad dampens xylo bar
>
>
>regards
>-Andreas
>
>
>2004 dec 07  kl. 09.12 skrev Ken Stone:
>
>> My advice, for what it is worth-
>>
>> do not use a rigid set-up for striking. I used 1/8" cane with 3/4" 
>> wooden
>> beeds glued on the end for strikers. When the solenoid is in its 
>> activated
>> position, the bead is above the metal bar, not touching it. When the
>> solenoid is activated, the momentum of the bead causes it to hid the 
>> metal
>> bar, and the flex of the cane will lift it clear. It sure beats trying 
>> to
>> electronically time the drive pulse to prevent the striker from 
>> damping the
>> bar after it hits.
>>
>> Ken
>>
>>> Hi!
>>>
>>>
>>> I'm planning to build electro-mechanical instruments; xylophone etc.
>>> Not really a synth, but close enough (?)
>>>
>>> Background:
>>> In Sweden (a small country) the cheapest solenoid seems to be about 12
>>> USD/ EUR. In the US some companies offer solenoids for less than 1 
>>> USD:
>>> http://www.mpja.com/category/Solenoids/Solenoids.asp
>>>
>>> The above company wants me to shop for at least 100 USD to ship
>>> overseas. This in itself is OK, I could always buy a soldering station
>>> or whatever. But how do I know that the solenoids are going to work in
>>> my project? I need about 30 of them, but it would be nice to check one
>>> out before ordering. Needless to say, the same brands don't exist
>>> here...
>>>
>>> Question:
>>> What should I look for in a solenoid? Do some solenoids have too slow
>>> response times? Could they be too weak? Why are some so cheap compared
>>> to others?
>>>
>>>
>>> any input appreciated
>>> -Andreas
>>>
>>>
>> _______________________________________________________________________
>> Ken Stone   sasami at hotkey.net.au or sasami at cgs.synth.net
>> Modular Synth PCBs for sale <http://www.blaze.net.au/~sasami/synth/>
>> Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
>>
>
>
_______________________________________________________________________
Ken Stone   sasami at hotkey.net.au or sasami at cgs.synth.net
Modular Synth PCBs for sale <http://www.blaze.net.au/~sasami/synth/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>