I'd imagine a solenoid would work, but probably someone here knows of a better method?
I want to make a musical instrument which strikes windchimes. So what mechanics would be best for that?
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A solenoid with a spring (or gravity) return and a rubber or plastic tip should produce a nice strike. It shouldn't take much to get a clear bell tone and you don't want to hit it hard enough to set it swinging. That would cause subsequent strikes to vary randomly in volume as the chime gets closer and further from the solenoid.
Thanks for the reply. I thought about a solenoid but imagined that there might be some sort of tiny electrical hammer out there. Oh well, back to the solenoid then.
Thanks again!
How about a striker on a servo? Program to swing 90 degrees & return
couple of places to look ...
http://www.hobby-lobby.com/servos_241_ctg.htm
http://www.servohobby.com/
CrossRoads:
How about a striker on a servo? Program to swing 90 degrees & returncouple of places to look ...
http://www.hobby-lobby.com/servos_241_ctg.htm
http://www.servohobby.com/
Adding a spring to such a striker might make it more realistic compared to a human striking it (rebound).
You could use an electromagnet to swing a hinged hammer rather than a solenoid, if that's easier.
How does electromagnet differ from solenoid? Form-factor?
CrossRoads:
How does electromagnet differ from solenoid? Form-factor?
An electromagnet is formed with a coil of wire around a (generally iron or some other ferrous metal) armature. The armature is immobile, surrounded by the coil.
A solenoid is an open-air core coil of wire, in which a free-moving iron (or other ferrous metal) armature is drawn into the coil upon application of power.
A transformer is, of course, two or more coils of wire on an armature (which can be open-air, or made of some metal, all depending on the characteristics and frequencies being handled), for changing the voltage level of an AC source or signal.
All of these items are technically known also as "inductors"...
So form factor then. In one case the electromagnet itself can move (say, drawn to the bell if it was iron/steel), vs moving the iron core out of the magnetic field.
Probably more effective to move the lighter core back & forth vs the electromagnet & all its wires (if it is even attracted to the windchime).
some examples
http://www.ledex.com/linear-solenoids/dc-open-frame.html
I would imagine the tried and tested doorbell design with a spring-return solenoid is probably the cheapest to make... The spring recoil can be used to strike a second bell. As in 'ding dong'
Thanks for all the great ideas.
In one of the links for solenoids "push models are available", I'd imagine that would be ideal. Activating the solenoid pushes the bar out and strikes the tube of the chime.
I think that for my application I don't need to use servos, I just need a single "hit".
Thanks again all.
I've just discovered that a thing called a "rotating solenoid" exists, but the ones I have seen seem expensive compared with linear solenoids.
Hell, solenoids are expensive!
I've found one quite cheap one which looks interesting, BLP Components do a small solenoid (series 151) which has (from the photo) an through bar which means it can be both a push and pull solenoid. 2W and probably more powerful than I need, but I may order one just to see if it is suitable.
Yikes. The 12v solenoids at DigiKey start at over $20 and go up from there. Perhaps you should buy a spool of magnet wire and wind your own.
It depends on how big your bell is. This little fellow is quite cheap:-
http://uk.farnell.com/ped/45-120-610-620/solenoid-pcb-12vdc/dp/9687939
But there is a lot ot go at before you hit the $20 mark:-
http://uk.farnell.com/jsp/search/browse.jsp?N=2031+203722&Ns=P_PRICE_FARNELL_UK|0&Ntk=gensearch&Ntt=solonoide&Ntx=mode+matchallpartial&D=*solonoide*&locale=en_UK&appliedparametrics=true&getResults=true&originalQueryURL=/jsp/search/browse.jsp%3FN%3D2031%2B203722%26Ntk%3Dgensearch%26Ntt%3Dsolonoide%26Ntx%3Dmode%2Bmatchallpartial%26D%3D*solonoide*%26No%3D0%26getResults%3Dtrue%26appliedparametrics%3Dtrue%26locale%3Den_UK%26divisionLocale%3Den_UK%26catalogId%3D%26prevNValues%3D2031%2B203722
Note this is a UK web site but Farnell have a US one as well.
Note this is a UK web site but Farnell have a US one as well.
I'm based in Italy, but Farnell have an Italian site, so I think I can order from there. Thanks for finding that solenoid, it is not push, but the push ones seem even more expensive than the pull ones.
ofransen:
Thanks for finding that solenoid, it is not push, but the push ones seem even more expensive than the pull ones.
It's rated for continuous duty so you could leave it pulled in all the time (1.5 Watts each) and drop the power when you want to plunger to come out. They each draw 1/8th Amp at 12 Volts so you just have to size your power supply to match. You'll need something like a logic-level MOSFET to do the power switching.
If I do the mechanics right "pulling" will hit the chime anyway. So I'd apply power, the plunger comes "in" and a lever attached to the plunger hits the chime. Or I suppose I could have the plunger resting on the chime cylinder, then a quick in-out-in motion would strike the chime.
I think I'll find out by experience which is best.
See my other post about how to power the solenoid. Is a MOSFET better for this than a "normal" transistor?
By the way, how do I "quote" you in posts. I can see a zillion icons, but none which say "quote post you are replying to."
The button to reply with a quote is right up here in the corner ------------------------------------------------------------^
Chagrin:
The button to reply with a quote is right up here in the corner ------------------------------------------------------------^
Ha! Just testing you all!
