Sep 10, 2008
MAKE Article published
I recommend that anyone interested in music, doing things yourself, and taking control of your reality pick up this month's copy of MAKE magazine. And if you like it, get a subscription- it's way cheaper.
My article "Drumbot Activate!" is contained within this new issue. In it, you'll find informative text and images that outline an easy-to-construct MIDI-controlled robot drummer.
It's based on the HighlyLiquid MIDI Decoder kit, with some simple additional parts.
A quick demonstration video:
Robot drummer from Michael Una on Vimeo
It was my goal this year to write an article for MAKE, and I'm a little surprised how quickly it happened. I expected to toil in obscurity for a lot longer.
*Edit* Some people have written me asking for a diagram as to how to hook up the solenoids or a similar device. Here you go:
MAKE reader Preston and I were just discussing one related problem-solving issue- namely, the relays can sometimes become "sticky" when activated and don't release the solenoid like they should due to a initial spike in current when the relay is tripped.
This problem can be attenuated by putting a resistor in series with the solenoid. Preston was able to stop the "sticking" with a 470-ohm resistor, but that was a little too harsh for the solenoid. It's sounding like the right range would be somewhere between 1 and 100 ohms. If anyone encounters that same problem and finds a better solution, let me know.
One other issue: If your solenoids aren't pulling as much as they should be, remove a bit of the spring and shorten the amount of rod sticking out of the sleeve. Sometimes the solenoid's sleeve needs a little more metal to grab onto when the EM field is activated to properly actuate. An extra cm or so should do it.
If anyone has any issues getting this project together, please feel free to write me at this blog or contact me directly via email: michael@una-love.com
Happy soldering! ¶ 9/10/2008 11:29:00 AM
My article "Drumbot Activate!" is contained within this new issue. In it, you'll find informative text and images that outline an easy-to-construct MIDI-controlled robot drummer.
It's based on the HighlyLiquid MIDI Decoder kit, with some simple additional parts.
A quick demonstration video:
Robot drummer from Michael Una on Vimeo
It was my goal this year to write an article for MAKE, and I'm a little surprised how quickly it happened. I expected to toil in obscurity for a lot longer.
*Edit* Some people have written me asking for a diagram as to how to hook up the solenoids or a similar device. Here you go:
MAKE reader Preston and I were just discussing one related problem-solving issue- namely, the relays can sometimes become "sticky" when activated and don't release the solenoid like they should due to a initial spike in current when the relay is tripped.
This problem can be attenuated by putting a resistor in series with the solenoid. Preston was able to stop the "sticking" with a 470-ohm resistor, but that was a little too harsh for the solenoid. It's sounding like the right range would be somewhere between 1 and 100 ohms. If anyone encounters that same problem and finds a better solution, let me know.
One other issue: If your solenoids aren't pulling as much as they should be, remove a bit of the spring and shorten the amount of rod sticking out of the sleeve. Sometimes the solenoid's sleeve needs a little more metal to grab onto when the EM field is activated to properly actuate. An extra cm or so should do it.
If anyone has any issues getting this project together, please feel free to write me at this blog or contact me directly via email: michael@una-love.com
Happy soldering! ¶ 9/10/2008 11:29:00 AM
Comments:
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Hey Michael,
I've read your Drumbot article in the latest issue of MAKE: and am dying to get into it. I'm hitting a pretty substantial hurdle right off the bat, though; Where did you get the solenoids you use in the article? I'm having trouble finding any with such range or cheapness. Thanks in advance for your help.
Cheers,
Preston
I've read your Drumbot article in the latest issue of MAKE: and am dying to get into it. I'm hitting a pretty substantial hurdle right off the bat, though; Where did you get the solenoids you use in the article? I'm having trouble finding any with such range or cheapness. Thanks in advance for your help.
Cheers,
Preston
Greetings gentlemen. I hope this comment reaches you- I couldn't find an email to contact you directly.
The solenoids I use can be found here: http://www.allelectronics.com/make-a-store/item/SOL-58/24-VDC-PULL-TYPE-SOLENOID/-/1.html
They say 24v, but they pull just fine with 12-16v.
Ordering them online costs $1.50 apiece, but I was able to find them at Axman Surplus in Minneapolis for only $1 apiece.
The solenoids I use can be found here: http://www.allelectronics.com/make-a-store/item/SOL-58/24-VDC-PULL-TYPE-SOLENOID/-/1.html
They say 24v, but they pull just fine with 12-16v.
Ordering them online costs $1.50 apiece, but I was able to find them at Axman Surplus in Minneapolis for only $1 apiece.
Hey Michael- my address is pedmands (at) gmail (dot) com if you want to continue this via email, but I have another question.
Will a 12v load be small enough for the MSA-R (seems kind of obvious that it would be, since you use 12v in your example), and how would you suggest I set up these circuits? Do I have to run 12v to each solenoid? And if so, does that mean a 12v power supply for each circuit? I want to implement all 8 relays, so I'm trying to figure out the best way to do this. Also, A/C or D/C?
Your help is much appreciated!!
-Preston
Will a 12v load be small enough for the MSA-R (seems kind of obvious that it would be, since you use 12v in your example), and how would you suggest I set up these circuits? Do I have to run 12v to each solenoid? And if so, does that mean a 12v power supply for each circuit? I want to implement all 8 relays, so I'm trying to figure out the best way to do this. Also, A/C or D/C?
Your help is much appreciated!!
-Preston
I'm also interested to know what kind of circuit you used for each solenoid. Can you give an example?
I'd also like to get some more info about exactly how you are running the solenoids. I'd like to give this project a try, but I'm unsure how to hook the motors or solenoids up and power them.
Thanks!
-Myke
Thanks!
-Myke
Hi Michael,
I was wondering if you have seen any issues with these solenoids overheating? I see that they are rated for intermittent duty and there are some comments on the All Electronics page that they heat up quite a bit. Have you seen this?
-Myke
I was wondering if you have seen any issues with these solenoids overheating? I see that they are rated for intermittent duty and there are some comments on the All Electronics page that they heat up quite a bit. Have you seen this?
-Myke
Hi Myke.
I've run mine for long periods of time and haven't had a problem- I think the fact that I'm running them at 12v instead of 24 lightens the stress and runs it cooler.
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I've run mine for long periods of time and haven't had a problem- I think the fact that I'm running them at 12v instead of 24 lightens the stress and runs it cooler.
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