Robot Hackday Oct 30th - Preparations?

Google Groups
1

I’ve signed up to http://madlab.org.uk/content/robot-hackday/ - which
looks ace btw! Really looking forward to it, despite my n00bness :wink:

Now, I have something I want to make - which is almost exactly the
machine @ 01:53 in this video: http://www.zappinternet.com/index.php?video=nobLdeLkuJ
(definitely NOT the machine @ 05:00 !!)

My question is - is there anyone I could have a quick chat to about it
beforehand so that I can get hold of whatever components (solenoids
for example) I’d need before I turn up? I can’t make Wednesdays -
which is a massive bummer - but I should be able to come along this
Sat 16th if there’d be anyone there who might be interested in talking
about it?

Cheers,

Luke

2

I did something similar to this.

You need solenoids. The “knockers” in the vid look quite specialised. I wouldn’t know where you’d get them - I just used fairly small ones I salvaged from some printers. The ones in the vid also look quite heavy-duty.

There are two ways you can actuate them. In the vid the guy appears to just be hitting a switch, which makes the solenoid activate, which I’m guessing would just be a case of connecting the power to each solenoid via a separate switch.

When I did my project, the solenoids were not triggered by someone hitting switches, they were triggered with an Arduino, so I used a transistor circuit on each output so the low voltage Arduino could actuate the higher voltage solenoid circuit. Basically, something like this… http://www.electronics-tutorials.ws/io/io30.gif

The solenoid acts as an inductor and generates a high reverse voltage when you remove the power - the diode in the above circuit is required to protect the transistor from this voltage.

Solenoids take a lot of power. Measure the current through your solenoids and make sure everything is rated appropriately

-Paul

3

Hi Paul - thanks for your reply!

So you did something with an Arduino board? I’ve found this chap, was
it something (vaguely) like this: http://jazarimusic.com/ ? Do you
have any more info on your project it does sound interesting! I am
somewhat of an electronics / robotics n00b (can you tell? haha) so
every piece of info I can get is of great use :slight_smile:

He also seems to use much less hardcore solenoids, and they still make
pretty loud sounds so that seems ok. I’ve asked him if he can give me
any info about his solenoids - if anyone recognises them or knows
where to source some like that in the UK please do let me know! :wink:
Everywhere I look for them online seem to either want to make them
industrially to my specs, or you can buy specialised ones for doors on
cars. : /

I’ll try and come down on Saturday to this printersmash thing
(especially useful if you can get solenoids out of them!) and do some
more research in the meantime too.

Thanks again,

LukeOn Oct 13, 11:47 am, Paul Plowman madstu...@hotmail.com wrote:

I did something similar to this.

You need solenoids. The “knockers” in the vid look quite specialised. I wouldn’t know where you’d get them - I just used fairly small ones I salvaged from some printers. The ones in the vid also look quite heavy-duty.

There are two ways you can actuate them. In the vid the guy appears to just be hitting a switch, which makes the solenoid activate, which I’m guessing would just be a case of connecting the power to each solenoid via a separate switch.

When I did my project, the solenoids were not triggered by someone hitting switches, they were triggered with an Arduino, so I used a transistor circuit on each output so the low voltage Arduino could actuate the higher voltage solenoid circuit. Basically, something like this…http://www.electronics-tutorials.ws/io/io30.gif

The solenoid acts as an inductor and generates a high reverse voltage when you remove the power - the diode in the above circuit is required to protect the transistor from this voltage.

Solenoids take a lot of power. Measure the current through your solenoids and make sure everything is rated appropriately

-Paul

Date: Tue, 12 Oct 2010 06:54:29 -0700
Subject: [HACMan] Robot Hackday Oct 30th - Preparations?
From: brokeb...@gmail.com
To: hacman@googlegroups.com

I’ve signed up tohttp://madlab.org.uk/content/robot-hackday/- which
looks ace btw! Really looking forward to it, despite my n00bness :wink:

Now, I have something I want to make - which is almost exactly the
machine @ 01:53 in this video:http://www.zappinternet.com/index.php?video=nobLdeLkuJ
(definitely NOT the machine @ 05:00 !!)

My question is - is there anyone I could have a quick chat to about it
beforehand so that I can get hold of whatever components (solenoids
for example) I’d need before I turn up? I can’t make Wednesdays -
which is a massive bummer - but I should be able to come along this
Sat 16th if there’d be anyone there who might be interested in talking
about it?

Cheers,

Luke

–
You received this message because you are subscribed to the Google Groups “HACMan” group.
To post to this group, send an email to hacman@googlegroups.com.
To unsubscribe from this group, send email to hacman+unsubscribe@googlegroups.com.
For more options, visit this group athttp://groups.google.com/group/hacman?hl=en-GB.

4

Hi Paul - thanks for your reply!

You’re welcome!

So you did something with an Arduino board? I’ve found this chap, was
it something (vaguely) like this: http://jazarimusic.com/ ? Do you
have any more info on your project it does sound interesting! I am
somewhat of an electronics / robotics n00b (can you tell? haha) so
every piece of info I can get is of great use :slight_smile:

Well, I wanted to make a device which played samba-type rhythms which could be controlled by Twitter (don’t ask!). So far I’ve got it playing rhythms, but not the Twitter bit.

It consists of a cowbell, two bongos, and a larger ‘bass’ drum. There are lots of patterns stored in the code, and every two bars each instrument chooses a pattern to play at random (the bongos count as one instrument), making a huge number of possible rhythms.

The solenoids were salvaged from printers, which is a bit of a bummer since they are all different, and I think may be different voltages. The one on the cowbell works really well, the others not so much. They look a bit like this: http://is.gd/g1uEV

Basically I just cable-tied a ‘stick’ (in this case a bit of pencil) to the solenoid lever. It’s all a bit of a hack really. If I could afford it, I’d buy some decent solenoids and do a proper job!

I’ll try and come down on Saturday to this printersmash thing
(especially useful if you can get solenoids out of them!) and do some
more research in the meantime too.

I won’t be there on Saturday, but my project is at the Hackspace, if you ask Bob I’m sure he’ll show you. He won’t be able to show it working though, because I have the Arduino in my flat! :slight_smile:

There are a couple of pages here from a guy who made actuators out of car door locking solenoids:
http://kylejanzen.blogspot.com/2010/01/clyde-drumming-mechanism.html
http://kylejanzen.blogspot.com/2009/06/clyde-drumbot-test-2.html

Most solenoids are probably usable, it’s just a case of giving them the right power, and working out a mechanism to make them hit the drum!

-Paul