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Motors for a Spirograph

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Hey everyone.

I have looked everywhere, but I can't seem to find any "flat-top" motors for a spirograph or anything. Anyone have any suggested retailers of good motors for this use? I am looking for something that preferably runs off of 3-5V (I have a 9V input, plan on regulating speed through a simple 1k pot, hopefully that's enough to bring it up to full speed and also stop it dead).

Also - front surface mirrors? I live in a dorm, so I can't really use the chemicals to make one... any suggestions?
 





Fenzir

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If you take apart a CD player ($8?) and "hotwire" one of the two motors directly to the batteries and add an on/off switch, that has peen working GREAT for me. It's a bit bulky and looks unprofessional, but it works for my desires.

Front Surface mirrors are surprisingly expensive. I know somebody on LPF has a shop and sells them, but I can't find it right now. If I remember I'll chime back in.
 
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Yeah, I just don't like how they are bulky and are not able to be bolted down/have a flat surface at one side.

The spirograph I am making is hopefully going to look rather professional, because I am going to have a glass window to see the inside of the device (I always like windowed electronic devices - looks neat), so I want it to look good inside. Anyway, I need something with a datasheet so that I can figure out what kind of configuration I need to be able to use my potentiometers to bring 'em up to full speed *and* bring them to a stop.
 

Kevlar

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Hmm... how much current draw? Any datasheet you got?

I don't have a datasheet, unfortunately, and I'm not to sure about current draw either.

I was having a problem with current draw on them myself.

My plan was to power my spiro with a 1A walwart OR 3 Tenergy NiMH 10,000 mAh D size batteries. I also have a 50mW green module in there that according to it's datasheet doesn't pull more than 280mA. When using the walwart, I couldn't power more than 2 motors at full RPM before the laser module would cut out due to not enough current. And powering with the batteries I couldn't get the motors to run at full RPM (but it could be that batteries were faulty).

I ended up using a 2.5A walwart to get full power to all motors running at the same time at full RPM.

Sometime today I will try and do a current draw test for you because I've been curious myself.
 

LaZeRz

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Whats wrong with using motors from a cd/dvd player or burner?

I made a spiro using 2 of those powered by 2 seperate 9v batts....

Just use some superglue to get some mirrors on (they stick well) and use some PVC to stick them onto a piece of wood or in a project box

EDIT:

they look like this except they have little plastic gears that you can stick mirrors on to

34xkhmb.jpg


I think flaminpyro sells FS mirrors... atleast he used to...

EDIT #2
http://www.surplusshed.com/search.cfm
 
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To be brutally honest, about the CD players? I can never successfully get the motors out of CD players. Haha. Nor do I have access to broken things like that.
 

Kevlar

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So I measured the current today off my 1A walwort with 3V input. At full RPM, with a 1" diameter, 3mm thick FS mirror, it draws 800mA.
 
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Hmm. So a 1k pot should bring it to a halt then! What's the minimum current it can take to be moving?
 

Kevlar

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What's the minimum current it can take to be moving?

Not sure, but it can't be very much. I would have done more tests for you but unfortunately I have to be out of this place by Friday so I did that one test and then packed everything up.

In my setup I'm using 25 Ohm Rheostat pots and it won't bring the motor to a complete stop but pretty darn close. I also have DPDT switches hooked up to each motor so I can stop and reverse the motor with that.
 
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Hmm. So maybe the 1k pots will be overkill... well, in any event, I can always just put it in parallel with like a .5k resistor or something like that.
 

Kevlar

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If it helps, here is a link to the spiro I built with some videos. I'll try and take another video of just a motor running at the lowest RPM too.

http://laserpointerforums.com/f42/four-motor-spirograph-63752.html

EDIT: Here is a short clip of 1 motor running, lowest RPM, then 2 motors, lowest RPM. It's really hard to tell but the best I can do ATM.


Maybe you sticking with a 1k pot and/or a resistor if needed is a good idea. The setup I have works for me because the pots I use, even though they won't stop the motor completely, have really good control over a wide range of RPMs so there is unlimited patterns I can make. Plus, as I stated above, I have a DPDT switch I can turn the motor off, or reverse it.
 
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Yeah - I have the three DPDT too. Mine's gonna be a 3-mirror spiro with three adjustable and reversible mirrors.
 




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