Arduino?

[Kusha]

Ok, I'm waiting on my mentor to give me the product key for autocad and I will start working on a model. In inventor, since the trial does not give access to it.

Today one of our mentors gave me 6x 12" Cold Cathodes never opened from 2007's game, since we were cleaning out the shop/redoing it.

I was wondering how I can control these with an arduino/ how much this would affect battery life (one thing I haven't even thought about) Lets say I had 4-6x AA batteries powering this robot. Would it even be possible?


Also, what the heck do the little black boxes that the cathodes plug into do? I assume ground and 12v?

I've also got some plywood for testing the prototype on, and some plexi to mount the final product on.

[EricH]

Normally, those cold cathodes were powered in groups of 4 off a single robot battery (or arena power). The black boxes are power and ground, IIRC. If you wanted to power them off an Arduino, you'd probably need to put in an extra power supply just for them--or have the Arduino trip a transistor as a switch.

[Kusha]

Originally Posted by EricH

Normally, those cold cathodes were powered in groups of 4 off a single robot battery (or arena power). The black boxes are power and ground, IIRC. If you wanted to power them off an Arduino, you'd probably need to put in an extra power supply just for them--or have the Arduino trip a transistor as a switch.

So here is the question at hand, should I bother with them? Or is it too much of a hassle

[DonRotolo]

The black boxes take 12 V DC and convert it to whatever the CCFLs use.
To control something that draws 'relatively large' power (more than a few milliamps) a transistor switch is cheap & easy, or use a small relay. IIRC the Arduino can sink or source about 20 mA on a Digital IO pin.

[Kusha]

Originally Posted by DonRotolo

The black boxes take 12 V DC and convert it to whatever the CCFLs use.
To control something that draws 'relatively large' power (more than a few milliamps) a transistor switch is cheap & easy, or use a small relay. IIRC the Arduino can sink or source about 20 mA on a Digital IO pin.

The transistor would be the option I would pick. I've worked with transistors in powering a DC motor from a cd drive, so I have some small experience.

So now I know I can handle putting in a cathode.

The question remands what about battery life, would this basically kill off my battery life?

[sanddrag]

Originally Posted by Kusha

Ok, I'm waiting on my mentor to give me the product key for autocad and I will start working on a model. In inventor, since the trial does not give access to it.

Are you registered on the Autodesk Student Community? I believe you can get 3-year licenses of all their software titles.

[Kusha]

Originally Posted by sanddrag

Are you registered on the Autodesk Student Community? I believe you can get 3-year licenses of all their software titles.

I haven't, what are the requirements?

[sanddrag]

Originally Posted by Kusha

I haven't, what are the requirements?

I believe any educator or FIRST Team mentor can register on the site, then send students a special link to register. students.autodesk.com

[Kusha]

Originally Posted by sanddrag

I believe any educator or FIRST Team mentor can register on the site, then send students a special link to register. students.autodesk.com

WOO! Alright THANK YOU! This is amazing, I now have autocad mechanical activated, along with inventor activated.
Thanks!

[Kusha]

[excuse the double post here]
I need good suggestions for motors, besides vex. As I am a high school student with no job, please keep the price ranges low.
Good enough to power a 3 wheel 9" diameter kiwi drive robot.

[EricH]

Seeing as you already have the CD-drive motors, you should be able to use those. Mounting and gearing, though, are for you to figure out (hint: glue might work pretty well for mounting, depending on type).

You could also check a local RadioShack to see if they have small motors--there are some decent ones, if you get the "hobbyist" type of RadioShack instead of the "consumer electronics" type.

[DonRotolo]

Your choice of motors depends on two factors: Speed and cost. Powerful (=fast_ motors are more expensive than less powerful (=slower) motors. CIMs are what I'd call "expensive" and the Denso window lifter motors can be had for much less.

CD drive motors are not a bad option.

I always keep my eyes open for sources of motors. On trash day look for things that might be useful. Most appliances have AC motors, not useful, but treadmills have large, powerful DC motors free for the taking. If you live in an area where they have cars, look for a salvage yard (aka Junkyard) - you can buy window motors for $5 each or less, maybe even free if you explain nicely what you're doing with them (the 'poor high school student building a robot' routine works well). Just learn how to get the door panels off a car, as they'd like for them to be in sellable condition when you leave...


You asked of the cold cathodes would kill your battery? Not much, they are not very power-hungry. Once you connect one, measure the current (you do have a multimeter, right? If not Harbor Freight sells then for $3)

[Kusha]

Originally Posted by EricH

Seeing as you already have the CD-drive motors, you should be able to use those. Mounting and gearing, though, are for you to figure out (hint: glue might work pretty well for mounting, depending on type).

You could also check a local RadioShack to see if they have small motors--there are some decent ones, if you get the "hobbyist" type of RadioShack instead of the "consumer electronics" type.

I have no idea how to gear them, but mounting wouldn't be that much of a problem. I have a radioshack near me, 5 minute walking distance I'll go tomorrow after school to check it out.

Originally Posted by DonRotolo

Your choice of motors depends on two factors: Speed and cost. Powerful (=fast_ motors are more expensive than less powerful (=slower) motors. CIMs are what I'd call "expensive" and the Denso window lifter motors can be had for much less.

CD drive motors are not a bad option.

I always keep my eyes open for sources of motors. On trash day look for things that might be useful. Most appliances have AC motors, not useful, but treadmills have large, powerful DC motors free for the taking. If you live in an area where they have cars, look for a salvage yard (aka Junkyard) - you can buy window motors for $5 each or less, maybe even free if you explain nicely what you're doing with them (the 'poor high school student building a robot' routine works well). Just learn how to get the door panels off a car, as they'd like for them to be in sellable condition when you leave...


You asked of the cold cathodes would kill your battery? Not much, they are not very power-hungry. Once you connect one, measure the current (you do have a multimeter, right? If not Harbor Freight sells then for $3)

Your post gave me a great idea, I can go to a thrift store and check around for some rc cars without controllers or something of the sort. Thanks for the tips tho. I will go around and look for motors creatively.

I'm very skeptical about the cd drive motors working that big of a robot...
I'm all for it if you guys can provide me a little guidance. How would I gear up a cd drive motor?

As for the cold cathodes I decided that I will give it a shot once I get it to light up more than halfway using a transistor(still doing my research on it)

[EricH]

Originally Posted by Kusha

I
Your post gave me a great idea, I can go to a thrift store and check around for some rc cars without controllers or something of the sort. Thanks for the tips tho. I will go around and look for motors creatively.

I'm very skeptical about the cd drive motors working that big of a robot...
I'm all for it if you guys can provide me a little guidance. How would I gear up a cd drive motor?

Don't be too skeptical. ONE can drive an 8-inch, 3-wheel Arduino-controlled robot. http://www.youtube.com/user/SDSMTMec...28/hG9tZ9O60dA

How do I know it was a CD drive motor? I'm one of the guys who took a CD drive apart, raided the motors, and wound up using it for the robot drive.

Now, when you dig up that R/C car, raid the gearbox. The more R/C cars, the more gearboxes. Then you can tweak the powering/gearing to suit your motors.

[Kusha]

Originally Posted by EricH

Don't be too skeptical. ONE can drive an 8-inch, 3-wheel Arduino-controlled robot. http://www.youtube.com/user/SDSMTMec...28/hG9tZ9O60dA

How do I know it was a CD drive motor? I'm one of the guys who took a CD drive apart, raided the motors, and wound up using it for the robot drive.

Now, when you dig up that R/C car, raid the gearbox. The more R/C cars, the more gearboxes. Then you can tweak the powering/gearing to suit your motors.

All I can say is wow. That's freakin' epic.

I'm really excited about this project now. I'll get crackin' soon, HOPEFULLY Tuesday I get to mill out a frame for this robot and get some kind of prototype running by the end of the week.