Magic Smoke and Shrapnel

[KenWittlief]

Originally Posted by dude__hi

Yesturday we were testing the camera on the robot and we were running our shooting mechanism and the camera lens flew off the board and shot across the room ..

that would be a neat feature if you could do it with the whole camera: remote viewing!

your robot would have an out-of-body experience

Originally Posted by aaeamdar

We just had some magick smoke let out. We are trying to figure out why. I was the operator and aparently the hopper was smashing into some wires, and damaged the insulation enough so that... ooopps, black, red, power, ground, poof!

Thought I'd share the story since it happened 10 minutes ago as of now.

Two wires touched.

Paul Dennis

This is the author of the original post...you wouldn't hapen to have a photo of the wires would you?...if so, please post it

[Bemis]

That happened to us two years back, except it was while bringing a mast down. wires crushed, scary sound, bad things. Don't think you were on the team then, Doug.

[Simon Strauss]

this year i learned that you can get magic smoke and a nice sized spark if you let the wires of a motor touch after they have been unplugged directly from your battery if the wheel they are spinning is still going fast enough. A logical occurrence if you look at it in retrospect but still quite scary and confusing when it first occurs.

no double posting kids....lol

[Taylor]

In the words of one of the students as he was working with our launcher prototype, "The real surprise came when it bounced off my face." He wasn't referring to the ball, by the way.
Make sure your screws and bolts are tight, boys and girls!
Oh, and we got magic(k? Aleister Crowley lives again?) smoke from our joysticks earlier. That was interesting.

[Taylor]

Originally Posted by pyro20911d

no double posting kids....lol

You got it.


Wait.


Um.


Shoot.

[Hieb]

We did get a little magic smoke this year--apparently Victors don't like having the battery wired to the motor side. At least we had some fun pulling it apart and looking at the damage.

[Sachiel7]

Yeah, make sure that youre running your Victor's for any spinwheels in Coast mode. Trying to brake them can cause some bad results if they're still spinning too fast. At least for our team, that helps.
Make sure your shooters are well enclosed too.

[KenWittlief]

Originally Posted by Sachiel7

Yeah, make sure that youre running your Victor's for any spinwheels in Coast mode. Trying to brake them can cause some bad results if they're still spinning too fast. At least for our team, that helps.
Make sure your shooters are well enclosed too.

Im surprized to hear that (actually I am shocked and dismayed :^)

if the Victors can spin a motor up, it should be able to coast or brake it

in fact you should be able to spin the shooter up to full speed, then throw it into full reverse (to stop it) without hurting the victors.

But then again, maybe the shooter wheels being built this year are using them in ways they have never been used before? If you blow one out using it this way I would definately send it back to IFI for failure analysis.

And if we start seeing a lot of victors fail on shooter wheels, it would be useful to instrument one and see how much voltage and current it is seeing when it brakes the motor.

[Mike AA]

Originally Posted by KenWittlief

Im surprized to hear that (actually I am shocked and dismayed :^)

if the Victors can spin a motor up, it should be able to coast or brake it

in fact you should be able to spin the shooter up to full speed, then throw it into full reverse (to stop it) without hurting the victors.

But then again, maybe the shooter wheels being built this year are using them in ways they have never been used before? I you blow one out using it this way I would definately send it back to IFI for failure analysis.

And if we start seeing a lot of victors fail on shooter wheels, it would be useful to instrument one and see how much voltage and current it is seeing when it brakes the motor.

I will run an inline amp test in about an hour or so and post how much ours takes. Given that it runs at about 31A it'll probably be close to twice that ?

-Mikw

[KenWittlief]

I would expect you might see 100A on the motor for a brief period. A DC clamp-on ammeter might be the best choice.

[orelinde]

WOW and i thought you meant sparks flying when your robot hits another robot and flames shootingt into the air and the balls are shot at the target and smoke pour out when your robot hit the ramps silly me. pyrotechnics is where i was thinking. **runs to talk to team**

When one refers to magic smoke he/she is referring to the smoke that comes from faulty wiring or electronics.

check out this link for the real definition............you must read this short article in order to fully understand what "magic smoke is"................there's more to it than what I explained to you.

[fnsnet]

As a Field Supervisor this year I think I'm going to wear my safety Glasses AND a hardhat... I'm sitting WAY to close to the action :-D
(At least if we had these problems last year, while I was a ref, I'd be watching the machines at all times and could duck out of the way or something...)

Heh. Please... don't impale the Field Supervisors... I beg you...