View Full Version : Electromagnets to pick up tetra?
I was wondering if we could use an electromagnet to pick up the tetra?
tkwetzel
08-01-2005, 23:45
Considering that they will be made out of PVC, you would not be able to pick them up with an electromagnet. And I think that it would be somewhat pointless to use an electromagnet just for the four corner pieces.
They all have bolts at the corners to attach them together.
+ the magnet mite mess up
the controls of all the bots
Billfred
08-01-2005, 23:48
Having read the now-decrypted chunks of the manual roughly twice each, I don't see anything in there about an electromagnet.
But I would definitely post on the FIRST Q&A before I invested much time or effort into it.
They all have bolts at the corners to attach them together.
This is true. Whether you would be able to actually grasp them by the bolts is an issue that your team would have to work out. As far as legality, I would suggest using the flow chart in section 5 of the manual to see if this (or any other part) is legal on your robot.
i have heard they fixed that problem but maybe not. I couldn't find a rule against it anywhere in the robot section of the manual.
Greg Marra
09-01-2005, 00:46
Interesting, a giant crane-like configuration could be quite good.
Just please don't turn on your magnet anywhere near my controller.
Considering that they will be made out of PVC, you would not be able to pick them up with an electromagnet. And I think that it would be somewhat pointless to use an electromagnet just for the four corner pieces.
Didn't the construction manual show them being made out of a sort of plastic material?
The models at our area were made out of metal though...
Maybe I'm mistaken?
Enterprize
09-01-2005, 00:51
As far as practicality, keep in mind that electromagnets tend to draw a lot of juice...but on the flipside, it would be easy to turn and rotate a tetra by a corner...
Sam, I think you're probably thinking of the stationary goal stations. I believe the scoring tetras are made of PVC.
n0cturnalxb
09-01-2005, 00:54
Would PVC make it weigh 8.5 lbs?
I'm sitting here thinking .. maybe we should build a scoring tetra before anything else, heh. It wouldn't take too long ..
Would PVC make it weigh 8.5 lbs?
I'm sitting here thinking .. maybe we should build a scoring tetra before anything else, heh. It wouldn't take too long ..
The manual said the vision tetras weighted in at aprox. 12.5...
So that's another challenge to overcome if you're working for a good autonomous mode.
Alex Pelan
09-01-2005, 00:56
Wouldn't a strong electromagnet crash robot controllers / field controlling computers?
Enterprize
09-01-2005, 00:59
Wouldn't a strong electromagnet crash robot controllers / field controlling computers?
Probably not field-controlling computers, distance is a large factor, but nearby robots could suffer some damage depending on the strength of the magnet.
I'm guessing they wont allow it because it's accidental damage waiting to happen...
Mike8519
09-01-2005, 01:06
The main thing adding weight to the tetras are the steel brackets at the corners. I was lucky enough to be assembling pieces at a remote kickoff.
Actually, an electromagnet probably wouldn't adversly affect the robot controller. The controller is designed entirely using solid state devices (no magnetic storage), so it should be immune to any magnetic field that could be generated by a FIRST robot.
I'm pretty sure Dan is correct... An electromagnet wouldn't hurt the controller... think about all your motors... CIM's in particular... they generate a HUGE EMF field (we were messing about with a compass one year and they messed it up)... but they dont hurt the controller, even when placed side by side. I'm pretty sure magnets are harmless to the controller.
Per the 2005 Part Use Flow Chart, from page 14 of Section 5 The Robot, electromagnets are not allowed.
An electromagnet is by definition a solenoid, i.e. a coil of wire, wound around a form, that induces a manetic field by the introduction of electricity, to attract another metalic object.
Wetzel
Mike Ciance
09-01-2005, 02:41
even if the magnets are completely harmless, the only metal on the tetras are the bolts. an electro magnet would use power, and a regular magnet would present the problem of getting stuck to other robots. there is definitely a possibility of a megnet being used (if legal), but just make sure you design the mechanism good
I think an electromagnet on the arm may be able to be pulled off(providing its legal) but its just not practical.
There shouldnt be anything in the robot controller that could be dammaged by a magnet. The data in the controller is stored in an EEPROM which you have to access through a serial connection in order to erase. Thats what I think at least. What I know is that they designed the field with magnets in it, and plus, I have personally run a chiwopuha motor (electromagnets make motors go) on top of a robot controller just to make sure nothing happens, and it doesnt.
In any event:
Per the 2005 Part Use Flow Chart, from page 14 of Section 5 The Robot, electromagnets are not allowed.
Wetzel
There's not much more discussion to be had on the topic.
Didn't the construction manual show them being made out of a sort of plastic material?
The models at our area were made out of metal though...
Maybe I'm mistaken?The small, scoring tetras are made of plastic (PVC). The larger goals (which you place the tetras on top of) are constructed of metal. There was a few changes relatively close to kickoff (apparently), so maybe your kickoff site or whatever used slightly outdated instructions.
The first thought in my after watching the videos was electromagnets, but now i am pretty certain its not the best way to go. Mainly because it will draw too much current and drain lots of power (snatching it from the motors), the electronic noise it will create has to be monitored using some H-bridges or something similar to save the motors, because it will hurt that for sure, thus increasing needless complexity. Also the magnetic grip wont be as powerful as you want it to be.
It would be pretty cool if some teams could actually use it effectively, so good luck to them. :rolleyes:
Vivek.
I was wondering if we could use an electromagnet to pick up the tetra?
the FIRST tetras will not have bolts, they will be glued together in some manner, so far as i was informed.
whilst they wont pick up the tetras, they could be useful in that you could hold the tetra in teh game by using an electromagnet to close a grip, but also when you turn the power off, the electromagnets will also go off and iwll fullfill the part of the rules for "you must be able to remove a tetra from
a robot which is deactivated"
"Per the 2005 Part Use Flow Chart, from page 14 of Section 5 The Robot, electromagnets are not allowed."
the further discussion of this topic is futile.
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