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Re: Robot Arm C

Posted: January 8th, 2017, 7:07 pm
by Bazinga+
Bluejet1179 wrote:Can a servo with a voltage range from 4.8v-6v be safely run at 7.4v?
There's a 2nd place regionals medal in my basement that says it's fine... There's also 15 burnt out servos there that say it's not.

My point is that it'll work but it's very likely to burn out under stress. I would advise against it. Once I switched from a 7.4v battery to a 6v almost no servos burned out.

Re: Robot Arm C

Posted: January 8th, 2017, 7:37 pm
by windu34
Bazinga+ wrote:
Bluejet1179 wrote:Can a servo with a voltage range from 4.8v-6v be safely run at 7.4v?
There's a 2nd place regionals medal in my basement that says it's fine... There's also 15 burnt out servos there that say it's not.

My point is that it'll work but it's very likely to burn out under stress. I would advise against it. Once I switched from a 7.4v battery to a 6v almost no servos burned out.
well said lol. Get a voltage converter. Id recommend this one:
https://www.amazon.com/gp/product/B00C4 ... UTF8&psc=1

Re: Robot Arm C

Posted: January 11th, 2017, 12:00 pm
by peartree423
Alright so has anyone been able to get a perfect score yet? It seems insanely hard, but that doesn't mean it won't be done :D . So have any of you folks? If not what kind of scores are we looking at at this point, and are there any other predictions for nationals? I personally feel like it won't necessarily take a perfect score to get up on stage this year. Thoughts?

Re: Robot Arm C

Posted: January 11th, 2017, 12:15 pm
by windu34
peartree423 wrote:Alright so has anyone been able to get a perfect score yet? It seems insanely hard, but that doesn't mean it won't be done :D . So have any of you folks? If not what kind of scores are we looking at at this point, and are there any other predictions for nationals? I personally feel like it won't necessarily take a perfect score to get up on stage this year. Thoughts?
First you have to define what a "perfect score" is (What really is the max number of pennies that can fit in each ring?)
If you take the previous post as the max score (12 in 1st inner ring), (36 in 2nd ring), (2 in 3rd ring).

I certainly agree not every team in the top 6 at nats will have this "perfect score" (if any honestly), but it will certainly take at least 11 in the inner ring, 33 in the second ring, and 6 in the 3rd ring for top 3 I would presume. MIT raw scores will certainly aid in this prediction...

Re: Robot Arm C

Posted: January 11th, 2017, 3:05 pm
by Bazinga+
windu34 wrote:
peartree423 wrote:Alright so has anyone been able to get a perfect score yet? It seems insanely hard, but that doesn't mean it won't be done :D . So have any of you folks? If not what kind of scores are we looking at at this point, and are there any other predictions for nationals? I personally feel like it won't necessarily take a perfect score to get up on stage this year. Thoughts?
First you have to define what a "perfect score" is (What really is the max number of pennies that can fit in each ring?)
If you take the previous post as the max score (12 in 1st inner ring), (36 in 2nd ring), (2 in 3rd ring).

I certainly agree not every team in the top 6 at nats will have this "perfect score" (if any honestly), but it will certainly take at least 11 in the inner ring, 33 in the second ring, and 6 in the 3rd ring for top 3 I would presume. MIT raw scores will certainly aid in this prediction...
You can fit 12 in the inner ring and 38 in the second inner most ring, so that's the max score.

I would agree with that prediction more or less. It's unlikely more than 1 or 2 teams will be able to get the full score since the precision necessary is incredible ;).

Re: Robot Arm C

Posted: January 12th, 2017, 6:47 pm
by Complexity
Hello, I have been placed in the event Robot arm for my invite next week. All I have is an nxt2.0, so is it possible for me to make anything that could possibly reach a stack or two? I don't want to embarrass my team and turn out empty handed. I have been searching online for designs, but none that would work in robot arm with a 2.0

I saw a team get 60 points with a claw that they dragged across the ground, and it pulled 2 stacks to the center

Re: Robot Arm C

Posted: January 12th, 2017, 8:33 pm
by Bluejet1179
So I need help with an issue. I currently have as a power source 2 7.2v NiMH batteries. I bought a voltage regulator mentioned before in the forum. I am trying to run a hitec 805bb servo at 6v. There seems to be barely any current going to the servo from the regulator. I put the batteries in series and parallel into the voltage regulator to test it and neither worked. I did plug it in directly breilfy to one of the batteries and it worked flawlessly. What am I doing wrong?

Re: Robot Arm C

Posted: January 13th, 2017, 8:04 am
by Bob_117
Bluejet1179 wrote:So I need help with an issue. I currently have as a power source 2 7.2v NiMH batteries. I bought a voltage regulator mentioned before in the forum. I am trying to run a hitec 805bb servo at 6v. There seems to be barely any current going to the servo from the regulator. I put the batteries in series and parallel into the voltage regulator to test it and neither worked. I did plug it in directly breilfy to one of the batteries and it worked flawlessly. What am I doing wrong?
First off have you tried adjusting the potentiometer on the on the regulator? And why do you need 2 batteries, seems like overkill to me. As long as you are not maxing out the servos the 7.2v shouldn't really be to bad, maybe? Last year we ran our arm off of a 6v pack like this one:https://hobbyking.com/en_us/turnigy-rec ... -nimh.html. They are less than 10 bucks and have plenty of power for something like this.

Re: Robot Arm C

Posted: January 13th, 2017, 12:59 pm
by Bluejet1179
I did turn it to 6 volts. It's only the 805bb that doesn't work. I have mg995s that work. When the 805bb runs it barely draws any current.

Re: Robot Arm C

Posted: January 13th, 2017, 2:38 pm
by Jdoglloyd
Hey guys,

My partner and I bought a Lynxmotion arm complete with servos, circuit board, and everything. We bought a wrist rotate attachment to go with it, so would that count as a "modification?" Also, would you think that a wrist rotate is enough to flip a few stacks over, or are there any more efficient mechanisms to turn the pennies tail side up? At the moment, I was thinking about transporting penny stacks in bulk by picking them up at the bottom and then knocking them over in the middle of the target, but I'm not sure if that's efficient enough.

Thanks.