Robot Arm C

[NinjaChicken]

The best place i think to buy transmitters are hobby king.com ( i used to be into airplanes). http://www.hobbyking.com/hobbyking/stor ... F2%5F.html is a good pair for cheap and it could control up to 6 motors. Then you would still need a battery and stuff like a ubec for powering the receiver. On a side note: just buy plain cable for now, but if the controls only work some of the time, it could be because of the signal getting lost, if that happens try to wrap the cable in aluminum.otherwise your going to need to buy something like this, http://servocity.com/html/boosted_servo_extensions.html along with regular extensions cable.

I appreciate these answers, thanks.
So if I were to get a TX/RX, is there programming involved? It looks like it's not ready to use out of the box according to the reviews

[chalker]

I doubt you'll be able to stretch those servo cables 70cm, you'll have to buy something to extend the cables. And yup, a 4 channel receiver will be able to connect to maximum of 4 servos.

Sweet. So could I pick up some of these extension wires at RadioShack?

Also, would you happen to know how much a transmitter / receiver combo would cost?

You should also check out some local hobby shops. Servo extension wires are pretty common in the RC model airplane world since the servos can be rather far from the receiver on the plane. 70cm won't be a problem.

[harryk]

Simple, you just plug the servo into the receiver

Oh good haha. More questions, sorry...

So say I had 2 or 3 servos... would the wires be able to reach 70 cm to the other side?
And I can plug two or more into a receiver with say 4 channels, right?
Lastly, what is the average cost of a transmitter and receiver?

For 70cm you shouldn't have any problems with signal loss, from what I read it can take tens of feet of wire before you will have problems
As for radio costs for sumo I got a fantastic 2.4ghz 6 channel radio, lightly used, for $100. So check your local hobby stores they almost certainly have used units for sale
There is a cheap one available for $40 here:http://www.robotcombat.com/products/0-GWS24TR.html
And you'll need a battery too!

[ichaelm]

I agree that 70 cm of servo wire won't be a problem, assuming your servos aren't huge.

About wired vs. wireless systems, the only advantage to using a wireless system (besides the freedom of holding your controller wherever you want, which I see as a very minor issue) is that they often come in standardized systems designed for hobbyists who want to focus more on the mechanics of their bot than the electronics. There are other plug-n-play type systems that aren't wireless, such as legos, vex, or some other kit. The wireless hobby system is relatively cheap, though. This transmitter/receiver pair is extremely cheap, not that bad in terms of quality, and very easy to use. Just buy some servos on the same site, and you can probably keep it under $100, without having to do much electrical tinkering at all. Personally, I'm a fan of electrical tinkering, and if you're like me, you have way more options, some cheaper and some more expensive (I prefer the cheaper ). If you're willing to get your hands dirty, you can use much more powerful motors, instead of making your arm extremely light and flimsy to compensate for small vex, or lego motors. Learn about the meaning of torque before you go shopping for servos. There's a lot more information on that topic in the old sumobot thread, I think.

[Taxi]

HI I am a parent coach for High School and I have two female students who are new to SO doing this event this year as our robot expert had the nerve to graduate. Last year we did fine with the sumo bot but this arm seems to be above us. I have a budget of about $400 to purchase a kit to use. Please can someone tell me what is a good kit. I have found kits that are $50 which I assume is not enough and then the next price seems to be $1000. Please someone help talk me through this assuming I don't know anything. I can tell you that is a very safe assumption. The girls are looking to me for guidance. Ha

[harryk]

HI I am a parent coach for High School and I have two female students who are new to SO doing this event this year as our robot expert had the nerve to graduate. Last year we did fine with the sumo bot but this arm seems to be above us. I have a budget of about $400 to purchase a kit to use. Please can someone tell me what is a good kit. I have found kits that are $50 which I assume is not enough and then the next price seems to be $1000. Please someone help talk me through this assuming I don't know anything. I can tell you that is a very safe assumption. The girls are looking to me for guidance. Ha

Lynxmotion has some great kits within your budget, http://www.lynxmotion.com/c-27-robotic-arms.aspx

[dandaman]

still no word from scoi about the bluetooth... IF one has 2 nxt's they can be programmed to be used as a remote control, one for the other. So if your school has em and your good with the progrramming then that might be a cheaper way to do it. Downside is that you're limited to 3 motors, but one can add another one if it doesn't need as much control. SO far thats worked, having trouble with the "synthetic counterbalance" (an arm connected to the vertical tower that rotates around the tower and holds the arm levle without needing additional weight).

[illusionist]

Actually, Bluetooth operates on 2.4 GHz, which is explicitly allowed by the rules.

[rutabega234]

Is there any rule that would prevent me from using a laptop wired to my robot arm for control? I'm using a modified lynxmotion kit, and I hope to make at least partially autonomous.
Also, if I can't use a laptop, is there any other way I can control a lynxmotion AL5D arm?

[chalker]

Is there any rule that would prevent me from using a laptop wired to my robot arm for control? I'm using a modified lynxmotion kit, and I hope to make at least partially autonomous.
Also, if I can't use a laptop, is there any other way I can control a lynxmotion AL5D arm?

There is a posted faq answering this: http://soinc.org/node/851