Robot Arm C

[harryk]

What is everyone using for the actual structure of the arm? I was considering softening PVC and creating boards, like the person in this blog post http://www.diniro.net/fabbblog/bortolo.html but I'm not very comfortable with putting PVC pipe in my oven Any ideas?

You could just buy a small sheet of PVC online, or you can probably find some nice pieces of polycarbonate at Home Depot/Lowes

[NinjaChicken]

Ok, I've gone into this event knowing next to nothing about robotics/electronics/the like.

If I get a transmitter and receiver, how will the receiver connect to the servos? I read something about a microcontroller, looked it up, saw they can cost $200 and ran away from it. If the answer is too lengthy for a post, does anyone have a suggestion as to where I could read up on stuff like this?

[harryk]

Ok, I've gone into this event knowing next to nothing about robotics/electronics/the like.

If I get a transmitter and receiver, how will the receiver connect to the servos? I read something about a microcontroller, looked it up, saw they can cost $200 and ran away from it. If the answer is too lengthy for a post, does anyone have a suggestion as to where I could read up on stuff like this?

Simple, you just plug the servo into the receiver

[illusionist]

Yeah, he's right. Most receivers will accept the servos directly. No adapter necessary.

[NinjaChicken]

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?

[illusionist]

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.

[NinjaChicken]

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?

[Jdogg]

Watch out for extending servo cables too long, it could lead to interference. Especially if the cables are near each other, but more importantly the voltage drops due to the cable's size and length. So it might be smart to look at either buying thicker cables for greater insulation, or (build or buy) your own amplifier that takes the signal and boost's it. The wire resistance of a cable 70 cm is about .059 assuming you would be using 26 awg which is significant when you think of the small amount of amps and voltage you run though those lines. Building your own saves a lot of money but can waste valuable time if you don't know how electronic circuits such as op-amps work, this device is the marvel of almost all electronic devices of the 21st century. It can be used here to create a boost and maintain the desired pulse width produced by the microcomputer or what ever device you may be using.
Places like hobbypartz sell rc transmitters and receivers but the total cost of buying the batteries and devices can put a serious dent in your pocket, or the school's pocket. i would recommend looking at the robotstore.com for stuff and having the whole system wired, its a lot cheaper and nicer.

[NinjaChicken]

Watch out for extending servo cables too long, it could lead to interference. Especially if the cables are near each other, but more importantly the voltage drops due to the cable's size and length. So it might be smart to look at either buying thicker cables for greater insulation, or (build or buy) your own amplifier that takes the signal and boost's it. The wire resistance of a cable 70 cm is about .059 assuming you would be using 26 awg which is significant when you think of the small amount of amps and voltage you run though those lines. Building your own saves a lot of money but can waste valuable time if you don't know how electronic circuits such as op-amps work, this device is the marvel of almost all electronic devices of the 21st century. It can be used here to create a boost and maintain the desired pulse width produced by the microcomputer or what ever device you may be using.
Places like hobbypartz sell rc transmitters and receivers but the total cost of buying the batteries and devices can put a serious dent in your pocket, or the school's pocket. i would recommend looking at the robotstore.com for stuff and having the whole system wired, its a lot cheaper and nicer.

Alright, like I said, I have no idea about any of this. The ones I picked up are here: http://www.parallax.com/Store/Accessori ... roductName

If I need to extend the servo cable, it would only be one of them. I'm planning on using 4.

Are we allowed to have a wired system? Our school has a very old one but I don't know how we could adequately 'modify' it.

[Jdogg]

Alright, like I said, I have no idea about any of this. The ones I picked up are here: http://www.parallax.com/Store/Accessori ... roductName

If I need to extend the servo cable, it would only be one of them. I'm planning on using 4.

Are we allowed to have a wired system? Our school has a very old one but I don't know how we could adequately 'modify' it.

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.