first robot help

[mrjameslat]

Hey,
I'm thinking about making my first robot and (obviously) I never made one before.
What I want to do is mount a pvc spring cannon onto a tilt with a laser pointer, and a MaxSonar (or type of rangefinder that's good for about 10 meters) and hook them all up to a microprocessor and connect that to my laptop so I can raise/lower the tilt with my computer and tell how far away the target is.

I never tried any of these things before,  so I was wondering how to do this, or even if it was realistic for a first timer.
Like our their tutorials out there for first timers with connecting parts and making it work?

Whats the most well documented (and economical) microprocessor that I can use for this  project?

Also know of any sites that offer very decent rates on parts?
(as a side note i'm an alright computer programmer)

Thanks a lot!
-James

[Hawaii00000]

Hey James, welcome to the forum! Sounds like a good project to start with.

I recommend you buy an Arduino, and tilt the cannon using servos or motors (depending on how heavy your cannon is). The Arduino can process the data from the MaxSonar and control the servos. The computer can send instructions to the turret (up, down, left, right etc.), and give you distance feedback through serial.

Here's the Arduino site: http://www.arduino.cc/
An some info about Arduino and serial library: http://arduino.cc/en/Reference/Serial

Your biggest problem will be the cannon weight- the lighter the better.

[mrjameslat]

I did some math and estimations and the total wight of the cannon should only be something like 2.7 or 3 lbs.
(which isn't too heavy).

But I'm afraid that once I buy the parts I won't be able to figure out how to put it together.
Is it pretty straight forward?

Thanks.

[rbtying]

2.7 to 3lbs isn't really what most would consider light.  Your project is doable, but you'll have to be quite careful with the servos you choose (and how long your PVC pipe is).  The stall torque of an average RC servo is just about 60 oz-in, which converts to 3.75lb-in (thus you're reasonably close to the limit with a 1-inch arm).  I assume your pipe is over an inch long, so you'll likely have to counterweight it or have some other method of reducing the torque.  Alternatively, you could spend more money and get a higher-torque servo.

[mrjameslat]

So the hardest part won't actually be hooking all the electronics together but to have an efficient design?
ya the pvc pipe will have to be about 1.5 feet long at 3" diameter (which is about 1.4 lbs/ft)

I do  however need some help in finding my servo/tilt/thing to make it go "up","down".
I was thinking about something along the lines of this
http://www.robotshop.com/servocity-ddt550-drive-tilt-hitec.html
(refer the bottom image on that site)
It has 4 pound limit and can rotate/tilt 360 degrees, but would it be possible to gauge it so that I can tell it (through my computer) to rise or lower itself to a certain degree measure? (like 0,45,90 and everywhere in between)

If not are you familiar with something similar that I can raise or increase to a certain degree level?

Thanks again!

[Hawaii00000]

The more weight you have the more your going to spend.
The mount you found looks fine, but keep looking. I think you could find something cheaper.

If not are you familiar with something similar that I can raise or increase to a certain degree level?

That's actually what servos do. You tell is the number of degrees and it goes to that angle.

[mrjameslat]

awesome! well I'll search/research and post a video of the final product here on the forum.
thanks a lot guys!
-James

[mr roboto]

I am excited to see that video. when do you think it will be ready?