Beetleweight Robot Parts

[acealeam]

First ever robot, it's going to be a pneumatic flipper.

Can anyone recommend me some cool parts?
I've found these and would like some input on them:

Motor (2): http://banebots.com/pc/MOTOR-BRUSH/M3-RS390-12
Battery (1): http://www.hobbyking.com/hobbyking/store/__7636__ZIPPY_Flightmax_2200mAh_3S1P_25C.html

Thanks.

[R1885]

Both the motor and the battery are way to large, beetleweights can only go up to 3 lbs.
This is what most current beetles use:
http://www.robotmarketplace.com/products/KB-1000RPM.html
This is basically standard now.
Also, a better suited battery:
http://www.hobbyking.com/hobbyking/store/__11901__Turnigy_nano_tech_1000mah_3S_25_50C_Lipo_Pack.html

[acealeam]

Thank you, and that leads me to another question

What are good weight budgets for a beetleweight?

[R1885]

The motors, speed controllers, battery(ies), and wheels should take priority if at all possible. The main construction/frame should take the next priority. A basic sketch of your bot(Or an approximate design from another bot) would be nice.

[Badnik96]

Really one 1000mAh lipo should be all you need, especially for a pneumatic flipper, since the drive motors are the only electrically powered parts.

You in the US or UK? Don't think it means much but it'll help us recommend you some parts you can easily get in your country.

I'd think motors and a strong frame should get priority, both the US and UK have some very nasty beetleweight spinners.

[acealeam]

I'm in the US.

Here's a basic sketch of the design:

And how much weight should I dedicate to weapons (pneumatic cylinder, co2 canister, spikes, etc)?

[Badnik96]

First of all how old are you? Pneumatics are serious business and I wouldn't advise anyone who doesn't know what they're doing using them, you could get seriously hurt.

Have you done any research into what parts you're going to use, what materials and your overall layout? I'd advise getting some graph paper, a ruler and a pencil and sketching out your design in full size. That's what I've done for both of my robots, and even though the second one hasn't been built yet the first one came out perfectly. Do you know where you can get pneumatics that small, what's involved in running them and how you're going to make it? Do you have proper tools?

The sketch and the way you're going "3lb pneumatic flipper, piece of cake" makes me very very nervous that you have no idea what the forces involved are.

Also, where in the US are you? Maybe I'll run into you at an event sometime, I'm over on the east coast.

[acealeam]

I'm very inexperienced to say the least, but this is something I would really like to pursue. I know it won't be easy or even if it will be feasible, this is just an idea at the moment, but I'm hoping it can turn into something amazing.
Maybe a flipper was the wrong way to go, but for simpler things, like wedgebots, as far as I am aware, they are not allowed in some battles, and I don't want to go out of state (Fl) for competitions, so the more I'm eligible for the better.

[Badnik96]

Wedgebots are only not allowed in the 30lb sportsman class, which has a very specific set of rules. You can ask SKBT or MikeNCR about those, they've built several Sportman class bots.

Florida does have a ton of robot competitions, but sadly none I can go to up here in CT. :P

I'd say a pneumatic flipper is not a good idea for your first bot. I would definitely start with something more simple.

[R1885]

If you still want build a flipper like robot, try a servo lifter. It wont have nearly the power of a pneumatic flipper, but will be much easier to build and much safer too.

[acealeam]

I suppose a lifter could work, I will look into it.

[Natef]

here's a good servo lifer BW:

[SKBT]

lol 3lb pneumatic bot.



pop quiz time


if you cannot answer all of these questions on your own, you should not attempt to build a pneumatic robot


tell me what stroke and bore mean

tell me the difference between a 3 port and a 5 port valve

tell me how to wire a valve so it failsafes correctly

what npt means and pressure ratings are

the difference between regulated and unregulated

how to store your gas/air and relevant safety information / operating pressures for each

what parts you will need to build a pneumatic system and how you plan to source them.

draw a diagram of your proposed system



i'm asking you these questions to think and understand there is more to a pneumatic system than you probably think.


and your robot looks like sid

[RFS]

I'll chime in I suppose.

I built a total of two completed beetleweights (Kill Switch, Earth-Quake) and began work on quite a few others that were never completed for whatever reason. This was over a decade ago and I picked almost all of my parts from scrap, so your mileage may vary.

First, definitely look into a gearmotor, it's just easier than building (or finding) a gearbox for an existing motor. It can be done, but for the sake of convenience gearmotors are good. The motor you linked in your OP is similar to one that I used in a personal non-combat project and it's capable of putting out quite a bit of oomph but it's also kinda heavy and also requires its own gearing which of course is burning up even more weight. Once you're able to find out the stats of a motor (current, etc) you can calculate what size battery you need. It would be wise to buy two batteries; the first one you keep in the bot, the second one you swap out after a fight so you can charge the first, repeat as needed.

I unfortunately am very out of the loop when it comes to specific robot combat parts so I cannot recommend a speed controller (ESC) or a radio to you, sadly, however you'll probably want to get a 3 or 4 channel radio because the first two channels will be devoted to your drive system most likely.


Regarding pneumatics:
Pneumatics are a tricky thing to work with and for such a small weight class I would definitely consider getting a servo motor. A servo is essentially a motor with limited range that has ridiculous torque. You generally see servos used in remote controlled airplanes to adjust the wing flaps and all of that (they need to be strong to go against the wind and stay there). I used servo motors in my antweight and UK antweight successfully for lifting and clamping applications. The torque of a servo motor is really only applicable for lifting weapons in the 3 pound class and lighter which makes them a perfect fit (plus the gearing is done for you and it's usually very easy to mount things onto the motor outputs). My first official combat robot that wasn't an open class creation was a servo lifter.

Pneumatics are not impossible on a small bot, but they have their own challenges. BattleBots alumni Brett Dawson (Mobious) and Alex Rose (Toro) put together a pretty solid guide on understanding the parts of a pneumatic system as it applies to combat robots. If you are dead-set on using pneumatics in your design I would definitely give this a read and take a look at the interactive graphics they have: http://www.teamdavinci.com/understanding_pneumatics.htm (When I was learning pneumatics for a design I ultimately never finished this guide was EXTREMELY helpful).

[cephalopod]

Yeah, pneumatic beetles are possible and very effective but look quite tricky to fit into the weight limit