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Knex "K*bot" competitions (kbotworld.com) Answered


I was bored and decided to google "Knex". What I found was very interesting. Apparently there are competitions for Knex robots that do battle with each other. As I read this I thought about how us Knex gunners at Instructables could easily dominate these competitions; because we are the kings of Knex warfare.
We could have a collaboration group based around K*bots, where we will post ideas and eventually have designs for the ultimate robot. Then when the competitions come around we could find somebody who lives closest to the competition to build the robot and enter on behalf of our collaboration.

But there's a catch: There are rules, an one rule states that projectile weapons are banned. But I believe there are ways around this, as the exact ruling on this goes:

"Projectile weapon systems which can launch a K'NEX part clear off the K*bot are banned due to safety reasons. Any other weapons systems which the organizers deem too dangerous will also not be permitted."

This could easily be avoided by fixing the projectiles to the robot. For example: My cannon could use an extremely long bullet that has rods in the back of it, preventing it from ever leaving the robot while still delivering a deadly impact. But don't forget that weapons NOT based on guns will also be essential.

So what do the rest of you think?


the way to win is to:
1. Build the robot that is lowest to the ground so others will drive over it.

2. Gear down the motor as much as possible so that it drives very slow so if another robot drives over it then the other will go over the table first. Also if it were a pushing contest the other may be faster but it will not have as much torque and traction as our robot, therefore the wheels of the other robot will spin out and not take it anywhere.

So basically you just push the other robot off... Well projectile weapons would be pointless anyway... Obviously you just build something that protects the wheels, preventing it from flipping over. On the front, you just build a big shovel thing that flips the other guy over... I don't think a your cannon could deliver a deadly impact to a Knex robot. At most it might punch out a snowflake piece or simply snap the bullet. Plus if the bullet stayed on it would be unwieldy.

OR, do any of you watch Robot Wars....cuz do a design like TORNADO, then, if it flips, it carries on driving, just in the opposite direction

You underestimate the cannon. If you look at the majority of the robots, even a rod-shooting gun could do some damage. The cannon would completely impale most of them; and if it doesn't, it should send it flying off the table. And with some good engineering, I could get one motor to pull it back in and release it. And lets stray away from our guns for a second. A rubber band powered flipper would work good too. If it doesn't have enough power to flip the opponent, it would lift their tires up while pressing ours harder to the table, it'll have more traction and win.

Well these aren't like real robots where much of the inside is packed with vital electronics. Even if it gets impaled, it's unlikely it will have any effect. The only thing that's important would be the motor box, and I doubt any Knex gun can damage that since it's covered by a solid layer of plastic. Also, a bullet can't send it flying off the table. It does not have enough momentum (assuming it is a rod). And for that to be possible, it would need to be very heavy and big, which would thus negatively impact the robot's mobility. If the bullet is physically connected to your robot, you would have to ensure that your robot is heavier than the opponent's; otherwise your robot would go flying off the table. Projectile weapons are out of the question. The only way to win would be through power and maneuverability.

I said cannon didn't I? I said extremely long bullet didn't I? I'm not so naive as to think that a rod could send a robot flying. And it's not a projectile when it's on the robot, it's a powerful ram. A cannon bullet that's a foot+ long will have a lot of momentum behind it.

And the weight issue can be overcome by your own robots velocity. It would be easy to make a robot that has a mechanical timer that starts the robot moving with rubber bands as it's means of movement. This will give it some awesome speed (well, for a Kbot). A switch could be mounted to the front of the robot so the cannon could be activated on impact with the switch (this is assuming it's in the 1-motor division). Then the combined speed of the robot an the ram will hit the opposition. Shortly after the robot switches to the motor for movement (if it hasn't won already).

I know, I was simply saying regardless of size, projectiles are out of the question anyway. The ram method you described may work if your robot is heavier than the opponent's.

Hmm, brilliant! We'll just add an EMP to the robot, turn ours off, set off the EMP, then turn ours back on, It will work!

Electromagnetic pulse!? Hmmmm.. I think we would get disqualified and we might blow some stuff up-like the venue!

Hmmm... Just a few minor flaws (possibly).

What if you haven't won? What if your bullet didn't knock the opponent off the table, and the bullet was left hanging? I'm sure that if you made a motor to pull the bullet back it would take a long time. Meanwhile, when the bullet is left hanging, you are vulnerable because an opponent (assuming they have a "flipper") can easily flip your bot over and/or off the table. Unless you can overcome that (assuming you havn't won on your first try) then it may not work as well as you thought. Sometimes the most simplistic designs can take you farther than the most complicated ones. For example, your post at *Sep 14, 2007. 4:45 PM* seems like it would be almost flawless.

Yeah obviously there's flaws. But thats just why it's fun. We can drop this idea for a while, I'd rather think of new ones than work out one design. So here's a design I made back when I was around 11 (before Knex guns i made robots)). The front with be a wedge, and 2 sections of the wedge will be part of a torque-geared lifter. If anything drives up the wedge it will be lifted up and flipped. The wedge could be made extremely low to the ground and use the openings of connectors to grab hold of any other wedges (like the other design I posted). It's a lot more simple than the cannon bot and has a good possibility to beat the flat bot.

You could try to make it so the robot had spikes on the ground so it could go forward but not back.

Have you ever watched Robot Wars? It used to be on KERA (can you believe that?) every Super Bowl. I've never seen it again :( It was a great show.

I saw that show before. But my favorite robot fighting show was "Robo Wars". It was just an awesome show and it really got me into engineering.

Flipping works very well, because unlike Robot Wars, where the arena ground is uneven and has spikes (to counteract unflippable bots), the stage is smooth, so a an unflippable robot can easily be designed.

Here's an idea for the 1-motor division. Have the robot be completely flat. like 1 rod thick for the whole front of the robot. It could be made of the flat pieces an have blue washers for rollers. The flat area will be on hinges that only allow it to fall downward (you'll see why later). Then the wheels and motor will be in the very back .

When the robots meet in the middle, the opposition will drive on top of the flat area, completely taking all the wheels off the ground. Then when it carries the other robot to the end of the table, it dumps it off the edge...
Quite ingenious if i do say so myself =D

I have an idea for you. Make a robot that has a good bit of weight in the back and put a forklift on the front that raises up to pick up the other robot and have it drive to the edge of the table (your robot). Have your cannon (on top of your robot) shoot the other robot off the forklift so it takes a nice fall to the ground (off the table).

It is your idea but a little different. If the other robot drives on top of yours what keeps it from rolling back off? If you use a forklift to pock through the mane body of the other robot and lift it off the ground it wont be able to get off till you dump it.

Maybe have short spikes (small black connectors) to grab onto the frame?

OR, you could have big grooves that stop the wheels
i mean like
=== ===================== ===

= means knex bits

make something flat and big that is strong and can be lifted up and down so the other robot will roll onto it and wont be able to get off because it is lifted up in the air

I just posted an idea for a lifting robot (great minds think alike I guess). Yours is like a hybrid of that and the cannon robot. But if the lifter can already overpower the other robot and take it to the edge, it's best to leave it at just the lifter maybe?

Read the other post below this too. I thought the cannon would be a cool because it is more extreme.

Here's a prototype picture. It needs more weight on the back.


i think it would work better on a slope and a pusher on the slope if the other robot is stubborn and wont budge of the last bit of arena

It would be terrible on a slope. Anyways, the flat area falls down when it gets to the end of the table, it doesn't need to push anything.

i dont get the need for the big panel, explain

when the other guy drives on top of the flat area, he obviously wont be able to move and I'll be in complete control. Then it dumps him off the table.

how about when he reverses or turns

It's for the one motor division. You can't turn or control the robot.

what stops ur robot goin off the table as well?

As soon as the enemy falls off the match is over. Even if mine falls off 1 second afterwards.

ohhhhh why didnt u say so

Looks pretty effective, the classic motor wouldn't be strong enough to get enough speed to keep the other robot on though, you would need to make sure it can drive faster then the other robot can, because if it weren't the other robot could be able to back out. A manouvrable robot would also be able to just turn of of it. Ofcourse this is just a quick prototype, but that's just a quick overview of the problems I see right now.

It's for division 1. You only only get 1 motor and don't control the robots.