Chasis Construction

Before beginning to build a chassis, you need to understand that this must be the sturdiest part of your lego bot. Because you will only build from here, an unstable chassis makes an even more unstable robot, only adding to natural drift problems and other unavoidable problems with motors and programming. The fist step to avoiding this is when securing Motors, make sure they are snug. If they aren't securely surrounded by legos and pins, they will wiggle in turn causing the wheels themselves to be unreliable and unpredictable. On the opposing side however, if legos are too tight, they may snap apart at anytime including while running the bot. It is a tricky balance, but the idea is to secure the motors, not strangle them.

Secondly, for beginning teams, it is advisable to stick with mounting motors right next to each other. If you are bold enough to venture into mounting wheel motors separated, you mush make sure that each motor is level (use an actual level to make sure they are even) and both are extremely secure. A good rule of thumb to follow is that there should be a lego on each side of the motor to secure it.


Besides making sure that the motors are secure, the rest is a free rein for creativity! For beginning teams, follow the KISS motto (Keep It Simple, Stupid); follow the chassis built from the demobot diagrams or use the chassis model attached. For more advanced teams, still keep in mind the KISS motto, but try out a new way of mounting. Try mounting the motors vertically instead of mounting them horizontally, or mount them separated from each other. You must keep in mind though, that there are only a finite amount of pieces available in each years botball kit, so if you use too many legos in while building the chassis, you won't have enough parts to continue building claws and other such attachments.

You also have to keep in mind what the bot is being used for. For example, if you are going to attach a giant claw to it, you may need to leave space (or put an extra lego) so that a counter weight can be attached to the back or add a skid somewhere near the front (or the side where the claw will be attached) so that it doesn't topple over. If you are building a "garage door" attachment (something that just plows over tribbles in order to collect them and then deposit them) or any other attachment that will be on the floor, you need to be mindful of building out far enough so that you can properly attach the chassis and the actual attachment. Whatever the function of the bot is, should ultimately control what the chassis includes.


Testing your bots is probably the scariest part as a builder. For builders, there are two main ways to test your chassis (or entire bot in general) and neither is less nerve racking: the drop test and the stair test. The Drop test consists of dropping your chassis or bot (for the Bot make sure you take off both the CBC and any claws or attachments so it is the main structure) from about 3 to 3½ feet in the air drop it on the ground. If the chassis or bot stays relatively intact (you may need to re-attach a bushing or liftarm thin or two), you have a sturdy reliable bot that shouldn't cause any structural problems in the future. The second methods, the stair test, is this more or less same test, but instead of dropping it make sure it can safely travel down 4-5 stairs with minimal damage. Again, you may need to retighten where legos are attached with pins, push down any loose bushings, etc.

Chassis Construction 683 KB
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It is advisable to stay with

It is advisable to stay with mounting engines ideal by each other. On the off chance that you are sufficiently strong to wander into mounting wheel engines isolated, you mush ensure that each engine is level (utilize a genuine level to ensure they are even) and both are greatly secure. A decent dependable guideline to take after is that there ought to be a lego on each side of the engine to secure it. On the other hand, I want to get reviews of and this will be sound good approach for it.



PiPeep's picture

I gave this to my team last

I gave this to my team last year, and I'm doing it again this year. It is a great intro to lego-based robot building. Thanks for posting this.