Many teams have followed the same idea as the ELM team. To build a LEGO Mindstorms attachment for the robot and to lift the truck very lightly. In this way they could more the truck and place it in the special region. See what the ELM idea was.
Here we start with a second box robot that we would like to build. It is in a way improvement to the first robot and we would take a look at its features.
Build a similar mechanism to this one. Similar, but for your robot. This is the task for you. Try, give yourself half and hour or even an hour.
There were a few problems with the 40 teeth gears that we were using. Let's list some of them
In this video we discuss the durability of the construction of LEGO robots and how do we make them more durable.
Following the principles from the previous video, try to make the attachment that you've built, more stable and durable.
Let us do a quick recap of the whole lifting mission and its solution
We calculate the number of rotatios when a gear system is involved. The driving wheel will have to do a number of rotations for the driven wheel to rotate to a desired number of degrees. In our specific case when the driven gear wheel is rotate to about 90 degrees the legs will lift the robot.
Calculate the number of rotations you have to do with the motor to rotate the final small 8 teeth driving gear wheel to 1.25 rotations?
What should you do as a teacher when the students are calculating the gear ratios and number of needed rotations?
In the previous video, we found the correct answer for our task and it is 18.75, or is it?
Sometimes the answer that you get by calculating seems not to be right. Is it the calculation that is wrong. Probably it is not the calculation, but something is happening with the robot.
Connect the attachment to the box robot and find the correct number of rotations of the middle motor that would bring the robot up and forward and would attach it to the mission model.
This is a teacher's note about the math behind calculating gear ratios with for our lifting attachment. It math model we build in previous tutorials is not exactly correct and here is the explanation why.
If you've done the calculation following the previous tutorials you would arrive at a result of 18.75 rotations. But this is not the correct answer. The calculation is wrong, because the math model that we've built, although kind of obvious, is not correct. When experimenting the correct number of rotations would be 37.5. This is a large difference. Two times larger. Exactly two times large. Something should be happening here - and this thing is "planetary mechanism"