# Video tutorials by D.Staykov

### Tetrix Gamepads. Controlling the motors with two separate GamePad Sticks

In this tutorial, we are controlling the FTC Tetrix robot with the two sticks of the same GamePad. The left stick is for forward and backwards, while the right stick is for left and right.

**#517**- 21 Apr 2017

### Improving FLL Robot Game. Task. Leave the Gecko

Think of an attachment that leaves the Gecko on the mission model. Don't use the robot attachment that we already have. Just the box robot and the gecko. Nothing should support the Gecko when it is hanged on the mission model.

**#481**- 17 Apr 2017

### Improving FLL Robot Game. How to hang the Gecko on the mission model

In this tutorial, we add another mission to our current program. This mission is - hanging the Gecko from the FIRST LEGO League Animal Allies.

**#480**- 16 Apr 2017

### Tetrix Gamepads. Simple program for moving the robot with the gamepads

In this tutorial, we would build a simple program for controlling the Tetrix robot motors with the GamePads. We use the stick and when the stick is pushed forward the motors move forward. When it is pushed backwards the robot moves backwards.

**#515**- 15 Apr 2017

### Improving FLL Robot Game. Teacher's Note. 9 out of 10 experiments

What should you as a teacher know when the students are trying to achieve a program and robot attachment that could reproduce their behaviour 9 out of 10 times.

**#479**- 15 Apr 2017

### Improving FLL Robot Game. Task. 9 out of 10 repeatable operations

The task in this tutorial is to execute the program 10 times and to do it yourself. If you have your attachment then use it. If you have our attachment then use it. But execute the program 10 times and make sure that it works.

**#478**- 14 Apr 2017

### Improving FLL Robot Game. 9 out of 10 times the attachment should work

How great is the great attachment for lifting that we built in this course? How many times can it lift the robot without making an error? How great are your attachments and how could you test them? - the answer is simple. Just try 10 times and they should work at least 9 of them as our attachment is.

**#477**- 13 Apr 2017

### Connect Tetrix Gamepads to the Motorola phones

In this tutorial, we connect the Motorola phones to the Tetrix controller using the USB hub.

**#514**- 12 Apr 2017

### Improving FLL Robot Game. The planetary mechanism for Lifting the robot

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"

**#476**- 12 Apr 2017

### Improving FLL Robot Game. Teacher's Note. Correct solution on calculating gears.

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.

**#474**- 11 Apr 2017

### Improving FLL Robot Game. Tasks. Find the number of needed motor rotations.

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.

**#473**- 10 Apr 2017

### Introduction to Tetrix GamePad control programming

We start with FIRST Technical Challenge and how you develop programs with the GamePads. It is up to you to decide how sticks, buttons and triggers from the GamePad will control the different motors of the robot and there are different decisions that you should make.

**#513**- 09 Apr 2017

### Improving FLL Robot Game. Losses in mechanical systems and especially in gears

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.

**#472**- 09 Apr 2017

### Improving FLL Robot Game. Our gear system calculation

In the previous video, we found the correct answer for our task and it is 18.75, or is it?

**#471**- 08 Apr 2017

### Improving FLL Robot Game. Teacher's Note. Calculating gear rotations

What should you do as a teacher when the students are calculating the gear ratios and number of needed rotations?

**#470**- 07 Apr 2017

### Improving FLL Robot Game. Task. Calculate rotations

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?

**#469**- 06 Apr 2017

### Improving FLL Robot Game. How to calculate gear ratio in complex systems

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.

**#468**- 06 Apr 2017