Tracked Robot - New Project

js1

congrats whit your dev kit.

Impressed with the amount of research you have done so far. Those are great steps to document for others. Thanks for sharing

A quick update I started with powering the EZB. That failed, just a small red flash and a zooming noise. After some help here on the forum, I bought new rechargeable batteries, recharged them overnight and after connecting to the EZB, a nice blue light came on. The Wifi connection was up and running.

My prototype Meccano structure on the tracked chassis is also finished. Nothing fancy yet, very basic, but I found Meccano is really great to test things out. One can mount servo's, fixed them, remove them, etc.. and no glue needed. Super for a first project. I things don't work out, I can easily make changes.

I have mounted four 180° servo's so far :

1. Servo to move the camera eye in the X plane
2. Servo to move the camera eye in the Y plane
3. Servo which works with the DC motor : reverse/off/forward
4. Servo which works with the DC motor : left track/right track/both tracks

The servo's I had to calibrate so there min-max range was OK and the 90 degrees setting at startup was in an neutral position when mounted in the Meccano chassis.

The camera eye was installed and also the radar for avoiding collisions.

I still need to buy a battery for the DC motor to see the vehicle in action and of course the programming will become important then

Best wishes Johan

@JS1.

I look forward to seeing your project. I like the idea of using meccano for a frame/chassis. I used to love playing with that as a kid. Happy memories. :)

Here some photos of my primitive construction.

It is not yet operational. The motor is from the 1980'ties (no voltage specified), and with my 7.2V battery it is was running very fast during a short test. So I need to reduce voltage to have a more realistic speed. Also, the motor switches direction when changing the + and -. The two available switches for doing this were defective, so I made a DPTD switch which is operated by a servo (not yet on the photo).

With the bad light conditions inside, my camera tests were only successful doing QRC code tracking, so I'm planning to use that in the future for following a path in the house. I already made a small script which first reads a file with the plan of the house, e.g. :

kitchen-living living-kitchen living-hall hall-bathroom etc.

The program reads the file and given a start and end location, the program will calculate a path to follow, eg. from living to kitchen to hall to storage. It only goes four levels deep, and eliminates circular paths. I hope to improve the script with distances (take short route), and compass bearings, but that is all for later when the tank actually runs.

Next step is to reduce the 7.2 battery voltage to 6V so I can move the tank at a realistic speed.

Cheers Johan

@JS1... Nice design.... I use a lot of Vex in my projects so I like metal frame robots like yours... If you use a motor controller like the H-bridge in the store here you will have much more control over your tank drive motors... This includes speed and direction changes... You won't need to use a different battery or the crude servo controlled toggle switching setup... The h-bridge is only $15...

Hi Richard

many thanks for the tip. Do you refer to this one :

https://synthiam.com/Shop/AccessoriesDetails.aspx?prevCat=9&productNumber=14

Kind regards Johan

Yep, that's the one... And @Rich has great tutorials on how to hook it up and use it.... I prefer the sabertooth serial motor controller, but the basic model is around $70 so not cheap but very easy to use and set up....

and I can the H-bridge for a 6V or 7.2V engine ?

Yes, I believe the H-bridge can handle between 5V - 35V.... It can control speed so you can still use the 7.2 battery. With the H-bridge you can slow the motors down to whatever speed you want even with the 7.2v battery... and of course change direction as well. One more benefit is if you use the h-bridge you will be able to use the H-bridge Movement Panel control in ARC.... This opens up things like voice control to move forward, backwards, left and right with voice commands....

Thanks Richard, this is just what I need !

Waw cool work in such a little time ! I notice you use Mecanno ! This takes me back to my childhood... I build one of my first robots with Mecanno, something like 40 years ago. I've still got Mecanno parts around and every now and then I still use them. Btw, how old are you ? Location ? Looking forward to see some videos. Keep up the good work !

Greetz,

I'm 53 years old and live in Lier/Belgium.

I collected Meccano parts together with my father years ago. We had one complete Box 10 set and parts for three additional boxes. I now have the collection and sometimes use it to make a small build. I think it a great toy ! Wish I had more time. To make a video, I first need to order the H-bridge to make the tank 'explorer' move :)

Cheers Johan

Guessed we're about the same year... Me 2, 53 turning 54 this summer. I live near Antwerp.

Greetz,

js1 and phg

am from antwerp to 2020 and 51 years old :D

Nice to know more EZ-Robot users live so nearby :)

js1

in 6 years you bolt are the first ive seen here in belgium

Richard you mentioned the sabertooth serial motor controller. Could you perhaps point me to a place were one can buy one. Can it be connected to the EZ-Robot brain like the 2.5a H-Bridge ? kind regards Johan

Here is some info on them... You would probably be good with the 2 x 5 version... Sabertooth 2x 5 motor controller