RoboWaiter 2013

RoboWaiter 2013

I was a little disappointed about my results this year but I still did better than my first year (2011). I only got 1 trial correct but that one trial was the best trial I’ve gotten ever, but, due to chance/human error, trial 2 and 3 were a fail, lowering my score. Trial 2 seemed to fail due to a shake of some sort. I slowed down that part in the video but I’m still confused as to what happened.  In trial 3, the table was lower (there was more than one arena), in the rules it did say that it was supposed to deal with a bit of variation (but it also has said that the last 2 years I’ve done this, but never changed the height). Overall, this is still the best robot out of all three years, if i had completed all three trials successively  I believe that i would have gotten second again. They have not posted the final results yet, so I just know that i didn’t get 1st, 2nd, or 3rd, since they announced that.

Forklift final version

Forklift final version

So the forklift worked pretty well, since the last testing video I made a few physical changes but I mostly made programming changes. The other change is the instructions for NXT 2.0.


Forklift programs for NXT 2.0

These programs are made for the forklift when using the building instructions. In each program it limits the top and bottom so that you can’t break anything.

You can download them here (in .zip format)

Forklift programs for modified forklift

These programs are made for the forklift but with 40 and 8 tooth gears as shown in the video instead of the 36 and 12 double bevel tooth gears giving a 1:5 ratio instead of 1:3 and it skips less than the double bevel gears.

You can download them here (in .zip format)

In each zip there are 3 programs, both sets of programs are similar but have different limits the modified ones have an m in the front of the file name

2 button forklift control

For use with using 2 touch sensors (plugged into ports 1 and 2). the touch sensors are used for driving and then you press the enter button to change the direction, the right arrow for moving the forklift up and the left arrow to move the forklift down

Fork control

This requires the PSP-NX-v3 (plugged into port 1). This uses the right joystick for speed and direction (up and down) and the left joystick for turning (left and right) I prefer this way as opposed to using one joystick for both (like in the next program down) because it is easier to go perfectly straight and it is also easier to control turns (once you get the hang of it). It also uses R1 to move the forklift up and L1 to move the forklift down. Select resets the forklift at 0 and then ends the program.

Fork control single joystick

This requires the PSP-NX-v3 (plugged into port 1). This uses the right joystick for moving the robot and the left joystick for moving the forklift, one of the nice things about this program compared to the other programs is that you can control the speed of the forklift moving up and down as opposed to the other ones where the speed is fixed. Select resets the forklift at 0 and then ends the program.


Instructions were made using the LDraw suit and is similar to the last instructions I made.

You can download the PDF here

you can download the MLCad files here.

Thanks to musikConomy for intro/outro music

Forklift testing

I’m back from vacation for good now and have finished my prototype of a forklift that uses no string, linear actuators, pneumatics or rack gears. It works pretty well. Ultimately I will have a  polished program and instructions but I first have to modify it for NXT 2.0 only (I think all I have to do is change the gears and the back wheel). Podcast with final version and instructions should be out by the end of the week.

Moment of Genius!!

Moment of Genius!!

So I just realized how I can gear the robot down without running into problems disused in the last post. This was my (accidental) strike of genius!

So I was gearing the robot to go a bit faster (big to small to medium – black gears) so that the ratio would be 1.8:1

And I accidentally put the last gear (show above, bottom left) on the wrong side of the lift arm (shown below)

and I really meant to put that gear on the other side like I had been doing with the other gear setups.

Then I thought, hey, why didn’t I switch the gears around since there doesn’t have to be a gear on the other side (which was what was causing the problem because it was hitting the motor when it was too close – so this is what I ended up with:

So I then had 1:1.8 – i was trying to get 1:2 or 1:3 but this is good enough since it is easy and strong.

And then, of course, I messed around with the rotocasters

By the way – new wheels come on tuesday

PSP-NX-v3 Testing

I got the PSP-Nx Combo with Wireless Controller for my Birthday. This comes with a PlayStation 2 Wireless controller and the PSP-Nx converter which you can plug a PS2 controller or wireless receiver into and get a sensor output for the NXT.  From that you can receive from the 16 buttons (Triggers, bumpers, R3, L3, D pad, Shapes, select, start) and X/Y axis from the 2 joysticks. To test this out I built 2 robots. First I built a simple skid steer robot with a rotocaster as the back wheel. Then I used a program from Mindsensors to start off with so that i could learn how the programming works. I also downloaded the NXT-G block. I then built the HiTechnic RotaBot and used ­R J McNamara’s program to make it work with the robot. – His code was written in NXC which I do not know so I couldn’t edit it. As you can see in the video – this robot can drive in any direction without turning. This robot requires Rotocasters and NXT 2.0 set.

Video: iPod

Thanks to musikConomy for intro music

Robowaiter Update

A quick update on my work from the Robowaiter competition.

I’ve setup two testing areas, first on the deck with a carpet but the carpet made the turning unreliable so i was not able to test the turns well. Then i set it up the in the kitchen and i got it to work after playing with it. The only downside with the setup in the kitchen is that it has to come down once i’m finished testing and it only shows the two table placement and 1 wall – does not show sink or dolls. I have gotten it to go home and work a bit better than shown in the video.

Thanks to musikConomy for intro music