Been very busy with different things the past few weeks but have been able to work on this. the idea is that you drive forward and then slam on the brakes and the whole robot tip forward, the person almost hitting the ground, then it pops right back. my problem has been getting a good balance. This is also my first 4×4 vehicle so i can stop the front wheels to make it tip but sometimes that’s not enough so it has to be put into reverse quickly but sometimes that makes it tip forward too much and get stuck. So, basically, it needs work.
UPDATE: building instructions are available on the building instructions page!
Double-tracked is my attempt at a robust tank using the rubber treads. I used the rubber treads instead of the hard plastic treads since they have much better grip (and I have no plastic treads). This worked very well. The only down side to this is that there was no suspension. Also, the gears connecting the front and back treads would often catch on the ground. Overall though, I think this could outperform almost any other Lego tank the same size with hard plastic treads.
Here’s some pictures of my next project. I’m waiting for a pack of differentials to come in so this will have 3 differentials in it when it is finished. The next things i need to do is add the PSP-NX-V3, and make it look nicer.
This is my half tracked vehicle. It is remote controlled by the PSP-NX-V3. In “normal” mode it is driven by one joystick, it has no differential but when turning, the back two motors go at different speeds, simulating a differential. When you hold down the R1 button, it goes into “two joystick” mode where the left and right joystick control the treads independently, great for getting around tight corners, the right joystick also controls the front wheels.
You can download the program here.
You can download the instructions here.
And the MLCad files here.
You can also see this on Rebrickable.
I’ve finished making the 3D model of the half track with MLCad and here’s what it looks like. Someone borrowed my camera so a video will probably be up on Friday.
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.
Got some new Lego related items for Christmas – both are great
Been working on building a snow crawler over break – need to get another set of tank treads. Needs a bit of work – especially with the steering connection. Using some part from my new Power Functions kit I got for Christmas.
Working on building instructions for the ‘Smart’ car 2.0, I’m mostly done with everything besides on thing, line following, i’m trying to get it to work but having trouble. But it can parallel park on it’s own, drive autonomously, and like the last ‘Smart’ car, help control while remote controlling – but it can do that better than the last one. So all around, just great improvements on the last ‘Smart’ car. For more info on what i’m trying to do with the line following, go here.
This robot will be similar to the last “Smart”car in the basic idea but this will have a lot more features. This is what I have built so far:
This hasn’t changed much from my testing video since I didn’t get to get the parts that I wanted (like the air tanks) but I’m still happy with the design overall. there is 1 motor to drive, geared 2:1. 1 motor for steering. and one motor for the arm gears 1:5.
the program is what changed the most since last time. for one, I made it so that all the operations (steering, driving, arm movement, etc.) where in separate loops so that if one got stuck (like the steering wheels got stuck, which happened a few times during early testing) then the rest of the operations wouldn’t stop and the driving and other things will still be controllable. the only problem with this is that this is almost too much for the NXT to handle so the response was not as fast at I would have liked, but the improvement that I liked the most with the up and down arrows for the arm. up reset it at the top. and down put it at the right height for picking up/dropping off the car, which made using the arm very easy.
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Thanks to musikConomy for intro/outro music
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