Fast Bike

Vex Robot - YouTube









Very nice. Does the code turn the wheels at different speeds during a turn.

Thanks, I was thinking about the steering depending on the speed but the speed is not so high that would add this feature, I have limited motor movement during the forward stroke, and a little less in the rear, as well realized a return wheel to the center (and do not use the function hold) because they do not know about it)) but the original problem I have not decided I wanted to create a drifting moto and turned fast. I add a couple of motors for traction, the other options I do not see to make it drift, tried various schemes of gears, but without a results, or do not have enough power to start motors or speed is very low.

I just thought to make two chains of gears in different capacities but unfortunately you can not turn the engines quickly their maximum speed as well as to make the motor run without coupling.

http://www.vexiqforum.com/forum/main…motor-228-2560

There are thought to try the scheme referred to in this top.

Just thinking…

Yes, Apalrd has some great posts. Differentials would be a good solution. It would require a larger bot and a more complex drive system, but you can definitely combine motor power and generate more speed using differentials. I posted some photos of a build like this recently in the post below. Look at the third picture for an example.:

Great build. I might try to build something like this after our classroom challenge is finished.

Final Update

Vex Bike Bot - YouTube









Looks like you added some more support to cover the brain. Looks nice. I am curious to see what you will build next!

Also, wanted to tell you that I started building a new chassis for the Peterbilt 379 because you asked about it. Pretty busy with other things right now, and I want to make some design changes, so it might take a while to finish. I will post some photos for you when I finish the new drive system.

As promised, a few sample drive systems.
Both have power only to the inside wheels. The outer wheels are free-spinning to make it easier for the bot to turn.

The 2-axle version also uses gears that are free-spinning. This lets two sets of wheels coast at all times. (I was designing it to match a particular drive system, so it delivers power to only two sets of opposite wheels.) I rarely post video, but I’ll add a short video of this one soon to clarify the gearing.

The 3-axle delivers power to all six sets with differentials to split power left and right. It’s movement is pretty smooth, so it operates well with only a single motor. (To test it, I put my marble bot on top - see entry in the showcase - and ran a cable from that brain to a single motor mounted under the chassis. Even with the weight of the other bot on top (1.548 kg), it accelerated almost immediately to full speed. For this build, I think the length of the gear train is actually an advantage because the brief pause as each new gear is engaged keeps the motor from being initially overloaded.



Here is a link to a short video showing the gearing of the original peterbilt drive in action.

Thanks for the “like”, Valeria :slight_smile:
Looking forward to your next post!