Re: Under 1 sec mini bot
 

That arrow better have a tetrix motor propelling its vertical motion.. as well as a battery. :]

Re: Under 1 sec mini bot
 

I predict that all of the fastest minibots will mount their wheels directly on the motor shafts. Our minibot team identified this as a necessity very early. Unfortunately we didn't have the fabrication abilities or man-hours to make it happen on our minibot.

Re: Under 1 sec mini bot
 

It would have been a more interesting engineering challenge if that were true. Team 1827 will contend that minibot speed is actually all about eliminating every gram that isn't mandated by the rules.

Re: Under 1 sec mini bot
 

We've got a solid 2.5-second minibot without doing that, but every attempt we have made to do a direct-mount has resulted in a bot that does not have the torque to climb.

I know it's possible because I've seen it done, we just can't seem to figure out how to do it! (Though we'll be spending a long Saturday tomorrow trying more ideas... We'd be working today if not for the Snowpocalypse.)

Re: Under 1 sec mini bot
 

This is true, to a point. Once every gram is eliminated, how do you make it faster? If you have a few weeks until your competition, I'd suggest exploring how (subject to your capabilities and resources).

I may investigate a direct-drive option this weekend; though we also need to do a better "V" for the deployment mechanism.

As for minibot that takes less than 1 second to go > 7.5 feet? Well, I've had a bit of foot-in-mouth about minibots this season so I won't really comment on it.

Re: Under 1 sec mini bot
 

Alan is absolutely correct. You will understand it when you get there. This isn't a meant to be insulting, just noting that it takes a lot of experimentation or very thorough design to not "luck" into a fast minibot.

Yes, weight is important, but so is frictions, traction (yes different), load distribution, and most important a matched gearing to the above parameters. When your gearing matches those, you get a very fast (maybe not 1 second, but fast none the less). We had 2 mini-bots of similar design, similar gearing, but one was significantly faster. Then we found and eliminated some scrub, and the slower one was significantly faster than the original fast one. After that, we got them both within 10% of each other with regards to run to run variability.

As JVN points out, iteration is often the key to incremental improvement. We tried approximately 5 "styles" of minibots before settling on an architecture that we liked. We have since gone through 7 different minibot chassis for this particular "style" of minibot. For those of you counting at home, that is around 12 minibots, and I hope to continue as i would like to revisit a completely different "style" that I am seeing get good results. It didn't have good results in Week 5, so we put it on the shelf to be revisited at a later date.

Re: Under 1 sec mini bot
 

Team 190 has quite the out of box approach to accomplishing the minibot task.
I recommend that come the WPI regional, watch match videos just to see it.

I am sworn to secrecy, but I will tell you this much, it's pretty brilliant.

Re: Under 1 sec mini bot
 

oops

Re: Under 1 sec mini bot
 

The trick isn't the motor, but what you use for traction.

Re: Under 1 sec mini bot
 

There are teams out there that have to be working meticulously on this right now. They aren't going to give up because of it. Trust me, there will be a sub 1 second minibot.

Re: Under 1 sec mini bot
 

No way. Not including deployment.

Re: Under 1 sec mini bot
 

I didn't add deployment factor to the post did I. I'm strictly just talking about the minibot. Quickest minibot plus deployment will be around 1.75 seconds. Maybe not, if so, prove me wrong.

Re: Under 1 sec mini bot
 

They will.

Re: Under 1 sec mini bot
 

That would be tricky, since clipping to the pole requires turning a horizontal force to a vertical force, and you can't leave too early after clipping because the minibot would bounce and slide around.

Our team bounced around an idea about a modified clay-pigeon launcher type thing that slams the robot onto the pole (lightly), but would deploy extremely fast.

We haven't had time, money, or enough of a workforce to build it or the minibot, so if anyone wants to use the idea, feel free.

Re: Under 1 sec mini bot
 

Actually it doesn't....

Unfortunately I can't say more.