UnEven Floor???
 

Ok,
Our mentor wants to build a chassis that pivots on one side. His reason for this is he says that the floor in the arenas will be uneven and he's worried about the wheels coming off the floor. Has anyone had any problems with this? Please let me know ASAP.

SGSDragons
Josh
Designer/Driver

Re: UnEven Floor???
 

I've never heard of uneven floors before. I wouldn't worry about it unless it is absolutely critical to your design. Most fields are on a concrete slab floor, etc. so level shouldn't be too much of an issue.

Re: UnEven Floor???
 

thats what we keep telling our mentor, but he seems to think otherwise. Anymore info would be nice, or imput from other teams.

Josh

Re: UnEven Floor???
 

Try looking at the event info for your specific team. The event should give away what surface you'll be playing on.

Re: UnEven Floor???
 

Unless you are using a holomonic drive system, this shouldn't be a problem.

Re: UnEven Floor???
 

We ARE planning on using one. We actually are building our wheels right now. Last year, I saw many omni-drive robots that didn't pivot and didn't have any problems. What do you think?

Josh

Re: UnEven Floor???
 

Then it's probably worth it to have the base pivot. If you are driving and hit one little bump in the carpet, you are going to go off in some crazy direction.

Re: UnEven Floor???
 

ok, Do you have any good ideas on how we should do this? We Have one idea, but thats it.

Re: UnEven Floor???
 

Are you sure that is the real reason?

Does he really want a 6 wheel drive with the center wheels offset a bit lower for traction??

We have done that setup sucessfully in the past and had no problems.

But then you have teams who think "hey, a .25" offset is good, why not try a 3" offset and be great", like one certain team in NJ did this past year.

Yeah.. not such a good idea.

Re: UnEven Floor???
 

We used a holonomic system last year, and managed to pretty much conteract the bumps in the floor and the loader platform by using high traction, neoprene "rollers" (we used the Andymark Trick Wheels). Additionally we made sure all 4 of our wheels were co-planar, so that they would all 4 be in contant on a level surface.
So, unless your planning on tackling the ramp with a holonomic system (which could be done with a custom active suspension, but would be very very difficult), you shouldnt need anything special.

Re: UnEven Floor???
 

if you're REALLY worried id just go with a more flexible frame. more twist itll keep all tires on the ground. less flex is waht we aimed for with 4wd this year tho. our stiffest chassis yet. and well softer tire compounds may help too.
but overall other than carpet being ripped up about 2 times in my robotics career . i cant really think of uneven ground affecting anyting

Re: UnEven Floor???
 

Send a PM to Ken Stafford from WPI. They had a flexible frame last year.. it was really cool.

I'll try to fish up some pictures and upload them later.

Re: UnEven Floor???
 

Is your team going back to Portland this year? I know one Spokane team (at least) is going somewhere else this year. In any event, the Portland arena, at least, is for all practical purposes dead flat. We had so little ground clearance under our bumpers last year that we would have high-centered on a paperclip.

Re: UnEven Floor???
 

No, we are not going to the portland regional. Our team is the only team from Spokane. We were there last year however. It was awsome, WE WON :D :D

And Tom Bottiglieri, if you could please upload those pics I would appreciate it.

Thanks
SGSDragons
Team Designer?Driver

Re: UnEven Floor???
 

my team this year is designing a six wheeled robot. two of the wheels that are located in the rear of the robot will be sitting about 1/8-3/16 above the rest of the wheels. why do this? this year our design has a high cg so if we get pushed our robot might tip. so the two wheels that sit up will only come into play when we are about to tip.

Re: UnEven Floor???
 

we did that last year, it work fairly well, however, we can't really do that since ALL of our wheels have to be on the ground at one time.

Josh

Re: UnEven Floor???
 

this so far seems to be a good idea for us and it is our first anti-tip mechanism we have ever constructed.

Re: UnEven Floor???
 

Are you building a holonomic platform such that it can move in any direction without turning or are you just using omniwheels to aid turning?

If the latter, there's a far greater chance your chassis will be twisted than the floor will be noticeably out of level.

Re: UnEven Floor???
 

We are building an omni-drive so that we can drive in any direction.

Josh