new wheel design
 

(i dont know if i posted the image correctly or not but i hope it shows if not it looks like an X with omniwheels on each end connected by chain to an outer center shaft and an inner shaft connected directly to the X)
hey im looking for advice. it was one in the morning and this idea hit me and i had to draw it. the little wheels are omniwheels and are rotated by the outer shaft and are connected to the outer shaft by bike chain. this would hapen during normal movement giving the robot a smooth motion. when the inner shaft is rotated it rotates the whole assembly rotates allowing it to
overcome heavy obstacles like stairs with no sweat. the rotation betwean inner and outer shaft would be switched by a gearbox. this means one motor can control each assembly. my only real concern is weight. i would have to experiment with making as much as possible out of plastics. any comments or ideas. note this design would kick $@#$@#$@# on stairs and other rugged terrain.

Re: new wheel design
 

A picture is worth a thousand words. Maybe you can post a link to it or upload it into the gallery? I'd really like to see, sounds interesting.

Re: new wheel design
 

A team did something similar in I believe 2004. http://www.firstrobotics.uwaterloo.c...s/wheels09.jpg

Re: new wheel design
 

yes that is very similar i guess the main difference is the omni directional wheels.

Re: new wheel design
 

Would you plan to have four of these on a robot? How big would the overall diameter (or distance across X) be and what would be the diameter of the little wheels?

Also, instead of bicycle chain, consider using standard roller chain. Easier to get sprockets for.

Re: new wheel design
 

first of all: im curious what team that was in the picture. second: keep in mind its just a concept so far so i guess the wheels would be 2" omni wheels and eack X if i do a X would be 8" or so in diameter. im still trying to figure out how to control the axles independently or how to handle the weight. the origonial reason i thought it up was becuase omniwheels are very small and i was trying to figure a way to overcome obstacles.

Re: new wheel design
 

The team in the picture was 1218, Cha-Bots. If you haven't gotten a chance to see their robot, (www.SOAP108.com generally has, well, everything), it was amazing to see. Their implementation of the idea was par excellence.

Re: new wheel design
 

and if my memory serves me right it twas spam in '04 who used the same omni directional type of drive and was in the top 5 at nats too.

Re: new wheel design
 

SPAM used a holonomic drive in 2004, along with 1083, but it was nothing like 1218's tri wheels.

Re: new wheel design
 

any advice on how to make the outer wheels and the whole thing move seperately i was thinking a gear box of some kind similar to the type that would change speed.

Re: new wheel design
 

what i saw on the pic was the 4 wheels at 45 deg. am i seeing that correctly?

Re: new wheel design
 

yes four wheels at 90 degrees and each one would rotate independently for going over normal surfaces and then the entire thing rotates for going over rough terrian like stairs.

Re: new wheel design
 

each seperate wheel would be an omni wheel and so the whole assembly would act as an omni wheel too.

Re: new wheel design
 

The leftmost picture is an elevation, not a plan view.

Re: new wheel design
 

i dont know if this will clear anything up or not but here is an updated picture (just a little clarification) like i said im not sure how to switch (the mechanism not the actual rotation) between small wheels and large wheel

Re: new wheel design
 

I've added the picture to your first post and deleted some of your posts that were about the picture initially being unavailable.

As a head's up, note that you can edit recent posts by clicking the button labeled as such in the bottom right corner of each post. Editing your posts to add brief additional content will keep the thread easier and faster to read.

Re: new wheel design
 

Looks like everybody is getting confuse with what Mechanical brain is trying to accomplish. (this was pointed out before in THIS thread).. if you remember team 1218's 2004 season robot, you will understand how this works. The only difference between two modules are, 1218 has 3 wheels, this design will have 4 wheels. Now I hope I am pointing it out right.

Hold on... this post just confused me. Are you trying to do something like what I pointed out in this thread (1218's modules) or is it completely different. Do you have any 3d drawings of what you are trying to do, because right about now, I am getting confused too.

Re: new wheel design
 

i dont know what those teams did or not but one difference from pictures ive seen is the use of omni wheels on each end which allows the entire wheel to act like an omni wheel. when placed diagonally at each end of the robot the whole robot can move in any direction im also trying to figure out how to get the robot to rotate and move at the same time

Re: new wheel design
 

looks like the 1218's kind of wheel and a spam kind of base from '04 season for both. hmm, interesting idea can't wait to see some 3d drawings or a robot with this. correct?

Re: new wheel design
 

i wont be able to do any 3d work until school starts but ill start playing with it anyway. ill show some pictures of this and some of my other projects (some of the stuff is really cool) as the summer goes on.

Re: new wheel design
 

One thing to keep in mind is that a drivebase with diagonally-placed omniwheels at every corner doesn't work well unless all of the wheels are solidly in contact with the ground. A "climbing omniwheel" is going to violate that, and it's probably going to slide around to the side a lot more than you want.