this is my newest Coaxial crab drive drawing i put bearing support both below and above the axel Kevlar belt stearing linkage and Chain drive I know its not perfectly mechanicaly accurate, Gimmie a break all i got is 3ds-max
Another cool design Tytus. Keep up the good work. Maybe some day you can have a robot will all this stuff you’ve designed on it.
With this one, it seems like if you had four of those it would pretty much be your whole robot right there. I guess it’s hard to tell from the pic but this module seems pretty large.
well i draw one and copy it, that will make four add the robot controller, the battery the gearbox, motors, the victors, the Flux Compactor, the Sterling engine, the chassis, the linkages, the belts the “manipulators” ,gullwing doors,x-rays, laser beams, armor, decals, sponsor logos, paint, wash, wax, kitchen sink, toaster, sensor array, and all the other stuff and program it, wheel be done.
I have to get my ideas drawn and get them “Out there” at least I need autocad If we built SwampThing armed with half the stuff i come up with it Would Seriously make heads turn, But My ideas are expensive and complex. I’m afraid we may never have those “Nice Toys” like a Mill or a lathe or Good Stock to work with. or qualify for Atlanta this year, Right now were gearing up for the Robot rodeo. Its an organization challenge right now but I’m sure we can pull it off
Wow, Ive actually been thinking something like that up in my head! Or atleast the drive power coming in through a sprocket on top, and having a pulley of some sorts for steering.
In my design, I am trying to use off the shelf parts, and support it twice on top, but not on the bottom.
The main problem is torque steer, because all the power to the wheels will make it want to steer.
Team 5, the Robocards, did something very similar to this last year.
I understand it’s different, but it’s comparable none the less
See:
http://www.robocards.org/images/2003/robot/rear_suspension2.jpg
Perhaps someone from 5 can explain it all out?
Tytus, I like your designs, they look great on the computer. But as you stated, they may be more fancy than required. If a machinist looked at the design, I am 100 percent sure he would probably want to simplify the little supporting rods with maybe 2 vertical plates, that way you can easily assemble the thing without having to weld everything perfectly and have it all still parallel (after the warping of the aluminum during welding). We did something like this 2 years ago but the modules were powered instead of the bevel gearset. For your next challenge think about making your design easy to service. After studying Wildstang, you can see the importance of ‘Modules’ as your robot gets more complex. Nothing should take longer than 5 - 10 minutes to swap out on a first robot.
Tytus,
That is a very useful implementation of the crab, because it allows for a separate gearbox that can shift and doesn’t have to rotate with the wheel. Matt R. is right about the simplicity and here is a cross section of our 2003 crab design:
2003 Crab module cross-section
It requires no welding and uses a moment carrying bearing to take the entire load. We have used this bearing for 2 years now.
You can actually take your differential transmission and couple it with your crab module and have a pseudo-CVT with crab steering.
Thanks for sparking the discussions with your inventive designs.
-Paul
*Originally posted by Gadget470 *
**Team 5, the Robocards, did something very similar to this last year.I understand it’s different, but it’s comparable none the less
See:
http://www.robocards.org/images/2003/robot/rear_suspension2.jpgPerhaps someone from 5 can explain it all out? **
i see whats going on they have Front and rear “Tetter-totter” suspention and they have 2-wheel fenders, witch is easier to build but with combination to their suspention there having only 2 wheels touching aything while going up the incline of the ramp and its powered by 2 drill motors, I admire the desing, but personaly i wouldnt use it ,i dont know how Team 5 did, im shure it was good with all that manuverabilty, my plan is the 4 wheel independent doubble-wishbone suspention and powered by two(2) CIM-Bosch merge gearboxes, Problem being It would Probaly end up being The Most expensive Robot ever and were not very indowed when it comes to Funds, equiptment, Materials, and organisation
The support above and below is very good. That is one of the major shorcomings of our crab design last year. The grearboxes were too tall, so they could ben too much. That ended up putting more stress than was good on the upper connection of the gearbox. Your design eliminates that tilting ability of the grearbox. If we did crab again it would be vary similar to this. (Right now we will just go back to making a robot that actually drives! 
)
–Damian Manda
i dont think im the first to do the bearing below the axel, i think i saw it somewhere before, or mabie i was looking at one wrong and Got a new idea,
Funny how the mind works sometimes
espicaly my ADHD And Dislexic one