Re: Turning problems, we need suggestions PLZ
 

We already did that and it didn't help. But we were able to get it working by putting the pwms at full power but it makes it to uncontrollable so we have to change out the wheels :( and they want to change to 2 joystick drive. I forgot my digital camera :ahh: so I will get pics tomorrow

Re: Turning problems, we need suggestions PLZ
 

56kers beware!!! MUWAHAHAHA!!!!
We more or less have our problem fixed but any input is good so here are a few pics. I told him to try and get a few pics from all angles...well these are the only 3. but I think it has enough to be able to get a good look at it. It so pretty :p

Re: Turning problems, we need suggestions PLZ
 

Having tread on two diagonally opposed wheels (as I think I see in the pictures) is terrible for turning.
Move both treads to either the front, or the back.

PLEASE read Chris Hibner's whitepaper, it will explain everything.

Re: Turning problems, we need suggestions PLZ
 

Ok, I didn't have much controll over it. It was just kinda done. I'll talk with my team about it and give them that paper.

Re: Turning problems, we need suggestions PLZ
 

allright i know exactly whats wrong becuase our drivetrains are exactly the same. two things. one the diagonal traction not only will cause turning problems but probably also makes it hard to drive straight. the second problem is well... traction on our robot we cant turn unless we gun it and even then it "swings out". despite what other people have said this design sucks for turning. it has nothing to do with an individual teams gearbox or anything its just a fact of physics (the wheels work agianst each other). i sugest using a different drive train next year were looking at a crab drive with omni wheels. good luck. :D

Re: Turning problems, we need suggestions PLZ
 

well we had the traction wells on all four and only had 2 spare wheels and I'll make sure they are changed tomorrow but as for that drive train stuff....I have no clue what ya said but I'll tell the others what you said and see if they can get it ;)

Re: Turning problems, we need suggestions PLZ
 

Yes, put the high traction material wheels across from each other instead of diagonal. And then make sure your program is working correctly because I'm not convinced that it is. There could be something screwy going on in your one joystick code. Try some default code with two joysticks and see if it turns better.

Also, remember to only change one thing at a time so you can see which thing solved the problem.

You could also take a multimeter to the motor side of your victors and see what voltages you are getting at different joystick positions, but be extremely careful not to short anything.

Last, I have one question that I'm not sure has been answered (if it has I apologize). Did the robot ever turn well? Has it always had this problem or has it shown up recently? If recently, what has changed since the last time it worked?

Re: Turning problems, we need suggestions PLZ
 

Just pass along the whitepaper...
It shows the relationships between wheel configuration, CG placement, wheel traction, and turning.

Mechanicalbrain has mentioned a few of these principles in generalities, but hasn't quite hit the root of it yet. The math is very clearly laid out in the whitepaper. (Again, kudos to Chris Hibner).

Re: Turning problems, we need suggestions PLZ
 

Ok, we have nothing to do besides driving tomorow so I'll pass along the paper. But yes the robot did turn the things we changed is the wheels to get more traction, if I had known about it I might have said something they just kinda appeared there. we can get it to turn now. and the controlls are fine now, we had some guy come over and help.

Re: Turning problems, we need suggestions PLZ
 

Now that I look at it, is that a linear actuator driving the arm?

Re: Turning problems, we need suggestions PLZ
 

sun-of-a-gun i think he's right. huh.

Re: Turning problems, we need suggestions PLZ
 

Why yes it is a linear actuator but dont be impressed it might have quite a bit of power but its slow as crap

Re: Turning problems, we need suggestions PLZ
 

Was that actually used in competition? If so, what motor did you use to power it? How did you adapt the kit motor to the actuator? Thanks.

Re: Turning problems, we need suggestions PLZ
 

i don't know if you have done this already but, try to balance out the center of gravity on the arm, if you can afford the weight. By the look of it there is a lot of mass out towards the manipulator. That will decrease the load on the arm, and gravity will work more to your advantage, therefore improving your speed.

Re: Turning problems, we need suggestions PLZ
 

to sandman: Its not been used in competition yet, our old arm broke on us. Um...Yes! to your second question, Brian you should field that one.
to cdr: I'll give that idea to the others and see if they can work with it.