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-   -   pic: 1710's Recycle Rush Chassis (http://www.chiefdelphi.com/forums/showthread.php?t=132604)

Chief Hedgehog 11-01-2015 01:33

Re: pic: 1710's Recycle Rush Chassis
 
Your first problem is Apple. If you couldn't reconfig the pic, then the second problem is more suspect.

Your second problem is the casters. But since you couldn't realize the problem with the use of Apple (really? posted upside down?) then you do have problems.

But wait - maybe the misuse of the apple machine and your problems posting a right-side-up machine may be a hint!

Auggghhh! A red-herring! Your are planning to use your posted frames as intake mechs and use the casters as feeders.

Really - I give up. What in the heck is going on?

Good Luck and I wish you the best!

Edit - yes, there is a lot of sarcasm in this post.

Jpatterson1710 11-01-2015 01:34

Quote:

Originally Posted by AdamHeard (Post 1426007)
Please elaborate.


Arcade style drive on the controller.
Turtle mode for precise driving.
Encoders on either side to match RPMs when needed.

Jpatterson1710 11-01-2015 01:38

Quote:

Originally Posted by Chief Hedgehog (Post 1426080)
What in the heck is going on?


As far as the iPhone issue, if I flipped it it would post upside down, and if I didn't, it would post upside down. I gave up.
As far as the robot, check back on the Saturday before bag day.

CalTran 11-01-2015 01:39

Re: pic: 1710's Recycle Rush Chassis
 
Quote:

Originally Posted by Jpatterson1710 (Post 1426081)
Arcade style drive on the controller.
Turtle mode for precise driving.
Encoders on either side to match RPMs when needed.

Perhaps I'm missing something, but how does that prevent the castor from free spinning and scrubbing while turning or traversing the scoring platform?

Nuttyman54 11-01-2015 01:43

Re: pic: 1710's Recycle Rush Chassis
 
Interesting to note that if I open just the image itself in Chrome, it flips it right side up for me.

I also second those saying casters will be difficult to control. They like to do funny things when changing direction, and will provide inconsistent turning resistance. At the very least, make them ball casters so they ride smoother. Omnis will drive nicer still.

Jpatterson1710 11-01-2015 01:46

Quote:

Originally Posted by CalTran (Post 1426085)
Perhaps I'm missing something, but how does that prevent the castor from free spinning and scrubbing while turning or traversing the scoring platform?


If our traction wheels are spinning at our desired RPM, it doesn't matter what the casters do as long as they're supporting the front of the bot. They're simply used as a low friction support to the front of the bot.

JorgeReyes 11-01-2015 02:09

Re: pic: 1710's Recycle Rush Chassis
 
Can this go over the scoring platform? And what size is the rear wheel?

Jpatterson1710 11-01-2015 02:14

Re: pic: 1710's Recycle Rush Chassis
 
Quote:

Originally Posted by JorgeReyes (Post 1426095)
Can this go over the scoring platform? And what size is the rear wheel?

Yes it drives over the platform. Traction wheels are 6in.

Jpatterson1710 11-01-2015 02:18

Re: pic: 1710's Recycle Rush Chassis
 
Quote:

Originally Posted by ThunderousPrime (Post 1426006)
Your code affecting the driven wheels right? I don't see anything hooked up to the castors in that picture.

Yes, code only controls traction wheels. The way we drive the traction wheels solves any potential issues caster wheels could introduce.

Amar Shah 11-01-2015 02:23

Re: pic: 1710's Recycle Rush Chassis
 
Quote:

Originally Posted by Jpatterson1710 (Post 1426087)
If our traction wheels are spinning at our desired RPM, it doesn't matter what the casters do as long as they're supporting the front of the bot. They're simply used as a low friction support to the front of the bot.

Try pushing a wheeled swivel chair in an arbitrary direction. You should notice a bit of resistance and a pull sideways before the wheels all align in the correct direction.

Woolly 11-01-2015 03:58

Re: pic: 1710's Recycle Rush Chassis
 
Quote:

Originally Posted by Jpatterson1710 (Post 1426087)
If our traction wheels are spinning at our desired RPM, it doesn't matter what the casters do as long as they're supporting the front of the bot. They're simply used as a low friction support to the front of the bot.

While it's great to think outside the box, it might be an idea to replace the casters with omni wheels for reliability sake. In the event of a code, electrical, or general sensor issue, it would be trivial to have a way of toggling back to a simpler teleop drive code that doesn't use the encoders. That way if something of that nature goes wrong, the robot doesn't become completely un-drivable, nor would it make the robot control like a wet mop on a 54 foot pole.

Kevin Kolodziej 11-01-2015 10:34

Re: pic: 1710's Recycle Rush Chassis
 
OP, if you have tested this drive (or will be) and find that it does what you want it to do with the casters, then more power to you! Casters ARE NOT inherently a bad thing. Be aware of what the casters can do while going over the scoring bump, especially if you're turning into the bump rather than going straight at it from any distance away (this would give the casters time to straighten and align with your direction of travel). There is good advice in this thread, but don't be scared to try things!!

I drove a robot (casters in the back) in 2001 and never had any alignment or drive issues caused by the casters. We did, however, have a second set of drop-down traction wheels to aid in going over the teeter-totter however, but those were engaged for maybe 10 seconds of any given match.

IndySam 11-01-2015 11:13

Re: pic: 1710's Recycle Rush Chassis
 
Quote:

Originally Posted by Gregor (Post 1426064)
While I think that's a good idea for most games, and I would almost never choose castors myself for a drivetrain, I don't think that's a fair bias to have this year.

This year needs to be approached differently in every aspect of it, including alliance selection. Don't let years of bias creep into this year, when some things actually don't matter.

If 1710 scores more points that x 6 wheel tank, or y 4 wheel mecanum (and fills the void that my alliance needs), I'll pick them.

I said "almost"

Madison 11-01-2015 11:38

Re: pic: 1710's Recycle Rush Chassis
 
There is a lot here that can be improved. I'd encourage you to heed some of the advice you're getting in this thread.

Casters make driving unpredictable. You can mitigate the effect of that unpredictability better over long distances than over short ones using feedback.

The casters may not be a problem if they're never touching the ground, though. Your weight distribution is, so far, bonkers. You want your points of contact with the floor to be as far from your center of mass as possible, generally. Putting your gearboxes and CIM motors outside your points of contact is negatively impacting your center of mass in a big way. If you continue to add structure between or over those gearboxes, it'll only get worse.

It's not too late to save yourselves a lot of headaches later.

weaversam8 11-01-2015 11:38

Re: pic: 1710's Recycle Rush Chassis
 
Wouldn't having the battery off to one side like that affect driving? We moved our battery slightly to the side and our chassis turns due to the extra weight.

P.S: The flipped image is due to iPhone EXIF data. Remove the EXIF data, or modify it, and it will not be flipped.


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