Making your robot drive easier

[Andrew Schuetze]

SNIP

to make your bot turn easier you need to 6 wheel drive and lower the middle set of wheels about 5 thou lower then the other ones and there you have a killer drive system.

I would really like to hear more about this idea. Anybody make a six wheeled robot with all wheel drive??? I saw team 418 at the Lone Star Regional but didn't get an up close look at their drive. I was more impressed with their ball catcher and laminated wood biggens ball arms

post some pics or PM me or send a link to your site with photos

Thanks,

next year.

APS

aschuetze@sbcglobal.net

[Zorkinian]

Team 233 has a 6-wheel all drive system. I'm assuming, when you say 6-wheel all drive, you simply mean all wheels are drive wheels.

Anyway, each side is linked to a joystick for tank driving. The middle wheels are lowered just a bit to give us the ability to turn well, and the friction of six wheels sitting on the ground makes us very hard to push sideways. I don't think our team will ever change from this 6-wheel setup (unless we get a radically different game from FIRST).

[abeD]

Originally Posted by Andrew Schuetze

SNIP


I would really like to hear more about this idea. Anybody make a six wheeled robot with all wheel drive??? I saw team 418 at the Lone Star Regional but didn't get an up close look at their drive. I was more impressed with their ball catcher and laminated wood biggens ball arms

post some pics or PM me or send a link to your site with photos

Thanks,

next year.

APS

aschuetze@sbcglobal.net

Here's a link to the 47 robot who uses a sweet 6 wheel drive with chain drive on each side team 47's bot

and here is the 254/60 "bionic poof" with their 6 wheel drive with the middle ones lowered a little bit

i think, correct me if i am wrong, that 25 was one of the teams that most successfully implemented this last year and many teams have used similar ideas.

[JakeGallagher]

We had a 6-wheeled robot this year...I don't know whether it was six-wheel drive though. It took us a few days to get the middle-axle lowering set the right way, but it helped a LOT. Oh I should tell you that we used some spiffy donated tracks, and it made us look like an R/C tank out there.

Robo pics and videos are here: http://www.sau53.org/net9/First/media.htm
You may also see the team at PARC in May. I wish I could go, but I'm going to Washington D.C. that weekend :-C

[Solace]

i posted a pic of our 6 wheel drive train. theres some stuff in the way, but you can still see most of it.

http://www.chiefdelphi.com/forums/pi...gle&picid=7644

[Ryan F.]

Watch your speed. I saw some teams build robots that were incredibly fast, but I can just imagine the nightmare those drivers go through whenever they try to do something rather than getting from point A to B.

[KenWittlief]

feedback - PID control loop on the steering

using the default code to let the position of the joysticks control how much voltage (pwm) is thrown at the drive motors is as crude a control method as you can get (well, there is one thats worse, only having a GO/STOP switch :^)

no matter what your drivetrain is if you put yaw rate and/or linear speed sensors on the bot, and use feedback, you can remove all the nonlinearitiy, inertia, friction.... from the control system and MAKE the bot do exactly what the driver is commanding at any given instant.

another idea is to add a 'jog' function to your control system - I posted stuff about this before - let me search and see if I can find it...

yep,heres the thread - BTW it contains several other simple ideas on how to make your bot better:

http://www.chiefdelphi.com/forums/sh...&highlight=jog

[Pat Roche]

Originally Posted by JakeGallagher

We had a 6-wheeled robot this year...I don't know whether it was six-wheel drive though. It took us a few days to get the middle-axle lowering set the right way, but it helped a LOT. Oh I should tell you that we used some spiffy donated tracks, and it made us look like an R/C tank out there.

Robo pics and videos are here: http://www.sau53.org/net9/First/media.htm
You may also see the team at PARC in May. I wish I could go, but I'm going to Washington D.C. that weekend :-C

Let me elaborate a little. We used the brecoflex tracks this season. They have and awesome amount of friction (cof ?). The problem we had was we could turn because they spread out on the floor 26" and was only 21" wide. To solve the we put a larger we wheel in the center reducing the amount of track on the ground by about 45% in either direction. This gave us just the right amount of track on the ground to turn and allowed us to move alittle faster.

If you have any questions about it PM me or IM me.

-Pat

[Greg Perkins]

if you are really looking for a good team's drive that uses 6 wheels, check out team 42. for the past 4 years they have gone with the same drive, and its really worked out well for them.

[Tyler Olds]

Best way to drive well.......... have a great driver! A great driver can overcome and drive system.

[Bob]

You could aso check out team 25. They have had a great 6 wheel drive system for the last two years.

[RogerR]

Originally Posted by Andrew Schuetze

Anybody make a six wheeled robot with all wheel drive???

we did six wheel direct drive, with lowered center wheel.

here it is without any end-efffects:

http://www.chiefdelphi.com/forums/pictures.php?s=&action=single&picid=6516&direction =DESC&sort=date&perrow=4&trows=3&quiet=Verbose

[Greg Perkins]

Roger, where those red plates powdercoated? or just painted? where did you get those wheels btw?

[RogerR]

Originally Posted by Greg Perkins

Roger, where those red plates powdercoated? or just painted? where did you get those wheels btw?

plates are powdercoated, and the wheels are 2" x 8.5" skyway bead-lok modified using a dremel and a belt sander.

[sanddrag]

Well, while we're on the subject of Home Depot cart type drive systems (you know, 6 wheels with center ones lower), 980 and 599 had them too.