three wheels can work very well because they'll always stay on the ground.
With 4 wheels on a rigid chassis one or two wheels will usually have a lot less load (and hence grip) than the others.
This is why I'm doing a three wheel setup on DDR (which may end up being four wheels, but with suspension in the front to keep the wheels on the ground) _________________ The Engine Whisperer
- fixer of things
Mon Feb 06, 2006 9:37 pm
Valen Experienced Roboteer
Joined: 07 Jul 2004
Posts: 4436
Location: Sydney
depends on how squidgy you are ;->
kinda like air filled tyres. but with out the air _________________ Mechanical engineers build weapons, civil engineers build targets
"Make sure that your wheel spacing front to back is greater than the wheel spacing side to side or your bot will be difficult to drive."
This is for a 4 wheel drive bot. I would have thought equal or wide spacing side to side would be better. There implying a narrow bot would be better to drive.
Taken in context their advice for a heavy weight running go-cart wheels fighting in a very large arena is probably very good advice.
In an Australian feather comp straight-line stability is not as desirable, I would go for short wheelbase, wide track for a ram. Still good for cross-arena box rushes but less load on batteries, speed controllers etc and turn quicker. Watch the Vertical limits Rat fight, it looks like Rat is running away from Vertical limits as he cant turn quick enough to keep him lined up.
The house of Carnage is fairly small, not a lot of room for a slow turning ram.
Driving skill can overcome limitations in basic design, Rob can generally hit things with Reboot and you can see from its spin move that it has no straight-line stability at alland it doesn’t use a gyro.
Tue Feb 07, 2006 11:29 am
assassin
Joined: 27 Jun 2004
Posts: 1105
Location: SunshineCoast
Does six driven wheels affect skid steering? With the four outside wheels equal distance apart, and one more wheel in between each side.
Thanx.
Sun May 28, 2006 9:02 pm
dyrodium Experienced Roboteer
Joined: 24 Aug 2004
Posts: 6476
Location: Sydney
I would be interested in knowing that as well for my lightweight. _________________ ( •_•)
Joined: 16 Jun 2004
Posts: 9481
Location: Where you least expect
the old singularity had 6 wheels. it didnt seem to have a problem turning. the narrow version struggled a little but it was nothing crippling _________________ www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz
Sun May 28, 2006 9:17 pm
Damien (not Damian)
Joined: 15 Sep 2005
Posts: 327
Location: The other side of The Wall...Melbourne
I'm putting one drive wheel at the back and one at the front. The back one is placed at the left side and front at the right. Next to each of them is a un-powered wheel. I'm doing this because the drill motors can't fit next to each other. Will this affect my steering? _________________ It seemed like a good idea on paper...
Fri Sep 01, 2006 4:23 pm
dyrodium Experienced Roboteer
Joined: 24 Aug 2004
Posts: 6476
Location: Sydney
It will yes, although foward and back should be alright, you'll get differences in your turns, but it will still drive. Some full body spinners do this and seem to manage (prancing queen?) _________________ ( •_•)
Joined: 15 Sep 2005
Posts: 327
Location: The other side of The Wall...Melbourne
Will it still make a powerful rammer? _________________ It seemed like a good idea on paper...
Sat Sep 02, 2006 6:49 am
kkeerroo Experienced Roboteer
Joined: 17 Jun 2004
Posts: 1459
Location: Brisbane
It'll drive prefectly fine. We only had problems turning in one direction on Prancing Queen (Right turns I think) but with the other 2 unpowered wheels your robot should be stable enough not to have problems. _________________ Get Some!!!
Secretary of the Queensland Robotics Sports Club inc.
Sat Sep 02, 2006 9:28 am
Damien (not Damian)
Joined: 15 Sep 2005
Posts: 327
Location: The other side of The Wall...Melbourne
I have an idea about a two-wheeler rammer that may or may not work. If you place the two wheels along with their motors and gearboxes at the front, that might concentrate more power at the front, making the rammer more powerful than if you had placed the wheels at the back (this could also apply with 4-wheelers with the powered wheels at the front and un-powered at the back). _________________ It seemed like a good idea on paper...
Mon Sep 04, 2006 7:53 am
Daniel Experienced Roboteer
Joined: 30 Aug 2005
Posts: 2729
Location: Gold Coast
2 wheeled robots with the wheels at the front are a lot harder to control then robots with the wheels at the back. You'll find that your robot will drive straight for a few meters and then spiral out of control. With the wheels at the back the robot will drive sdead traight. It seems that the longer the robot is the more likely this will happen. I have no idea why it happens but I'm moving all my wheels to the back of my robots.
Mon Sep 04, 2006 8:16 am
Totaly_Recycled Experienced Roboteer
Joined: 15 Jun 2004
Posts: 1346
Placing the drive wheels at the front is not a good idea for a ramer as front wheel drive tends to lift the weight of the front of the machine and make them slip rear wheels on the other hand tend to try and lift the whole machine hence putting more weight over them if they have enough traction which in doing so gives them more traction. there was a thread devoted to this discussion some where have a read through past threads and posts . You never see many front wheel drive drag cars
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum