Steering (was Mini-X Body on Rocket Racer)

tiny_dealy · #1 08-14-2002, 03:25 PM

Hey TinyRC

I am having a couple issues with steering on my car. When I turn the wheels to full right travel and then to full left travel, the right wheel in the full left travel moves farther *turns better* than the left wheel in full right travel. *the left and right are from the behind the wheel perspective*

So this means that right truns tend to understeer a little with some push in the corners...and yet left turns with anything other than the lightest most sensitive touch result in an imediate spin out....or with a light touch...much sharper turns. I have been trying to fix it by adjusting the position of the horn on the servo and also by adjusting the length of the servo to stearing linkage arm.

Right now because of that imbalance it's very difficult to drive.....I have tried everything....but I know there is an answer...something I missed. Have you experienced this at all with your car?

BTW running this car in a Tennis court is amazing...even with freaky stearing you have enough room to make a mistake...and with a little throttle modulation she hooks up just fine....it flies!!! but I know I can gear it quite a bit taller and increase top end...it has soo much torque with the 7.2v and HPI 180 motor. Once I get handling worked out...this car will be amazing.

Thanks for the any help you can offer!

tinyrc · #2 08-14-2002, 05:59 PM

If you turn the Tx wheel say 1/8 turn in each direction, is the one side still further, or is it only the total travel difference that differs? If so, have you tried adjusting your dual rate (if you have D/R on your Tx)?

tiny_dealy · #3 08-14-2002, 08:01 PM

Hey.....oh...thanks for posting this seperately! I thought I should have done that after I posted it.....

The original *and rather phalic* Rocket Racer Remote died after the second run. I actually repair electronics *sorta* because in a past life I did that sort of thing. However I can get a slightly nicer 27band am radio for about 10 bucks so there is no point in trying to fix it until I need it for a project....besides the original Rocket shape...well...you know........ My point? I am borrowing a controller that as not equiped with Dual Rate adjustment....so I can't mess with that until friday when my new remote comes in, did I mention how un~phalic like my new one is? Thank goodness....I still get jokes abou the old one

Anyhow I will charge the batt and see what it does as per your instructions. I will post my results.....like I said though...I am sure that even with rates turned down. it will still be twitchier to the left than to the right...."PAIN"

Siress · #4 12-12-2002, 08:52 AM

I think your problem is a poorly adjusted upper stearing arm. Its the piece that comes from the servo with the threaded rod./

irc · #5 12-12-2002, 11:57 AM

This may sound off here but check your rear suspension. If the T bar is tweeked it would cause your car to handel like that. Again how much further does it steer from one side to the other?

Siress · #6 12-12-2002, 08:27 PM

I agree but thats pretty unlikely.
unless its been steeped on

feishiaada · #7 12-23-2002, 10:34 AM

just got my own drr,
and i have the same problem regarding steering,
basically, the wheel connected to the servo
turns at a faster rate than the other wheel.
I've seen this quite often, even in the kawada m-24 mid,
basically with all two arm setups that i've seen...
any input on this?
i fixed my kawada problem by centering the servo and using
a single tie rod setup....connecting both servo arms
to the single servo horn in the center...
any way to do this with the DRR?
thanks!

dtmracer · #8 12-23-2002, 06:52 PM

if it steers one way better than the other then you have the same problem i had. the problem is that the cars front end is tweeked. if you go in slow circles(both left and right) youll notice that one of the front wheels is not moving. this means that one wheel is slightly higher than the other. there are two ways to correct this. 1. untweek it by bending the chassis until both wheels have equal contact to the ground. 2. put in small shims on the bottom of the suspension shat on the other wheel to make it the same height as the other wheel. this small shim will change your suspension stiffness but not noticeable when driving. my drr and my friends drr both had the right front wheel slightly higher than the left. this will correct your uneven steering. hope this helps. by the way, i used 1/10 motor shims.

feishiaada · #9 12-24-2002, 10:02 AM

cool, thanks, i'll give it a try...
last night though, i made my own modified tie rod
and it does correct the problem, but it isn't as stable
on straight line...
basically, i took two standard 2-56 ball ends for
each wheel, and used one of those du-bro connectors
to attach to the shaft connecting the ball ends,
i then used a sub-micro servo so that the servo horn
could be placed at the center of the chassis...
basically, this setup fixes the tweak persay...
but perhaps due to too much free play where the dubro connector
connects to the servo horn, my car isn't as stable as before..
i'll try fixing up this imprecision, as well as trying out
tweaking the front chassis tonight...

other than that, the DRR flies pretty well..hehe...
i'm using a flat pack 7.2v 600mah li-ion 2cell from a sony phone
on this thing and an mrs4 stock motor i had lying around...
it's basically faster than my mini-z with bb motor and stacked
fets now....pretty much as fast or faster than my mrs4!

except for the wheels, the drr seems like a pretty good buy so far...

feishiaada · #10 12-24-2002, 10:05 AM

hmm, as well, was wondering, other than shims or tweaking,
perhaps stiffer springs would work as well?

dtmracer · #11 12-24-2002, 11:04 PM

the tweak is in the chassis. i race 1/10 rc at my local track and when you crash hard you have to check for tweak. 1/10 rc has adjustable shocks that allow you to adjust ride height on each suspension arm. you could cut the suspension spring on the drr but it would need to be super precise to make it right. the dtm has a much more flexible chassis so it corrects itself with the weight of the car.

ag04 · #12 01-14-2003, 08:21 PM

there is a simple solution, the upper left steering arm needs to be lengthened. I took the ball cup off the right side (with the car facing away from you) with a precision screwdriver and lengthend it. but I crashed later on, to find out that the threads got stipped because I lengthened one side too much and the threads didn't grab very well. so I used superglue to make new threads. the car tracks straight now, and it has had a bunch too many collisions with a rustler and nothing's wrong, aside from 4 broken body posts (replaced with stanless screws).

ag04