how to stop a twichy front end on carpet
12-05-2005, 10:33 AM
#16
Tech Regular
are you using a front one way? if so switching to a diff will make a ton of difference.
12-05-2005, 10:43 AM
#17
Originally Posted by CIVIC91
You could also try laying the front shocks down.
.This should make the car a little less responsive but still keep good grip through the rest of the corner.
IMHO leave the expo settings alone and learn how to tune the chassis, then you aren't just trying to cover setup errors. A little more difficult maybe but you should end up with a faster more consistant car in the end.
12-05-2005, 10:57 AM
#18
Originally Posted by teamgp
My $0.02.
Using -EXP can definitely help. Just keep in mind that if you've been driving RC vehicles for more than a couple months, you're really masking a setup flaw when doing this though. If time is short, or you simply don't have the opportunity to work on setup, then it is definitely the way to go. But if you have the time and parts/tools needed, figure out the setup changes needed until you can put the radio EXP back to 0.
Using -EXP can definitely help. Just keep in mind that if you've been driving RC vehicles for more than a couple months, you're really masking a setup flaw when doing this though. If time is short, or you simply don't have the opportunity to work on setup, then it is definitely the way to go. But if you have the time and parts/tools needed, figure out the setup changes needed until you can put the radio EXP back to 0.
A cars mechanical setup may be 100% spot on. However do you really think any human has the reflex speed to keep up with a $100.00 digital servo that can transit end to end in less than .13 seconds???
Negative expo and reducing steering speed dampen what would otherwise be over-controlling inputs made by a human driver. Mechanical setup has nothing to do with that.
Where the mechanical setup of the car comes in is when you have your radio setup ok and the car is still not doing what you want it to do. If it is still scrubbing speed, hooking, over or under-steering...then you have a flaw in your mechanical setup.
P.S. - Reduce your steering throw until you can't make it around every turn on the track at race speed...then turn it up about 5% -10%.
It blows me away that we drive our $800.00 cars with $300.00 radios and some folks still have zero clue how to effectively use that Hyper-expensive radio to help tune their car!
Last edited by Soviet; 12-05-2005 at 12:43 PM.
12-05-2005, 12:13 PM
#20
I'll jump on the bandwagon. Negative expo is the ticket. If you are a person who gives a lot of "extra" steering inputs, this will slow the initial servo reaction and make you much smoother.
12-05-2005, 01:02 PM
#21
Originally Posted by Soviet
some folks still have zero clue how to effectively use that expensive-ass radio to help tune their car!
Do the following to set up the steering, trust me it will help!!:
1. Set throw to max. (Some radios have an additional feature to increase the max throw, make sure this is set to max)
2. Adjust end points (or "balance") Left to Right equally and the steering is travelling as far as it can without binding up.
3. Set car on the track, turn the car left slowly in a circle, then right slowly in a circle. Dial back the throw (little wheel near the trigger) until the car can make a full circle in the smallest lane of the track. You may need to re-adjust the balance to make sure the turning radius is equal.
4. With EXPO set at zero (i.e.: wheel 1/4 turn = car 1/4 turn; wheel 1/2 turn = car 1/2 turn; wheel full turn = car full turn), try driving it around the track. You will notice it is very twitchy when turning into the corners (you will most likely run into walls like this).
5. Set EXPO to max (i.e.: wheel 1/4 turn = car 1/16th turn; wheel 1/2 turn = car 1/4 turn; wheel full turn = car full turn), you will notice the car will take a while to turn in, almost like a bad push. It will only make the full turn at the last little bit of the wheel turn.
6. Now that you know what no EXPO and full EXPO will do, keep test driving at different settings (25%, 50%, 75%) till you feel comfortable with it.
7. Along with this, you can try adjusting servo speed. By trying 75% servos speed it will slow the servo down but it will be linear throught the full range. Some radios have dual step servo speed (my KO mars does), so you can have 75% speed at the first 50% of wheel turn and 100% speed at the half of wheel turn. This is like EXPO but has two linear steps instead of an exponential curve (you add EXPO to this and you have a combination of the both).
8. Add or remove throw as needed for tighter or more open tracks.
Good luck!
12-05-2005, 01:26 PM
#22
Couple of beers slow everything down.
12-05-2005, 01:27 PM
#23
Originally Posted by ddesros2
For the longest time I didn't know how all the features on my radio worked. When I started to adjust everything my lap times dropped significantly!!
Do the following to set up the steering, trust me it will help!!:
1. Set throw to max. (Some radios have an additional feature to increase the max throw, make sure this is set to max)
2. Adjust end points (or "balance") Left to Right equally and the steering is travelling as far as it can without binding up.
3. Set car on the track, turn the car left slowly in a circle, then right slowly in a circle. Dial back the throw (little wheel near the trigger) until the car can make a full circle in the smallest lane of the track. You may need to re-adjust the balance to make sure the turning radius is equal.
4. With EXPO set at zero (i.e.: wheel 1/4 turn = car 1/4 turn; wheel 1/2 turn = car 1/2 turn; wheel full turn = car full turn), try driving it around the track. You will notice it is very twitchy when turning into the corners (you will most likely run into walls like this).
5. Set EXPO to max (i.e.: wheel 1/4 turn = car 1/16th turn; wheel 1/2 turn = car 1/4 turn; wheel full turn = car full turn), you will notice the car will take a while to turn in, almost like a bad push. It will only make the full turn at the last little bit of the wheel turn.
6. Now that you know what no EXPO and full EXPO will do, keep test driving at different settings (25%, 50%, 75%) till you feel comfortable with it.
7. Along with this, you can try adjusting servo speed. By trying 75% servos speed it will slow the servo down but it will be linear throught the full range. Some radios have dual step servo speed (my KO mars does), so you can have 75% speed at the first 50% of wheel turn and 100% speed at the half of wheel turn. This is like EXPO but has two linear steps instead of an exponential curve (you add EXPO to this and you have a combination of the both).
8. Add or remove throw as needed for tighter or more open tracks.
Good luck!
Do the following to set up the steering, trust me it will help!!:
1. Set throw to max. (Some radios have an additional feature to increase the max throw, make sure this is set to max)
2. Adjust end points (or "balance") Left to Right equally and the steering is travelling as far as it can without binding up.
3. Set car on the track, turn the car left slowly in a circle, then right slowly in a circle. Dial back the throw (little wheel near the trigger) until the car can make a full circle in the smallest lane of the track. You may need to re-adjust the balance to make sure the turning radius is equal.
4. With EXPO set at zero (i.e.: wheel 1/4 turn = car 1/4 turn; wheel 1/2 turn = car 1/2 turn; wheel full turn = car full turn), try driving it around the track. You will notice it is very twitchy when turning into the corners (you will most likely run into walls like this).
5. Set EXPO to max (i.e.: wheel 1/4 turn = car 1/16th turn; wheel 1/2 turn = car 1/4 turn; wheel full turn = car full turn), you will notice the car will take a while to turn in, almost like a bad push. It will only make the full turn at the last little bit of the wheel turn.
6. Now that you know what no EXPO and full EXPO will do, keep test driving at different settings (25%, 50%, 75%) till you feel comfortable with it.
7. Along with this, you can try adjusting servo speed. By trying 75% servos speed it will slow the servo down but it will be linear throught the full range. Some radios have dual step servo speed (my KO mars does), so you can have 75% speed at the first 50% of wheel turn and 100% speed at the half of wheel turn. This is like EXPO but has two linear steps instead of an exponential curve (you add EXPO to this and you have a combination of the both).
8. Add or remove throw as needed for tighter or more open tracks.
Good luck!
Simply perfect explanation! That is nearly exactly how I go about setting mine. I use a KO Mars as well...
12-05-2005, 01:52 PM
#24
I would be careful about going beyond -20% on the steering expo. It will slow down the initial throw off center but if you go beyond that # as soon as you go half way through the throw it gets more sensitive. If your car is still real twitchy at -15% you might have to work on youre set up a little more.
i would have to say make sure your car set up is in the ball park first before messing with the expo.
i would have to say make sure your car set up is in the ball park first before messing with the expo.
12-05-2005, 03:25 PM
#25
Tech Master
iTrader: (5)
Join Date: Jul 2002
Location: A step closer to where I need to be a step further from where I was
Posts: 1,186
Trader Rating: 5 (100%+)
Reggie
I know a certain 2005 National Champ in 1/12 Mod that uses neg. Expo, sometimes more than -15%. If it works for him it's definitely worth a shot if you are confident in your setup. Brandon can surely get you right.
Rod
I know a certain 2005 National Champ in 1/12 Mod that uses neg. Expo, sometimes more than -15%. If it works for him it's definitely worth a shot if you are confident in your setup. Brandon can surely get you right.
Rod
12-05-2005, 06:55 PM
#26
Originally Posted by Soviet
A cars mechanical setup may be 100% spot on. However do you really think any human has the reflex speed to keep up with a $100.00 digital servo that can transit end to end in less than .13 seconds???
I agree with that idea in principle, yes, but if the car isn't absolutely 100% mechanically correct, then you are masking real handling problems with electronic gadgetry.
I use a 3PK and I absolutely have to slow down the speed of my steering servo, because I can't react nearly as fast as it does (I run mine at 70%), and I have been racing R/C cars for 20-odd years. It is very important that the mechanical setup and grip of the car is stable before fine tuning the radio to suit your driving style. Screwed up, funky front end geometry will cause more problems than a neutral-setup transmitter every day of the week. A mistakenly input degree of toe-out instead of toe-in will NEVER be solved with radio settings, I don't care how expensive of a radio you have.
The setup needs to be at a logical, time-tested neutral (there are plenty of baseline setup sheets out there for every car) setting before adjusting anything in the radio to suit the feel. And using your eye to set up a car doesn't cut it anymore. If you aren't using a set-up table/fixture to align the car correctly, and using a tweak board to get corner weights right, you'll never find the right feel by dulling the radio down.
Mechanical (to find a neutral baseline) first, then electronic (for feel), then aero (for speed and stability).
Just my experiences...
doug
12-05-2005, 09:45 PM
#27
Tech Fanatic
Thread Starter
Originally Posted by Brandon Melton
What's up Reggie, come see me this weekend, we'll get it straightened out for ya.
12-05-2005, 09:46 PM
#28
Tech Fanatic
Thread Starter
Originally Posted by RKeasler
Reggie
I know a certain 2005 National Champ in 1/12 Mod that uses neg. Expo, sometimes more than -15%. If it works for him it's definitely worth a shot if you are confident in your setup. Brandon can surely get you right.
Rod
I know a certain 2005 National Champ in 1/12 Mod that uses neg. Expo, sometimes more than -15%. If it works for him it's definitely worth a shot if you are confident in your setup. Brandon can surely get you right.
Rod
12-06-2005, 06:25 AM
#29
Originally Posted by Soviet
Total BS Guy...
A cars mechanical setup may be 100% spot on. However do you really think any human has the reflex speed to keep up with a $100.00 digital servo that can transit end to end in less than .13 seconds???
A cars mechanical setup may be 100% spot on. However do you really think any human has the reflex speed to keep up with a $100.00 digital servo that can transit end to end in less than .13 seconds???
If you can't figure out the setup in time to race, then by all means use as many band-aids and crutches needed. I did it a lot last year. No one will fault you for limping across the finish line on the podium.
I guarantee that if you gave me your car/transmitter with however much -EXP you use today, that I could dial in the setup where you could put it at 0 and be faster around the track as well.
Doh! I forgot, you still run a dinosaur. I may have to break out my antique tool collection and ask XRAY for an exception with this challenge. I'm not sure I can dial out the chassis design flaws though...
Don't get yer knickers in a twist mate. I'm just havin fun with ya and the AE nation in the last paragraph.
BTW, there is a better way to state that you disagree with someone's opinion than the first derogatory phrase you used above. Tact is in these days.
Last edited by teamgp; 12-06-2005 at 06:38 AM.
12-06-2005, 06:27 AM
#30
Originally Posted by Francis M.
I would be careful about going beyond -20% on the steering expo. It will slow down the initial throw off center but if you go beyond that # as soon as you go half way through the throw it gets more sensitive. If your car is still real twitchy at -15% you might have to work on youre set up a little more.
i would have to say make sure your car set up is in the ball park first before messing with the expo.
i would have to say make sure your car set up is in the ball park first before messing with the expo.