R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Electric On-Road

Reply
 
Thread Tools Search this Thread
Old 06-24-2014, 12:42 PM   #1951
Tech Elite
 
andrewdoherty's Avatar
 
Join Date: Jan 2005
Location: ★Wylie, TX★
Posts: 3,763
Trader Rating: 47 (100%+)
Default

Quote:
Originally Posted by Quantra View Post
Don't know for sure if this is the reason the FL and RR are 'heavier' but I put it down to the way the shock towers tighten up onto the bulkheads. As I tighten the front shock tower screws the shock tower might rotate slightly clockwise adding preload to the FL and removing it from the FR. When I turn the car around and tighten the rear shock tower it too can rotate clockwise a little and add preload to the RR and remove it from the RL.

Although that rotation might only be small but since it has an effect on both front and rear and it adds and removes preload all at once I think it could be the cause. Countersunk holes in the shock tower could help =]
I like the way you think
__________________
"Whether you think you can, or think you can't, you're right." -Henry Ford
"[Driving] Genius is 1% inspiration, and 99% perspiration" -T.A. Edison
|◤Hobbywing◢|◤SpeedzoneUSA.com◢|◤Pro-One◢|
|◤ReflexRacing.net◢|◤Protoform◢|◤AVID R/C◢|
andrewdoherty is offline   Reply With Quote
Old 06-25-2014, 06:29 AM   #1952
Tech Adept
 
Quantra's Avatar
 
Join Date: Oct 2011
Posts: 122
Default

Quote:
Originally Posted by metalnut View Post
Yeah, so, the whole corner scale process is still a bit of a mystery to me. I've heard a lot of different opinions on how it should be done, and I'm not sure any one person is right. Do you measure the corner weight with shocks on the car, or do you somehow lock the arms in place?
I think if you lock the shocks out then you are measuring static weight distribution. With the shocks on you are measuring the pressure each wheel is putting on the track aka corner weights.

The method I use is as follows:

Balance car left to right, I use ball bearings instead of Hudy spikes.
Balance anti roll bars.
Set ride height, droop, toe, steering symmetry, camber. I set ride height with same number of turns on each shock.
Fit setup wheels and do corner weights by adding/removing preload from the light/heavy corners.

There are a few different ideas on how this should be done and how it can be done but the important thing is the result. So long as toe and steering symmetry is set accurately the car can be taken off the scales and put on the track and it will go straight as an arrow and handle the same left and right. This gives awesome confidence in the car.

It is also something that can take a while to get the scales setup sweetly and make the process work. I think if your car is well balanced, the chassis is free from tweak (by doing something like tightening screws evenly in kit order), you set the ride height with even turns on the shocks and the kit is high quality it will get you close enough without having to worry about corner weights. Corner weights are then the icing on the cake.
__________________
Vince Coleman
Quantra is offline   Reply With Quote
Old 06-25-2014, 07:45 AM   #1953
Tech Fanatic
 
daleburr's Avatar
 
Join Date: May 2010
Location: Oxfordshire, UK
Posts: 775
Default

Quote:
Originally Posted by Quantra View Post
The method I use is as follows:

Balance car left to right, I use ball bearings instead of Hudy spikes.
Balance anti roll bars.
Set ride height, droop, toe, steering symmetry, camber. I set ride height with same number of turns on each shock.
Fit setup wheels and do corner weights by adding/removing preload from the light/heavy corners.
I do pretty much the same (except I do use the Hudy spikes, which does take a bit of tipping the chassis left and right to make sure it really is balanced).

And I don't use setup wheels as I like to corner-weight the car at the track regularly to detect any tweak picked up during runs, and its often too rushed at smaller meets to be taking the wheels on and off.
__________________
Team Xray
RC-Timing Software - http://www.rc-timing.com
Mercedes AMG F1 - http://www.mercedes-amg-f1.com/
daleburr is offline   Reply With Quote
Old 06-25-2014, 08:33 AM   #1954
Tech Adept
 
Quantra's Avatar
 
Join Date: Oct 2011
Posts: 122
Default

Quote:
Originally Posted by daleburr View Post
I do pretty much the same (except I do use the Hudy spikes, which does take a bit of tipping the chassis left and right to make sure it really is balanced).

And I don't use setup wheels as I like to corner-weight the car at the track regularly to detect any tweak picked up during runs, and its often too rushed at smaller meets to be taking the wheels on and off.
I've managed to corner weight my car after every run only at one meeting but it was a real struggle to get any settings changed and get a decent tyre prep in so I completely understand not using the set up wheels in that case. I just find it makes the measurements more repeatable. With wheels and tyres I can rotate a wheel 1/4 turn and the measurements change.

I think it's important to mention that corner weighting a car isn't a 100% precision exercise. There is always a certain amount of error and we have to decide how much error we can eliminate and how much we can accept but always keep that error in mind when taking readings.
__________________
Vince Coleman
Quantra is offline   Reply With Quote
Old 06-25-2014, 09:18 AM   #1955
Tech Elite
 
metalnut's Avatar
R/C Tech Elite Subscriber
 
Join Date: Feb 2013
Location: Seattle
Posts: 2,726
Trader Rating: 36 (100%+)
Default

So I think we're saying the same thing, but also talking about two different things...

The process you guys are describing, ending with setup wheels, is what I do as well. But instead of using scales in that final step, I pick the car up by the middle of the chassis in that final step, and I ensure that both wheels pick up off of the setup board at the same time.

When I think of using scales, I think purely of weight distribution. To me, that would mean locking the arms (so, something like replacing the shocks with equal length turnbuckles), and setting the car down on 4 scales. I'd then distribute the extra lead weights I need among the chassis to try and get side-to-side weight distribution as close as possible.

I think the scale method would then result in much less preload having to be used to detweak the car. At least in theory.
__________________
Team Nervous | Team Scruffy | Team Orange

"If you ain't first, you're last!"
- Ricky Bobby
metalnut is offline   Reply With Quote
Old 06-25-2014, 12:55 PM   #1956
Tech Adept
 
Quantra's Avatar
 
Join Date: Oct 2011
Posts: 122
Default

Not flaming you and I think whatever method works for you is the best method for you which is not the same for everyone. However that method doesn't work for me for a few reasons. Droop screws can affect each wheel lifting at the same time as the other or not, so I better be super accurate with setting them. When I lift the front of the car is it the front preload affecting the wheels lifting together or the rear? I think it is rear. And I can only sort one end of the car at once whilst I believe the cross weights are what is important so I want to be adding/removing preload from opposite corners at the same time. Like I said though it's about what works for you and just because I can't get my head around your method it doesn't make it wrong by any means.

I think you are right about having a good left to right weight distribution reducing the amount of detweaking required. In fact I think that if you cover everything like equal shock length, everything moving freely, balanced anti roll bars etc you can minimise the detweaking to the point where it becomes non critical and just a nice bonus for super sweet feeling in the car. Something I do find really makes a difference to the amount of detweaking required are the springs being used. For example I find my T-Shox springs always require less detweaking than my Xray springs. So even building the car perfectly you can't avoid a bit of suspension tweak.

And I think to answer your original question about uneven ride height left and right I would say don't worry so long as it isn't huge and so long as the car goes straight and handles well as this is what is important. If it is huge it is likely something bent, binding or unequal settings (such as shock angle) left and right. Some racers I know don't check the ride height on each corner rather they check it in the middle of the chassis front and rear only. I guess it's part of what fascinates me with setup, so many different methods and theories that give positive results. Sad life perhaps :P
__________________
Vince Coleman
Quantra is offline   Reply With Quote
Old 06-25-2014, 01:57 PM   #1957
Tech Elite
 
metalnut's Avatar
R/C Tech Elite Subscriber
 
Join Date: Feb 2013
Location: Seattle
Posts: 2,726
Trader Rating: 36 (100%+)
Default

I agree with everything you've said, Quantra. Everyone does it a certain way, the only thing that matters in the end is lap times

Just to clarify, when I pick the front of the car up by the chassis (in the middle), I look for the front wheels to lift up at the same time, but I'm adjusting the rear springs to ensure they do. So I do one end of the car at a given time. When I lift the rear, I look for the rear wheels to lift up at the same time and adjust the front springs accordingly. But you're right, this assumes you've gotten the droop screws exactly even. It's pretty close with droop blocks and a droop gauge, but in the end we're talking about plastic toy cars
__________________
Team Nervous | Team Scruffy | Team Orange

"If you ain't first, you're last!"
- Ricky Bobby
metalnut is offline   Reply With Quote
Old 07-03-2014, 04:49 AM   #1958
Tech Fanatic
 
daleburr's Avatar
 
Join Date: May 2010
Location: Oxfordshire, UK
Posts: 775
Default

Looks like roche were listening to our discussion earlier this year about finer toe and width adjustment

http://www.redrc.net/2014/07/roche-t...ts/#more-83298

Not something I usually bother changing (3deg rear toe and 0.5 front arm sweep seems to work everywhere I race), but I'm sure others will find them useful.

Last edited by daleburr; 07-03-2014 at 03:12 PM.
daleburr is offline   Reply With Quote
Old 07-04-2014, 09:04 AM   #1959
Tech Master
 
mac853's Avatar
 
Join Date: Feb 2007
Location: Dirty place
Posts: 1,725
Default

Could somebody tell me is possible to fit these spur gears in T4, please:

http://www.rcmart.com/kawada-sm6482-...r-p-37139.html
http://www.rcmart.com/kawada-sr6486-...r-p-33632.html
mac853 is online now   Reply With Quote
Old 07-04-2014, 10:56 AM   #1960
Tech Master
 
ngo8's Avatar
 
Join Date: Apr 2003
Location: Winnipeg Manitoba Canada
Posts: 1,263
Send a message via ICQ to ngo8
Default

Quote:
Originally Posted by mac853 View Post
Could somebody tell me is possible to fit these spur gears in T4, please:

http://www.rcmart.com/kawada-sm6482-...r-p-37139.html
http://www.rcmart.com/kawada-sr6486-...r-p-33632.html
http://www.rcmart.com/pinion-spur-mo...id=211&sort=1a .....these will work for sure the other ones you posted might not .
__________________
Xray|Kyosho|Exotek|Hobbywing|Sanwa|Trinity|Xpert|KoPropo
ngo8 is offline   Reply With Quote
Old 07-04-2014, 12:21 PM   #1961
Tech Elite
 
niznai's Avatar
 
Join Date: Feb 2009
Location: All over the place
Posts: 2,735
Default

Kawada spurs are a bit thicker than Xray. Not sure the holes match either, but I would not be surprised if they did.
__________________
Team Greasy Weasel

The best upgrade to any car is some driver skill.
niznai is offline   Reply With Quote
Old 07-04-2014, 02:22 PM   #1962
Tech Elite
 
metalnut's Avatar
R/C Tech Elite Subscriber
 
Join Date: Feb 2013
Location: Seattle
Posts: 2,726
Trader Rating: 36 (100%+)
Default

What's wrong with Xray spurs? I find them to be perfectly round and very well made, unlike some other brands I tried.
__________________
Team Nervous | Team Scruffy | Team Orange

"If you ain't first, you're last!"
- Ricky Bobby
metalnut is offline   Reply With Quote
Old 07-04-2014, 08:12 PM   #1963
Tech Elite
 
Join Date: Nov 2009
Location: Woodinville, WA
Posts: 2,512
Trader Rating: 8 (100%+)
Default

Quote:
Originally Posted by metalnut View Post
What's wrong with Xray spurs? I find them to be perfectly round and very well made, unlike some other brands I tried.
Personally, I'm not a fan of the offset.

-Mike
grippgoat is offline   Reply With Quote
Old 07-04-2014, 08:37 PM   #1964
Tech Master
 
locked's Avatar
 
Join Date: Mar 2010
Location: Toronto
Posts: 1,758
Trader Rating: 1 (100%+)
Default

Quote:
Originally Posted by grippgoat View Post
Personally, I'm not a fan of the offset.

-Mike
I agree. For stock classes I've been using CoreRC spurs for a while now. I really like them. Those Leespeed gears looks really good too. Might try them out next. I'm very curious to hear the sound(or lack thereof) of 84P gears.

I use the kit xray 84Tooth 48P spurs for mod. Funny how those aren't offset, but all of the smaller 64P xray spurs I've seen are offset.
__________________
Dave Locke
Team PerformanceHobbies.ca | ORCA RC | Bodies by Brandon | Team Meeting
XRAY T4'15 x2 | XRAY XB4 | XRAY XB8E | XRAY XB8
locked is offline   Reply With Quote
Old 07-04-2014, 08:58 PM   #1965
Tech Elite
 
metalnut's Avatar
R/C Tech Elite Subscriber
 
Join Date: Feb 2013
Location: Seattle
Posts: 2,726
Trader Rating: 36 (100%+)
Default

Quote:
Originally Posted by grippgoat View Post
Personally, I'm not a fan of the offset.

-Mike
Although I wish the gears were more centered, I haven't run into trouble do to the offset (yet). I've tried Serpent spurs as you recommended, but two different ones were both not truly round. One of the two actually made me nervous enough to switch it out, as it went from almost too tight to almost too loose when spun 180*. The Xray spurs are perfectly circular.

Though, I suppose it could be a mounting error on my part
__________________
Team Nervous | Team Scruffy | Team Orange

"If you ain't first, you're last!"
- Ricky Bobby
metalnut is offline   Reply With Quote
Reply



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



All times are GMT -7. It is currently 04:53 PM.


Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net

SEO by vBSEO 3.5.0