Go Back  R/C Tech Forums > General Forums > Electric On-Road
TC Chassis balancing: Hi tech or low tech? >

TC Chassis balancing: Hi tech or low tech?

Like Tree8Likes
  • 1 Post By sosidge
  • 1 Post By cplus
  • 1 Post By Lonestar
  • 1 Post By LzREngineering
  • 1 Post By glennhl
  • 3 Post By Bry195

TC Chassis balancing: Hi tech or low tech?

Reply

Old 07-13-2019, 04:02 AM
  #1  
Tech Elite
Thread Starter
iTrader: (41)
 
Dan the Man's Avatar
 
Join Date: Mar 2003
Location: Perth, W.A
Posts: 2,141
Trader Rating: 41 (100%+)
Default TC Chassis balancing: Hi tech or low tech?

Never balanced a chassis before, so wondering before I drop some $$$.

What's everyone's preference and/or opinion: will balance pins do an accurate job, or is it worth spending the cash on one of the digital balance setups?

Thanks in advance
Dan the Man is offline  
Reply With Quote
Old 07-13-2019, 04:16 AM
  #2  
Tech Master
iTrader: (3)
 
Join Date: May 2010
Location: Chi-Town West Burbs
Posts: 1,649
Trader Rating: 3 (100%+)
Default

Low tech works fine. Nail-in chair feet work as balance pins and are CHEAP.
mooby64 is offline  
Reply With Quote
Old 07-13-2019, 06:52 AM
  #3  
Tech Elite
 
sosidge's Avatar
 
Join Date: Dec 2001
Location: Bristol, UK
Posts: 3,919
Default

For actual balance, pins are simpler and arguably better - the extra information on the scales can easily be misinterpreted, the pins are solely for balance.

I use golf tees if the chassis has holes drilled in the underside. If the towers have holes, you can use strong thread or fishing line.
eR1c likes this.
sosidge is offline  
Reply With Quote
Old 07-13-2019, 07:21 PM
  #4  
Tech Elite
iTrader: (11)
 
Join Date: Jul 2010
Posts: 2,607
Trader Rating: 11 (100%+)
Default

Balancing on pins vs balancing via corner weights can’t really be compared.

You can corner weight car by adjusting spring loads and it still won’t be “balanced” left to right. You need to remove the variable of the tyre and the springs (setup wheels and lock out the dampers) to use scales for balancing.

Right tool for the right job.
Lonestar likes this.
cplus is offline  
Reply With Quote
Old 07-13-2019, 08:22 PM
  #5  
Tech Regular
 
Join Date: Jul 2018
Location: Florida
Posts: 421
Default

springs distribute the weight around the tires based on preload. Pins arent effected by the springs. i use both but after i set weight with pins i never need the pins again. I use the scales to balance traction.
Bry195 is offline  
Reply With Quote
Old 07-15-2019, 01:59 AM
  #6  
Suspended
iTrader: (13)
 
Lonestar's Avatar
 
Join Date: Oct 2001
Location: Switzerland
Posts: 2,547
Trader Rating: 13 (100%+)
Default

the static balance is one thing. Corner weights is something else. And "bad" corner weights can be driven by (1) unbalanced static weight (2) structurally tweaked car (3) wrong spring load.

If the car is battery-side (or motor-side...) heavy, toying around with the spring pre-load will not fix anything. it will however alleviate some of the discrepancies driven by structural tweak so the scales read better, but not fix the car which will still drive like crap.

The correct sequence is
1- install balanced electronics (any pack > 300g will make a modern TC battery-side heavy)
2- (re-)build a tweak-free car... every run, unscrew, flatten, rescrew. Anything but a perfect run will tweak the car a bit, any hit, any track dots, any roll. some cars are more sensitive to this than others, but they all do it to some extent.
3- THEN the corner scales. But if your car is hi-Q and so are the springs used, a simple symmetric preload on the springs mostly does the trick.
Markus likes this.
Lonestar is offline  
Reply With Quote
Old 07-15-2019, 05:26 AM
  #7  
Tech Regular
 
LzREngineering's Avatar
 
Join Date: Jul 2017
Posts: 277
Default

Originally Posted by Lonestar View Post
3- THEN the corner scales. But if your car is hi-Q and so are the springs used, a simple symmetric preload on the springs mostly does the trick.
Unfortunately most springs aren't very well matched (I'm using xray as an example). Measure and match your springs - it helps a lot. I still check the car on corner scales.

Lonestar likes this.
LzREngineering is offline  
Reply With Quote
Old 07-15-2019, 04:15 PM
  #8  
Tech Master
iTrader: (14)
 
Join Date: Sep 2013
Location: Arizona
Posts: 1,185
Trader Rating: 14 (100%+)
Default

By the way, a set of corner scales are all you need to balance a car side to side (weight) and to set up the chassis (spring preload). Even if you have the car screwed up and have most of the weight on 2 opposite corners of the car (i.e. left front and right rear), it will still tell you which side is heavier. So what I do is first set the ride height I want with the spring preloads. Then I adjust the springs so that the difference between the left front and left rear is the same as the difference between the right front and right rear. I will add a little spring preload to the light comers (for example right front and left rear) and then take a little preload out of the heavy corners (left front and right rear in this example). Doing it this way will keep the ride heights pretty close to what you set. This balances the car the best you can without adding weight. If you are still under the weight limit, you can then add weight to the light side.

As an example, without a body, my latest setup had 306.4 right front, 313.4 right rear for a difference of 7 grams. My left front was 293.5 and left rear 299.4 for a difference of 5.9 grams. That's close enough for me. Now if I want to balance it out, the right side is 26.9 grams heavier than the left side. So I need to add 27 grams to the leftt side. Good luck.
LzREngineering likes this.

Last edited by glennhl; 07-15-2019 at 05:09 PM.
glennhl is offline  
Reply With Quote
Old 07-15-2019, 08:13 PM
  #9  
Tech Elite
iTrader: (2)
 
DesertRat's Avatar
 
Join Date: Mar 2011
Location: Sniffin the 'Sauce Fumes
Posts: 3,410
Trader Rating: 2 (100%+)
Default

I like my $4 harbor freight scales. With the pins your chassis can be all in a twist and still balanced.
DesertRat is offline  
Reply With Quote
Old 07-15-2019, 08:20 PM
  #10  
Tech Regular
 
Join Date: Jul 2018
Location: Florida
Posts: 421
Default

The only issue with scales is that if they are not all at the same height your readings are off. I find the highest scale and glue shims under the 3 that are lower to get them all to the same height.

i see that someone has put out a corner scale kit that you can screw the height up and down to make them all the same height.

Last edited by Bry195; 07-16-2019 at 06:37 AM.
Bry195 is offline  
Reply With Quote
Old 07-15-2019, 09:58 PM
  #11  
Tech Champion
iTrader: (1)
 
Join Date: Feb 2011
Posts: 6,980
Trader Rating: 1 (100%+)
Default

Use the same identical scales on a flat, level glass table, and you'll be fine.....
bertrandsv87 is offline  
Reply With Quote

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


Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service