Wheel Scales?

Reply

Old 07-14-2010, 06:41 AM
  #1  
Tech Apprentice
Thread Starter
iTrader: (8)
 
kjdad's Avatar
 
Join Date: Oct 2009
Location: Illinois
Posts: 81
Trader Rating: 8 (100%+)
Default Wheel Scales?

Anyone here use scales to corner weigh their cars? Kinda like how 1:1 race cars are prepared? I don't know if such a tool is on the RC car market other then the tweaking tools? I am interested to see how my TC5 scales out at each corner especially since I need to add weight for the class I run. I thining if building one with some used pocket scales and some MDF for fun.
kjdad is offline  
Reply With Quote
Old 07-14-2010, 08:35 AM
  #2  
Tech Master
iTrader: (24)
 
pinggoy's Avatar
 
Join Date: Mar 2006
Location: WBP Florida
Posts: 1,263
Trader Rating: 24 (96%+)
Default

you can use pocket scales... also i think muchmore sells one.. but your better of buying a 9-13$ pocket scale at walmart.....
pinggoy is offline  
Reply With Quote
Old 07-14-2010, 09:30 AM
  #3  
Tech Regular
iTrader: (1)
 
RossoTorro's Avatar
 
Join Date: Dec 2008
Location: Euro-Thrash
Posts: 400
Trader Rating: 1 (100%+)
Default

I bought 4 of these.

http://cgi.ebay.com/Mini-Electronic-...item1c11559187

Works great!
RossoTorro is offline  
Reply With Quote
Old 07-14-2010, 09:39 AM
  #4  
Tech Fanatic
iTrader: (1)
 
lochness42's Avatar
 
Join Date: Feb 2008
Location: London, UK
Posts: 824
Trader Rating: 1 (100%+)
Default

Originally Posted by RossoTorro View Post
+1 got same make
lochness42 is offline  
Reply With Quote
Old 07-14-2010, 10:02 AM
  #5  
Tech Apprentice
Thread Starter
iTrader: (8)
 
kjdad's Avatar
 
Join Date: Oct 2009
Location: Illinois
Posts: 81
Trader Rating: 8 (100%+)
Default

Thanks guys...

Here is what I am looking to do.

http://grassrootsmotorsports.com/art...orner-weights/

I am also interested to see what happens when I put a large fan in front of the body. Nothing scientific..just intrested to see if downforce produced.
kjdad is offline  
Reply With Quote
Old 07-14-2010, 11:35 AM
  #6  
Tech Regular
 
Join Date: Jun 2007
Posts: 326
Default

Originally Posted by kjdad View Post
Thanks guys...

Here is what I am looking to do.

http://grassrootsmotorsports.com/art...orner-weights/

I am also interested to see what happens when I put a large fan in front of the body. Nothing scientific..just intrested to see if downforce produced.
You not going to get good results but it will be fun to see.

The reason the results are not going to be accurate is because the air entering the wind tunnel needs to be flowing directly at the object and no turbulance. The fan is going to have air going in many directions. I have thought about this a lot and I think you would need to make a tunnel about 10ft long and maybe use small long cylinders for the air to go through before going over/under the object.

Also I think our bodies create a lot of drag which isn't always measured by scales.

I am still interested in your test. Please post your results.

Steve Dunn
sdunnmcp is offline  
Reply With Quote
Old 07-14-2010, 11:56 AM
  #7  
Tech Apprentice
Thread Starter
iTrader: (8)
 
kjdad's Avatar
 
Join Date: Oct 2009
Location: Illinois
Posts: 81
Trader Rating: 8 (100%+)
Default

Totally understand. I don't even own a air speed guage so my tests would be very subjective. If I do see a result I could build the Mythbusters style of air tunnel using boxes of straws clustered together to refine the air flow...but not sure I want to take it that far




Originally Posted by sdunnmcp View Post
You not going to get good results but it will be fun to see.

The reason the results are not going to be accurate is because the air entering the wind tunnel needs to be flowing directly at the object and no turbulance. The fan is going to have air going in many directions. I have thought about this a lot and I think you would need to make a tunnel about 10ft long and maybe use small long cylinders for the air to go through before going over/under the object.

Also I think our bodies create a lot of drag which isn't always measured by scales.

I am still interested in your test. Please post your results.

Steve Dunn
kjdad is offline  
Reply With Quote
Old 07-14-2010, 01:17 PM
  #8  
Tech Regular
 
Join Date: Jun 2007
Posts: 326
Default

Originally Posted by kjdad View Post
Totally understand. I don't even own a air speed guage so my tests would be very subjective. If I do see a result I could build the Mythbusters style of air tunnel using boxes of straws clustered together to refine the air flow...but not sure I want to take it that far
That would be fun. I have just little experience with the Wind Tunnel at Purdue University. We put a NHRA Pro Stock Motorcycle in the tunnel and we learned a lot. Even then I was thinking about R/C car bodies.

Maybe someday I will try the Mythbusters method....

Steve Dunn
sdunnmcp is offline  
Reply With Quote
Old 07-14-2010, 02:44 PM
  #9  
Tech Elite
iTrader: (10)
 
Brian McGreevy's Avatar
 
Join Date: Jan 2003
Location: Illinois
Posts: 4,081
Trader Rating: 10 (100%+)
Default

Definitely one of the better ways to get a perfectly balanced car. You need to add the corner weights (i.e. LR and RF, RR and LF) and get those close to get the right balance. Assuming your suspension is not bound, your droop is even and you don't have a lot of slop in your car, if you can get your corner weights within 10-15 grams you'll be good. It takes practice, but I often do it by hand when I have less time. It was easier with foam tires as they hardly deformed at all.
Brian McGreevy is offline  
Reply With Quote
Old 07-14-2010, 06:48 PM
  #10  
Tech Regular
iTrader: (1)
 
RossoTorro's Avatar
 
Join Date: Dec 2008
Location: Euro-Thrash
Posts: 400
Trader Rating: 1 (100%+)
Default

Originally Posted by kjdad View Post
Thanks guys...

Here is what I am looking to do.

http://grassrootsmotorsports.com/art...orner-weights/

I am also interested to see what happens when I put a large fan in front of the body. Nothing scientific..just intrested to see if downforce produced.
With the corner weights that is on ebay you can get same result.
Place one under each wheel and you see if you are tweaked or weight ratio front/rear. I use it on all my cars, also i have setup lots of other rc cars at our track.
RossoTorro is offline  
Reply With Quote
Old 07-14-2010, 09:34 PM
  #11  
Tech Adept
iTrader: (30)
 
Join Date: Oct 2007
Location: De Pere, WI
Posts: 182
Trader Rating: 30 (100%+)
Default

This is the 4-scale setup most of the oval guys use.....Includes a straight board that is recessed for the scales, and also a level to use. It is critical to have the scales be on a flat and level surface since it doesn't take much to change corner weights.

http://www.lefthander-rc.com/catalog...oducts_id=1685

They also make a 2-scale setup which is about $50, just takes more effort to use.
Kevin Koback is offline  
Reply With Quote
Old 07-15-2010, 10:41 AM
  #12  
Tech Elite
iTrader: (120)
 
JasonC's Avatar
 
Join Date: Apr 2003
Location: oceanside ca
Posts: 4,099
Trader Rating: 120 (100%+)
Default

This May help you out also

http://www.rctech.net/forum/electric...-tweaking.html
JasonC is offline  
Reply With Quote
Old 07-15-2010, 11:28 AM
  #13  
Tech Fanatic
 
Join Date: Apr 2004
Location: SF Bay Area
Posts: 815
Default

Originally Posted by JasonC View Post
There is also a very cool iPhone application, CrossWeight, that allows you enter each of your corner and the app will calculate the front weight%, rear weight%, left and right weight % as well as your corner %. There are six screens to allow you the ability to keep track of six cars and can also email the data to an email address.

Very cool!
Crashby is offline  
Reply With Quote
Old 07-17-2010, 12:38 AM
  #14  
Tech Regular
 
tudor_47's Avatar
 
Join Date: Jan 2008
Location: Sweden
Posts: 345
Default

Originally Posted by RossoTorro View Post
Very nice find!
I ordered 4 for myself aswell, in hoping they will work OK.
I am thinking it would be possible to make a board with 3 screws in to make it level before taking measurements.
tudor_47 is offline  
Reply With Quote
Old 07-17-2010, 03:16 AM
  #15  
Tech Regular
iTrader: (1)
 
RossoTorro's Avatar
 
Join Date: Dec 2008
Location: Euro-Thrash
Posts: 400
Trader Rating: 1 (100%+)
Default

Originally Posted by tudor_47 View Post
Very nice find!
I ordered 4 for myself aswell, in hoping they will work OK.
I am thinking it would be possible to make a board with 3 screws in to make it level before taking measurements.
I bought 2 cheap plastic levels and took out the bladder in middle that i fastened to a board, one on top and one on the side. That way i can place the board completely level before i put the car on.

RossoTorro is offline  
Reply With Quote

Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Terms of Service