| Using a laser level to measure caster [message #306934] |
Sun, 11 September 2016 10:11  |
 |
RF_Burns
Messages: 2277
Registered: June 2008
Location: S. Ontario, Canada
Karma:
|
Senior Member |
|
|
In straightening up the shop I came across my DeWalt self leveling laser. It Projects a laser line horizontal or vertical or both together. I got to thinking I could use this to easily check the Murray's caster to some degree of uncertainty.
I posted some photos
http://www.gmcmhphotos.com/photos/g6974-measuring-caster-with-a-laser.html
Setup the laser level for a vertical line just ahead of the front wheel. Now just measure back to the center line of the upper and lower balls joints (I used the center of the bottom of the bolts). You need to hold your measuring tape level to get a proper measurement.
Also note the point on the where you measured the center line from. You will need to measure the vertical distance between these points on the knuckle.
The photos are not the actual measurements. Hard to hold the camera, tape and read. You are only concerned with the difference between the bottom and top measurements, not the absolute measurement.
I read a difference of 2cm on the passenger side with a vertical measurement of 30.5 cm's between the ball joint bolt centers . The driver's side was 1.6cm difference with a 30 cm vertical distance. Not sure why the 0.5 cm difference, but it was a eye-ball measurement.
Using trigonometry I get 3.75 degrees on the passenger side and 3.0 on the drivers side.
Since the laser level gives a plum vertical line, I needed to compensate for the slope of the shop floor. Again using the Dewalt laser now set to a horizontal line. I measured at the rear bogie point from the floor to the laser line. Sorry for the tape being out of focus in the picture. Also measured from the floor to the laser at the front wheel.
I measured 5.9 cm difference on the passenger side which using the wheel base of 160" = 406.4cm and some trig that equals 0.79 degrees
On the drivers side it was 7cm difference which = 0.99 deg.
So my total caster passenger side = 3.75 + 0.79 = 4.59
Drivers side = 3.0 + 0.99 = 3.99
so rounding gives 4.5 and 4. and some uncertainty of maybe +/- 0.25 degrees
So by my calculations I have a fair amount of caster, however it likely should be more balanced.
What say yeah on my methodology?
Bruce Hislop
ON Canada
77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.
1 ton front end
http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
My Staff says I never listen to them, or something like that
|
|
|
|
GMCforum
Search
Help
Register
Login
Home
