This is a method estimating the front end caster using a digital camera and using Windows Paint to estimate camber angles from the picture.
Normally one would take 2 pictures from each wheel, one full left and a second full right. For this approximation we will assume both wheels are identical and simply use one camber picture from each wheel when the steering wheel is cranked full right.
NOTES ABOUT THE CAMERA SETUP:
1. Camera lens should be in line with the outside side of the wheel.
2. Camera should be mounted on top of a stand (I use a bin that sits upside down on the ground) that sits on the ground such that the camera is parallel to the vehicle. The vehicle needs to be parked on a flat surface BUT being level is not a requirement.
This first picture is taken in line with the outside of the drivers side wheel and measures a camber of NEGATIVE 2.5 Degrees.

This second picture is taken in line with the outside of the passengers wheel and measures a camber of PLUS 3.5 Degrees.

This picture is taken with the camera resting on the drivers side fender and captures the drivers side wheel to be cranked about 30 Degrees to the right.

This picture is taken with the camera resting on the passengers side fender and captures the passengers side wheel to be cranked about 33 Degrees to the right.

The estimated CASTER (K) is found as:
K = ( 180 / pi ) * ( ( C1 - C2 ) / ( T1 - T2 ) )
Where:
C1 is the +CAMBER when the DS wheel is FULL LEFT or the PS wheel is FULL RIGHT.
C2 is the -CAMBER when the DS wheel is FULL RIGHT or the PS wheel is FULL LEFT.
T1 is the +TURN ANGLE when DS wheel is FULL LEFT or the PS wheel is FULL RIGHT.
T2 is the -TURN ANGLE when DS wheel is FULL RIGHT or the PS wheel is FULL LEFT.

In this case:
K = (180 / pi) * ((+3.5 - (-2.5)) / (+33 - (-30)) )
K = 57.32 * (+6.0 / +63) = +5.5 Degrees

 

That's a very complicated way to get to such an approximate result. That method cant possibly be accurate.

Just go pay $60-$80 for a proper alignment check and be done with it.

Also, why such interest in caster? Even if your plan worked, what will you do with the information? Adjust the caster? No.

There's a tool for checking camber and caster on race cars. I believe it's made by Longacre. It works well.

 

Count me in on wondering how useful this process really is? I'm also hard pressed wondering how this approximates caster although I do see how it might reflect camber.

Impressive process even though results are a bit dubious. Thanks for sharing none the less.

 

I'll agree that "Alignment by Photoshop" is a little off the wall.

I would rather have the vehicle at a "PRO" shop, up on a rack, with rim brackets shooting a laser to a computerized machine, and a well trained tech doing the adjustments.

Your cost is about right for a regular sized van, normally about $90 around here.

Plus, as his pictures shows, he's dealing with an RV, I've had a Truck shop do my cut-away cube van, after the Dealer messed up the alignment and the tires leaned out at the top. The truck shop gave me a print out before they started the work, which I took back to the dealer and showed them the results, oh, of course they brushed it off.

Costs - This is for a "over size van" keep in mind......
Dealer - $140 = not done right.
Truck shop - $200 = done correct.

2nd cube van - Truck shop, the first and only time - $160 and on the rack 3 times, alignment done, road test, steering wheel off center, back on the rack, re-adjusted, road test, back on the rack, finial adjustment.
The tech was/is very meticulous on the work he preforms

Just pointing out, that an RV, over sized vehicle, can not be done at just any shop that has/can do alignments.

 

See Equation (8) in this link.
http://www.disco3.co.uk/gallery/albu...ent%5B1%5D.pdf


Here is a link to a report of loose steering and caster in a Jeep Forum, circa 2007
Why your steering wanders or seems loose. - JeepForum.com


And here is a link to my experience with my wandering E450 and +caster, circa 2010
E350/E450 Handling Problems are caused by too little + CASTER


We have had many success stories with adding additional +caster to E350/E450s on RV.NET over the years since my first post in 2010.

 

I also tried this out on our 2007 Honda Civic EX that has a Honda Spec for Caster is +7.0 on each wheel.

It is crucial that the camera sit on a stand which is parallel to the ground surface. The ground surface must be flat BUT not necessarily level.

Steering wheel is full right.

Drivers side camber measures NEGATIVE 1.853


Passengers side camber measures POSITIVE 4.618


Drivers side turn measures 27 Degrees


Passengers side turn measures 28 Degrees


Estimated Caster K:

K = (180 / 3.14) * ((4.618 - (-1.853) / (27 - (-28) )
K = 57.32 * ( +6.471 / +55 ) = +6.7 Degrees
as opposed to specified + 7.0 degrees.

Note: Implied resolution of camber degrees based on pixel counts in the high resolution original JPG files.

 

This is a link to the thread I recently started on RV.NET on this same topic.
It too drew a range of opinions which I would wish to share on this forum.

RV.Net Open Roads Forum: Tech Issues: Estimating Caster Using a Digital Camera

 

Yes, I did that exactly that in 2010, cost me $166.00 and all they did was tweak to toe. I still had the problem, so where does one go from that point ? One ends up adjusting the caster as a DIY project, just as I did. And the rest, they say, is history.

 

This post is to demonstrate that the ground must be an even surface BUT it does not need to be level. Here is the same 2007 Honda Civic parked sideways on a 7 Degree Boat Ramp.
I am using this car for experimenting because it is easy to set up quickly in any parking lot as we are sitting in an RV park for the winter.

The Left Hand wheel Camber turns out to be about NEGATIVE 2.4 Degrees

The Left Hand wheel is cranked about 33 Degrees

The Right Hand wheel Camber turns out to be about POSITIVE 5.7 Degrees

The Right Hand wheel is cranked about 38 Degrees

The estimated caster K:
K = (180 / 3.14) * ((5.7 - (-2.4)) / (33 - (-38)))
K = +6.5 Degrees.
This vehicle has McPherson struts so they are fixed at +7.0 Degrees according to the Honda Specification.

 

Bro: why?!
Why bother?

And even if your formulas are 100% correct, there's no way that your measurements are accurate. Too much room for human error- from the camera positioning to the picture manipulating...

It's like trying to calculate MPG by counting wheels revolutions and using injector pulse width charts...

No offense fella but this entire subject is unproductive.

 

So, here is an example of the target vehicle for this whole exercise.


This is a Ford E350 Class C sitting on a parking lot at a casino in Laughlin, NV. The question is, does this vehicle have a caster of +5.0 or over? The only inconvenience to the owner was to crank the steering wheel full right and allow me to take 4 pictures.


The left hand wheel camber measured about NEGATIVE 1.1 Degrees



The left hand wheel was cranked about 27 Degrees to the Right.



The right hand wheel camber measured about POSITIVE 2.6 Degrees



The right hand wheel was cranked about 32 Degrees to the Right.



The Estimated Caster K"
K = (180/3.14) X (2.6 - (-1.1)) / (32 - (-27))
K = +3.6 Degrees


In my opinion this vehicle caster could be set better FOR HIGHWAY DRIVING.


Just to confirm, it appears from this picture the shims are fixed shims probably installed on the production line.

 

Regardless how others view this or assess its utility OP seems quite intent on forwarding his concept. Once again I'd hate to quash anything truly useful but I agree much of this is at best pure theory and not proven by real world tests that confirm or refute it.

As with most who hold such theories dear we'll be inundated with repeated "proof" that's not born out of comparing calculated angles from photos to results from actual steering component alignment equipment.

The best advice found here so far is finding a knowledgeable shop specializing in providing an alignment more suitable to the best results rather than a strict adherence to specs known not to be optimal.

I'm in agreement while this is marginally interesting its not too likely to be useful outside shop talk about such things.

 

If a given E series is only used for city driving conditions then it is probably waste of your time to read. If you have an E Series RV or Touring Van then I think you will find it to be useful information.


Just to be sure we are all reading the same stuff, my sorry.


https://www.ford-trucks.com/forums/1...-cut-away.html

 

It has just occurred to me, one of the skill sets one must have to appreciate the relative accuracy/repeatability is that of counting pixels in Microsoft Paint. Otherwise, these numbers I profess to create would at best be wildly random.


BINGO....QUOTE: "The best advice found here so far is finding a knowledgeable shop specializing in providing an alignment more suitable to the best results rather than a strict adherence to specs known not to be optimal."

 

[QUOTE=Harvard;15027933]It has just occurred to me, one of the skill sets one must have to appreciate the relative accuracy/repeatability is that of counting pixels in Microsoft Paint. Otherwise, these numbers I profess to create would at best be wildly random.

That's the only draw back to all this? Are we being facetious now? Much like calculating the drag co-efficient of tassels on Aladdin's flying carpet its fraught with interpretation highly subject to incorrect results.




Correct---finally we have consensus!

Having followed OP's similar threads in other forums sadly there aren't too many owners or users who've undergone the +5 degree caster adjustment. While I fully intend to try this myself I'm eager to observe the difference.

Like so many others who assume an E-Series have built-in steering issues currently I have other suspension issues requiring attention and repair before moving into mostly untested theories of this topic.

I won't be using digital photography because ya know my skill set counting pixels is lacking, instead will depend on direct contact measuring devices physically connected to my vehicle.