Estimating Caster Using a Digital Camera

The primary reasons for measuring caster are; to make the vehicle track straight, to ease turn in or improve straight line stability. In order to make sure your measurements are accurate the amount of wheel motion must be strictly controlled. In theory you must start with a reading at true straight ahead and then your other 2 per wheel measurements must come from the exact same turn in/out point. The industry standard is 20 degrees but if you want to use more there is no reason you can not. You will not however be able to have a discussion with any one else about the effects of your caster settings on handling. Just using your steering stops is not accurate. You could easily be 5 degrees of turn in/out off from one side to the other at the stops. If you are not using turntables the load from the tire into the suspension will also cause inaccuracies in the readings. Now for the big question, Is the surface the vehicle is sitting on perfectly level side to side and front to back? If not none of your measurements are valid.