CASTER bubble gauge

[foreverfaster]

working on a mini wedge. Spindles have no makings. heim on top and bottom, upper is slotted lower is not. my bubble gauge is only good to +/- 6* screw on adapter. how can i accurately measure caster?
one of my karts has an L block and its already listed at 12* so that would have a base line. How would you get a true reading without knowing what the initial settings are?

Tonight we were going to set the air pressures and other settings, place the kart and driver on the floor and try and get a reading.. any suggestions would be greatly appreciated.

 

[95 shaw]

Set an angle finder against the L block with the kart on ground, driver in seat, will give a close approximation, depending on chassis design.

You are trying to use a 20 degree sweep type gauge?

 

[foreverfaster]

Set an angle finder against the L block with the kart on ground, driver in seat, will give a close approximation, depending on chassis design.

You are trying to use a 20 degree sweep type gauge?

yes, 20* sweep gauge. but the mini wedge has no L block. only a plate welded to the frame with a hole in the bottom for the base heim and a slot at the top. a Square would at least give me a 90* to the frame base ... maybe.

is there a way to determine the preset caster in a spindle?

 

[95 shaw]

yes, 20* sweep gauge. but the mini wedge has no L block. only a plate welded to the frame with a hole in the bottom for the base heim and a slot at the top. a Square would at least give me a 90* to the frame base ... maybe.

Setting the angle finder against spindle barrel on front side will net same thing.

If you need to, put a parallel piece between barrel and angle finder.

 

[95 shaw]

I have set my digital angle finder on my sweep gauge, turned the first 20 degrees back, level sweep gauge, zeroed the digital gauge, the swept to 20 degrees forward, level sweep gauge, and read angle finder for your caster.

Used this on a late model and sportmod. The direct method is not practical on these cars.
The direct method as suggested is quicker and less chance for errors.

 

[foreverfaster]

clearly the kart now (after adjustments- not on scales yet) has caster in the LF, as when i turn to the left, from straight, it raises the kart about 1/2 inch. measured at the body. you can see the wheel edge move into the floor. the question i have is, my bubble reads positive caster (5-1/2*) on the LF wheel. the RF is at about 1.5* neg caster..
am i reading this wrong, is it in my head wrong? i was confident that both wheels should read to the negative side or the caster gauge.??
is this an indicator that something is bent?

 

[95 shaw]

Are you still using the sweep gauge?

https://static.speedwaymotors.com/pdf/47578260.pdf
Make sure you are turning the wheel to the rear first, then to the front to get your reading.

Set a square on the floor in front of the wheel and measure to the kingpin at the top and bottom. If the top is tipped toward the rear, you have positive caster.

 

[foreverfaster]

Are you still using the sweep gauge?

https://static.speedwaymotors.com/pdf/47578260.pdf
Make sure you are turning the wheel to the rear first, then to the front to get your reading.

Set a square on the floor in front of the wheel and measure to the kingpin at the top and bottom. If the top is tipped toward the rear, you have negative caster.

yes and i have the same sheet. followed it 3 times.. will check it with a square, but i have the top set back a ton... to the point i'm confident i have excessive negative caster.. that's why i'm question myself.. guess it's time to roll it down the drive way and see if it turns itself left...

 

[95 shaw]

If you need to check the accuracy of the bubble level, you can set a simple angle finder on top of the sweep gauge.

Instead of zeroing, you can read gauge directly at back sweep, and do the math after you get turned forward.

This is the reason I recommended just using the angle finder against the spindle barrel. Less chance for error.

 

[95 shaw]

yes and i have the same sheet. followed it 3 times.. will check it with a square, but i have the top set back a ton... to the point i'm confident i have excessive negative caster.. that's why i'm question myself.. guess it's time to roll it down the drive way and see if it turns itself left...

I think I have told you wrong. Positive caster is the top rolled back. So gauge is reading correctly at 5.5 degrees at the left front.

At a glance, you should be able to see if left is rolled back further than right.

As you can see, it is easy to get positive/ negative turned around in your head.
Sorry for creating confusion.