Steering column off angle

[Harry S.]

Re: Steering column off angle

There is a formula for this but I can't find it. Trigonometry.

A bug takes off at an angle of elevation of 15 degrees 23 inches and travels in a straight line for 16 inches. What is the height of the bug above the ground at this instant?

[Chuck G.]

Re: Steering column off angle

This is a horizontal view and it may be the answer, is 15 degrees 23 inches over the span of the width of the steering wheel 3/4 of an inch?

I'm no engineer, nor am I a mathematician, but I think that figure gives us the horizontal elevation angle only. We need a "view from the top" to see the angle from the steering box to the steering wheel...

[Tom E.]

Re: Steering column off angle

Chuck,
I agree and is why I took the angle measurement of the steering shaft. See my post below. I said vertical angle but what I should have said was the vertical height of the horizontal angle. In Trigonometry this would be the hypotenuse of aright triangle.
To

[John P.]

Re: Steering column off angle

Now here is an interesting detail on my vehicle.

When i get on floorboard and trace the column, near the wheel is a bracket with adjustable nuts. This bracket appears to secure the column under the dash and attaches to the frame of the dash. One can see that the opening around the left side nut, and another not seen in this photo, have enlarged holes for adjustment of some kind. (the wires including the purple are directly beneath the column in this pic)

I have at times wondered what it is designed for. Could this be an answer?C15BD16C-33B3-446E-85A1-AEEF56FC12BA_4_5005_c.jpeg

[John P.]

Re: Steering column off angle

I also wonder if any mechanical advantage or disadvantage exists to having the wheel and column offset to the right, even a small amount.

[Richard M.]

Re: Steering column off angle

John, I think the slots are there to compensate for any variation in the column to rag joint and body(cluster) to frame.

Harry, Tom, Chuck.... Regarding the "H18" spec. GO to PDF page 46. On the right side it shows which angle. It isn't the one we're questioning.

Rich

[John P.]

Re: Steering column off angle

Under Steering -General there is reference to a 3 inch axial adjustment. This would suggest that the column can be adjusted to that amount when moving in an axial plane from its attachment, I believe-which would originate at the rag joint or the rag joint attachment to the steering box, or the attachment of the box itself to the frame. Of course the info does not specify if this is indeed the axis to which it refers.

It seems that the H18 angle of 15 degrees or so refers to the elevation of the column above a horizontal plane looking at the car from the side-that is, 15 + degrees above a plane parallel to the ground.

Just my impression .

[Tom E.]

Re: Steering column off angle

John, I think the slots are there to compensate for any variation in the column to rag joint and body(cluster) to frame.

Harry, Tom, Chuck.... Regarding the "H18" spec. GO to PDF page 46. On the right side it shows which angle. It isn't the one we're questioning.

Rich

rich, I agree which was the purpose of the inclinometer photo with the relative 15* pitch. It may have confused some! I went though both the 63 and 67 engineering data and can find no info on the angle we are trying to figure out. Perhaps it was a function of design and not an engineering requirement.
Tom

[Stephen L.]

Re: Steering column off angle

Assuming the face of the instrument cluster is at a right angle to the centerline of the car (front to back) I have a measurement from the perimeter of the steering wheel as follows:
The distance from the steering wheel (left side) is 12.5 inches to the surface of the instrument cluster. The distance from the steering wheel (in the horizontal plane) (right side) is 12 inches to the surface of the instrument cluster. This indicates there is a small angle in the steering wheel/column to the centerline of the car.
Never questioned this in the past.... not noticeable when driving.

[Tom E.]

Re: Steering column off angle

There is a formula for this but I can't find it. Trigonometry.

A bug takes off at an angle of elevation of 15 degrees 23 inches and travels in a straight line for 16 inches. What is the height of the bug above the ground at this instant?

Harry,
The trigonometry function is the Tangent Function wherein Tan=Opposite/Adjacent. For your Bug Dimension A =16”, Angle B = 15*23’, and Dimension (B) is unknown. Dim A x Angle B TAN = Dim B. Or 16 x .272256..... = 4.35 inches above the ground.

354C8782-F21C-4155-A1DC-63763D01CC79.jpeg

Following that same line of logic....

- The steering column length is 39 inches. Add about 5 inches to allow for the distance from the end of the steering shaft to the outer edge of the Steering wheel rim. We will call this Dim A = 44”
- The steering shaft is approximately 1* of angle from a straight line drawn from the rag joint to the firewall. The angle is to the right but that is not important for the math equation. We will call this 1 Degree Angle B.
- We know from several samples the amount the 16 inch steering wheel cants to the right is about 3/4 of an inch but in the math problem we will consider it unknown. We will call this dimension B (unknown)

if we use the Tangent Function we can determine: 44” x 1*TAN = Dimension B. OR 44 x .017455...= .07680. Here we can see the angle has caused the dimension we are measure to be almost exactly 3/4 of an inch.

FWIW I believe that all of the C2 corvettes have this slight steering column angle. I’m guessing the engineers figured it was so minor it wasn’t worth considering. And in light of the fact it has taken this long for everyone to notice.... just my .02.
Tom

[Mark F.]

Re: Steering column off angle

I did my trigonometry a little differently (geez, where did that come from).

I calculated the right side inward "cant" of 1/2" on my car toward the cluster is 1.8 degrees, as follows:

• a 16" diameter steering wheel as one leg of a right triangle;
• 0.5" "cant" dimension as the 2nd leg on the right side;
• a 90 degree angle of that dimension toward the cluster forming a perfect right triangle

Solving for the 2 known side dimensions and the one known angle above produces a cosine of 0.9995 for the included angle...
The inverse cosine of 0.9995 in "degrees" is 1.7899...rounded off to 1.8

All that being said (yes, Rich - isn't this fun ), if you push that right inward "cant" back to zero degrees back toward the driver, the outside radius of the Steering Wheel moves to the left toward the driver's side door. On my car, with the Wheel all the way in (I have tele N36) the rim of the wheel is closing in on the door handle pull pretty closely (i.e., your knuckles may be crashing into the door handle when you turn the wheel either way???).

I don't think there is a sensible answer to any of this - and I don't think it was "by design".
it is what it is - just my 2 cents. thx, Mark...broke thru a few math cobwebs on this one

[Harry S.]

Re: Steering column off angle

Harry,
The trigonometry function is the Tangent Function wherein Tan=Opposite/Adjacent. For your Bug Dimension A =16”, Angle B = 15*23’, and Dimension (B) is unknown. Dim A x Angle B TAN = Dim B. Or 16 x .272256..... = 4.35 inches above the ground.

[ATTACH=CONFIG]101861[/ATTACH]

Following that same line of logic....

- The steering column length is 39 inches. Add about 5 inches to allow for the distance from the end of the steering shaft to the outer edge of the Steering wheel rim. We will call this Dim A = 44”
- The steering shaft is approximately 1* of angle from a straight line drawn from the rag joint to the firewall. The angle is to the right but that is not important for the math equation. We will call this 1 Degree Angle B.
- We know from several samples the amount the 16 inch steering wheel cants to the right is about 3/4 of an inch but in the math problem we will consider it unknown. We will call this dimension B (unknown)

if we use the Tangent Function we can determine: 44” x 1*TAN = Dimension B. OR 44 x .017455...= .07680. Here we can see the angle has caused the dimension we are measure to be almost exactly 3/4 of an inch.

FWIW I believe that all of the C2 corvettes have this slight steering column angle. I’m guessing the engineers figured it was so minor it wasn’t worth considering. And in light of the fact it has taken this long for everyone to notice.... just my .02.
Tom

The answer is, The bug is .07680 inches off the ground.

Note very scientific, the bug took off from the left side of the steering wheel at 15 23. when he got to the right side of the steering wheel ( 16 inches ), he was .07680 inches off the ground, showing the change in angle of the steering wheel. The paper towel has the right side .07680 off the table.

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IMG_1608.JPG

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[Tom E.]

Re: Steering column off angle

The answer is, The bug is .07680 inches off the ground.

Note very scientific, the bug took off from the left side of the steering wheel at 15 23. when he got to the right side of the steering wheel ( 16 inches ), he was .07680 inches off the ground, showing the change in angle of the steering wheel. The paper towel has the right side .07680 off the table.

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[ATTACH=CONFIG]101868[/ATTACH]

[ATTACH=CONFIG]101869[/ATTACH]

[ATTACH=CONFIG]101870[/ATTACH]

Must be that New England Math at work lol!
i laid it out on the work bench... no calculator errors here!
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[Richard M.]

Re: Steering column off angle

Earlier today I sent John Hinckley a question regarding the angle in question. He said there was never any design criteria for steering column angle or wheel being parallel to the cluster. Thankfully we can put this to rest.

Some cars have it and some don't.

Rich

Hi, Rich -

I see this as "much ado about nothing"; there is no particular design criteria to control the plan view steering column angularity or steering wheel parallelism to the instrument panel. You can go bananas trying to ensure the frame is properly formed where the steering gear attaches, the gear is properly machined, the car has the proper 7-layer rag joint, the column hole in the firewall is the right size/shape and in the proper location, the pedal support is properly located and attached, and the column attaching bracket(s) and instrument cluster escutcheon are properly located. Ultimately, it's production tolerances that add up to variation, although this hardly qualifies as "variation" - most units exhibit this condition; to coin a phrase, "it is what it is", and I wouldn't lose any sleep over it.

Best Regards,

John Hinckley

[Tom E.]

Re: Steering column off angle

Rich,
Thanks for running this to the ground. Your contributions to NCRS and the community are immense and greatly appreciated. I know during the restoration of my car I learned a lot from your posts and documentation files.
Best Regards, Tom