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Old 09-30-2006, 02:47 PM   #195
John Stranahan
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Join Date: Aug 2002
Location: Houston, Texas
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No company to take video with so maybe next Saturday.

First run went 15 minutes. Car handled well.

Then I changed Reactive caster blocks to 0 degree. Kept the 1 degree of Caster, added slight negative camber. Results: the car had too much steering late in the corner. This caused many spins and an inability to give good power on corner exit. It became unstable on the bumpy straight (from camber). Went back to my posted setup and all is well. I had not tried the 0 degree block previously, so this was a good test to make.

Thanks for the tire rotation tip.

CASTER
I thought this would be a good time to post my thoughts on caster. Caster gives the car three benefits.
First on most cars it gives the steering some self centering ability. When you turn the radio wheel the whole front of the car actually lifts from the caster. It has a tendency to settle back down and return the steering to straight ahead. This tendency is almost absent in the pan car as the steering has very little slack and the digital servo holds it strongly to the position you put the radio wheel, so you need to physically straighten the last bit of the corner or you will induce a spin, more so than a touring car.

Second, Caster provides the outside front tire with a little more negative camber. This hurts the cornering early in the corner, but helps the cornering later in the corner after the car has rolled some. I was using the 5 degree reactive caster block to kill some of my caster late in the corner.

Third. If you put the front wheels of the car on scales and turn the radio wheel you notice the inside front wheel and thus the diagonal outside rear wheel gain some load. Easy to see on the scales. This adds wedge to the chassis and increases the steering traction of the car. I think this is the dominant effect on our RC cars. As you guys have posted the camber is not really a good tuning aid, just a wear aid. This is also what I have found to be true on touring cars and the pan car.

Last edited by John Stranahan; 09-30-2006 at 10:32 PM.
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