John St.Amant

iTrader: (1)

Better check that again M8.... I think thats backwards.
But then again I'm dyslexic.

vr01

Craig,

Yes that is the height of the hingepins / suspension mounts in order on the setup sheet but FR is the rear of the front arm and FF is the front of the front arm. If your set up sheet is correct then you are running pro dive because the front of the front arm is lower the rear of the front arm.

Unless I'm mistaken, front kickup = anti dive.

I think we need Josh on here to sort out all of us school kids...

Luke Hobson

If the front edge of the front arm is higher than the rear that's anti dive.
If the rear edge of the front arm is higher Han the rear that's pro dive.

On the tamiya cars we used to run 0.5mm pro dive. It's smoothed the car out on entry to the corner.

I'm currantly testing with ackerman positions to see how close I can get the outside wheel lock compared to the inner, I measured it before while running insert 10 in middle position. Outer wheel lock was 24-25 deg and inner was only 16-17 degrees.
When I compared this to other cars, this is was the lowest outer wheel lock of the cars I've measured, with most coming in at about 22-23 (usually only a degree or two lower than inner lock.....

I'm aiming to get it as close as possible to reduce front tyre scrub that I'm getting at the moment.
I'll do some more testing and report back when I get some more quantative data to give rather than theory.

Luke

CraigM

iTrader: (34)

kickup = pro dive, I am running anti-dive

Luke, forward position with insert 9 will be the least angle between inner and outer wheel, I think the difference is a bit over 5 degrees with that setting.

sosidge

You have this the wrong way around - Craig M is right. What we would call "kickup" - leading edge of the arm higher than the trailing edge - is a pro-dive geometry.

Luke Hobson

lol just seen what I wrote lol, yes it's the other way around

From what I've just built up on the car it's 12 that gives least difference between the wheel angles..... The inner bottoms out on the castor block at full lock anyway so a 12 increases the outer angle.... A 9 limits the outer wheel lock the most

John St.Amant

iTrader: (1)

+1

But I think he got the Ackermen backwards.

I guess it all depends on where you are looking at the #"s, beginning or end.

sosidge

Ackermann - increased difference in angle between inner and outer wheels.

So the setting with the most ackermann is back-12. Least ackermann front-9.

That's how I would see it.

John St.Amant

iTrader: (1)

If you look at the numbers they change with respect to degree angle of input ..
Id have to look again ,, and again... lol. Initial would be more relevant as most of my kits never get to full lock. Even in the tight turns.

I see what you are saying ... But initial is less in some cases by not much ...
The endpoints are definitely greater so I can see where you are coming from.
That is not always the case on the track.. make subtle changes at the wheel at the input angle you are looking for and not just by the overall degree difference.

sosidge

Intriguingly the measurements are very linear considering that you are changing both the position on the chassis and the width of the linkages. The order of the settings is identical on 5, 15, 20 and 25 degrees lock, and there is only one sequence change on the 10 degree chart.

John St.Amant

iTrader: (1)

Yeah .. thats what I meant ..

Josh Cyrul

iTrader: (1)

Wow... I'm starting to think I shouldn't have put all these adjustments in the car..lol.. Everyone seems confussed.

Ackerman:

21mm (short) Bell Crank w/ #12 Insert is the most ackerman you can run. This means there is a large difference between inside/outside wheel angles when turning.


24mm (long) Bell Crank w/ #9 Insert is the least ackerman you can run. This means there is a smaller difference between the inside/outside wheel angles when turning.

Endpoints:

Usually 25 degrees is the max endpoint setting for most tracks - Anymore than this you will scrub the front tires in excess. I think I posted that the castor block stop is at 30 degrees as we need that extra 5 degrees for some of those really tight indoor carpet tracks just to turn around in the lanes. If you use a .5mm shim between the castor block and steering block (at the stop) then this will get you 25 degrees.

RC:

On the set-up sheet - H = High and L = Low. If you run FF at "M" and FR at "H" then this is anti-dive. If you run FF at "H" and FR at "M" then this is kick-up.

Thirtybird

iTrader: (6)

I think people are confused because it's something they haven't had to work with to the degree they do with the Photon and we're climbing the learning curve. Once we've gotten there, it will become old hat and we'll move on to be confused by something else

Now I see how I read the chart wrong! The number along the top of the chart is the degree the inside wheel was from straight, and the number in the chart is what the outside wheel (which is closer to straight) will be turning.

mrrcguy

iTrader: (25)

Finally some clarity! Only one question left just to make sure the horse is dead...

Which of those two settings should provide the most aggressive steering?

John St.Amant

iTrader: (1)

That adjustment makes a difference on where you want the steering to work.
If that makes any sense.. Look back a few posts and read about where Josh tells where center feel and end are different. Too much scrub and overheating tires...