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Old 10-14-2009, 06:10 AM   #1
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Default ankermann & in-board toe questions

i got some questions about ankermann setting & front in-board toe.

less ankermann (more parallel) = better tighter steering?
more ankermann (less parallel) = better high speed steering?

i got a s400 n i like to know which setting give me more ankermann n which is less. can someone help?




what does in-board toe do? i need more steering for tighter turns. default for s400 is front in-board toe out is 2.0 degree. but most car uses no in-board toe.

thanks.
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Last edited by fly_wheel; 10-14-2009 at 07:28 AM. Reason: spelling
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Old 10-14-2009, 06:42 AM   #2
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Originally Posted by fly_wheel View Post
i got some questions about ankerman setting & front in-board toe.

less ankerman (more parallel) = better tighter steering?
more ankerman (less parallel) = better high speed steering?
flip that around and you'll be on the right track.

in order to increase the ackermann angle on that car, you'll want to spread the pivot points on the bellcrank. moving them back will achieve this as well, but you'll also be changing the speed of the steering.

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what does in-board toe do?
at the rear, it changes how the car rolls in a turn. generally, the inboard toe will make the car feel softer in the front, by inducing more roll over the front. in my experience it's not that coarse of a change.
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Old 10-14-2009, 07:16 AM   #3
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so more ankermann = better n tighter turn

which one of these bell crank n knuckles setting give more ankermann? can someone number them from more to less ankermann? thanks.

1)


2)


3)


4)


5)


6)


7)


8)
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Old 10-14-2009, 07:27 AM   #4
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Originally Posted by seaball View Post
flip that around and you'll be on the right track.

in order to increase the ackermann angle on that car, you'll want to spread the pivot points on the bellcrank. moving them back will achieve this as well, but you'll also be changing the speed of the steering.

at the rear, it changes how the car rolls in a turn. generally, the inboard toe will make the car feel softer in the front, by inducing more roll over the front. in my experience it's not that coarse of a change.
u mean like the setup in pic #2..?
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Old 10-14-2009, 07:32 AM   #5
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u mean like the setup in pic #2..?
Yes, #2 would be the most Ackerman & the fastets steering. If you switch the hole on the knuckle, your steering speed and ackerman is reduced...
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Old 10-14-2009, 07:33 AM   #6
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fly_wheel, with my S400 I kept the ackerman in the stock location (whatever the setup manual suggested) but I narrowed the front end by switching to different toe blocks. The stock toe blocks are 3* in the front and 1* in the rear. I switched to 2* and 0* which kept the 2* of arm sweep but narrowed the front end. This helped the overall steering, and it was a similar change to using narrow wheel hexes, which I didn't own.

I also knew some Serpent team drivers that preferred to run no arm sweep at all, which gives you more entry steering but less mid and exit steering.
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Old 10-14-2009, 07:38 AM   #7
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Originally Posted by fly_wheel View Post
which one of these bell crank n knuckles setting give more ankermann?
least:



most:



the complete order of the steps in between can't be determined w/o all the relevant geometry. there comes a point of diminishing returns with ackermann, where adding more will just make the car push. #2 strikes me as being across that line.
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Old 10-14-2009, 09:00 AM   #8
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The xray setup book says the more parallel the steering links are, the greater the ackerman affect, opposite of what you say above. Iv never really tested it or really examined it that closly... i just went by what my setup book says.

So which is it?
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Old 10-14-2009, 09:16 AM   #9
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thanks for all the inputs... i will try the #2 ankermann setup then change the toe blocks... i have all the toe blocks but never really play with them much... i never really do my car setup actually , i just drive what my fren did for me but recently i found out i need something different to go a little faster (besides buying a lot of rubber tyres, LOL)... the ankermann has been quite a little confussing topic as many has their different ideas... some books said this but some says that...

well, i got some rough idea to try out now, thanks again & also thanks to the PM i received regarding the wrong spelling of "ankerman to ankermann" hehehehe...
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Old 10-14-2009, 09:24 AM   #10
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Generally, all you need to remember is that in most situations, the more angled the steering linkages, the more steering for tight turns. The straighter the steering linkages, the better for fast flowing turns. So you need to find a happy balance for your track.
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Old 10-14-2009, 09:33 AM   #11
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This is great, just learnt more about Ackermann!! Thanks guys!

Cheers!!
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Old 10-14-2009, 09:48 AM   #12
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So which is it?
my last post is correct. (draw it in simulink, or matlab, etc.)

perhaps the xray book was referring to moving in the other direction (starting with links converging toward the front of the car and moving to more parallel). as the bellcrank pivot moves rearward (all other things unchanged) you will grow the ackermann rate.
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Old 10-14-2009, 03:12 PM   #13
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Generally, all you need to remember is that in most situations, the more angled the steering linkages, the more steering for tight turns. The straighter the steering linkages, the better for fast flowing turns. So you need to find a happy balance for your track.
both front n rear holes in the bellcrank create angles to the linkages... which one do u mean..? the one pointing to rear (rear holes at bell crank) or the one pointing at the front (front holes at bell crank)..? thanks...
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Old 10-14-2009, 03:33 PM   #14
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my last post is correct. (draw it in simulink, or matlab, etc.)

perhaps the xray book was referring to moving in the other direction (starting with links converging toward the front of the car and moving to more parallel). as the bellcrank pivot moves rearward (all other things unchanged) you will grow the ackermann rate.
According to Xray, you are wrong... unless I am not reading it correctly. Quoted from Xray:

Quote:
The rate of the increase, called Ackerman effect, can be changed by the angle of the steering rods connecting the servo saver to the steering blocks. The straighter the rods are in relation to each other, the more Ackerman effect will be applied to the inside wheel.

Changing the forward/rearward position of the servo saver has the greatest Ackermann effect
Position #1 (forward) – less Ackermann effect (steering rods more angled)
Position #2 (rearward) – the greatest Ackermann effect (steering rods straighter)

Or is this only the case with Xray steering systems?
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Old 10-14-2009, 04:44 PM   #15
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According to Xray, you are wrong... unless I am not reading it correctly.
50% of the time both are right. the other 50%, only i am correct.

**in brief, it depends which side of parallel you're working from**

if jurai's car can't go beyond parallel, the oversimplified statement about 'angle v. parallel' is all you need to know. but looking at the aligments posted so far, the s400 works on both sides of that. (in this case, making it a bad idea to use the xray book for the serpent car).
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