Does this part of F1 suspensions move or not ?

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firasf1dream
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Joined: 18 Apr 2014, 21:26

Does this part of F1 suspensions move or not ?

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hello guys,
i need to know please if this part, that is attached to the keel or the cockpit for the upper one, move or not ? and if it moves how much bigger is the whole that it get into it ?
Image
Last edited by Richard on 23 Apr 2014, 22:48, edited 1 time in total.
Reason: Moved to chassis forum

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mertol
7
Joined: 19 Mar 2013, 10:02

Re: does this part of F1 suspensions move or not ?

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Can't understand what you are asking but here I drew arrows showing the movements that the suspension can do:
Image

Dragonfly
23
Joined: 17 Mar 2008, 21:48
Location: Bulgaria

Re: does this part of F1 suspensions move or not ?

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I'd use the word "flexing" rather than "moving".
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beelsebob
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Joined: 23 Mar 2011, 15:49
Location: Cupertino, California

Re: does this part of F1 suspensions move or not ?

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Dragonfly wrote:I'd use the word "flexing" rather than "moving".
The word flexing would be very wrong. The suspension arms don't flex (significantly), the push rod pushes on the rockers. Most the movement comes from the rotation of the rocker in the nose.

The A arms then simply rotate around fixed points.

Scootin159
9
Joined: 06 Aug 2009, 21:09

Re: does this part of F1 suspensions move or not ?

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beelsebob wrote:
Dragonfly wrote:I'd use the word "flexing" rather than "moving".
The word flexing would be very wrong. The suspension arms don't flex (significantly), the push rod pushes on the rockers. Most the movement comes from the rotation of the rocker in the nose.

The A arms then simply rotate around fixed points.
I suspect he's referring to the fact that modern F1 cars all use "flexure joints" where the A-arms connect to the chassis. The arm itself is essentially inflexible - but there is a very carefully engineered piece of flexible carbon that attaches the arm to the chassis. It functions much the same as a standard rod end joint - but it's lighter and stronger, as well as having very little friction.

To picture what a flexure joint is, just imagine a very short piece of a thick leather belt attached to the end of the control arm. It flexes very easily in the up/down direction, but it's nearly impossible to bend it in the fore/aft direction.

Dragonfly
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Joined: 17 Mar 2008, 21:48
Location: Bulgaria

Re: does this part of F1 suspensions move or not ?

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Scootin159 wrote: ............................
I suspect he's referring to the fact that modern F1 cars all use "flexure joints" where the A-arms connect to the chassis.
You are quite right. That is what I referred to.
If I am not mistaken the question is about the lower wishbone. And again if my memory serves me right, for many years now teams have been using this type of design. Eliminating the classic bush type joints and using of the elasticity of the arm for the quite small travel of the suspension.
This was very noticeable with the keel-less type of chassis when high noses were the fashion.

(I think on a side note is interesting that we see again a pronounced keel. Some years back I remember there were a lot of discussions about keels and which design was better - single keel (Ferrari), twin keel (McLaren) and V-keel (Renault). Then IIRC Toyota came out with a keel-less solution.)

P.S. I think this thread belongs to the other section - Aero, chassis and tyres.
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riff_raff
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Joined: 24 Dec 2004, 10:18

Re: does this part of F1 suspensions move or not ?

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Every part of the suspension is an elastic structure, including A-arms, push rods, tires, etc. But some suspension components are more "flexible" than others. F1 A-arms use flexures at the attachment to the chassis because the flexures provide consistent and predictable kinematic characteristics.
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Tim.Wright
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Joined: 13 Feb 2009, 06:29

Re: does this part of F1 suspensions move or not ?

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riff_raff wrote: F1 A-arms use flexures at the attachment to the chassis because the flexures provide consistent and predictable kinematic characteristics.
I'd argue that they are kinematically difficult to use with their effective "joint centres" moving around with different loads.

The advantages of them would be reductions in weight and hysteretic friction which is important in suspensions with such a small stroke.
Not the engineer at Force India

Tommy Cookers
617
Joined: 17 Feb 2012, 16:55

Re: does this part of F1 suspensions move or not ?

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they can be designed for near-zero 'movement of 'joint centres' - or not
in most applications near-zero movement is essential
F1 doesn't care about this, because it's unimportant with such small suspension travel

btw the old 2 stroke Trojan car had no gudgeon/wrist pins
the con rods were cast integral with the pistons, the unusually small pivoting effect came from flexural sections in the integral part

firasf1dream
4
Joined: 18 Apr 2014, 21:26

Re: Does this part of F1 suspensions move or not ?

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aha well what i was talking about are the higher and the lower wishbones, i needed to know if they move, so the picture and you guys acknowledged that it moves, what i need to know is if the hole that this wishbone goes threw is big ? because i assume it's not which makes it less movable

and please i need to know if you have any pictures for the Keel of the mclaren MP4-27 and how is the wishbones attached in it ?
Last edited by firasf1dream on 24 Apr 2014, 01:27, edited 2 times in total.

thepowerofnone
23
Joined: 24 Apr 2013, 17:21

Re: Does this part of F1 suspensions move or not ?

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firasf1dream wrote:aha well what i was talking about are the higher and the lower wishbones, i needed to know if they move, so the picture and you guys acknowledged that it moves, what i need to know is if the whole that this wishbone goes threw is big ? because i assume it's not which make it less movable

and please i need to know if you have any pictures for the Keel of the mclaren MP4-27 and how is the wishbones attached in it ?
The wheels all have the ability to move up and down, that's the point of the suspension. If the upper and lower wishbones were fixed and unable to flex, you may as well not bother with any of the other suspension parts because either your wishbones are going to break or you are going to have no suspension travel. The question I believe you are asking is how much travel is there in F1 suspension, the answer is not at all a lot. Of the order of millimetres. More than that and your low speed performance will be terrible.

Some context might be useful, like why the MP4-27 specifically? As far as how it is attached, it will look very similar to the photo you showed us. The difference between a flexural joint and a rose joint is pretty small and since (no offence, and I apologise profusely if I am mistaken) you don't seem to be too familiar with suspension setups, it shouldn't affect the complexity of model I imagine you are using.

Richard
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Joined: 15 Apr 2009, 14:41
Location: UK

Re: Does this part of F1 suspensions move or not ?

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As I recall, a significant amount of the vertical travel takes place in the tyre walls. That came to light with the switch to Pirelli, some teams struggled to model the tyre wall so had to run higher ride heights with sub-optimal suspension settings to compensate. Hence McLaren's porpoising in the last two years.

If they switched to low profile tyres then we'd see more movement in the suspension. I guess the engineers would prefer that because they would have more influence on the behaviour, at the moment they're stuck with standard tyre walls.

firasf1dream
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Joined: 18 Apr 2014, 21:26

Re: Does this part of F1 suspensions move or not ?

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first my problem is that i have a lack of technical words and yes i have a bit of knowledge about F1 because i was trying to build a concept real one before then i stopped, i had the idea of getting back to paper modeling F1 cars, i already build 3 models in the past years and then i stopped (here is a link to my models build 5 to 7 years ago https://www.youtube.com/watch?v=rXYZKpMXBHI), then i had the idea of building a real F1 using the regulations but from paper then i didn't because i didn't have the real experience of doing it, my method in the video wouldn't work, so about 1 week and a half ago I knew about Paul from PaulsF1.wordpress.com and saw his work, and BOOM back again i was so motivated and so inspired by his work so that i started to build a model which i choose to make it as much possible similar to the MP4-27, which will be a very hard task ! why MP4-27 ? because the 26 is not much attractive, and i wanted to build a mclaren but problem is lack of technical pictures about it along side with using the 2012 regulations of course,
here are the pictures of my new model i am working on
http://i96.photobucket.com/albums/l196/ ... 8e3317.jpg
http://i96.photobucket.com/albums/l196/ ... a95293.jpg
http://i96.photobucket.com/albums/l196/ ... 391164.jpg
http://i96.photobucket.com/albums/l196/ ... e4f940.jpg

firasf1dream
4
Joined: 18 Apr 2014, 21:26

Re: Does this part of F1 suspensions move or not ?

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hello guys,
i posted a reply with link for pictures but it told that it needs a moderator to confirm it, i don't know why !!

DaveW
239
Joined: 14 Apr 2009, 12:27

Re: Does this part of F1 suspensions move or not ?

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richard_leeds wrote:As I recall, a significant amount of the vertical travel takes place in the tyre walls.
For the front tyres, your are correct, Richard, but not for the rears.
richard_leeds wrote:That came to light with the switch to Pirelli, some teams struggled to model the tyre wall so had to run higher ride heights with sub-optimal suspension settings to compensate. Hence McLaren's porpoising in the last two years.
Forgive me, but I can't think that is true. The vertical stiffness of both Pirelli tyres was greater than the Bridgestone's they replaced, particularly for the rear tyres. The evidence is can be found here, extracted from an earlier post.

One driver commented that the Pirelli tyres worked well, until they were "leaned" on. Then the compound appeared to be incapable of transmitting load generated at the contact patch to the tyre carcase. The effect was that compound was ripped from the carcase in a few laps, leaving strips of compound around the track, and (ultimately) no grip.

Maclaren's particular problem was that they had a habit of locking out the front dampers with spring, leaving the tyres to dissipate disturbance energy (inefficiently), but I'm not sure that I would call that "porpoising".
richard_leeds wrote:If they switched to low profile tyres then we'd see more movement in the suspension. I guess the engineers would prefer that because they would have more influence on the behaviour, at the moment they're stuck with standard tyre walls.
As a cynic, I would expect that most F1 teams would simply increase spring stiffnesses..... to get "better" control over aero...