Illegal skid block tricks discovered

[WardenOfTheNorth]

Can someone explain how a skid lock that gets bigger allows a lower ride height? Surely a bigger block would raise ride height?

What am I missing?

The heating extends the skid block, so the block is wearing (and sparking) rather than the wooden plank. It's not expanding that much so as to interfere with ground clearance, but just enough to wear first rather than have plank wear. This is allowing them to run at a lower height and remain within the regulations on plank wear.

Thanks. I get it now.

[CMSMJ1]

Can someone explain how a skid lock that gets bigger allows a lower ride height? Surely a bigger block would raise ride height?

What am I missing?

The heating extends the skid block, so the block is wearing (and sparking) rather than the wooden plank. It's not expanding that much so as to interfere with ground clearance, but just enough to wear first rather than have plank wear. This is allowing them to run at a lower height and remain within the regulations on plank wear.

I think I get what you are trying to say - but either it "expands just enough" to impact whether it wears more but not enough that it impacts ground clearance?

Just throwing some ideas about this

The block - metallic as it is - either expands uniformly or it doesn't?
They are bolted on? How does that not get impacted?
Is the expansion throught a lap, a race, a sector?
Assuming we would use electricity to heat this - we can't be using a fluid as any of the many crashes we've seen would cause a mess and fluid is heavy

Love the idea - can't see it though?

[michl420]

The skid block is relativ strikt regulated. The mounting iteself is under big observation from the FIA I can imagin.
I would think about a aktive heating of the block itself, or maybe it is even enough to thermal isolat it somehow that it is getting hotter in this 3-4 second at the end of the straight.

[SiLo]

It's not about RAISING the ride height, it's about allowing the ride height to be lower across the floor without it wearing by raising the height of the block.

[basti313]

I think I get what you are trying to say - but either it "expands just enough" to impact whether it wears more but not enough that it impacts ground clearance?

The skid block always wears as it is by the rule flush with the plank. Once it wears, the plank wears, as the plank is much softer -> DSQ if too much.
So they are trying to make the block bigger to wear less the plank. We are talking about 1mm maybe and more is not possible.

Just throwing some ideas about this

The block - metallic as it is - either expands uniformly or it doesn't?

Yes, of course. Where do you see an issue with this?

They are bolted on? How does that not get impacted?

Should not be an issue. The bolt will also expand and be enough flexible. I would just use a Ti screw on a Ti block...no issue...

Is the expansion throught a lap, a race, a sector?

I think it only makes sense to keep it all race:
- If you expand the block by 1mm (too much, something like 0.7mm is maybe realistic) you generate headroom to wear 1mm more. Might be substantial looking at the Ferrari issues for example.
- Sparking happens at 600 to 800°C. I do not think they can lift the temp of the block higher as it would wear even more due to the oxidation and at that temp it would burn anything around...
- The heating by hitting the ground happens when you hit the ground, the heat goes from surface to depth...basically too late, till the next major hit it cools again. So I think the heating just helps to keep the temp and have the block bigger all the time/before the hit.

Assuming we would use electricity to heat this - we can't be using a fluid as any of the many crashes we've seen would cause a mess and fluid is heavy

Well, you could run a oil or water hose close by. But I fail to see how any fluid can be hot enough. I think this block needs to be lifted by around 400°C to have enough thermal expansion to make a difference. This leaves us the electric.

[clownfish]

They are bolted on? How does that not get impacted?

Should not be an issue. The bolt will also expand and be enough flexible. I would just use a Ti screw on a Ti block...no issue...

Hopefully somebody can check the tech regs to verify as I'm not able to right now, but I seem to recall the mounting hardware for the skids must be steel (of specified grades).

Well, you could run a oil or water hose close by. But I fail to see how any fluid can be hot enough. I think this block needs to be lifted by around 400°C to have enough thermal expansion to make a difference. This leaves us the electric.

Yes this was my thought also, but even 400c does not cause a large amount of expansion of titanium due to the relatively low thermal expansion coefficient.

Perhaps instead of targetting the external parts (the skid, bolts etc) the mounting point that the bolts thread into could be made to expand with heat if it were a long piece of aluminium or something with a high CTE. (Again, need to re-read the regs, I can't remember how the mounting points are defined).

Intriguing report though!

[TimW]

For every 100 degC titanium would expand about 0.1%. So a 20mm block would only get about 0.02mm thicker. So it is not just that.

Bending is more likely. The bottom of the skid block gets heated, so if you make sure there is a heat sink at the top(maximizing deltaT between top and bottom), it will bend. Bending can give you much more deflection than just linear expansion. But it will also be more flexible, which will reduce effectiveness for protecting the plank. Making it bend a lot without being flexible seems challenging at first glance.

Maybe a cup shaped skid block, opening at the top, would give something that bulges relatively much and still be stiff

[CMSMJ1]

I think I get what you are trying to say - but either it "expands just enough" to impact whether it wears more but not enough that it impacts ground clearance?

The skid block always wears as it is by the rule flush with the plank. Once it wears, the plank wears, as the plank is much softer -> DSQ if too much.
So they are trying to make the block bigger to wear less the plank. We are talking about 1mm maybe and more is not possible.

Just throwing some ideas about this

The block - metallic as it is - either expands uniformly or it doesn't?

Yes, of course. Where do you see an issue with this?

They are bolted on? How does that not get impacted?

Should not be an issue. The bolt will also expand and be enough flexible. I would just use a Ti screw on a Ti block...no issue...

Is the expansion throught a lap, a race, a sector?

I think it only makes sense to keep it all race:
- If you expand the block by 1mm (too much, something like 0.7mm is maybe realistic) you generate headroom to wear 1mm more. Might be substantial looking at the Ferrari issues for example.
- Sparking happens at 600 to 800°C. I do not think they can lift the temp of the block higher as it would wear even more due to the oxidation and at that temp it would burn anything around...
- The heating by hitting the ground happens when you hit the ground, the heat goes from surface to depth...basically too late, till the next major hit it cools again. So I think the heating just helps to keep the temp and have the block bigger all the time/before the hit.

Assuming we would use electricity to heat this - we can't be using a fluid as any of the many crashes we've seen would cause a mess and fluid is heavy

Well, you could run a oil or water hose close by. But I fail to see how any fluid can be hot enough. I think this block needs to be lifted by around 400°C to have enough thermal expansion to make a difference. This leaves us the electric.

Appreciate the reply and I can see what it is you are saying..but

We want the skid block to be "expanded" by ??mm so that this prevents some of the excessive wearing on the plank?

If the ??mm is persistent in the race - either by increasing the base temp of the block and allowing the friction to increase it to an average higher temp/size* - then the minimum ride height is surely increased by atleast some % of this expanded size? Otherwise we'll be scraping it more and wearing it out?


As an aside on the possibilities but on the title of this thread - illegal tricks - what's the regs say? Is it illegal to have a material that can expand in this manner? Is it illegal to try to heat something so small and dense using electricity? Oil and water are not 400 deg C



*we do need to review the material property and consider what the explansion coefficient is?

[basti313]

For every 100 degC titanium would expand about 0.1%. So a 20mm block would only get about 0.02mm thicker. So it is not just that.

Bending is more likely.

I like this idea, as recalculating my number shows me that I did it wrong by a factor of 10...sorry. So your sub 0.1mm is totally correct.

But: Do we see anything else than round skid blocks? Is anyone having a square or other shaped skid block on the floor? I think to make this bending the whole block idea work you need to be long, rather very long and then you are just wearing spots out of it.

I think that they actually move the mount is more likely.

We want the skid block to be "expanded" by ??mm so that this prevents some of the excessive wearing on the plank?

Let me explain my thought on the plank without tricks:
The plank is soft. The only thing, that prevents the plank from being ripped away in the first lap is the skid block. The skid block is hard and wears slow. So we only need to discuss skid block wear, which is flush by the rule with the plank. I think the usual discussion on plank wear is strange, one might better measure or should measure the skid blocks.

If the ??mm is persistent in the race - either by increasing the base temp of the block and allowing the friction to increase it to an average higher temp/size* - then the minimum ride height is surely increased by atleast some % of this expanded size? Otherwise we'll be scraping it more and wearing it out?

As above...it is about skid plate wear, which is not measured. So if the skid is bigger under running, you can simply wear more.
I think that the expansion has nothing to do with ride hight directly.

As an aside on the possibilities but on the title of this thread - illegal tricks - what's the regs say? Is it illegal to have a material that can expand in this manner?

Certainly grey area....of course many things on the car get warm and expand. Once the engine is hot the exhaust is surely in a different position than when they scrutineer the car for example. But I would count everything like this plank games illegal under moving aero.

They are bolted on? How does that not get impacted?

Should not be an issue. The bolt will also expand and be enough flexible. I would just use a Ti screw on a Ti block...no issue...

Hopefully somebody can check the tech regs to verify as I'm not able to right now, but I seem to recall the mounting hardware for the skids must be steel (of specified grades).

Perhaps instead of targetting the external parts (the skid, bolts etc) the mounting point that the bolts thread into could be made to expand with heat if it were a long piece of aluminium or something with a high CTE. (Again, need to re-read the regs, I can't remember how the mounting points are defined).

Intriguing report though!

Yes, that might be more the case.
There is not much in the rules. Screws must be FIA approved, steel or Ti, aero grade usually. I do not see any rules preventing a special mount on the tub, the only issue is that they most likely do not have much space there.

[CMSMJ1]

The following provisions apply to the skids. The lower surface of the plank may be fitted with
flush mounted metal skids which:
k. May only be fitted in place of plank material.
l. Have a total area no greater than 24000mm² when viewed from below.
m. Are no greater than 4000mm² in area individually when viewed from below.
n. Are fitted in order that their entire lower surfaces are visible from below.
o. Must have a minimum cross sectional thickness of 15mm across its external boundaries
in plan view.
The minimum wall thickness between an internal fixing hole and the external
boundaries of the skid must be no less than 7.5mm.
p. Must have an upper surface no more than 3mm below the reference plane.
q. Must be designed such that they are secured to the car using the fasteners described in
items t) to w) of this article and that, when viewed from below, no part of the skid is
more than 50mm from the centre line of a fastener which passes through that skid.
r. Must be made from Titanium alloy (according to AMS4928 or AMS4911 in annealed
condition). Furthermore, they may only be machined from solid and no processes (such
as forging, rolling, welding, heat treatment or coating) may be carried out either before
or after machining.
s. If positioned entirely inboard of Y=120 and between XF= 425 and XF= 625, must be
fastened directly to the Front Floor Structure with zero degrees of freedom:
The following provisions apply to the plank and skid mountings. The plank and skids must be
fixed to the car using fasteners which:
t. Are no smaller than M6 and are made from grade 12.9 or 10.9 steel.
u. If used to attach a skid to the car, must employ at least 1 fastener per 1,000mm2 of skid
area.
v. If used to attach a skid to the car, the team must be able to show by calculation that the
shanks of the fasteners (which may be no less than 6mm diameter) are the weakest
point in the attachment of the skids to the car.
w. May use a load spreading washer if required.
The total area of the fasteners and any load spreading washers employed with them when
viewed from below must be less than 7,500mm2
. The area of any single fastener plus its loadspreading washer may not exceed 500mm².
No part of any fastener or load-spreading washer may be more than 8mm below the
reference plane. For the avoidance of doubt, the skids referred to in items k) to s) of this
article will not be treated as load spreading washers.



https://www.fia.com/sites/default/files ... -04-07.pdf

Fill your boots

[SiLo]

If the ??mm is persistent in the race - either by increasing the base temp of the block and allowing the friction to increase it to an average higher temp/size* - then the minimum ride height is surely increased by atleast some % of this expanded size? Otherwise we'll be scraping it more and wearing it out?

It's more about making sure the plank just wears less. So they can run the plank lower without fear of being DQS'd. The blocks aren't measured for wear at all.

[CMSMJ1]

If the ??mm is persistent in the race - either by increasing the base temp of the block and allowing the friction to increase it to an average higher temp/size* - then the minimum ride height is surely increased by atleast some % of this expanded size? Otherwise we'll be scraping it more and wearing it out?

It's more about making sure the plank just wears less. So they can run the plank lower without fear of being DQS'd. The blocks aren't measured for wear at all.

Absolutely - but with a block that is 'proud' of the plank there is surely an increase in ride height or we just see excessive grounding onto the blocks - a shower of sparks and effective bottoming out?

The skids not being flush will be where the rules are breached.

For me - it's an interesting thing to look at - but I can't see it in the way described. Maybe I need pictures

[basti313]

Absolutely - but with a block that is 'proud' of the plank there is surely an increase in ride height or we just see excessive grounding onto the blocks - a shower of sparks and effective bottoming out?

Well, the car always bottoms on the blocks. The only question is how much these wear and, thus, the track diggs into the plank. 1mm proud of the plank at the start means you can wear 1mm more.
At which height the car bottoms does not make a difference, a proud skid block would even be beneficial on this.

The skids not being flush will be where the rules are breached.

Good point, that makes even more sense than the more universal movable aero.

[TimW]

But: Do we see anything else than round skid blocks? Is anyone having a square or other shaped skid block on the floor? I think to make this bending the whole block idea work you need to be long, rather very long and then you are just wearing spots out of it.

It does not have to be 2D bending. A disk with a round recess in the top would work (so a cup shape). The bottom will want to expand, but the colder ring shaped side on top will restrain it, making the bottom bulge downward. I doubt you can get more from it than a few tenths of a mm. But F1 is all about small gains.

I think that they actually move the mount is more likely.

Agree that is much easier to be effective, but the zero degrees of freedom mounting requirement makes it very tricky. They would have to separate the skid mounting structure from the plank mounting structure. Would become a quite obvious thermal actuator it seems.

A beneficially deforming skidblock on the other hand, I don't think there is anything in the rules on that.

[vorticism]

Thermal expansion alone isn't enough to make a difference here.

It should, and you provided a perfect example of how.

I like this idea, as recalculating my number shows me that I did it wrong by a factor of 10...sorry. So your sub 0.1mm is totally correct.

You were not that far off, potentially. A 50mm long steel bolt would lengthen by 1/3 of a mm if heated by 400C.

Regardless, there would be numerous ways to take advantage of TE based on part geometry and material selection.