Scarbs T-Tray proposal

[hardingfv32]

1) "The large hole in the floor is for the tub. Why waste 5 mm of height on a floor when the tub can be lowered by 5 mm?"

Weak statement. Why does RB have a floor assembly? Using your logic we should see everything mount to the tub/chassis.

2) "The fasteners have to be visible from underneath" Your point?

3) "secondly the floor can be in 3 sections, the shortest being 1m long." Yes it can, but in the case of RB it looks like a one piece unit which is not impediment to this system.

4) "3.12.5 All parts lying on the reference and step planes...."

A) As this is found in the "Bodywork facing the ground" section. I would argue that the Skid block is not covered by this rule.
B) This statement clearly is discussing parts the "on" the reference plain. I would argue that this means above, not below.

"3.15 Aerodynamic influence.... must remain immobile in relation to the sprung part of the car."

A) Here I would argue that the splitter based on how it is currently tested is understood to be mobile when it hits a big enough track irregularity.
B) The movement of the plank has no aerodynamic influence. It influences the wear of the plank.

5) "Another thing to consider is hamilton's broken floor in australia GP."

What about it? Do we know if McLaren uses a "see saw" plank system?

Brian

[ringo]

You know i was going to address each of your points, but it's not worth it.
The regulations are very clear and the plank is considered bodywork, your interpretations don't hold as much weight.

Why don't you point out where you think the fasteners are on the front of the splitter?

Also explain the black streak that interrupts the wear on the first 1m of plank.

Is this black part curved up away from the track when the rest of it is pvioted flat.
Seems we have a wavy skid block on this car.

Explain why the throat of the diffuser is worn as well. Is there a pivot round there too?

My explanation is simply curb riding, debris on track, the fact that the track is not flat as a pool table, and also there is some wear during turning as well.
We've seen the sparks under braking on the stiffly sprunk cars slamming into the track.

This wear can be achieved with a cantelever, it doesn't need the pivot, and a really strong force, like curb riding or hopping.


as for hamilton in australia, you've dodged the question.

why isn't the plank falling off it's it's not securely fixed to the floor?

[hardingfv32]

1) "The regulations are very clear and the plank is considered bodywork, your interpretations don't hold as much weight."

Yes, the regulations are very clear to me to and I have provided logical arguements to support my views. Where in the rules does it state the plank is bodywork? I see nothing convincing coming from you.

2) Viewing the RB floor assembly in the Monza photo above, I would say two mounting hole out of a possible five are visible to the left of the mechanic's elbows. I do not know what the four white spots are.

3) I have no idea why the the wear is interrupted at the 700 mm location. The two large inspection holes are at the 750 mm location. Based on your calculations, what do you say is the cause? Remember no speculation.

4) I do not see wear at the diffuser. Do you have a better image to demonstrate this?

5) "My explanation is simply curb riding, debris on track, the fact that the track is not flat as a pool table, and also there is some wear during turning as well."

And the effects of all these activities mysteriously stops at the 750 mm test holes?

6) You "dodged" my question: Do we know if McLaren uses a "see saw" plank system?

I believe the RB plank is one piece and uses 5 fasteners at the front and the balance of the fasteners are beyond the 700 mm location. That should be go enough to keep the plank in place, although I do not have calculations to prove it.

7) Could the plank be made of a material the has very little strength to bending?

Brian

[Richard]

Ringo - I agree with your points about the plank needing to be fixed to the floor, and the mandated fixings. That's why I concluded this must be about engineering the back span to deform to a flat shape in the test rig and a banana shape on track. It also means the tray is stiff enough to not flap up and down on track.

Regarding continuity of the step plane bodywork, that means the CF floor. The plank is then bolted to the plane. Hence the rules say that the floor has to be continuous if the plank is removed, ie a cover plate would be needed over the hole we see on the RB floor.

[scarbs]

completely unrelated, but here are some nice pictures of the RBR at Monza

http://www.auto-motor-und-sport.de/bild ... ow_item=16

[hardingfv32]

Richard

1) "I agree with your points about the plank needing to be fixed to the floor, and the mandated fixings."

I agree that the plank is fixed to the floor. I do not believe there are any mandates about the fixings other than a fastener surface area restrictions. Location and quantity is free.

2) "Hence the rules say that the floor has to be continuous if the plank is removed, ie a cover plate would be needed over the hole we see on the RB floor."

Could this cover designed to flex with the plank attached?

3) Could the wear around the oval "no wear" zone located in front of the 750 mm wear test holes be caused by an oscillation in this area when hitting track irregularities. A kind of wave form of your banana description, where the area in front of the "no wear" area goes upward and the area behind this area does downward (contacting the track)?

At a minimum this zone of the floor is showing an unusual wear pattern that is not easy to explain.

4) Is there any reason that the plank can not have properties that allow stretch or bending?

Brian

[Richard]

Brian, I think the combined plank/floor would bend together in this scenario. That's where I differ from Scarb's see saw because it inferred a greater degree of freedom that would cause problems with the tray flapping around.

They might have some oversized holes for the plank fasteners to allow a bit of longitudinal shear under bending. Then the two would act in parallel which is much less stiff than composite action. Also that hole in the floor would result in a zone of reduced stiffness.

That unworn rectangle is odd. The plank is worn around the edge of it, so I can only assume that area is slightly countersunk for some reason. However the plank is continuous past that, and it doesn't look deep enough to significantly reduce stiffness.

As for making a wood composite plank less stiff, you simply bend it to the point where some of the fibres break. Try it with a bit of plywood, bend it until you hear it creaking, then straighten it. You'll find it less stiff when you bend it again.

[xpensive]

Brian, I think the combined plank/floor would bend together in this scenario. That's where I differ from Scarb's see saw because it inferred a greater degree of freedom that would cause problems with the tray flapping around.
...

I concur, while the even wear over the length of the splitter could be a result of the natural bending curve of the cantiver.

[hardingfv32]

I think Scarb's was just getting the general theme of this "see saw" system out in a simplified fashion. Richard's illustration is much more applicable.

1) Viewing the photo Scrab's just referenced of the RB plank there is an odd triangle shape discoloration around the forward test hole. Does not look like the wear pattern seen between this point the 750 mm test holes. Looks like the outer edges of the splitter flex downward from the from the support strut.

2) "That unworn rectangle is odd. The plank is worn around the edge of it, so I can only assume that area is slightly countersunk for some reason." I would say that counter sinking the plank would not be helpful for minimizing wear rates, especially in this apparently high wear zone. Would you not want as much surface area in contact as possible?

No, this is some kind on negative outcome or trait of an activity the team feels is more beneficial.

3) There seems to be as many as 7 fasteners in this area, which happens to be below the hole in the floor. Two fasteners are located on each end of the "no wear" rectangle.

4) Fastener head/surface color:

The three fasteners in front of the "no wear" rectangle have dark coloration, almost like they are below the surface. I would think you would want to use them as wear points.

Brian

[kalinka]

Just to add some different angle views on RBR's underfloor >

http://www.auto-motor-und-sport.de/bild ... how_item=8

There are lot more images there. Enjoy.

EDIT : Look at picture nr.14 ! It's clearly visible that that yellowish area at the end of the floor has nothing to do with wear. It's a different material used there.

[kalinka]

And wow ! I think we'll never get a better view >

[ringo]

Ok good, and i am now seeing the fasteners which must be visble.

In fact there are 7 fasteners around the the black part and 4 spaced widely at the front.

The is wear pattern is the inverse of this:

The same idea but with the tip pointing down so that the middle part stays clean.

The tip pointing down is opposite to what the see saw is trying to achieve.

What is also intereing here is tha the plank is not weared evenly. It's really just a bunch of streaks, made to look like the whole surface is worn.
I can actually see that the tip has more excessive wear than the other scrubbed parts. I am referring to around the most forward hole. Look how evenly scrubbed it is. The area aft of this hole is in fact quite clean.

So i would say this floor is behaving normally, except for the clean patch in front of the 2 big holes. And this could be purely because of the tolerance in the manufacturing of the plank.

[hardingfv32]

What is the wear limit of the plank? The rule says it must have a thickness of of 10mm +/- 1 mm and uniform thickness when new.

So if we start with a thickness of 11.49 mm (max) and require a minumum of 8.51 mm, so we have wear available of about 2.98 mm. I am rounding up the tolerance numbers to get the greatest result.

Brian

[tok-tokkie]

10 +/-1mm = 9 to 11 (10-1=9 10+1=11)

[xpensive]

What is the wear limit of the plank? The rule says it must have a thickness of of 10mm +/- 1 mm and uniform thickness when new.

So if we start with a thickness of 11.49 mm (max) and require a minumum of 8.51 mm, so we have wear available of about 2.98 mm. I am rounding up the tolerance numbers to get the greatest result.

Brian

Perhaps you added the same innovative "tolerance to the tolerance" as MrM and Ross Brawn did when Ferrari's
bargeboards were found to be too wide in Malaysia 1999?