Aston Martin AMR26

[AR3-GP]

This longbow leaf spring, with one degree of motion and 100% left-right faithfullness , how is it damped ? In what way can a damper be connected ? (not a mech engineer, hence the Q)

Since the longbow applies forces at the upright, then its vibrational modes are resolved by the pushrod/damper system.

[vorticism]

Good clear image of that component, as mentioned its been in other team designs recently too.

Possibly correct to assume that it is a spring component that is supplemented by the torsion bar used to produce a homogeneous "total" spring contribution in support.
The damping can't of course be achieved (well not to any great degree) and must be placed within pushrod internal destination within bellcrank area.

Yes, it may act somewhat as a leaf spring, although the addition may be trivial. I had taken to calling it the longbow when I first became aware of it on the RB18, owing to it being almost the same dimensions thereof, then found it in photos of earlier RBR cars. In this specific application the unique feature seems to be that the arm anchor/pivot-point can be placed ahead of the bulkhead, inside the nosecone. It also would not trace a perfectly circular at its outboard end, being a bending beam, although, again, this might be trivial and consequential.

Who else is using it this year?

Just by the way - such contious whisbones were used first by by Rory Byrne on the Ferrari F2001 in 2001. It was called "one-piece" or "monolithic"-wishbone back in these days. And it indeed acted like a kind of leaf spring. Ferrari used them untill 2007 (actually they stopped using it with the F2007) and Renault and Minardi copied it in 2002 and used it untill 2004.

Sort of. What RBR developed across six years or more may or may not be a wishbone, may just be a single spar that spans the 1,5m between the front uprights. The keel suspensions of 90s/00s provided a single central anchoring point, not a constrained span of a spar--this would impose different cantilever properties. You could say that those wishbones were continuous but not always monolithic because some (all?) of them had a metal flexure center, which was a common (and still is) type of alternative to a rose joint. If you go back far enough you'll find transverse springs and live/solid axles on grand prix cars i.e. other types of transversely continuous suspension members.

To the extent that the longbow has any appreciable spring rate, it may also provide some anti-roll effect. A bar twice constrained centrally will see one end raise when the other end is raised, while the center would deflect downward.

[venkyhere]

This longbow leaf spring, with one degree of motion and 100% left-right faithfullness , how is it damped ? In what way can a damper be connected ? (not a mech engineer, hence the Q)

Since the longbow applies forces at the upright, then its vibrational modes are resolved by the pushrod/damper system.

That was not what I intended with the Q. Let me ask with more words :
Given that left and right are 'solid connected' with something similar to the 'live solid axle' like in older trucks ; what about the need for some sort of isolation between left from right (even to a small degree, especially for situations where one wheel hits a kerb and the other is on tarmac) - is there any scope for some damping to accomplish this need ? The 'longbow' with 'more bendy' lateral ends connected by a rigid middle has a small degree of inherent flexion, but is that enough ?

[Andi76]

Yes, it may act somewhat as a leaf spring, although the addition may be trivial. I had taken to calling it the longbow when I first became aware of it on the RB18, owing to it being almost the same dimensions thereof, then found it in photos of earlier RBR cars. In this specific application the unique feature seems to be that the arm anchor/pivot-point can be placed ahead of the bulkhead, inside the nosecone. It also would not trace a perfectly circular at its outboard end, being a bending beam, although, again, this might be trivial and consequential.

Who else is using it this year?

Just by the way - such contious whisbones were used first by by Rory Byrne on the Ferrari F2001 in 2001. It was called "one-piece" or "monolithic"-wishbone back in these days. And it indeed acted like a kind of leaf spring. Ferrari used them untill 2007 (actually they stopped using it with the F2007) and Renault and Minardi copied it in 2002 and used it untill 2004.

Sort of. What RBR developed across six years or more may or may not be a wishbone, may just be a single spar that spans the 1,5m between the front uprights. The keel suspensions of 90s/00s provided a single central anchoring point, not a constrained span of a spar--this would impose different cantilever properties. You could say that those wishbones were continuous but not always monolithic because some (all?) of them had a metal flexure center, which was a common (and still is) type of alternative to a rose joint. If you go back far enough you'll find transverse springs and live/solid axles on grand prix cars i.e. other types of transversely continuous suspension members.

To the extent that the longbow has any appreciable spring rate, it may also provide some anti-roll effect. A bar twice constrained centrally will see one end raise when the other end is raised, while the center would deflect downward.

Yes, some had flexures at the attachment points, but most were indeed monolitic. But basically, it's the same idea, adapted to the respective requirements.

[vorticism]

Yes, some had flexures at the attachment points, but most were indeed monolitic. But basically, it's the same idea, adapted to the respective requirements.

https://postimg.cc/ygxnKnKC

I doubt it. I don’t think teams were experimenting much with carbon fiber springs at that time (late 90s, early 00s), wasn’t exactly the state of the art at the time. Piola’s illustration there depicts the center and outer ends in light blue, by which he means metal, which is to say, it’s not monolithic. If you can find any photos please post them. If your standard is simply that continuousness=insignificant then, as I said, you’ll find grand prix cars much earlier than the F2001 that had continuous suspension members. It wouldn’t stop there. For thousands of years wagons were constructed in this way.

Regardless, if we’re considering this as a spring element (plausible but not a certainty), constraining a beam across ~20% of its center does affect its cantilever properties, and would not compare to constraining only the center with no degree of freedom within the fixture point--which would simply be two independent flexures flanking a rigid central anchor i.e. there would be no way for a force to transfer from one side to the other. If the longbow is constructed like an archery bow or a cross-country ski, then I would assume some amount of force is transferring through the fixturing clamps like a seesaw.

Plus this could be multilink geometry (common these days), in which case, it’s not a wishbone, it’s simply a single continuous arm.

[AR3-GP]

Yes, it may act somewhat as a leaf spring, although the addition may be trivial. I had taken to calling it the longbow when I first became aware of it on the RB18, owing to it being almost the same dimensions thereof, then found it in photos of earlier RBR cars. In this specific application the unique feature seems to be that the arm anchor/pivot-point can be placed ahead of the bulkhead, inside the nosecone. It also would not trace a perfectly circular at its outboard end, being a bending beam, although, again, this might be trivial and consequential.

Who else is using it this year?

Mclaren, AMR, Mercedes, RBR.

Mclaren adopted after Rob Marshall arrived. Mercedes also adopted in 2024-2025.

[Farnborough]

Just watching this



in which there's some waffle in regard to previous iteration of Honda PU.

But .... if you frame by frame it when the current PU offering is in view, there's some interesting detail in layout for AMR26 installation.

Notable, that @ 8:10 timeline, just as the camera pans across the stage with PU in frame rhs .... there's good view of both turbo installation with hot side entry route, location and sizing clearly in view.

Also, the size of the gearbox driven off front of crankshaft to facilitate MGU-K is very clearly shown, that with the motor unit projecting forward and alongside battery store location.

The PU appears approx 4 times, each with interesting viewpoint if you frame by frame the footage.

[MIKEY_!]

I know some here talk down The Race's technical reporting, but this was interesting:

Honda observed abnormal vibrations that caused damage to the battery, although it is not sure whether the battery system itself is the initial problem. What Honda can see is the battery pack is being shaken because the structure it is attached to is vibrating more severely than expected.
Honda is investigating a combination of factors that likely caused these vibrations to emerge and running virtual track testing at its Sakura base with a chassis, engine and gearbox combined, but is yet to pinpoint the root cause.
"If we could identify a single cause, it would be easier to fix, but because multiple linked factors generate the vibration, we don't know whether fixing just one will solve it," said Takeishi.
Together with Aston Martin, Honda is assessing what countermeasures can be implemented on both the car and engine side - including what can be done before the season opener in Australia next weekend.
Aston Martin is willing to modify components on its car if necessary. Controlling the vibrations is critical for the engine's chances of running reliably in the early races of the season, which includes Honda's home grand prix in Japan at the end of March.
After managing the start of the season with interim measures, Honda will look to change reliability-related parts where possible within the cost cap.

The context seems to suggest the "structure the battery is attached to" refers to the front of the ICE, but is it possible Honda is referring to the chassis instead of (or as well as) the ICE? Late integration of the chassis and PU could have meant such a problem was not picked up until it was too late to resolve before testing. Pure speculation on my part.

https://www.the-race.com/formula-1/hond ... dentified/

[De Wet]

https://www.youtube.com/watch?v=ylHheLNqGOo


Interesting video in this issue.

[organic]

I know some here talk down The Race's technical reporting, but this was interesting:

Honda observed abnormal vibrations that caused damage to the battery, although it is not sure whether the battery system itself is the initial problem. What Honda can see is the battery pack is being shaken because the structure it is attached to is vibrating more severely than expected.
Honda is investigating a combination of factors that likely caused these vibrations to emerge and running virtual track testing at its Sakura base with a chassis, engine and gearbox combined, but is yet to pinpoint the root cause.
"If we could identify a single cause, it would be easier to fix, but because multiple linked factors generate the vibration, we don't know whether fixing just one will solve it," said Takeishi.
Together with Aston Martin, Honda is assessing what countermeasures can be implemented on both the car and engine side - including what can be done before the season opener in Australia next weekend.
Aston Martin is willing to modify components on its car if necessary. Controlling the vibrations is critical for the engine's chances of running reliably in the early races of the season, which includes Honda's home grand prix in Japan at the end of March.
After managing the start of the season with interim measures, Honda will look to change reliability-related parts where possible within the cost cap.

The context seems to suggest the "structure the battery is attached to" refers to the front of the ICE, but is it possible Honda is referring to the chassis instead of (or as well as) the ICE? Late integration of the chassis and PU could have meant such a problem was not picked up until it was too late to resolve before testing. Pure speculation on my part.

https://www.the-race.com/formula-1/hond ... dentified/

Interestingly, honda ran into exactly the same problem with red bull in 2021

https://www.formu1a.uno/le-vibrazioni-d ... -red-bull/

[Rasoose]

Interestingly, honda ran into exactly the same problem with red bull in 2021

https://www.formu1a.uno/le-vibrazioni-d ... -red-bull/

I recall at the time, the short-term fix was simply dialing back the power mode of the ICE a bit, which they did mid-GP in Bahrain. It was believed that their 'ultra-fast combustion' technique was giving them some warning signs so they played it safe, without losing too much performance.
Perhaps it was simply to protect the ES/CE all along, and not the ICE. I know they went back to full power later in the season(France possibly), and they also had a battery/ES upgrade mid season (Netherlands) as well.

[organic]

Interestingly, honda ran into exactly the same problem with red bull in 2021

https://www.formu1a.uno/le-vibrazioni-d ... -red-bull/

I recall at the time, the short-term fix was simply dialing back the power mode of the ICE a bit, which they did mid-GP in Bahrain. It was believed that their 'ultra-fast combustion' technique was giving them some warning signs so they played it safe, without losing too much performance.
Perhaps it was simply to protect the ES/CE all along, and not the ICE. I know they went back to full power later in the season(France possibly), and they also had a battery/ES upgrade mid season (Netherlands) as well.

I had always heard it was ES related..

[Martin Keene]

I know some here talk down The Race's technical reporting, but this was interesting:

Honda observed abnormal vibrations that caused damage to the battery, although it is not sure whether the battery system itself is the initial problem. What Honda can see is the battery pack is being shaken because the structure it is attached to is vibrating more severely than expected.
Honda is investigating a combination of factors that likely caused these vibrations to emerge and running virtual track testing at its Sakura base with a chassis, engine and gearbox combined, but is yet to pinpoint the root cause.
"If we could identify a single cause, it would be easier to fix, but because multiple linked factors generate the vibration, we don't know whether fixing just one will solve it," said Takeishi.
Together with Aston Martin, Honda is assessing what countermeasures can be implemented on both the car and engine side - including what can be done before the season opener in Australia next weekend.
Aston Martin is willing to modify components on its car if necessary. Controlling the vibrations is critical for the engine's chances of running reliably in the early races of the season, which includes Honda's home grand prix in Japan at the end of March.
After managing the start of the season with interim measures, Honda will look to change reliability-related parts where possible within the cost cap.

The context seems to suggest the "structure the battery is attached to" refers to the front of the ICE, but is it possible Honda is referring to the chassis instead of (or as well as) the ICE? Late integration of the chassis and PU could have meant such a problem was not picked up until it was too late to resolve before testing. Pure speculation on my part.

https://www.the-race.com/formula-1/hond ... dentified/

I assume there are some electronics in the battery, such as the invertor, if that is the case then mounting the battery to the engine fully or partially is crazy, electronics hate the high frequency vibrations that engines create.

[Stu]

My takeaway from that report is that it sounds like a natural frequency issue, it could be related to the engine mounting creating a resonant frequency that is damaging the internal structure of the battery.

[Farnborough]

One aspect of these regulation is that on full potency regeneration, under maximum braking phase, they are passing very significant torque back through the whole crankshaft at unused before levels.

That's quite different from previous regeneration demand, also from a crankshaft normal operation in that torque from each successive piston "plane" accumulation as that collection moves toward the flywheel output.

Presumably there is a wave form characteristic of the MGU-K device that can also influence this demand, particularly at peak output.

Gear set drives are typically harsh in transferred frequency input, to shift that up or down dependent on ratio etc. Thats caught out the designers in many PU over the years, with mitigation or change in design to side step that eventuality.

A complex topic, that may or may not have a complex answer. The real "Art" is in fully identifying the cause firstly. Then to understand IF that can be moved or "phased" out of range in avoiding its destructive effect.