Mercedes-Benz 300 SLR working air brake is it possible ?
- Thread starter ling
- Start date
were are the flaps parameters ? HDV file ?
and could the air brake be animated to open when the brakes are applied and close when the brakes are off ?
thanks
mantasisg
Registered
I don't know anything about the animations. IIRIC there is some way to manipulate controller file to have flaps activated with pedal inputs, but then they still don't work in the right way iiric. Because you'd want it to go on with pressed pedal, and off with released pedal, but it will more likely work like a button even with pedal. So perhaps just have it assigned to button. Was the real car actuating it with pedal ?
Heres how I had it for 1967 pack xF car for rear wing:
Perhaps you can edit it from there, just hit much more drag, and much less downforce with activated air brake. Also make it so the forces are applied to subbodies, not spindles.
We always had one big issue with this car though, never solved. Even though AI was operatign flaps properly, for some reason they would always have lower top speed than they should. We never figured out why it was like that.
Also iiric the way flap effects are added up is not entirely simple and intuitive, I think I had worked it out, I need to look at old conversations.
Heres how I had it for 1967 pack xF car for rear wing:
Code:
[REARWING]
RWForceDistrib=(0.5:RL_SPINDLE,0.5:RR_SPINDLE)
RWRange=(0, 1, 1) // rear wing range
RWSetting=0 // rear wing setting
RWDragParams=( 0.108, 0.015, 0.0001) // base drag and 1st and 2nd order with setting //( 0.045, 0.012, 0.0001)
RWLiftParams=(-0.232, 0.009, 0.0002) //was (-0.122,-0.03, 0.0002) base lift and 1st and 2nd order with setting
RWDraftLiftMult=1.05 // effect of draft on rear wing's lift response
RWLiftSideways=(0.31) // dropoff in downforce with yaw (0.0 = none, 1.0 = max)
RWLiftPeakYaw=(3, 1.01) // angle of peak, multiplier at peak
RWLeft=(-0.29, 0.03, 0.00) // aero forces from moving left
RWRight=(0.29, 0.03, 0.00) // aero forces from moving right
RWUp=( 0.00,-0.315, 0.010) // aero forces from moving up
RWDown=( 0.00, 0.308,-0.002) // aero forces from moving down
RWAft=( 0.00, 0.090,-0.005) // aero forces from moving rearwards
RWFore=( 0, 0, 0)
RWRot=(0.060, 0.040, 0.100) // aero torque from rotating
RWCenter=(0.0, 1.15, 0.71) // center of rear wing forces (offset from center of rear axle at ref plane)
//REAR WING FLAP
FlapDrag=(0.001,0.09) // base drag when activated, multiplier by deactivated drag to add in //0.005
FlapLift=(0.21,1.0) // base lift when activated, multiplier by deactivated lift to add in //0.27
FlapTimes=(0.5,0.55,0.5,0.55) // visual activation, physical activation, visual deactivation, physical deactivation
FlapRules=(-1.0,2.0) //(0.5,0.03)// throttle threshold, brake threshold for automatic deactivation //(-1.0,2.0)Perhaps you can edit it from there, just hit much more drag, and much less downforce with activated air brake. Also make it so the forces are applied to subbodies, not spindles.
We always had one big issue with this car though, never solved. Even though AI was operatign flaps properly, for some reason they would always have lower top speed than they should. We never figured out why it was like that.
Also iiric the way flap effects are added up is not entirely simple and intuitive, I think I had worked it out, I need to look at old conversations.
the real car used a lever to activate it i think, i found this.
"A hydraulic pump driven from the back of the transmission provided power for the second electrifying innovation of Le Mans: the air brake.
The 300SLR's air brake worked on a completely different principle than the rooftop brake that had appeared so dramatically and briefly in practice at Le Mans in 1952. It also kept on working reliably in spite of the tremendous forces it was asked to withstand.
The air brake's surface was formed as a second skin over the full width of the body just behind the seats. When it was down, a body-surface moulding along its front edge prevented air from getting under it and flipping it up prematurely. Made like an airplane wing with interlocking ribs and stringers skinned with light-alloy sheet, the brake was hinged at its rear edge to the inner frame structure of the car. It had a single small plexiglas window in it at first; a second was added at the request of the Le Mans scrutineers.
Two operating rods reached up out of the deck to connections on the air brake surface. The one on the left came from a shock absorber whose only chore was to damp the violent impact of the brake's opening at high speed. The right-hand rod came from the hydraulic cylinder that made it work. It was powered by engine oil, drawn from the main reservoir and brought to a pressure of 220 p.s.i. by a special pump at the back of the gearbox. From the pump the oil went to a control valve on the instrument panel, moved by a protruding lever, and then to the operating cylinder.
When the brake was folded down, pressure was automatically maintained on the piston to hold it in the `down' position. When the driver flicked the control lever up it prompted the cylinder to elevate the brake. After the car had been slowed and the corner taken, the cylinder was signalled to pull the panel down again either by a further movement of the control lever or by an interlock with the gear-lever gate, depending on the way the car was set up.
The brake panel, which included the headrest on its upper surface, had an effective area of 7½ square feet. Drivers found it to be very powerful, slowing the car at a rate of 0.31 g. at 175 mph, diminishing to 0.27 g. at 150 mph.
John Fitch first tried it at Hockenheim, where a full 24-hour Le Mans dress rehearsal was scheduled with the only complete spare 300SLR during the week before the race. The test was cancelled when the car was written off by a factory test driver, but Fitch had already noted that "an unexpected bonus from the new device was the stabilising effect it had on the car through fast bends.
"Since the centre of its air resistance was behind the centre of gravity of the whole car," Fitch concluded, "it felt as though the rear of the Mercedes was held into the curves against its normal tendency to drift out as if restrained by some invisible but delicately handled cable. Although there was a good deal of wind buffeting when the flap was up, the total result was most satisfactory." Like the men who designed the brake, Fitch was aware that it offered special advantages when the road surface was slippery, since its retardation was unaffected by road conditions.
Stirling Moss interpreted its effect differently when he first tried the air brake at Le Mans, saying that "this device increased rear-tyre adhesion due to aerodynamic download. I first discovered this download effect as the flap was on its way down after I had used it to slow into the tricky White House bends. With it still lowering and loading up the rear wheels I found I could apply the power earlier and harder than normal. I wrote in my diary, `The airbrake was fantastic!'."
Rudolf Uhlenhaut further elaborated on the advantages of the `wind brake' as quoted by Briton Rob Walker: "He said that if you were to take a course like the Swedish Grand Prix, where there was one corner which started as a very fast one, then suddenly tightened up on you; if you braked hard in the middle of the corner where it tightened up, it would naturally tend to send the car out of control, but if you used your wind brake in the same position it would tend to give you more control and hold the tail down, rather than making it difficult; in fact it generally helped the cornering ability of the car."
The Swedish G.P. at Kristianstad, the next event after Le Mans on the Stuttgart schedule, was the only other race in which the air brake was used."
"A hydraulic pump driven from the back of the transmission provided power for the second electrifying innovation of Le Mans: the air brake.
The 300SLR's air brake worked on a completely different principle than the rooftop brake that had appeared so dramatically and briefly in practice at Le Mans in 1952. It also kept on working reliably in spite of the tremendous forces it was asked to withstand.
The air brake's surface was formed as a second skin over the full width of the body just behind the seats. When it was down, a body-surface moulding along its front edge prevented air from getting under it and flipping it up prematurely. Made like an airplane wing with interlocking ribs and stringers skinned with light-alloy sheet, the brake was hinged at its rear edge to the inner frame structure of the car. It had a single small plexiglas window in it at first; a second was added at the request of the Le Mans scrutineers.
Two operating rods reached up out of the deck to connections on the air brake surface. The one on the left came from a shock absorber whose only chore was to damp the violent impact of the brake's opening at high speed. The right-hand rod came from the hydraulic cylinder that made it work. It was powered by engine oil, drawn from the main reservoir and brought to a pressure of 220 p.s.i. by a special pump at the back of the gearbox. From the pump the oil went to a control valve on the instrument panel, moved by a protruding lever, and then to the operating cylinder.
When the brake was folded down, pressure was automatically maintained on the piston to hold it in the `down' position. When the driver flicked the control lever up it prompted the cylinder to elevate the brake. After the car had been slowed and the corner taken, the cylinder was signalled to pull the panel down again either by a further movement of the control lever or by an interlock with the gear-lever gate, depending on the way the car was set up.
The brake panel, which included the headrest on its upper surface, had an effective area of 7½ square feet. Drivers found it to be very powerful, slowing the car at a rate of 0.31 g. at 175 mph, diminishing to 0.27 g. at 150 mph.
John Fitch first tried it at Hockenheim, where a full 24-hour Le Mans dress rehearsal was scheduled with the only complete spare 300SLR during the week before the race. The test was cancelled when the car was written off by a factory test driver, but Fitch had already noted that "an unexpected bonus from the new device was the stabilising effect it had on the car through fast bends.
"Since the centre of its air resistance was behind the centre of gravity of the whole car," Fitch concluded, "it felt as though the rear of the Mercedes was held into the curves against its normal tendency to drift out as if restrained by some invisible but delicately handled cable. Although there was a good deal of wind buffeting when the flap was up, the total result was most satisfactory." Like the men who designed the brake, Fitch was aware that it offered special advantages when the road surface was slippery, since its retardation was unaffected by road conditions.
Stirling Moss interpreted its effect differently when he first tried the air brake at Le Mans, saying that "this device increased rear-tyre adhesion due to aerodynamic download. I first discovered this download effect as the flap was on its way down after I had used it to slow into the tricky White House bends. With it still lowering and loading up the rear wheels I found I could apply the power earlier and harder than normal. I wrote in my diary, `The airbrake was fantastic!'."
Rudolf Uhlenhaut further elaborated on the advantages of the `wind brake' as quoted by Briton Rob Walker: "He said that if you were to take a course like the Swedish Grand Prix, where there was one corner which started as a very fast one, then suddenly tightened up on you; if you braked hard in the middle of the corner where it tightened up, it would naturally tend to send the car out of control, but if you used your wind brake in the same position it would tend to give you more control and hold the tail down, rather than making it difficult; in fact it generally helped the cornering ability of the car."
The Swedish G.P. at Kristianstad, the next event after Le Mans on the Stuttgart schedule, was the only other race in which the air brake was used."
svictor
Registered
Rear flap animation can be done by adding pivot point to the object that needs to be rotated. If you work with 3dsimed, you can do this by:
1. open "air brake" object in 3dsimed via "Import as objects". Note, the "rear flap" object must be a separate object from other car parts.
2. Select the object, on "Object instance Edit" panel, click [+] button and select "pivot point set to geometic center". Then write down "X Pivot" value from "Tag Attributes > Pivot Point".
3. find and set the rotation center on Y & Z axis. You can do this by move mouse cursor to the rotation center of the object and "right click" > "Memorize XYZ", then open notepad and hit "Ctrl+V" to paste down XYZ coordinates. In this case it would be somewhere near the bottom of the "air brake piece" object.
4. fill in each XYZ Pivot in "Tag Attributes > Pivot Point" with "X Pivot" value that you were written down from step 2, and YZ Pivot from step 3.
5. set object as "moveable", and export the new GMT file, done. You can also preview rotation in 3dsimed by adjusting "Rotation > Pitch" value with mouse wheel, just remember to set value back to zero before export.
Last, in Cockpitinfo.ini file, add following line:
RearFlapOriChange=(45.0, 0.0, 0.0) // pitch, yaw, roll angle
And in GEN file, add something like:
Instance=REARFLAP
{
Moveable=True
MeshFile=rear_flap.gmt CollTarget=False HATTarget=False LODIn=(0.0) LODOut=(800.0) ShadowCaster=(True, Solid) Reflect=True
}
1. open "air brake" object in 3dsimed via "Import as objects". Note, the "rear flap" object must be a separate object from other car parts.
2. Select the object, on "Object instance Edit" panel, click [+] button and select "pivot point set to geometic center". Then write down "X Pivot" value from "Tag Attributes > Pivot Point".
3. find and set the rotation center on Y & Z axis. You can do this by move mouse cursor to the rotation center of the object and "right click" > "Memorize XYZ", then open notepad and hit "Ctrl+V" to paste down XYZ coordinates. In this case it would be somewhere near the bottom of the "air brake piece" object.
4. fill in each XYZ Pivot in "Tag Attributes > Pivot Point" with "X Pivot" value that you were written down from step 2, and YZ Pivot from step 3.
5. set object as "moveable", and export the new GMT file, done. You can also preview rotation in 3dsimed by adjusting "Rotation > Pitch" value with mouse wheel, just remember to set value back to zero before export.
Last, in Cockpitinfo.ini file, add following line:
RearFlapOriChange=(45.0, 0.0, 0.0) // pitch, yaw, roll angle
And in GEN file, add something like:
Instance=REARFLAP
{
Moveable=True
MeshFile=rear_flap.gmt CollTarget=False HATTarget=False LODIn=(0.0) LODOut=(800.0) ShadowCaster=(True, Solid) Reflect=True
}
I must be doing something wrong, i ended up with thisRear flap animation can be done by adding pivot point to the object that needs to be rotated. If you work with 3dsimed, you can do this by:
1. open "air brake" object in 3dsimed via "Import as objects". Note, the "rear flap" object must be a separate object from other car parts.
2. Select the object, on "Object instance Edit" panel, click [+] button and select "pivot point set to geometic center". Then write down "X Pivot" value from "Tag Attributes > Pivot Point".
3. find and set the rotation center on Y & Z axis. You can do this by move mouse cursor to the rotation center of the object and "right click" > "Memorize XYZ", then open notepad and hit "Ctrl+V" to paste down XYZ coordinates. In this case it would be somewhere near the bottom of the "air brake piece" object.
4. fill in each XYZ Pivot in "Tag Attributes > Pivot Point" with "X Pivot" value that you were written down from step 2, and YZ Pivot from step 3.
5. set object as "moveable", and export the new GMT file, done. You can also preview rotation in 3dsimed by adjusting "Rotation > Pitch" value with mouse wheel, just remember to set value back to zero before export.
Last, in Cockpitinfo.ini file, add following line:
RearFlapOriChange=(45.0, 0.0, 0.0) // pitch, yaw, roll angle
And in GEN file, add something like:
Instance=REARFLAP
{
Moveable=True
MeshFile=rear_flap.gmt CollTarget=False HATTarget=False LODIn=(0.0) LODOut=(800.0) ShadowCaster=(True, Solid) Reflect=True
}
and when i press the brake nothing happens
but thanks
svictor
Registered
You will need to setup HDV with proper physics and rear flap condition trigger (as the "FlapRules" parameter mentioned by @mantasisg) before it can work properly.
Normally rear flap(DRS) only works and animates when you first activated it via rear flap button and also in DRS zone (as you would with other DRS cars), then the wing (or whatever is the rear flap object) will rotate according to pivot point(rotation center). And when you trigger one of the rear flap deactivation conditions (some common condition like coasting, braking, etc), the rear flap will return to its initial position.
However, in your case, you want rear flap to activated on brake (without press rear flap button), and deactivate when not braking, which is completely the opposite of how RF2's rear flap (DRS) normally works. Normally if rear flap button is not pressed, rear flap simply won't activate, and usual condition is that rear flap deactivates on braking (as set in "FlapRules" parameter for deactivation condition), and you will probably have to manually press rear flap button at the same when braking to simulate it. I don't know if there is a way to "auto-activate" rear flap. You may try mantasisg's tweaks in HDV see if works.
Normally rear flap(DRS) only works and animates when you first activated it via rear flap button and also in DRS zone (as you would with other DRS cars), then the wing (or whatever is the rear flap object) will rotate according to pivot point(rotation center). And when you trigger one of the rear flap deactivation conditions (some common condition like coasting, braking, etc), the rear flap will return to its initial position.
However, in your case, you want rear flap to activated on brake (without press rear flap button), and deactivate when not braking, which is completely the opposite of how RF2's rear flap (DRS) normally works. Normally if rear flap button is not pressed, rear flap simply won't activate, and usual condition is that rear flap deactivates on braking (as set in "FlapRules" parameter for deactivation condition), and you will probably have to manually press rear flap button at the same when braking to simulate it. I don't know if there is a way to "auto-activate" rear flap. You may try mantasisg's tweaks in HDV see if works.
Last edited:
it would of been nice to see in rfactor 2 but as I only use a xbox 360 controller i think i will give up on this and get back to playing the game.
but thanks for your help.