Are pneumatic pedals as reliable as those based on elastomers? (NT)

[Elaphe]

I've already ordered the pedals (GTR black ed. with red pads and heel rest), so I'll tell you when they arrive and I install and test them. I've also cut a 8mm thick aluminium plate to keep on using the same sliding system I already have: manual nuts over longitudinal profiles. The baseplate provided with the pedals already have some slots, but they only allow 1,5 cm forwards and backwards.

Please don't laugh at my 3D modelling skills.

Oh, if you are interested, there's a 10% discount for preorders for when the pedals are back on stock on 15th december.

 

[Bob73]

But late in seeing this thread… simworx also use pneumatic cylinders on their pedal set.

https://www.simworx.com.au/controls/pro-gt-v3-1-lc

 

[Neilski]

But late in seeing this thread… simworx also use pneumatic cylinders on their pedal set.

Am confused... The SRG video description mentions pneumatic damping. The product at the Simworx link mentions hydraulics (for damping and possibly more?) but not a single mention of pneumatics.
Were you thinking of another product?

 

[Bob73]

Am confused... The SRG video description mentions pneumatic damping. The product at the Simworx link mentions hydraulics (for damping and possibly more?) but not a single mention of pneumatics.
Were you thinking of another product?

The cylinder used on the throttle is pneumatic, you can see the bolts with the vents at top and bottom of the cylinder.
The cylinder on the brake has a vented bolt at the top of the cylinder and a sealed bolt at the bottom so I would assume the cylinder is now holding a fluid of some type.

 

[Neilski]

The cylinder used on the throttle is pneumatic, you can see the bolts with the vents at top and bottom of the cylinder.
The cylinder on the brake has a vented bolt at the top of the cylinder and a sealed bolt at the bottom so I would assume the cylinder is now holding a fluid of some type.

What you say sounds entirely plausible but I'm baffled that a company would fail to mention anywhere in the product sales info (or the product manual - I just checked) that there are pneumatics involved. They don't even mention the pneumatic dampers. Freaky.
I didn't watch the SRG video (obvs, cos it's more than one hour long! ) but perhaps it comments on them?

What's your own view on how/why/where pneumatics are better than mechanical springs?

 

[Deleted member 197115]

What's your own view on how/why/where pneumatics are better than mechanical springs?

Pneumatics is always better, look at Citroën 2CV suspension, can withstand anything.

 

[stigs2cousin]

Pneumatics is always better, look at Citroën 2CV suspension, can withstand anything.

That´s what you get for believing a word Clarkson says

Sources:

Les suspensions de la 2CV – Le site référence sur la 2CV

Citroën’s Innovative Hydropneumatic Suspension — A Result of Adaptive Engineering

It was really the combination of adoption and innovation that was the formula for Citroën being distinct in automotive market.

citroenvie.com

HYDRO Pneumatic was the selling point of the De´Esse aka "the Goddess"
Quite a bit over the price point of the 2CV.

I concurre that the 2CV felt like "driving on air" (which was always a horror for me as I like my cars firmly planted on the earth) but for the asking price of a 2CV ( a pig and two chicken) there was no pneumatics involved.

 

[Neilski]

HYDRO Pneumatic was the selling point of the De´Esse aka "the Goddess"
Quite a bit over the price point of the 2CV.

I concurre that the 2CV felt like "driving on air" (which was always a horror for me as I like my cars firmly planted on the earth) but for the asking price of a 2CV ( a pig and two chicken) there was no pneumatics involved.

I drove a BX for several years, and there were times when I was glad of the trick suspension...

 

[Bob73]

What you say sounds entirely plausible but I'm baffled that a company would fail to mention anywhere in the product sales info (or the product manual - I just checked) that there are pneumatics involved. They don't even mention the pneumatic dampers. Freaky.
I didn't watch the SRG video (obvs, cos it's more than one hour long! ) but perhaps it comments on them?

Yes there Is a distinct lack of decent info on these pedals from either the website or from gear reviewers. I don’t recall Barry @ SRG going into much detail about the cylinders on the throttle or the brake. The review by FLOEB sim racing on the v3.0 was the same. There was a third review I came across on v3.1 but that was in Japanese, and I don’t think YouTube had got the auto translate working when I came across it a few years ago.
There used to be a Facebook group but that’s been deleted for some reason.

What's your own view on how/why/where pneumatics are better than mechanical springs?

Unfortunately I haven’t been able to use different pedal systems so can’t comment on whether pneumatics are better or worse than springs. For me the modified pneumatics caught my attention as a possible alternative to using a hydraulic oil based set up.

 

[blekenbleu]

I don’t recall Barry @ SRG going into much detail about the cylinders on the throttle or the brake

Barry went into detail about the throttle cylinder, which contains a spring.
Its piston and filter plugs are mostly about damping.

 

[Neilski]

Barry went into detail about the throttle cylinder, which contains a spring.
Its piston and filter plugs are mostly about damping.

OK that's wacky, cos it has a separate damper (or what looks like a damper) in the pic above

 

[blekenbleu]

a separate damper

Nope, that is a Hall effect linear position transducer.

 

[Neilski]

Nope, that is a Hall effect linear position transducer.

Holy smoke!

 

[Neilski]

Yes there Is a distinct lack of decent info on these pedals from either the website or from gear reviewers. I don’t recall Barry @ SRG going into much detail about the cylinders on the throttle or the brake. The review by FLOEB sim racing on the v3.0 was the same. There was a third review I came across on v3.1 but that was in Japanese, and I don’t think YouTube had got the auto translate working when I came across it a few years ago.

OK so my curiosity got the better of me and I watched the majority of Barry's review. (Thank heavens for 2x on YouTube! )
From what I saw, the accel pedal is unambiguously not a pneumatic spring; it's pneumatic for damping only, plus a mechanical spring (Barry could feel the air pushing in/out through both vented plugs).
The brake pedal is a weird one - a vented plug at the top, as you mentioned, and a sealed plug at the bottom.. so maybe hydraulic. However, Barry made no mention of that and the manual does no better, but yet the product page proudly says "Hydraulically loaded Load Cell brake". (I can't get my head around a manual not mentioning hydraulics if they are truly present.)
Frankly I'm also 100% unable to understand how the video footage of Barry driving is reconcilable with there being any hydraulics present - the brake pedal piston goes a loooong way into the cylinder, and if there were liquid in there, where could it possibly be going? (NB: I have no personal experience with hydraulics pedals so I may be missing something obvious and crucial here. Also, the video didn't reveal the position of the load cell so I know I have holes in my understanding of the unit.)

 

[Bob73]

OK so my curiosity got the better of me and I watched the majority of Barry's review. (Thank heavens for 2x on YouTube! )
From what I saw, the accel pedal is unambiguously not a pneumatic spring; it's pneumatic for damping only, plus a mechanical spring (Barry could feel the air pushing in/out through both vented plugs).
The brake pedal is a weird one - a vented plug at the top, as you mentioned, and a sealed plug at the bottom.. so maybe hydraulic. However, Barry made no mention of that and the manual does no better, but yet the product page proudly says "Hydraulically loaded Load Cell brake". (I can't get my head around a manual not mentioning hydraulics if they are truly present.)
Frankly I'm also 100% unable to understand how the video footage of Barry driving is reconcilable with there being any hydraulics present - the brake pedal piston goes a loooong way into the cylinder, and if there were liquid in there, where could it possibly be going? (NB: I have no personal experience with hydraulics pedals so I may be missing something obvious and crucial here. Also, the video didn't reveal the position of the load cell so I know I have holes in my understanding of the unit.)

Good to read curiosity got the better of you

The Facebook group had some useful information on how the pedals worked but it’s no longer active and you can’t get into it to read the posts. It wouldn’t surprise me if there is an Australian discord group as I got the impression these are a popular pedal set there as they are based on a v8 super car style pedal box, but I haven‘t found it yet.

The load cell is at the base of the cylinder.

I had a look at Barry’s video again regarding the travel on the brake pedal. There are two adjustments on the brake. The first is the spring at the top of the cylinder. That controls the initial travel of the piston rod into into the cylinder. So I guess this simulates the pads engaging the brake disc?? Under the cylinder is large disc type nut that drives down onto what we know as an elastomer. This controls the final “feel” of the pads and disc once they are engaged if that makes sense..?? The questionable cylinder with its air vent and its mysterious liquid fill helps bring it all together to achieve the final result of simulating the brake pedal in a v8 super car. The v2 version the brake pedal was rated at 200kg the v3.1 has been toned down to 140 kg

 

[Neilski]

The load cell is at the base of the cylinder.

Aha, had failed to spot the cable...

There are two adjustments on the brake. The first is the spring at the top of the cylinder. That controls the initial travel of the piston rod into into the cylinder. So I guess this simulates the pads engaging the brake disc?? Under the cylinder is large disc type nut that drives down onto what we know as an elastomer. This controls the final “feel” of the pads and disc once they are engaged if that makes sense..?? The questionable cylinder with its air vent and its mysterious liquid fill helps bring it all together to achieve the final result of simulating the brake pedal in a v8 super car.

Yeah, the whole thing still has me 100% confused.
If the piston that drives the air back and forth through the vented plug has another piston below it (touching the liquid), with the pistons coupled with another hidden spring, then that (a) would explain the behaviour and (b) would be pretty barmy. If that's not what's inside the cylinder then I am not sure what to think, cos the rod moves a long way into the cylinder - it's not just flexing of the whole assembly against the elastomer.
Or just a slug of air between the liquid and the piston? That would be awful, surely...

I still can't imagine how the liquid is delivering any extra realism/feel here - there is clearly no hydraulic line coupled to a caliper. And if it's just a bit of liquid in the bottom of a cylinder, pressing on a load cell (outside the liquid? hmm) then surely a solid block in place of the liquid would produce precisely the same feeling... I mean how could you possibly tell that the hydraulics have been removed if the liquid doesn't flow at all? (If it flows, where to? Sorry, I'm spiralling here, I'll stop now! )

 

[Bob73]

Sounds like some retail therapy is required buy a set for further investigation

 

[Elaphe]

Pedals received and installed.

 

[Elaphe]

Pedals tested. Ergonomically they feel great, good size, default inclination is right for my sitting position, excellent pedal faces, good distance between them and everything feels sturdy with no play. The pedals come in their lightest settings, which I find adequate. Even with these settings the brake is too hard for me and I had to adjust the max force in the software. The throttle is smooth, with not very long travel and has some dampening at the end. The brake feels quite natural and controlling the preasure is easy because the default travel is fine and helps too. The difference with elastomers is not night and day, but it's there. I have found problems with the COMs interfering with my NJMotion Compact R (it stops working). It's weird because the pedals use COM10 and the seat mover uses COM5. However, I think this only happens when I load the software to calibrate and adjust the pedals. I'll investigate this issue.

 

[Neilski]

However, I think this only happens when I load the software to calibrate and adjust the pedals.

I wonder if the software scans all COM ports...?