Showroom DIY hydraulic load cell pedals (best on earth.)

Hi !

I spent two years trying to build pedals. I tried everything, springs, elastomeres, air spring, hydraulic dampers and all the solutions available on the market... but nothing was near than realistic.

Then I moved to hydraulic pedals with a master cylinder, inspired by REALGEAR GTPRO3 XTREME TILTON pedals, that I had the pleasure to test. I didn't understand there design at first.

Then I got my hydraulic master cylinder and understood that there design was kind of...stupid. Effectively, they just put a hydraulic circuit to put pressure on urethane springs... that is useless. It's just like putting an hydraulic circuit to put pressure on the keys of a low quality keyboard, it won't improve anything. And effectively I didn't find those pedals really good.

Then I got an idea : why not recreate a real braking system ? It won't be so onerous ! So I bought a slave piston caliper and build the whole system and oh magic : it feels real ! Not real like better, but like real. You feel like you are driving a real car, with that hydraulic feeling, and same hard point etc. The difference is the same as going from gamepad to serious steering wheel ! It's not just better consistency or lap times improving, it's more about : "damm I drive a real car " !

Now you are probably asking how I managed to put the load cells in my system. I tried a lot of things, ending with this solution : placing load cell directly at the disk location ! I use load cells for human scales. This way, the piston put pressure on a metal part, like a real disk brake !!

For the moment I don't have a nice and shiny model, but it already feel great ! I will upload more pictures as my project is progressing ( I am building a 2DOF motion rig with diy steering wheel too).

Edit : I now use an hydraulic pressure sensor, it's plug and play. I had hard times trying to make load cell amplifiers work.

Great. But why not just use pressure transducer for 1000 psi. And build then what ever, with, or without calipers, drum brake cylinders. et.c.
https://www.xsimulator.net/community/threads/hydraulic-pedals-on-real-car-bedals-box.12649/

3 reasons :
1) pressure sensors are quite expensive

2) brake power is directly proportionnal to the pressure put on the disk brake, so it is more logical to get the measurement here.

3) I already tought about pressure sensor but i feared that you will get useless signal. I mean that if you put pressure on the pedal to move the brake pads to the disk, you will have signal before the brake pads touch the disk.

This is only my thoughts, i may be wrong right ?^^ but pressure sensors is probably the only thing i didn't try ^^

1) They goes for 20 bucks. Even less then load cell.
2/3) All of this can be set up. Weather in a game (axis dead zone), or by DXTweak2 utility for the brake axis of your controller. DXTweak2 is preferable.

Any way, Hydraulics is very DIY user friendly and is a good chose for it. If it's better for you to build it that way, NP and very interesting experience to note further on.

Any Caliper & LC photos?)

By the way. With those rubber pads, it's more likely that the pedal travel is simulated, for more common worked out brake system. Couse, in a new brake system state, a new car for example, there are no literally pedal travel but a very progressiva braking from the very beginning. And ofcourse, there are also some master and caliper cylinder diameter difference in compared to ordinary car and sport braking gear. So that also can be the reason. The distance for "pad touching the disk' it constantly has ~1mm between pads and a disk. So nothing much to simulate out there with it. With worked brake system state, there emereges a soft braking with that travel range any way. With vacuum booster in road car "off", the pedal travel also is all the same, depending on the brake system state, but just a different force range applied to the pedal.
So the whole bunch of stuff can be excluded, as is for that sake. I left direct connection of pressure transducer with no callipers or brake drums for that. )

Thanks for your reply. In fact I didn't find anything satisfying with rubber pads... The disk brake calipper just surpasses from far anything I tried before. And I got a progressive braking from the begining, even if the pistons put pressure on a metalic part.

I ordered a oil pressure sensor today. I hope that it will be more reliable that the INA122 circuit I use...

Pictures in attachment, the load cells just fit perfectly in it ^^

Cool.

Please also take a note on what thread is used. May be, some fitting will require. Or may be not) Depends.
As an example - "Adaptor 1/8" NPT Female to M10 x1.25mm Male for Brake Hose Connectors Fittings" as per full name of it.

Yep, I also ordered some adaptors !

Good)

@Lebois have you seen my setup : https://www.xsimulator.net/communit...ulic-load-cell-brake.14909/page-3#post-241842
I used a button type loadcell in a opposed piston caliper. after much tweaking I have it setup so it is a real brake and my braking in-game is superb. I can trail brake like a champion and modulation is so easy.
Now I just need to get a decent set of pedals to match the awesome hydraulic set up to.