Hydraulic Brake Build [V2] (G27 Based)

  • Thread starter pilmat
  • 154 comments
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pilmat
Seal compatibility with different fluids is an issue I didn't want to get into, but I might have too...
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That's why I suggested considering silicone brake fluid. It is for sure braking system seal compatible and plastic loves it too. Not sure about mineral fluid, have not looked into that. Silicone needs to be the only fluid in the system, it does not care for old brake fluid or left over moisture.
 
ravey1981
How about mineral oil? Its used in shimano mountain bike disc brakes and is non corrosive.
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Hmm,

Taking a sidestep on that, how about some oils used in the kitchen?
Olive oil, sunflower ( don't know the exact word) oil or soja oil?
Guess these are also plastic and inhouse envirement friendly.
And as a added benefit, easy to come by if a refill is needed.

Trying to contribute in the discussion ::)
 
RSwagoneer
Hmm,

Taking a sidestep on that, how about some oils used in the kitchen?
Olive oil, sunflower ( don't know the exact word) oil or soja oil?
Guess these are also plastic and inhouse envirement friendly.
And as a added benefit, easy to come by if a refill is needed.

Trying to contribute in the discussion ::)
Click to expand...

Mazola!!!! :lol:

You ARE contributing to the conversation 👍 Just as other users are (except kikie's milk :yuck:). (just poking fun kikie :))

The Dot 5 (silicone) suggestion is also interesting except for the material cost and it's poor compatibility and lubricity.

I'll look into how the seals react to simple kitchen oils. I'm leaning towards olive oil as it has good lubricity...
 
mineral oil will do just fine with no compatibility issues.as long as it is a 5 weight or less
the reason why i say that is because anything higher could cause a problem with pressure release from the transducer ( slow to release )
several oem companies use it in there clutch systems.
one example is KTM Motorcycles - they use it in there clutch master cylinders
5 weight motorcycle fork oil should do fine as well.
one thing for sure is you will not have to worry about fluid boiling.
 
novadave
mineral oil will do just fine with no compatibility issues.as long as it is a 5 weight or less
the reason why i say that is because anything higher could cause a problem with pressure release from the transducer ( slow to release )
several oem companies use it in there clutch systems.
one example is KTM Motorcycles - they use it in there clutch master cylinders
5 weight motorcycle fork oil should do fine as well.
one thing for sure is you will not have to worry about fluid boiling.
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What do you mean with 5 weight or less? Viscosity? I could imagine that for a fast response hydraulic system the viscosity of the used oil shouldn't be on the lower side.
 
Why not using organic brake fluid. It's not that agressive. I believe that the Perfect Pedal uses organic brake fluid. Can't find the info anymore.
 
RSwagoneer
What do you mean with 5 weight or less? Viscosity? I could imagine that for a fast response hydraulic system the viscosity of the used oil shouldn't be on the lower side.
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Hi.
#1 - in this case the viscosity should be as low as possible so as to not effect the return of the brake master piston. the return orifice in these masters is extremely small and if the oil is too thick it would inhibit the return response of the pedal. in this case the only way for the piston to return is from the internal spring of the master. if it was installed in a automotive application there would be other devices used to help in the return of the pedal.
#2 - the transducer also has a very small orifice which if used with a higher viscosity oil would also reduce the response of the signal produced when applying and releasing the pedal.
all brake fluids have a viscosity equivalant of about 2.5 so as to not effect braking in colder climates due to changes in viscosity and to not hinder brake responsiveness..

to put it simply - a thick oil would damper both brake application and release.
 
Have you considered starting with a real solid pedal set like this (Tilton Pedals) and add all the electronics to it?

Link to Ebay Motors

$T2eC16N,!zcE9s4g09trBQko9kUpww~~60_12.JPG


Link to more pedals.
 
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lol Radracing, read the sim brake thoughts thread....you will see where all this came from... and the DIY hydraulic brake thread...they are all pretty much interlinked
 
ravey1981
lol Radracing, read the sim brake thoughts thread....you will see where all this came from... and the DIY hydraulic brake thread...they are all pretty much interlinked
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:) Thanks! I wasn't sure how to answer that one as we'd already talked about those exact pedals.



A little update for today: Olive oil and Dot 3 seem to play well together!
​
Here the two have been mixed and stirred several times. It looks like oil and vinegar mixing.


I'll flush the system tomorrow with the olive oil and see how it goes. Fingers crossed :scared:

I chose "light" olive oil too! :lol:
 
:lol: Olive in the brakes and Popeye's Spinach to give the clutch and/or thottle a better feel :P

Jokes aside, I hope it works!
 
Mayaman
Wont an organic oil go rancid?
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Good question, light and oxigen are usualy the reason for oil to go rancid, so it should be safe inside the braking system, also going rancid might not affect its fluidity so might not be a factor anyway. Might not be fit anymore for ingestion after use in a SIM. LOL
 
Today I finally got to put some time into the project :)

I had a 1/4" aluminum plate made. It is designed to fit the stock G27 cover still, but only with 6 screws as the cover is no longer stressed. The attachment on a Human Racing GT Chassis is through the threaded plates in the gas and clutch pedal, so those holes are still provided. The 4 screws used to mount the gas and clutch are still there, but I have only used 2 in this config as they really are there to hold things until you get the main screws in (the 4 attaching to the rig). The brake provision has been made for the hydraulic mount only. The other major change is that everything is now made for countersunk screws (flush mount to the bottom of the base plate). Oh, and no carpet gripper... :lol:

Here you can see the 6 flush mount screws to hold on the cover (there really is a cover in the dark photo!):

And this is what the pedals look like installed:

And with the G27 wiring. Note the brake wiring is "capped and stowed":

And installed:

You will note that the elastomer stack is again changed. I really liked the feel with this stack. I tried a softer middle barrel bushing but it was too much. With the previous Doh-Doh blue there was not enough modulation (my opinion).

The amp is set at about 75-80% from no amplification (or minimum). This gives about 3600 steps of resolution at approximately 300 psi pressure. The control harmony at this point was very much to my liking.

And how does it feel? There feels like ZERO base plate flex now :D The progressiveness of the pedal and the super smooth release for accurate trail braking is unparalleled by any other brake solution I have tried. This thing is just AWESOME!!

Now that I have a stable platform, and hopefully iRacing doesn't change the tire model on me again this week :rolleyes:, I can work at doing a video. It MIGHT happen tomorrow if I decide to NOT take a day off (I'm allowed one a month, right?).
 
Mayaman
F'ing sweet! Might have you make me a G27 heal plate like that. Nice work man.
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LOL, the plate is a reaction to the hacked cover. I got the pedals for nothing (as you could imagine) and I shoved them into a corner as I didn't want anybody to think I did that :embarrassed:. But as the hydraulic build idea started in the Sim Brake Thoughts thread, I pulled these out as a donor. Our fabricator knocked this out when he saw I was taking pictures of the thing with the hacked off end!

It would be pretty easy to make one to fit a coverless G27 set ;) In fact I like smooth heal plates, like taking the one off the T500 pedals :D
 
ravey1981
Great progress, and excellent quality of work. I love it. Keep up the good work!
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Carson79
Great idea and well done on an excellent job!
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Thank you :)

A summary parts list of what is working and also a "junk pile" of weenie parts.
Current Configuration:
  1. G27 Pedals, complete. These are stripped and the following parts are kept:
    • Gas pedal, complete
    • Clutch pedal, complete
    • Wire harness, brake wires capped and stowed
    • Cover plate, modified for brake pedal mount and master cylinder clearance
  2. King Autosport G27 1/4" Aluminum Base Plate
  3. CNC Steel Pedal with Master Cylinder Mount. The steel pedal is modified to suit sim application, including a mount to accept the stock G27 pedal pad.
  4. CNC Slave Cylinder
  5. Wilwood 5/8 bore Master Cylinder
  6. -3 plumbing between master and slave cylinders
  7. Mounting clamp for slave cylinder
  8. (optional) Brake pressure gauge
  9. Elastomer stack and washers. My current stack is:
    • 2x Doh-Doh Black Barrel (100a)
    • 2x Doh-Doh Blue Cone (88a)
    • 1x Khiro Orange Barrel (78a)
  10. Millivolt Pressure Sensor: M3421-000006-01KPG
  11. DSD Pedal Pal (for connecting the gas and clutch to the main control board)
  12. DSD 12-bit Control Board with Integrated Amp (sorry Derek, I had to take "load cell" out of the title :D)
  13. "Brake" fluid
  14. Fist full of hardware. Things like the screw changes for countersunk in the base plate, clamp mounts, cylinder mounts, etc.

The "junk" pile:
  1. CNC 3/4" Bore Master Cylinder
  2. G27 stock base plate... Including brake pedal adapter plate
  3. Bag full of elastomers
  4. Small pile of hydraulic fittings and 1 hose (thankfully I can recycle these onto race cars :lol:)
 
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pilmat
Thank you :)

A summary parts list of what is working and also a "junk pile" of weenie parts.
Current Configuration:
  1. G27 Pedals, complete. These are stripped and the following parts are kept:
    • Gas pedal, complete
    • Clutch pedal, complete
    • Wire harness, brake wires capped and stowed
    • Cover plate, modified for brake pedal mount and master cylinder clearance
  2. King Autosport G27 1/4" Aluminum Base Plate
  3. CNC Steel Pedal with Master Cylinder Mount. The steel pedal is modified to suit sim application, including a mount to accept the stock G27 pedal pad.
  4. CNC Slave Cylinder
  5. Wilwood 5/8 bore Master Cylinder
  6. -3 plumbing between master and slave cylinders
  7. Mounting clamp for slave cylinder
  8. (optional) Brake pressure gauge
  9. Elastomer stack and washers. My current stack is:
    • 2x Doh-Doh Black Barrel (100a)
    • 2x Doh-Doh Blue Cone (88a)
    • 1x Khiro Orange Barrel (78a)
  10. Millivolt Pressure Sensor: M3421-000006-01KPG
  11. DSD Pedal Pal (for connecting the gas and clutch to the main control board)
  12. DSD 12-bit Control Board with Integrated Amp (sorry Derek, I had to take "load cell" out of the title :D)
  13. "Brake" fluid
Click to expand...

The thickness of that plate :scared:
Looks like it could withstand all you can throw at it.
Did you had a go with the olive oil? Or are you satisfied with how it is now?
 
Man, I am so scared to venture my mind into this topic, worry I might not be able to stop lol. That is pure engineering beauty Pilmat.
 
RSwagoneer
The thickness of that plate :scared:
Looks like it could withstand all you can throw at it.
Did you had a go with the olive oil? Or are you satisfied with how it is now?
Click to expand...

You grabbed that quote in between me clicking "preview" and "submit". :lol: I shouldn't be on here without any coffee in my system...

The plate thickness was really simple economics, 3/16 was only a couple of bucks less! And it gives me lots of meat for the countersunk 1/4" diameter screws that mount the brake pedal. There is still almost 1/8" of straight material with the countersink screw flush to the bottom. Plus it means there is no shimming required to mount the plate in the G27 cover, it is basically the thickness of the stock molded plastic one.

I have not changed the fluid yet. When I took the pedals apart after the base plate melt down, I kept the hydraulic system together (no need to re-bleed). I finished this much later than I wanted yesterday, and flushing the system dropped incredibly low on my priority list :grumpy:

As for the fluid, I'll be building another couple of conversions (one for me at home :)). The first one I do will get the olive oil treatment!
 

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