Page 1 of 3 123 LastLast
Results 1 to 10 of 21
  1. #1
    75+ Posting Member



    Join Date
    Sep 2013
    Location
    California, USA
    Posts
    109
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Hydraulic Brakes

    Hi Guys, I have a pedal set from a PA28, all 4 toe brakes have hydraulic master cylinders so naturally I'd like to make a pressure sensitive brake input into link2FS via an arduino. I've searched the forum with no luck. The arduino part is easy but the mechanical part isn't.

    I have one concept but it's ugly and heavy. My idea is to make a complete hydraulic brake system using automotive calipers, only have them press on load cells rather than brake rotors. Can anyone steer me to a better solution?

  2. #2
    150+ Forum Groupie BuzziBi's Avatar
    Join Date
    Mar 2013
    Location
    Norway
    Posts
    275
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Re: Hydraulic Brakes

    Quote Originally Posted by SteveL View Post
    Hi Guys, I have a pedal set from a PA28, all 4 toe brakes have hydraulic master cylinders so naturally I'd like to make a pressure sensitive brake input into link2FS via an arduino. I've searched the forum with no luck. The arduino part is easy but the mechanical part isn't.

    I have one concept but it's ugly and heavy. My idea is to make a complete hydraulic brake system using automotive calipers, only have them press on load cells rather than brake rotors. Can anyone steer me to a better solution?
    I have no idea how those pedals look like, but how about this: use steel springs in the hydraulic master cylinders, below the piston to provide resistance, and Slide Potentiometers mounted on the sylinders piston?
    EPSON001.jpg
    Life was hard, but then came Windows 7.
    Now we can fly! --------
    --------

  3. #3
    75+ Posting Member



    Join Date
    Sep 2013
    Location
    California, USA
    Posts
    109
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Re: Hydraulic Brakes

    PA28 pedals.jpgThey already have return springs on them, but your reply got me thinking. I could add a second spring, shorter than the existing so the pressure would increase quickly once the second spring engages. I'll just have to program a custom response curve, no big deal and much better than my original idea. Thanks BuzziBi

  4. #4
    10+ Posting Member
    Join Date
    Jul 2012
    Location
    Madison Al.
    Posts
    10
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Re: Hydraulic Brakes

    What about plumbing hydraulic pressure transducers to the pressure ports of the master cylinders? Should cost about 30 bucks a side.

  5. #5
    75+ Posting Member



    Join Date
    Sep 2013
    Location
    California, USA
    Posts
    109
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Re: Hydraulic Brakes

    Hi Nukem, thanks for the reply. I like your thinking, but it wouldn't provide pedal travel. To have a realistic feel it should operate the same way your automobile brake does: Some pedal movement, then rapid pressure increase as the brake pads engage.

  6. #6
    300+ Forum Addict Tom_G_2010's Avatar
    Join Date
    Mar 2011
    Location
    Central Mass
    Posts
    437
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Re: Hydraulic Brakes

    For my 172 sim pit I purchased gas shocks that were the same overall length and piston travel length as the original cessna master cylinders and attached slide pots to them. The only tricky part was estimating the pressure rating to use. You can order them online from several different companies with various lengths, pressure ratings, connecting hardware and so on.



    https://www.facebook.com/mycessnasim PC: Intel Core i7 Haswell @ 3.8GHz, 8Gb Ram, Win 7 64Bit, dual SSDs, GeFroce 780 SIM: FSX w/Aclrtn Pk, FSUIPC4, ASN, UTX, GEX, REX 4

  7. #7
    75+ Posting Member



    Join Date
    Sep 2013
    Location
    California, USA
    Posts
    109
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Re: Hydraulic Brakes

    Hey, Tom. You are a wizard. Do these shocks keep increasing pressure as you compress them further or do the act like gas struts? (can you stand on the brakes and have a firm foot pressure or will the pedal sink).

  8. #8
    300+ Forum Addict Tom_G_2010's Avatar
    Join Date
    Mar 2011
    Location
    Central Mass
    Posts
    437
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Re: Hydraulic Brakes

    Quote Originally Posted by SteveL View Post
    Hey, Tom. You are a wizard. Do these shocks keep increasing pressure as you compress them further or do the act like gas struts? (can you stand on the brakes and have a firm foot pressure or will the pedal sink).
    There are some shocks that have non linear pressure but I was having trouble finding the sizes I needed with that. As a result, mine are fairly constant but on a small GA I'm not too concerned about that reality gap.

    I can't find the link to the place I ordered them from, if I get a chance I'll through my invoices to see if I can find it there.

    Thinking about it, if you likewise can't find a shock configuration with non linear pressure that fits in your build, I wonder if you could connect your pedals to the chocks via a push rod linked to the shock with an offset cam so that the further the travel the lower the mechanical advantage and therefore greater pressure required.
    https://www.facebook.com/mycessnasim PC: Intel Core i7 Haswell @ 3.8GHz, 8Gb Ram, Win 7 64Bit, dual SSDs, GeFroce 780 SIM: FSX w/Aclrtn Pk, FSUIPC4, ASN, UTX, GEX, REX 4

  9. #9
    75+ Posting Member



    Join Date
    Sep 2013
    Location
    California, USA
    Posts
    109
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Re: Hydraulic Brakes

    Tom, BuzziBi, Nukem - Thanks a lot guys. Got it sorted out, will post some pics when I finish. Couldn't have done it without your help.

  10. Likes BuzziBi liked this post
  11. #10
    75+ Posting Member



    Join Date
    Sep 2013
    Location
    California, USA
    Posts
    109
    Contribute If you enjoy reading the
    content here, click the below
    image to support MyCockpit site.
    Click Here To Contribute To Our Site

    Re: Hydraulic Brakes


    PA28 Rudder Pedals Adapted for SIM Use

    Hi Guys, I have completed the assembly of the rudder/toe brake assembly. I'm sure many have done this before, but here is a short description of how it goes together.Thanks for the help.

    Rudder pedal assembly as removed from a Piper Cherokee PA28.
    Attachment 8587


    Here is the completed pedal assembly ready for cockpit installation:
    Attachment 8588

    Construction details:
    Pedals are mounted onto a sheet of ” MDF to serve as a firewall, using blind rivets backed with aluminum angle.
    Attachment 8589

    The side support pylons are attached to the fire wall, and the center support pylon was rotated 90 to provide a rigid connection for mounting the rudder linkage. 2” aluminum box tube is fastened to the pylon and the fire wall. The bell crank is made from aluminum flat stock, using a ” shoulder bolt & thrust washer to serve as the pivot. 1/8” stainless cable connects the left and right pedal arms to the bell crank.
    Attachment 8590

    A 2-56 rod is used to connect the bell crank to a 60mm slide potentiometer.
    Attachment 8593


    Hydraulic lines were removed from the toe brake master cylinders and 60mm slide potentiometers were attached to the cylinders. A full travel spring with a spring rate of 10lbs/inch provides resistance, and a second spring with a spring rate of 50lbs/inch engages at travel, effectively simulating brake pad contact while still allowing further pedal travel. The pedal linkage provides a 4:1 mechanical advantage, so the actual pressure on the pedal is of the spring rates. A wire push rod operates the potentiometers.
    Attachment 8591

Page 1 of 3 123 LastLast