Page 1 of 3 123 LastLast
Results 1 to 10 of 24

Thread: suspension travel sensor?

  1. #1
    Newbie
    Join Date
    Apr 2006
    Posts
    17

    suspension travel sensor?

    Anyone know of any (perferably cheap) ways of reading suspension travel? something like a variable resistor that changes resistance the more you compress the shock? Looking at making a data-loggerfor my truck

  2. #2
    Admin
    Join Date
    Aug 2005
    Posts
    214
    You could use a magnetic sensor mounted to the frame coupled with a permanent magnet on the suspension. I'm not sure if the response time would be quick enough, but it;s worth a shot.

    -g.

  3. #3
    Calm
    Down
    Or
    Get
    A
    2
    Week
    Vacation
    -Love
    The
    Forum
    Policeman
    Wiredwrx's Avatar
    Join Date
    Jan 2003
    Posts
    3,605
    Quote Originally Posted by flipster125
    Anyone know of any (perferably cheap) ways of reading suspension travel? something like a variable resistor that changes resistance the more you compress the shock? Looking at making a data-loggerfor my truck

    Please tell us more. Like, each individual wheel, how accurate must it be, does it have to be completely linear, how much resolution (6 inches, 1 inche, centimeter, millimeter, decameter etc.....)

    That will help.

    Michael
    ...I love the French language...especially to curse with...Nom de Dieu de putain de bordel de merde de saloperies de connards d'enculés de ta mère. You see, it's like wiping your *** with silk, I love it.

  4. #4
    Newbie
    Join Date
    Apr 2006
    Posts
    17
    12 inches long, minimum accuracy ~1 inch (ie be able to tell if it's 1 inch, 2 inches, 3 inches etc, more accurate is better, but not neccessary)

    It's also linear, somethings wrong if your shock isn't moving in a linear motion :P

    I only need one wheel, (if I need to, I could just make more and put them on other wheels)

    Thanks

  5. #5
    Calm
    Down
    Or
    Get
    A
    2
    Week
    Vacation
    -Love
    The
    Forum
    Policeman
    Wiredwrx's Avatar
    Join Date
    Jan 2003
    Posts
    3,605
    Quote Originally Posted by flipster125
    It's also linear, somethings wrong if your shock isn't moving in a linear motion :P
    I didn't mean whether the motion was linear, whether you needed it to be linear, such as 1,2,3 or 1, 2.5, 5, 9, 12.

    First, why do you need to be able to tell how much the suspension is moving?

    Next,

    Here are the issues I see. Attaching something to the suspension that won't move no matter what.

    While you think that the suspension moves up and down, it DOES NOT move in a straight line up and down. The is some lateral movement. There has to to be because the ??lateral links?? remain a constant length in the suspension. Also, your strust is NOT mounted directly above your where to go straight up and down.

    So, a variable resister won't work because there is none that has 12 inches of travel that I know of. Also, they are not the most rugged piece of equipment that you would want to mount it outside the car, especially in the wheel well. Then you have to connect the varister with the suspension some how, to measure the motion.

    Magnets might work, but you run into a problem with the resolution. Magnets have a "field" which would cause multiple magnets to be sensed at the same time.

    Sorry, can't think of anything right now

    Michael
    ...I love the French language...especially to curse with...Nom de Dieu de putain de bordel de merde de saloperies de connards d'enculés de ta mère. You see, it's like wiping your *** with silk, I love it.

  6. #6
    Low Bitrate
    Join Date
    Oct 2005
    Location
    Oshawa
    Posts
    81
    Use a spring and a PIC, as the spring stretches, its resistance will increase, so you can measure that with the ADC on the PIC voila!

    Got this idea off of Myth Busters, although they didnt use a PIC, they used it to determine the whiplash Buster would endure during the Airplane seating/crash myth, and measured it with a DMM Ohmmeter.
    Hey Laserlips, your momma was a snowblower!!

  7. #7
    Calm
    Down
    Or
    Get
    A
    2
    Week
    Vacation
    -Love
    The
    Forum
    Policeman
    Wiredwrx's Avatar
    Join Date
    Jan 2003
    Posts
    3,605
    Quote Originally Posted by adaminc
    Use a spring and a PIC, as the spring stretches, its resistance will increase, so you can measure that with the ADC on the PIC voila!

    Got this idea off of Myth Busters, although they didnt use a PIC, they used it to determine the whiplash Buster would endure during the Airplane seating/crash myth, and measured it with a DMM Ohmmeter.
    That is sooooo cool. But how do you calibrate something like that??

    Michael
    ...I love the French language...especially to curse with...Nom de Dieu de putain de bordel de merde de saloperies de connards d'enculés de ta mère. You see, it's like wiping your *** with silk, I love it.

  8. #8
    Newbie
    Join Date
    Jan 2005
    Posts
    9
    I think a "String pot" (one of many names) may work well for this. Basically, it is a thin cable wrapped around a spool mounted to the end of a multi-turn rotary pot. So you just have a flexible cable providing the length, rather than the actual resistive element. There is some sort of coil spring that pulls the cable back in I guess... Here is a link to a picture that probably describes the concept better: http://www.celesco.com/faq/cet.html

    I don't know much about sources of inexpensive units, you might be able to build something yourself with a 10-turn pot, a spool, cable, and something to retract the cable. For more info, google string pot or cable-extension transducer. Not sure how quick they will react (recoil), probably depends on inertia, recoil spring tension, and pot friction.

    Sounds like a neat project, would be cool to do on my bike to help tune the suspension. Here is a link to a commercial unit called the ShockClock that uses long linear pots for suspension travel pickup. http://www.race-tech.com/SubMenu.asp...es&showPage=da

    Have fun!

    Andy

  9. #9
    Constant Bitrate
    Join Date
    Oct 2002
    Posts
    176
    I like the string pot for this.

    I'm not following the spring thing. Expecting it to act like strain gauge?

    A rotary pot placed at suspension-chassis pivot point and an arm on the wiper attached to the moving parts should track reasonably well.

  10. #10
    Constant Bitrate techeros's Avatar
    Join Date
    Sep 2004
    Location
    Mississippi
    Posts
    222
    Hey this sounds neat, but what is the overall goal here?
    03' Toyota Tundra T3 Special Edition - Polk Audio speakers - Sony 4ch amp - RF Sub amp
    Carputer Planning |---------*|
    Overall Implementation |---------*-|
    (Stereo complete)
    Computer installed and working

Page 1 of 3 123 LastLast

Similar Threads

  1. Relocating Portable DVD Remote Sensor...
    By AEFL92 in forum General Hardware Discussion
    Replies: 1
    Last Post: 09-10-2007, 03:03 PM
  2. Offset for phidgets / temperature sensor
    By skippy76 in forum Road Runner
    Replies: 2
    Last Post: 10-10-2005, 05:04 PM
  3. Gamma control by light sensor
    By kronos in forum General Hardware Discussion
    Replies: 28
    Last Post: 03-14-2005, 07:57 AM
  4. Painting a reverse / parking sensor?
    By modemide in forum General Hardware Discussion
    Replies: 0
    Last Post: 09-06-2004, 08:05 PM
  5. sensor
    By llmask in forum General MP3Car Discussion
    Replies: 5
    Last Post: 03-21-2004, 09:10 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •