My attempt to weigh the trailer - it begins

Discussion in 'Tow Vehicles, Hitch & Towing' started by Anthony Hitchings, Feb 14, 2020.

  1. Anthony Hitchings

    Anthony Hitchings Well-Known Member

    Messages:
    3,057
    Likes Received:
    1,810
    Joined:
    Mar 2, 2019
    Location:
    Oakland, California
    Follow up: I went back to may weight spreadsheet, and the only way that the 2003 OEM weight placard could be close to true for my axle wheel load (including wheels) would be if the weight was totally NOT an outfitted weight - no tables, no cushions, no frig, no batteries, not even a propane tank.

    So as many others have said - if in doubt - go to the scales and weigh your camp trailer. Its easy. Watch a couple of videos. And call first if needed, to be sure about which end to enter from. From your comfy chair at home take a peek at the location on Google Maps and street view. Cost me $12 here in Oakland, CA. I did only a "first weigh", and not a 2nd weigh without the trailer, because I was no interested in my TV weight, and I can (and did) get my tongue weight at home using bathroom scales (my Aliner is light enough to make this easy).

    BTW - tongue weight is 97 Lbs, so total "empty" trailer is about 1,300 Lbs, a lot more than UVW = 895 Lbs on the placard. This empty weight is without appliances, without tables, no frig, no proapne tank. The only adds are two batteries and two spare tires.

    FWIW - when we are loaded for a trip the tongue weight is higher, and meets the 10% minimum guideline.
     

    Attached Files:

    Last edited: Nov 21, 2020
    Econ likes this.
  2. Anthony Hitchings

    Anthony Hitchings Well-Known Member

    Messages:
    3,057
    Likes Received:
    1,810
    Joined:
    Mar 2, 2019
    Location:
    Oakland, California
    End of fall trip, 2021

    total wt = 1,8123 Lbs before unloading; tongue wt. was 13%. Left wheel load = right wheel load, this time
     
  3. popup-flyer

    popup-flyer Active Member

    Messages:
    237
    Likes Received:
    170
    Joined:
    May 11, 2021
    Location:
    Central Texas
    Anthony, I am big into microcontrollers such as arduino and raspberry pi. Your project inspired me to take a look in that direction. There are multiple projects that include the HX711 amplifier for load cells and a little screen that will let you display scale weights based on the converted/amplified signal. I just received my load cell and HX711. I will see if I can come up with a project that anyone with some soldering skills could build.

    This is the amplifier board:

    https://learn.sparkfun.com/tutorials/load-cell-amplifier-hx711-breakout-hookup-guide/all

    One such project:
    https://create.arduino.cc/projecthu...-gauge-weight-scale-w-loadcell-arduino-7a7fd5
     
    Last edited: Nov 15, 2021
  4. Anthony Hitchings

    Anthony Hitchings Well-Known Member

    Messages:
    3,057
    Likes Received:
    1,810
    Joined:
    Mar 2, 2019
    Location:
    Oakland, California
    buying and using the load cell monitor was easy,, the real trick was the spreadsheet math to convert loads measured under the springs to wheel loads, which are usually not the same
     
  5. Anthony Hitchings

    Anthony Hitchings Well-Known Member

    Messages:
    3,057
    Likes Received:
    1,810
    Joined:
    Mar 2, 2019
    Location:
    Oakland, California
    you also need two batteries, 12v to operate the amplifier and around 20v to feed the load cell (I used a Ryobi 18v battery)

    my system is easy to use, the hardest part is dragging out the floor jack, which I used to carry the load cell up under the springs
     
  6. popup-flyer

    popup-flyer Active Member

    Messages:
    237
    Likes Received:
    170
    Joined:
    May 11, 2021
    Location:
    Central Texas
    The project I am working on uses 5V from the microcontrollers own power circuit and the amplifier board to get a readout.

    I plan to build 2 so I can put both under the wheels at the same time. There are even "combiner" boards where you can put together multiple load cells and get total weight across all of them (like a bathroom scale does)
     
  7. Anthony Hitchings

    Anthony Hitchings Well-Known Member

    Messages:
    3,057
    Likes Received:
    1,810
    Joined:
    Mar 2, 2019
    Location:
    Oakland, California
    well, if you put the load cells under the wheels and not under the springs, no math is needed.

    but its smart to look at each wheelload and compare them, to help you keep the camper-trailer balanced, and nopt overload the suspension on one side
     
  8. Anthony Hitchings

    Anthony Hitchings Well-Known Member

    Messages:
    3,057
    Likes Received:
    1,810
    Joined:
    Mar 2, 2019
    Location:
    Oakland, California
    I found tha tthe "scale factor" in theload cell was not toohigh so I cheated and used a higher voltage to get more resolution
    (on the least significant digit).
     
  9. popup-flyer

    popup-flyer Active Member

    Messages:
    237
    Likes Received:
    170
    Joined:
    May 11, 2021
    Location:
    Central Texas
    That is what the amplifier board is for. It takes the low voltage return signal and converts it to something the microcontroller can easily digest and display.

    Perhaps between the two of us we can come up with a project that folks on here can build without paying $1000 + for a digital scale system that can weight 2 or 4 wheels.
     
  10. Anthony Hitchings

    Anthony Hitchings Well-Known Member

    Messages:
    3,057
    Likes Received:
    1,810
    Joined:
    Mar 2, 2019
    Location:
    Oakland, California
    my system takes (almost) zero skill to assemble . the little monitor-amplifier thingie is simply put in a mounting box for convenience with a push to operate buttom and some terminals for each battery
     

    Attached Files:

Share This Page