aknovaman

iTrader: (7)

Put this together tonight. eBay $50 1000kg load cell, $2 hx711 adapter amp, LCD shield and arduino uno board. Wrote the code and loaded it. Need to swap out the load cell output wires so it reads positive pounds and not negative. Put it in a case and add a 9 volt battery. Taking it into work and calibrate it. Buddy is going to use it on top of a floor jack to scale his race car.

Total cost is less than $70


Next step is to build a dash gage cluster with a TFT display.

aknovaman

iTrader: (7)

Read 1974 when standard read 1982.

Janz99

Great project!

aknovaman

iTrader: (7)

Plans are to mount this on top of his floor jack and adapt a platform so he can jack up the suspension and "scale' each corner of his car.

Next I am looking for a water brake, hydraulic pump or Brake retarder and build a engine dyno. Not a fan of inertia dyno's as they require such a large mass drum for any significant load. Torque and speed measurement is easy with an Arduino.

DW SD

that is too cool!

I assume you need one arduino per load cell?

Have you built any fixture to put the load cell in to platform for measuring individual wheel weights vs. setting on a floor jack? Seems like it'd require something non-compressible (not wood) to push on the button?

Seems like at least two setups would be a good starting point to corner balance?
Thank you for this!
Doug

Forcefed86

iTrader: (4)

This worked very well. Just got the front/rear weights at the moment. I'll build a jack pad of some sort to get the corner weights eventually.

DW SD

Thanks for the reply. Please take a look at the pictures you added.. the turbo forums.com doesn't seem to want to share the pictures.... same as in your thread.

Clicking on the link returns a note about stolen pictures.

Doug

Forcefed86

iTrader: (4)

That always gets me because they show up on my side fine. I'll fix them, thanks.

aknovaman

iTrader: (7)

Note, the numbers below the pounds reading is just a running counter to show the user that it's taking readings.

You can actually use several load cells as the Arduino has more inputs. If you use a 4 line LCD it has enough space to show all 4 corner readings, average, total, etc. Just need to adjust the code accordingly.

I was pretty surprised at how accurate it was after comparing it to the calibration standards at work.

Forcefed86

iTrader: (4)

Is there any reason to do all 4 sides at once? I'd think with 2 of these you could get each of the front corner weights pivoting on the AFT wheels and do the same for the rear corners.

DW SD

Hi Adam,
If you are making adjustments to the coil-over perches to settle out the corner weights, it is much easier with 4 than moving a pair of the scales around. For a modest amount more, I'd get 4 channels, but still haven't 100% thought that through.

A used, digital corner balance setup can be found for $500 or so. I never wanted to spend that much. $250-ish would make sense given my use patterns.

The balance between time and money is not always easy to strike

Proper corner balancing can be really important to car setup, including alignment and even for a street car.

cheers,

Doug

1320king

iTrader: (4)

DO you have any part numbers and such that you can forward? Sources for parts also would be awesome.

Forcefed86

iTrader: (4)

Gotcha. I was planning on trying to leave the perches the same and just adding ballast where it's needed. Last outing I raised the pass side perch up to compensate for weight. This worked well with a mild launch, nice and straight on 1.4X 60's. Driver side wheel comes up a few inches, pass side still planted.

Then I tried to turn it up. With both wheels in the air, the added preload on the pass side drove the car left. I'm thinking I need to square the perches and just add weight where needed at this point.

I can't believe the difference adding 100lbs of ballast to the back of the car made.... I went from a year of traction issues to dead hooking. Now I just need it to stay straight with the front wheels in the air.

aknovaman

iTrader: (7)

1320 King,

You need to buy the following parts.
Hx711 board
Arduino uno
LCD shield by DFrobots
1000kg load cell

There are tons of sources like eBay and specific robot sites.

Download the sketch from the Internet, load it in the arduino and wire it up as shown on the Internet. Just google arduino scale for details.

Connect power and you are good to go. It will be close but not calibrated as good as the one I built for forced.

98redorangeta

iTrader: (10)

Pretty cool project sounds like a fun project may have to try something like this

merim123

iTrader: (11)

@aknovaman you take the video down?

aknovaman

iTrader: (7)

yes i updated to a full color display and need to load a new vid.

LSswap

Great project. Gotta bump it up.