Q&A Forum
We're getting very close to getting our L&S Dyno (with all YourDyno controls) in the ground, and we will need to be able to calibrate the load cell. I know the best way is to have an arm straight off the arm that pushes on the load cell, but with the unit in the ground this will be basically impossible.
So what has anyone else done to make an arm that is above the ground, but calibrates accurately? I'm sure there's some formula to work out the distance above and out from the pivot point what the effective load is, but I don't even know what to use as search terms to begin to look for what that formula would be.
A stand that pushed down directly on the load cell would be a fairy easy thing to setup, but from what I understand the father out the weight is (within reason), the better, or easier it is to calibrate the load cell, because less actual weight can be used, due to using leverage as an advantage here.
Ive got a similar situation with the dyno in ground. We put a 20kg gym weight right above the load cell where the connecting rod attaches, calibration worked fine.
Ive got a similar situation with the dyno in ground. We put a 20kg gym weight right above the load cell where the connecting rod attaches, calibration worked fine.
Awesome.
I went searching on this topic last night to see if I could find anything.
One post I came across it talked about not using the distance from the pivot (axle that runs through the brake in my case), to the location of the weight, but the distance between the weight and the load cell to be more accurate. what did you enter for the arm length? The distance between the axle center and the load cell, or 0 for putting the weight on the load cell directly?
Yes, we entered the distance from centre of flywheel/coils to pivot point above the load cell and placed the 20kg directly on that point, got it to balance freely and pressed the button.
Awesome, thanks.
I do this with a crane scale.
This is simple and works very well.
I do this with a crane scale.
This is simple and works very well.
I don't really understand what is going on in that first picture. Could you explain what it is that you are doing to calibrate the load cell?
Thank you.
Hi,
so on one side of the brake is the load cell and on the other side the scale.
The scale is at the same distance from the center of the brake to the load cell and the scale is pulled down with a left / right threaded nut.
This pulls the cell apart and simulates the weight.
You can increase the weight by tightening the left/right nut.
No problem using a calibration arm that points upwards in some angle. However, if the arm is for example 45 degrees up, it only applies half the load on the load cell compared to a horizontal arm. So use the horizontal distance when calculating the load on the load cell.
See attached an excel sheet to help with calibration.
No problem using a calibration arm that points upwards in some angle. However, if the arm is for example 45 degrees up, it only applies half the load on the load cell compared to a horizontal arm. So use the horizontal distance when calculating the load on the load cell.
See attached an excel sheet to help with calibration.
I'll have to examine that a bit, but it look like it doesn't take into account any angle of the load arm.
@six_shooter Yes, that is the point. You key in the horizontal distance, that is what matters for the calibration arm. Think of it in terms of what torque it applies to the load cell.