I need to buy a force gauge, or sometimes called a push/pull scale. I checked online and some costs over $500. I need something for FIRST robot use that I can measure force but I do not need display up to two decimal points. Any recommendation of an inexpensive model that will do the job for most FIRST applications? I searched on CD but can not find anything.
For something not super-accurate, I’ve seen scales intended for weighing airplane luggage. They typically have a handle with a digital display in it and a hook to attach to the luggage. This would probably work fine, depending on the application, and would be fairly affordable.
EDIT: Here’s some for under $20.
What range of forces are you planning to measure?
Can you purchase a spring at the hardware store and calculate its spring constant using a known mass?
What if you fix the head of a torque wrench so it doesn’t turn, then tie a string to the wrench a known distance from the head?
A digital fish scale might do what you need.
a few years ago I saw a picture or video of some of the 842 folks showing how they measure the pushing power of their robot…they use an old analog bathroom scale, leaned against a wall, and have the robot push against it.
Without knowing what you’re trying to measure, and how accurately (why you need the numbers), it’s kind of hard to answer your question.
I’ll second this if all you need to do is measure force in a pulling direction. They key is mounting it in a situation that allows the robot to keep full contact with the floor (i.e. don’t have the scale “pulling” the robot “up”).
For pulling up to 75 pounds, a $10 luggage scale might work:
Otherwise make something with a spring.
Thank you to all for the ideas. I really like the fish scale and luggage scale idea, and I don’t have to spend a fortune. I will look at amazon.com and other places.
Harbor Freight (Every FRC teams fav tool store ) has a few,
We used the second one last year with good results. A lot more accurate than a cheaper fishscale we bought.