strain gauge loadcell.
strain gauge loadcell.
(OP)
i want to build a load cell that's using one or more strain gauges connected to a wheatstone bridge. so i was thinking to a beam (12mm X 24mm, 80mm long), fixed to one end and free on the "load" side. the strain gauge will be glued to the bottom of the beam (on the surface of 12X80) (would be a compression cell)
than for a maximum elongation, i'll drill a hole of 18.5mm in diameter on the surface of 24X80 with the center above the gauge,.
any idea of what is the best method to estimate how much the elongation would be based on the force applied at the free end of the beam?
Thank you very much
(sorry for my english)





RE: strain gauge loadcell.
good luck
RE: strain gauge loadcell.
you're funny, thanks man
cezar
RE: strain gauge loadcell.
If they think you're going into the load cell business, the strain gage manufacturers will be happy to bury you in technical information about using strain gages and building load cells.
If your time is worth anything at all, and this is not just a learning experience, and you want to end up with a load cell that you can trust, it's much much much cheaper to just buy it.
Mike Halloran
Pembroke Pines, FL, USA
RE: strain gauge loadcell.
the answer is yeah, it's a learning experience as well as a building something i will use.
the company i'm working for is in rubber industry (automotive). we have to overmold a metal washer (insert) with rubber for an air conditioning application, using a primer that will create a bond inbetween the rubber and metal.
the primer we utilize is very very sensitive to the relative humidity during the drying time (drying of the primer). also the bond is affected by the process parameters.
i was designing a fixture to be able to quantify what a "good bond" is. right now all we can say is: ooohh, that's a good bond, oops, that's not very good and so.
i asked about $5,000 for a load cell (compression, 1kN), it wasn't approved.
Now I want to build it myself and after running about 1,000 parts (destructive test) I'd have an idea of what a bond is. i need a way to verify the consistency in time, maybe with a spring, i did not think about it now.
so, as you can see I don't want to know perfectly what the maximum penetration force is as an absolute value. i'll use just the voltage as a reference. also for the test i will use an old drilling press in order to have the same speed for all the parts tested.
(btw i had to work a lot with office guys to let me bring the press on the office area to get stable environmental conditions. lol)
after that i'll be running a DOE and figure out where we actually are
ohh, it's so hard to get what u want sometimes, but i never give up.
thank you too
cezar andrei
guelph, ontario
RE: strain gauge loadcell.
The cheapest load cell is often a pressure gauge on a hydraulic ram, or a dead weight. Are neither of those applicable?
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: strain gauge loadcell.
I'm with Greg on this: Pressure gage and cylinder, spring and dial indicator, dead weight, etc.
There's also the political issue to consider. If you ask to buy something, are refused, then go out and build the same thing, you might be perceived as insubordinate, at least in some outfits. If you build something else, you have a more defensible position.
Mike Halloran
Pembroke Pines, FL, USA
RE: strain gauge loadcell.
guelph, eh
i'm in toronto
RE: strain gauge loadcell.
RE: strain gauge loadcell.
Very good info from Vishay's guys
RE: strain gauge loadcell.
I'll go in parallel, pressure gage and load cell. It's a nice exercise from the repeatability standpoint.
Thank you again.
Any idea what kind of steel would be better (for the load cell)?
Thanks again
ps. hi rb1957
cezar
RE: strain gauge loadcell.
RE: strain gauge loadcell.
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: strain gauge loadcell.
i knew i can count on you guys
cezar
guelph, on