Yes, this was the last thing I needed: another project. But I just couldn't stand seeing it get thrown away...
Long story: our local high school robotics team used to occupy one of the old school buildings in our district. The building was no longer needed for students due to population decline so all the extra curricular groups (including First Robotics) were able to use the building to house their activities. The robotics team maintained an e-bay store for fundraising and sold all kinds of donated items. Well, the district decided to tear down the building, displacing all the teams. The robotics team packed up all the essential stuff and left most of the "junk" behind, including a lot of the e-bay items that were just too hard to move. The wind tunnel was one of those items. I didn't want to see it thrown away, and I figure that I may be able to incorporate use of it at some point when doing rocket building activities with Scouts, science groups, etc (I've been involved with quite a few different groups over the years).
The wind tunnel is a LabVolt Model 40576. It is very basic, and really just meant for basic science class room lessons, but I figured heck, it's pretty cool.
So on to my question. The setup includes a balance which measures both lift and drag and displays the values on two separate LCD displays on the front of the unit. Only the lift is working. The drag force is not working. I opened up the electronics, and observed basically two identical sets of circuits one to read the lift load cell, and the other to read the drag loadcell. I swapped the amplifier IC (BurrBrown INA120) to see if it followed the IC or the loadcell, and it follows the loadcell.
I'm figuring the load cell was abused in it's former life. I'd like to find a way to replace it. The problem is I've never seen a load cell like this one and I can't find anything with google searching.
Here is the loadcell (removed from the wind tunnel):
The rod is fixed in the tunnel where I'm holding it. I "THINK" that the rod is the first load cell and measures the lift force, and the square piece at the end is the drag load cell. This one is fixed into the aluminum frame with two screws on the bottom. The test sample is mounted on a rod that inserts exactly where I've drawn the drag arrow (the sample extends to the left in the pic).
Here is a closeup crop of what I think is the drag (only) loadcell:
Anyway, anybody know what type of loadcell this is, or what type of load cell I'd look for if trying to replace it? I think I need one that would measure shear forces, as the loadcell is fixed at the bottom and measures force along the same axis. I've written to the manufacturer, and am waiting to hear back from them. But I'm not optimistic so I'd like to see if I can come up with a solution.
Thanks for reading!
Long story: our local high school robotics team used to occupy one of the old school buildings in our district. The building was no longer needed for students due to population decline so all the extra curricular groups (including First Robotics) were able to use the building to house their activities. The robotics team maintained an e-bay store for fundraising and sold all kinds of donated items. Well, the district decided to tear down the building, displacing all the teams. The robotics team packed up all the essential stuff and left most of the "junk" behind, including a lot of the e-bay items that were just too hard to move. The wind tunnel was one of those items. I didn't want to see it thrown away, and I figure that I may be able to incorporate use of it at some point when doing rocket building activities with Scouts, science groups, etc (I've been involved with quite a few different groups over the years).
The wind tunnel is a LabVolt Model 40576. It is very basic, and really just meant for basic science class room lessons, but I figured heck, it's pretty cool.
So on to my question. The setup includes a balance which measures both lift and drag and displays the values on two separate LCD displays on the front of the unit. Only the lift is working. The drag force is not working. I opened up the electronics, and observed basically two identical sets of circuits one to read the lift load cell, and the other to read the drag loadcell. I swapped the amplifier IC (BurrBrown INA120) to see if it followed the IC or the loadcell, and it follows the loadcell.
I'm figuring the load cell was abused in it's former life. I'd like to find a way to replace it. The problem is I've never seen a load cell like this one and I can't find anything with google searching.
Here is the loadcell (removed from the wind tunnel):
The rod is fixed in the tunnel where I'm holding it. I "THINK" that the rod is the first load cell and measures the lift force, and the square piece at the end is the drag load cell. This one is fixed into the aluminum frame with two screws on the bottom. The test sample is mounted on a rod that inserts exactly where I've drawn the drag arrow (the sample extends to the left in the pic).
Here is a closeup crop of what I think is the drag (only) loadcell:
Anyway, anybody know what type of loadcell this is, or what type of load cell I'd look for if trying to replace it? I think I need one that would measure shear forces, as the loadcell is fixed at the bottom and measures force along the same axis. I've written to the manufacturer, and am waiting to hear back from them. But I'm not optimistic so I'd like to see if I can come up with a solution.
Thanks for reading!