Wireless Motor Analyzer Video Overview

[Jeffmhopkins]

Overview of the operation of my wireless motor analyzer and serial wifi bridge:

[video=youtube;O97WVG27jjM]https://www.youtube.com/watch?v=O97WVG27jjM[/video]

 

[rharshberger]

Sounds like kit form of the electronics might be in order, nice design.

 

[watermelonman]

That looks amazing and I am jealous.

 

[cavecentral]

Looks good! I seen the video in a different thread. I had no luck building my own test stand. Good job on that and the programming behind it! A buddy recently bought a system and am using that.

I am a bit curious how well the wooded frame works out. We have our load cell mounted on a 1/4" steel plate. We do a calibration of the load cell with weights before burning (not sure if required each time). I think we used 0lbs and 190lbs as the 2 calibration points. This is 100Kg load cell. Not sure if we are going overkill, or if it is something you need to think about.

 

[Jeffmhopkins]

I have a bunch of quarter bridge 50kg load cells, which I can wire up in single, double, or quadruple connections for different motor thrusts.

The wooden frame just holds things square and true. The load cells push against 1" oak, but metal would work well too.

I have another iteration that uses the INA125 for amplification, but I ended up with more noise than I liked.

I usually calibrate at 2 values (3 if you include zero) but overall the load cells I use are very nicely linear.

I calibrate before each day of testing, but usually only test 1 or 2 motors on it at a time. Calibration changes a little bit over time, but hardly anything really.

I've only had one test with the pressure transducer, but I've been working on designing a BATES grain testing apparatus with the pressure transducer playing a higher part of the testing.

I'm looking at cleaning up the source code and finalizing a PCB design, but it might be after I go down the path of my controlled descent project.

 

[cavecentral]

I tried making my own amplifier off the INA125 chip 2-3 times before I gave up on soldering. Bought a few amps and screwed them up even .

I had a nasty cato on my buddy's stand that took out one of his test cases (lost since I didn't put a tracker on the test case) and the load cell was overloaded. The pressure transducer held up nicely at least. I think one of my chems was bad or not labeled correctly.

Does your system have the battery / launcher in there as well? I am guessing it does, but was had to tell. Nice to integrate the parts so there are less pieces to carry / remember / leave in the field.

The pressure feed is on the forward closure with most systems I seen. You may need to slot the opening the motor drops into to accommodate wired / plumbing that is connected to the test case.

 

[Jeffmhopkins]

My igniters are all low voltage ematch, so they are ignited via a large 1F super capacitor right there off the board. Battery to the electronics are supplied by one of those USB cell phone charger bricks... I also have a power board I can hook up to convert down my lipo or nicd battery packs to the right voltage and supply different excitation voltages if needed.