Motor test stand Arduino based

Hi all
I have few years ago built a motor test stand but that was quite expensive.
I have been looking around and it looks like it is now a lot cheaper to do with some Arduino board.
I bought a load cell amplifier for a couple of dollars
https://cgi.ebay.fr/ws/eBayISAPI.dl...eName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
and I was wondering if any of you have used it for test stand?

Here is a link to build an Arduino scale with that sensor
https://www.dfrobot.com/wiki/index.php/Weight_Sensor_Module_V1
I will use it has a base to build my new test stand
Boris

No experience here but interesting. Is this a stand alone design that does not require a laptop as far as displaying and recording the trust curve?

Steve G

This sounds like a great use for a pcDuino!

No you need a laptop and write a software to display the curves
Those are the components that I think are needed to build a test stand prototype (prices in Euros)
an Arduino pro: 1,88 euros
https://www.ebay.fr/itm/New-ATMEAG3...428?pt=LH_DefaultDomain_0&hash=item2c7f792b6c
A ttl cable: 1,15 euros
https://www.ebay.fr/itm/USB-To-RS23...668?pt=LH_DefaultDomain_0&hash=item5d4a2c776c

The amplifier:1,58 euros
https://cgi.ebay.fr/ws/eBayISAPI.dl...eName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

A 60kg load cell: 21,88 euros
https://www.ebay.fr/itm/Zemic-singl...t=LH_DefaultDomain_0&var=&hash=item3f33f068d1

so a total of 26,49 euros for the test stand electronic.
I am going to try it out and I will write a Java front end to display the curve
As usual I will publish the code

I found specs for that at https://www.dfrobot.com/image/data/SEN0160/hx711_english.pdf. Looks like it will do 80 samples per second.

With a pcDuino you could build the prototype and have an HDMI graphing output without need for a laptop since it comes with ubuntu installed.

well for the moment I will keep a standard Arduino as I know it really well. Also it is quite handy to have the curves on the laptop so that I can use them in Openrocket.
Also the idea might be to design my own arduino board with everything needed for the test stand (a bit like what I did with my altimeters)
I might also use the blue tooth arduino module to communicate with the laptop

The problem is that the system is too slow for a test stand. The off-the-shelf packages you can buy today are really hard to beat. They just plain work out of the box and include all the software and analysis.

My favorite entry level systems are DataQ and Measurement Computing. Im there are others.

https://www.dataq.com/data-acquisition-starter-kits/data-acquisition-starter-kits.htm
https://www.mccdaq.com/solutions/USB-Multifunction-DAQ.aspx

--MCS

.

The problem is that the system is too slow for a test stand

Click to expand...

I disagree. 80 samples a second is plenty for a thrust curve with 12 bit or higher resolution. I've had great results with as sample cycles as low as 50/sec. Do agree with the DataQ system. I've been using a model DI-158U for my test stand for quite a while now. Sometimes what's really needed is an inexpensive stand alone data logger. If bdureau's system will record the data for later analysis then it's worth building IMHO.

Steve G

80 samples per second is more than enought
I have a test stand using a dataQ so I will be able to compear the results of the 2.
The problem with dataQ is that whenever you live outside the US it is expensive.... it costed me more to get it shipped than the actual system
Secondly I did not like the libraries that I had to use (Active X) to build the user interface
I would rather write a Java interface with an Arduino that can work on any computer and which is 5 to 10 time cheaper

I have now received the module and started playing with it.
The good news is that when I plug the load cell it gives me a voltage and I can make it vary.
I am debugging by printing to the serial line but it seams slow.
Looks like I will need to add some memory to store the flight and then retrieve it.
It might not sound too bad because I do not need to have long wire from the test stand to my computer if I retrieve the motor curve later.
Plan is to test it over the summer