We are now shipping the RCbenchmark Series 1520. It measures overall efficiency, current, thrust, voltage, and motor speed. The device communicates with our open-source software, which displays and records data, and controls the motor manually or through a scripting system.
Whether you want to increase flight time for aerial photography, or performance for racing, the tool will help you obtain the data you need on your motors, propellers, ESCs, servos and batteries quickly and accurately.
A year ago, I posted here asking if people would be interested in a low cost, automated thrust stand. My colleague and I, both recent graduate from M.Sc. Mech. Eng., developed the Series 1580 dynamometer, and we obtained excellent feedback from a large number of businesses and universities. Many hobbyists asked us for a simpler, more affordable tool. We heard you, and we are now offering the Series 1520 for $165.
Get it at $149 if you order before March 1st! Additionally, for a limited time, we will refund an additional $40 if you post a video review about our tool, which will lower the product’s price to only $109. Check the product page to see if the offer is still valid.
Here are the specs:
Voltage (0-35 V)
Current (40A continuous, 50A burst)
Power (0-1400W)
Thrust (±5 kg)
Motor speed (100k RPM)
Overall efficiency (%)
USB interface
ESC manual control
Three servo control ports
Output data to CSV files
Real-time sensor plots
Automated tests and recording
Powerful scripting abilities
Safety cutoffs
We want to offer more than a test tool. You might also be interested in our ongoing video tutorial series on motor and propeller theory. For more more information, check out our website or the Series 1520 product page. I will be available here to answer questions on our tools and on motor and propeller testing.
Comments
@Marc, the project under http://www.rcgroups.com/forums/showthread.php?t=2337523 is interesting but has a few issues. The hardware has a very low sample rate which can lead to aliasing of results. Also the results can be very sensitive to test setup. Our method is more straight forward and follows industry standard practices. We also cover 2 plane balancing etc. We are happy to guide users through the process. We are passionate about good vibrations :)
Just what I have been looking for! Ordered one. Awesome tool, thanks Charles.
I have to say even though this thrust stand might have some flaws, they can by the looks of it easily be corrected DIY. Nothing stops anyone from removing the motor mount and replacing with actual frame arms or anything else. This thrust stand is by far superior to the 'comparable' offering from hobbyking. Saying 'comparable' is actually insulting to Charles...
thanks for the paper links. Interesting reading!
I'm not Darius nor know this guy or whatever, I hope that intro helps avoiding confusion.
Some points:
Not all props produces significant thrust with its inner parts, but some do.
Drone industry has actually become better at designing props, and it is for a very good reason that high-efficiency props are shaped such that they become wider and much higher pitched at the inner part. The r^2 argument is obviously correct, however it does not take into account span and pitch. I think just from common sense you all will agree that a higher pitched prop produces more trust at the same rotation. Besides the tip region it is actually the design of the inner part there a lot can be gained. All this is 100% along basic propeller theory (blade element theory).
=> it is IMHO misleading to distribute categoric it-does-it-does-not statements here, since it might be correct for one prop but fail for another
=> it is IMHO highly misleading to argue that the inner parts are irrelevant, because it may EXACTLY be the part which makes the difference in e.g. efficiency between prop A and prop B, and which may EXACTLY be what you want to explore with your test stand
If or if not test stand data are worth anything for judging about realistic situations, where realistic is to be read as in "results reflecting the behavior in my particular model, copter, plane, etc." is a long a troubled story, largely because we always can find arguments which supports the one or the opposite view, but no one of us really knows for lack of actual systematic investigations. I have seen many threads with long and by times heated discussions but with no conclusion ever reached. I'm not sure this is an avenue which is worth to be repeated here.
Of course the test stand is not for scientific purposes, and I think no one expects that. But just from common sense I think it is obvious that no one of us would add such obstacles to our copter arms. I would thus never use this stand as it is for this use case. For a plane, common sense also tells all of us that any test stand result will not reflect the "in-the-model" behavior. I would not conclude from that though, that it is irrelevant how the stand is constructed, but, since our common sense tells us that we won't get realistic data (with realistic in the aforementioned sense), one may legitimately ask what else should we want.
My conclusion is that the test stand should produce data which is as little as possible affected by the test stand itself. This makes a lot of sense to me, but that's of course my very private, personal criteria for a test stand, and only few may agree. Judged by that criteria the shown test stand fails. It is likely that any of the DIY stands shown out there (and my own wood construction) produce more reliable data, where reliable is to be read as in "characteristic for this prop-motor-esc combo". Sadly enough, it would be easy to resolve such issues by few quick and easy construction changes.
I actually like these test stands, the 1580 is an innovative and robust design, and all comes with a great analysis app, but I also think that the 1520 could need some redesign.
Great product & well done!! Sorry to put the plug in here but to answer some of the previous questions, www.dynexhobby.com already provide dynamic balancing solutions for all kinds of platforms, from gas turbines to electric brushless motor /propeller /fan configurations.
Hi @Darius,
Have you considered that the position of the plate may actually be closer to real world conditions? Imagine not a multi but a plane, the fuselage does exactly what the stand is doing.....
He's also said
Hope that makes sense to you.
Now on other matters, nothing wrong with asking questions but you do tend to put extremely high standards on everyone but yourself. You don't answer questions put to you, when I raised why your selling of group was not working you pretty much ignored what I recommended, by your standards I should have hounded you till you did everything I said. Note I didn't do that did I, I gave you my advice and I moved on. Try to imagine being in their shoes and how they would react. Like others I'm almost at the place where I will skip your comments shortly - try to be constructive not destructive.