RC POWERPLANT TEST STAND
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- เผยแพร่เมื่อ 11 ก.ย. 2024
- PARTS LINKS BELOW.
This is the setup that I will use to test the thrust, wattage, amp draw, temperature, and other parameters for an assortment of HobbyKing electric powerplants that I like to use for my EA foamboard fleet. The testing will be part of a broader review of some of the motor, ESC, and propeller components I recommend.
Static thrust measurement is not without its limitations but it is the best objective comparison between different motor, ESC, and propeller combinations in an economical and accessible way for hobbyists. Please note that actual flight characteristics, dynamic thrust, and efficiency will vary, depending a lot on the propeller pitch and the pitch speed of a powerplant combination, among other things. But in any case we can still get a rough idea how these perform.
Stay tuned for testing of the Turnigy 2826 2200KV, 2836 1100KV, and NTM 3536 1400KV motors with a variety of different propellers and ESCs.
HK-010 wattmeter and voltage analyzer:
www.hobbyking.c...
Turnigy servo tester:
www.hobbyking.c...
Turnigy TY-P1 "HEXFET" ESC 25 amp:
www.hobbyking.c...
Turnigy XP D2826-6 2200KV motor:
www.hobbyking.c...
Harbor Freight IR thermometer:
www.harborfreig...
Turnigy NanoTech 2200mAh 3s packs (many other variations available, I use these):
www.hobbyking.c...
Turnigy 1 meter white LED strips:
www.hobbyking.c...
excellent and you are one of the very few guys who are proficient reflecting limitations and applicable methods instead of mindless throwing out so called test results.
Outstanding Ed!!! Very complete, clean and efficient! I built a static tester that has the motor on the upper end of a three legged device with the scale sitting on a table. This lets the prop push against a small area (the mount) instead of the large disc area of the scale. Think of a triangle with the upper point where the motor mounts, the scale under the far end of a lower end and a pivot on the other lower point directly below the motor. Better send a picture eh :)
Nice set up. I just use the actual plane tied to a luggage gauge. A watt meter is used as well. My purpose was to validate my power plant before maiden. My test also predicts the flight time with maximum and average throttle situations.
This is awsome! I know it can't be perfect but it will do! Thanks so much for setting up and doing these tests. You will save a bunch of people from making the wrong choices, especially me as I know nothing of which components to use other than seller reccommendations.
I think I follow that, sounds like a nice rig. This one of mine actually does only press on the scale at one small point of contact at the very center. Having the actual scale a few inches away from the motor is not optimal though. I did this partly so I could get all the necessary parts in-frame for the videos and be able to shoot from the side and not the top, if the scale was laid flat. It's always a compromise....
Static thrust will be less than dynamic thrust in low-speed flight, which decreases up to the pitch speed of the powerplant, where the propeller is spinning as fast as it theoretically will go and basically windmilling. There are so, so many other variables it's hard to account for the thrust at all speeds. The simplest one to consider is that high pitch propellers can actually stall and lose thrust while static, but generate plenty of thrust with some forward speed.
Coming in the next video, in great detail. The short answer is: any decent 30 amp, or 40 amp if you don't mind spending a little more and like the option of moving to a larger motor/different plane.
Ed, Maybe instead of a swinging aluminum arm you could use a drawer slide (like from a kitchen drawer) with one peice anchored to the top of the concrete block and the other slider part mounted to the motor. Mount the scale behind the block and let the motor push the slider against it. This will get the scale out of the prop wash.
Wow, that sure beats the rocks and sticks I was thinking about using. 🤣
I think NASA should contract with you to build the manned vehicle to Mars.
Another fantastic and informative vid. Thanks Ed. :)
In the subsequent videos I do test maximum as well as two other power settings for efficiency (specific thrust) and it usually seems to be optimized at the lower power settings, to a certain point. I would love to test different voltages, airspeeds, etc. but I don't have infinite resources. I kind of have to draw the line somewhere, and so 3s is probably going to be the only one I test as it's the most prevalent - for me, and in general. But otherwise you are totally right.
Clearly that's true, and I did not intend to simulate flying conditions at all. No static test environment can simulate flight without a wind tunnel, and that's out of the budget. This is just a coarse method for comparative thrust and efficiency measurements between various powerplant combinations. There are way too many other variables to contend with to get a "true" thrust measurement - pitch, RPM, pitch speed, pusher vs. tractor, etc.
I'm looking forward to the results of this more than the next Star Trek movie sequel. Can you film the results in 3D?
thanks Ed very informative as usual
Unfortunately it's very complicated to compare static thrust and dynamic flying thrust. The best I can do is keep as many variables the same in order to compare. But it's not perfect. With a wind tunnel, it would be much better, but I can't afford one!
Great tested!!!
I guess because the scales are so close this will measure the maximum thrust in the ground effect. I've often wondered what measurements you could get in air using accelerometers (averaged over a flight).
Thanks Ed!
Isn't the best efficiency of a motor found at around 60-80% throttle? Measuring only max throttle and thrust per watt doesn't entirely make sense to me. Also, are you planning to test using 4s as well? I think that if the objective is to determine motor efficiencies, then higher voltage is a must...
As always, great video and looking forward to future videos...
What i was wondering, how does the static thrust compare with the thrust in flight ? i mean if you don't do this in a wind tunnel, is the static thrust a good representation of the actual thrust in flight? Nice setup!
Just to be clear..
Are you saying the static thrust measurement is LESS that actual thrust in clean in flight air..
Or that static the static thrust measurement is MORE because of the low pressure in front of the prop.?
So, I am doing an science fair experiment like your setup but when I connected everything, all the motor does is beep. I am using the same esc and servo tester and the servo tester does nothing when I turn it. What did I do wrong?
hi which esc I should use for this motor?