Hi Smith
I don't think it makes much difference with the thrust, maybe the foam will insulate the scale from some of the vibrations tho?
You know you and others are ahead of me on the test gear and thrust gauge, super.
Some might criticize my strong leaning on the manf. prop tests and references to them, but I only use what I can trust, and this is all I have right now, I don't have a scale I even really like, much less a test stand or eLogger setup
Concessions made to those making those criticisms.
I think most anything Nerdnic and Dr Kiwi (RCGroups and tests at flybrushless) posts can be trusted, along with Cobra and Scorpion motor test charts.
Even without the test gear, from these I can make some very good predictions about similar motors, what they will do.
Nerdnic simply did a power test, with a wattmeter and maybe with a temperature sensor.
He simply ran the Suppo 1490kv (calling it 90kv higher because they all seem to test that way, see Dr Kiwi test the 2217 "Beef" motor on flybrushless.com) with an apc 9x6 e and determined it would be OK WOT and pull 41A 445W
Below in the pics posted on 8.5x11", the Suppo and 2 Cobra that show about what we should expect from the Suppo with either a 9x4.5 or a 9x6
OK the thing I see is the Suppo seems to be stronger than the Cobra 2814 and weaker than the larger one in the list with apc props, I think you can look in between these two and see what you should expect
I look at the 41Amps/445W of the Suppo and see what the others do rpm/thrust near same power level but also bearing in mind differences in efficiency .... well see these chart excerpts below, Smith:
The heavier gram weight of the 109g Cobra, by which we gauge motor power capabilities, may be due to the fact that they make the structural bodies and shaft bigger and heavier, that extra weight IMO, is just not in the stator where the performance differences can be seen. I really like the heavy duty construction Cobra uses, they use harder larger 5mm shafts where other makers use smaller 4mm shafts! But this also means that I would look for a heavier gram weight in Cobra to compare to another motor. Maybe their 109g 2814 better compares to another lighter motor of like 85grams? And the Suppo seems pretty solid at its 100g weight and performance, but, then, sometimes like this one also just has the 4mm shaft, I like the shafts a little larger and harder, especially as the motor get longer.
That odd noise you heard while testing, it may not necessarily be the motor, I'm learning more and more that, just like the fire triangle takes 3 things to make fire Ox, Fuel, Heat... it could also be the motor controller, I bought 2 of the cheaper brands, the 40A ZTW that have 5A BECs from Altitude Hobbies, and I hope they will be really good.
The quality of the ESC should be considered, their upper switching frequency limit and also the PWM frequency (pulse width modulation frequency) setting, with a motor with either high kv or one of these new motors with like 24 or more poles, it takes a higher PWM and more switching occurs to run these motors.
What differences would you see in your motor test of the 2814 Suppo, if you switched PWM from 8khz up to medium or the 16khz setting?
I don't know conclusively but have been reading and think like this motor, at med-hi 1490kv, there seem to be 2 things, a timing setting and the pwm setting that could affect performance. Test at pwm 8khz then same test at 16khz, check for smooth and good throttle response all along the range and check the power consumption at different rpm levels, wish I had the test gear set up to do this myself ( see on RCGroups, Dr Kiwi 2 or 3 threads on his motor thrust test stand constructions )
An ESC with my pulsar glider, always had a problem with a slow throttle response that I really did not like at all!!!!! I hand launch, throttle up and it would not throttle up and I am close to the ground. That was yrs ago and I did not know how to troubleshoot that problem, then.
Here is a link at flyinggiants where "scalefreak" explains a lot about timing and pwm settings
http://www.flyinggiants.com/forums/showthread.php?t=27555&page=2
We know that some of the cheaper brands of stuff cannot be trusted at it's claimed limits. How many vids have you seen where somebody crashed a plane, it really lost browned out, and you come to find it was one of those cheap orange receivers?
That said, I don't yet know if I can trust Turnigy ESCs yet, I have two 40A ZTW, a 40A Cobra, and a Castle 50A all with 5Amp BECS
Check all connections, make sure you don't have any bad solder joints on the bullits, and other places
New thing I learned, you have to add capacitor filters if you want to make the battery leads on either side longer because longer leads make for higher transient spikes that can kill your ESC if not filtered out, add like 2 or 3 high frequency caps same size as the stock ones in parallel right by the ESC and you can make the leads longer, and you cannot just add a bigger cap either because IT will take more of the load, heat up, blow up, then your ESC will fry and your plane falls out of the sky.... Ron van Sommeren has a very interesting post on RCGroups about this. And you cannot use those cheap caps from Radio Shack either, goto a good electronic store, pick caps by same micro farad size, and going up on the voltage spec is good but not going lower than stock spec on ESC caps for sure.
Been thinking about getting some caps n awg12 noodle wire to make my ESC leads longer.
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All this time and I still haven't built an FT Power pod or any DTFB planes, so I am making this very special low wing warbird power pod(3.5oz) for any warbird but the top removeable canopy where the batt will be, is for the FT Mustang incognito as Hawker Hurricane. Pod here only needs bottom rails, finish hatch cvr and include a good looking clear canopy, that's the 2217/7 1340kv "Beef" w/ gws 9x5dd/ep/hd prop, see?
Features:
1: Durable lite-ply 1g/inch, won't get crunched on hard nose-ins, cut big holes in face for cooling
2: Built-in thrust correction 4deg Right & 4deg Down
3: Top hatch batt access, just set it in there, plug in and close hatch, hatch will hold batt with a pin n spring
4: Space problem for ESC solved, 3/4" rails will go on bottom as spacers, ESC goes here and will get plenty of cooling from the front
5: 6-32 firewall blind nuts ( for blind squirrels ), use w/ hex head screws, easy to swap different motors
Add: make a bottom shelf in the fuse that the pod will be supported by, you might even leave out side pinning the fuse then, with it also taped at the top of fuse/pod.
Just set it in your FT warbird, tape the top pod sides to the top edge sides of fuse lengthwise and pin it in thru fuse
That fiberglass sheeting you see is behind the clear canopy and is a very hard hand grip to handle/remove canopy by.
*** I did start out building a stock FT power pod out of lite ply, but wanting the top access hatch to put bat in pod, like if you have seen End Of The RoadRCs FT Mustang? It just ended up this way, all of these I believe are good ideas, but, this could have been planned better, like one whole panel for the sides extending that extra 3/4" where the spacer will go
Another one with all these ideas, but, just a better layout, would really be the thing to do, and not just stumble on this, this way, but it's discovery as you build, I guess. I'll know better what to build and plan for the next one.
Actual Size here too, I used the WRX formula I made up, I wanted 11"=W, image =32.5"=X, rate "r" to decrease=.3385 so 34% worked just fine
This image was taken close up so you get dimension errors on a side view, that would be reduced on a more distant picture, in natural light 10 feet away
Here's the full size plan of the 40 inch FT Mustang made disguised as a Hawker Hurricane with the new power pod design:
This eliminates a little of the top and nose construction, provided, you build a Hurricane or a different canopy cover.
After you watch The Battle of Britain ( 1969 ) with Michael Caine, Robert Shaw, Kenneth More, Edward Fox (Day of the Jackal) and Laurence Olivier, you may want to build a Hawker Hurricane.
"We have before us an ordeal of the most grievous kind. We have before us many, many long months of struggle and of suffering. You ask, what is our policy? I will say: It is to wage war, by sea, land, and air, with all our might and with all the strength that God can give us; to wage war against a monstrous tyranny never surpassed in the dark, lamentable catalogue of human crime. That is our policy. You ask, what is our aim? I can answer in one word: It is victory, victory at all costs, victory in spite of all terror, victory, however long and hard the road may be." Winston Churchill
Well, then, go see Reach for the Sky, The Story of Douglas Bader ( 1956 ) Kenneth More, another great movie with Hurricanes.
Leonard
I did not want to crowd your thread, I might move this pod addition to a thread, it might be a good idea others might want to build with.
