|Aug 20, 2009, 01:18 PM|
Depends on the current load of the motor. If you go HV you need less motor mass and add a cell extra I noticed on a wm400 fan a 2w20 does get hot when static tested but is plain cold after 4 min wot flight. It has been proven a 120gr motor can run 1200W all day long on HV. Only issue is that the Voltage margin on HV can be quite difficult to predict because of the lower Amp draw/voltage sag. The KV tolerances of a motor may result in a suprisingly wide power range when going HV. I think this is the reason why mf do not want to advertise HV?
|Aug 20, 2009, 01:38 PM|
Erik, I think it's more about having the motor run near it's max efficiency. Often times we over amp 2 pole motors because they have small wire and too many turns to get the kv low enough for us. I just toasted one such motor
Gary, that looks (words I can't say here) !!!
I wouldn't expect that motor to last at much more than 1200 watts, but maybe the aluminum will make a big difference. If it does, then you have a product there with a nice advantage.
|Aug 20, 2009, 02:29 PM|
My interest in this EDF was purely by design, without having yet proved it's self to me. (But the tests are coming)
The heat sinking capabiltilites are wonderful, in my opinion. (see below) And the rotor, well..You have that info already.
The motor will have to prove it's self though.
I disassembled the unit (after I assembled it for installation) and got some dims for you guys. Yeah, good long motor. All 57mm of it.
Motor shaft dia.................3.17mm
motor fairing ID................28.18mm
EDF motor hsg ID.............28.16mm
EDF motor hsgOD.............30.41mm
EDF motor hsg depth............21mm
EDF rotor hsg ID..............68.70mm
A note about heat sinking and motor mounting:
As you can see from the dims above the clearances between the motor and the EDF housing/motor fairing are only are only .004-.005 (0.10mm) per side.
Very Important: When assembling the unit, The thermal transfer compound must not only be applied to the front end cap of the motor, but to the body tube, axially, in ribbons from the front to the rear. Slide the motor fairing on without rotating it. this will allow for air to pass from the front of the motor to the rear. The motor fairing is now a hest sink, as well.
Also note the orientation of the motor wires in relation to the wire slot in the motor fairing. Bending the wires in this fashon will ease assy of the motor fairing. DO NOT rotate the fairing during assy.
See photo below.
After assy, I removed the excess compound with a Q-tip and cleaned up with denatured alch.
Please note the dia of the motor hsg ID, as this may cause fitment problems with other inrrunner motors.
More to come, Gary
|Aug 20, 2009, 02:55 PM|
"OOPS....I did it again"
^^^ what's her name?..............
Oh well, just call me 'Brittany'
Photo of thermal compound is being edited to show the compound applied axially, in ribbons from front of the motor to the rear.
|Aug 20, 2009, 04:12 PM|
we load our motors in edf always over the mf specs starting with NiCd
If you fry it you pushed it a tad to hard.
|Aug 20, 2009, 04:29 PM|
Another design discovery??
I think this is very important.
I noticed this previously, but dismissed it as a non critical machining difference between the front and the rear of the EDF Housing. There is a step (reduction) in the dia (about .010-.015) at the front of the stators, and continuing to the rear. (That much?..what was I tinking?) I now believe this is intentional, and would add to the efficiency of the unit by reduction of the (already minimal) Rotor/Housing gap. I also noted that the rear of the Rotor can be mounted very close to the step without any rotational interference.
For what it's worth, me likey.
|Aug 20, 2009, 05:15 PM|
I just ran it a half thottle, while temporarily mounted in the jet. My Thrust Fixture is still waiting completion. So I have to run it in the jet. Sounds sweet at half. I'm currently positioning all components for CG balance before I can mount the fan permanently. final assy and run up is next. The alum definatlety displaces the heat as the EDF is warm, and the Motor fairing is warmer. I ran it on a FP 30c 4500 4s.
Actual flight test and Eagle Tree data will be on FP 30c 3200 4s, because I have two of them.
You can get the compound from Mcmaster Carr, Rodger. If you want I'll post a link later.
"AOS Heat Sink Compound"... 2oz tube
I bought it a while back but I believe this one had the highest conductivity rating of the ones on the site. price..?
Please note that a quantity of the compound will be supplied with the pre ordered EDF/motor units. from the mfgr.
|Aug 21, 2009, 12:18 AM|
Looks good Gary! How certain are you that these will be available soon or are we going to have to wait over 9 months for these to be available like a certain larger fan system is taking??? LOL
|Aug 21, 2009, 12:31 AM|
The RTV that's retaining the EDF will be cured in the morning. Don't have a regular watt meter. but I still need to swap the Dean's on my Eagle Tree to bullets. I converted everything except the Eagle Tree. Will get that done tonite.
So you like my mini quasi dynawhatzit?
The order has been placed and they should be here in 13 days.
|Aug 21, 2009, 12:40 AM|
This is the worst customer service ever!!!!! I ordered my fan a few days ago and still didnt get it. Plus the owner of efflux wont even return Pm's!!! LOL!!!
Just kidding Gary!!!!
Its nice that a lot of us know you already on here. I cant wait just to see the shroud and this rotor.I hope it is stronger than my Rcmart 8-bladed sickle fans. Makes me wonder if I should start that project next!!
I have three of the 90mm 8 bladed rotors already. I dont have a clue as to what they will take as far as watts go.
All I do know is the 70mm fans sound great.
|Aug 21, 2009, 02:23 AM|
I guess I'll have to reply to that first part in a PM (I dare not say it here )
Haven't you been reading.........NOT the RC mart fan...30% glass filled.....70mm:....3.56lbs at 1274w. EDF that sucks motor heat like a..........
Yeah good thing I know you.
BTW: if folks are interested in preordering the 90mm. I'll get the specs.
I just wanted to see how the 70mm units work out first.
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