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Old May 16, 2012, 11:36 PM
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Australia, VIC, Melbourne
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DP.... just take it that the loss without lip will be 30 - 45% range.
More important to you is "What is the design INSIDE the plane, leading to the EDF housing?"
If it is dead flush to the rim, then that is fine. But if it is not a good flush alignment then it would benefit from a having a lip fitted on it, and make it all fit somehow.

Once either of those cases is satisfied, re-test.
Check volts and current.... work more out from that result. Or post them here.
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Old May 16, 2012, 11:57 PM
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Madison, MS
Joined Oct 2006
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Originally Posted by anlucas View Post
Yes, no problem. But I don't know if the results will be of any use to you. For what batteries do you want numbers for?
You can just use the same batts you listed in your spreadsheet or whatever works for you. Thanks for doing that, I'm curious to see how much of a thrust reduction there is.

D
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Old May 17, 2012, 12:59 AM
3DHOG
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USA, CA, Aromas
Joined Sep 2010
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roughly 25%....depends a lot on how many cells you run, more cells = more loss
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Old May 17, 2012, 01:31 AM
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Greece, Attica, Athens
Joined May 2011
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Quote:
Originally Posted by dpowellmeii View Post
You can just use the same batts you listed in your spreadsheet or whatever works for you. Thanks for doing that, I'm curious to see how much of a thrust reduction there is.

D
Much more reduction than I expected(about 50% reduction)......here goes.....L2855-2100kv + CS10 without a lip

4S 4000mah 25c
15.8V
28Amps
485Watts
0.55Kg thrust

5S 3300 25c
19V
37Amps
700Watts
0.75Kg Thrust

6S 4500mah 25C
22.5V
50Amps
1100Watts
1.1Kg trust....


****CAVEAT - To anyone else reading this. These tests were without an inlet lip and cannot be used to indicate possible performance of the motor/fan combo.


Two things impressed me.
1. How much lower thrust one gets without proper inflow to the fan.
2. The white noise generated was awesome....

With the lip on, the fan is very quiet when balanced properly.
With the lip off, inlet turbulence noise is just a great white noise generator.


It may be worthwhile experimenting with inflow disruption to generate white noise....
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Old May 17, 2012, 06:50 AM
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Antarctica
Joined Apr 2012
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Quote:
Originally Posted by Extreme_RC View Post
Cheap and good is not easy to find, Landers are cheap but the machining is not as fine or accurate in the main section of the housing as, so there are differences in whats available.
My current 70mm housings are a new design, the centre section of the outer shroud where the thread is has been reduced to a small ridge rather than a large flange, motor mount holes have been resized & optimised for most inrunners, and the stator finish is much finer. They are designed to fit into pre-molded foam models and all composite models that have ducting made for the common wemo/het housings.

Housings are due in tomorrow, and this CNC run I made sure there was no production over run of my designs left laying around that could end up in other peoples hands...
your housing looks like those...bulk buy from skyworld?
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Old May 17, 2012, 08:44 AM
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United States, TX, Grand Prairie
Joined Nov 2005
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Quote:
Originally Posted by anlucas View Post
...It may be worthwhile experimenting with inflow disruption to generate white noise....
I've seen people take the intake ducts and not pin them to the mold sides of the models intake rounding so it almost create the same effect as the shroud without the lip but by time it gets to the blades the air is already smoothed out
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Old May 17, 2012, 08:51 AM
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Greece, Attica, Athens
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Originally Posted by erh7771 View Post
I've seen people take the intake ducts and not pin them to the mold sides of the models intake rounding so it almost create the same effect as the shroud without the lip but by time it gets to the blades the air is already smoothed out
I was thinking of not sealing the gap bewteen the housing and the inlet ducting. This will lead to losses and lower amps. Question is how much loss and if it is tolerable. I will also try using a slightly higher kv motor....

I am thinking of trying something along those lines in my super quiet T-45....
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Old May 17, 2012, 10:12 AM
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Madison, MS
Joined Oct 2006
802 Posts
Quote:
Originally Posted by anlucas View Post
Much more reduction than I expected(about 50% reduction)......here goes.....L2855-2100kv + CS10 without a lip

4S 4000mah 25c
15.8V
28Amps
485Watts
0.55Kg thrust

5S 3300 25c
19V
37Amps
700Watts
0.75Kg Thrust

6S 4500mah 25C
22.5V
50Amps
1100Watts
1.1Kg trust....


****CAVEAT - To anyone else reading this. These tests were without an inlet lip and cannot be used to indicate possible performance of the motor/fan combo.


Two things impressed me.
1. How much lower thrust one gets without proper inflow to the fan.
2. The white noise generated was awesome....

With the lip on, the fan is very quiet when balanced properly.
With the lip off, inlet turbulence noise is just a great white noise generator.


It may be worthwhile experimenting with inflow disruption to generate white noise....
Thanks for doing that. Man that's a huge difference.

D
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Old May 17, 2012, 11:52 AM
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Madison, MS
Joined Oct 2006
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Kg=oz
.55=19.40
1.3=45.85
Diff=26.45
% drop=57.6%

.75=26.45
1.8=63.49
Diff=37.04
% drop=58.3%

1.1=38.80
2.4=84.65
Diff=45.85
% drop=54.1%

That's some pretty big differences.

D
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Old May 17, 2012, 12:50 PM
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Greece, Attica, Athens
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Quote:
Originally Posted by dpowellmeii View Post

That's some pretty big differences.

D
Yeah, but in an airframe it's a different story.
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Old May 17, 2012, 01:14 PM
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Madison, MS
Joined Oct 2006
802 Posts
Not a whole lot, check my post a few pages back about my install in my Phase 3 F-16. It's about an 8-9oz thrust gain installed in this airframe from the no inlet lip numbers. Of course every airframe is going to be a little different.
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Old May 17, 2012, 02:59 PM
Diverted by planks
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South Florida
Joined Dec 2010
5,162 Posts
All this talk about gaps, and metal versus plastic housings, and fan flex made me think of something.

I was going to go ahead and do it myself first and post video, rather than even talk about it, but then I decided I'm not sure I want to put my #16 cam at risk, or really mess around with the idea.

BUT:

If someone were to carefully secure a keycam into the fuse, looking back at a EDF fan unit... maybe even add a tether to secure it to the front, in case the velcro comes loose in flight...


AND... add one of those superbright white LEDSs to a spare 5volt header on the radio to power it (I have a bunch of these that came with resistor included, to run off 5 volts directly), just leave it in there for illumination...


THEN...

Run that thing through it's paces in the air!

You'll hear it straining, you will see it turning... you can see if the gap stretches or not... determine how much wobble there is.... maybe even catch the whole darn thing tweaking in the fuselage under thrust pressure?

OR it might be boring and see nothing.


Seem like it might be fun to try, tho'....
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Old May 17, 2012, 04:52 PM
Extreme CNC Alloy EDF
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Australia
Joined Mar 2006
11,639 Posts
Quote:
Originally Posted by viperviper View Post
your housing looks like those...bulk buy from skyworld?
Huh?? Housing looks like what? My 70, 80, 90, & 127mm housings are my design, engineering drawings converted to CAD at considerable cost and then large quantity produced as is required with your own product schedule.
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Old May 17, 2012, 05:03 PM
It should fly at least once
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Australia, NSW, Grenfell
Joined Mar 2006
2,596 Posts
Quote:
Originally Posted by efflux RC View Post
We also stock the E-flte BL32 (2150kv, 5mm shaft) motor and a few other E-Flite products. If you don't see what you need, please PM or email us.

We are located in CA.
Gary - effluxrc@gmail.com
Heres a thought..........Why not run a full page add on here
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Old May 17, 2012, 05:36 PM
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Australia, VIC, Melbourne
Joined Nov 2006
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hehe... well someone did ask where to get some alloy housings...... (and to test a BL....)
So I guess it is fair enough to respond, even if you are a seller of those.
And sometimes it has been handy to have some place post their link so you can go and check what they sell, or what they said they have etc. Mainly the first time you have ever seen them.
Though often I have totally forgotten about a place and then it jogs your memory to check them out once again.

Maybe if the "near term post count" gets too be too many then it over-steps the friendship, lol.........
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