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Old Jun 10, 2012, 09:43 PM
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amtpdb's Avatar
Fontana,Ca.
Joined Aug 2005
181 Posts
Isn't there some way to check for a vacuum inside the inlet at full power? We used to check the inches of water vacuum on a supercharger with a tube fastened to the inlet and draped down and then back up with water partially in it. Start the turbines and measure the difference in the height of the water on each side. At least you could be sure if the turbines are getting 100% of what they need.
Just a thought.
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Old Jun 10, 2012, 09:51 PM
Capt. Z
falcon5's Avatar
United States, NV, Las Vegas
Joined Dec 2004
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After conferring with the engineering department Corsair Nut and R/C groups I made a few changes to the plane and will take her out in the morning for some more test runs. I put a 1 1/2" square cheater hole in front of each fan. Increased the exhaust diameter to 80mm from 76.

Tomorrows runs will be at the bigger lake bed so I will have more room than the one in the vid.
Plan is to see how she accelerates, if she looks better than today and with a little back pressure she rotates freely I will let her go and attempt flight. I won't force her into the air though as I feel that would be asking for trouble. If she rotates with gental back preasure it's a go..if not i will abort.
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Old Jun 10, 2012, 09:55 PM
check for reversed controls
alpea 41's Avatar
United States, CA, Chino
Joined Oct 2007
10,275 Posts
Looks good rolling along in the sunshine. If the nose doesn't lift with half of your elevator thro shut down and let it roll out to a stop when you are on your take off roll. I posted as you were saying the same thing lol
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Old Jun 10, 2012, 10:01 PM
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United States, TX, Grand Prairie
Joined Nov 2005
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Quote:
Originally Posted by falcon5 View Post
After conferring with the engineering department Corsair Nut and R/C groups I made a few changes to the plane and will take her out in the morning for some more test runs. I put a 1 1/2" square cheater hole in front of each fan. Increased the exhaust diameter to 80mm from 76.

Tomorrows runs will be at the bigger lake bed so I will have more room than the one in the vid.
Plan is to see how she accelerates, if she looks better than today and with a little back pressure she rotates freely I will let her go and attempt flight. I won't force her into the air though as I feel that would be asking for trouble. If she rotates with gental back preasure it's a go..if not i will abort.
I was working with a twin jet this weekend and couldn't believe how low the thrust was, less than half bench numbers after rigging up a scale

Opened thrust tubes to 90% FSA and it takes off at 3/4 throttle now and flys like bat outtah hell...I prolly got FSA numbers all wrong on that one..
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Old Jun 10, 2012, 10:13 PM
Have Fun! Land, Sea or Air
jetcaptain's Avatar
United States, TX, Austin
Joined Jul 2006
1,357 Posts
Quote:
Originally Posted by falcon5 View Post
After conferring with the engineering department Corsair Nut and R/C groups I made a few changes to the plane and will take her out in the morning for some more test runs. I put a 1 1/2" square cheater hole in front of each fan. Increased the exhaust diameter to 80mm from 76.

Tomorrows runs will be at the bigger lake bed so I will have more room than the one in the vid.
Plan is to see how she accelerates, if she looks better than today and with a little back pressure she rotates freely I will let her go and attempt flight. I won't force her into the air though as I feel that would be asking for trouble. If she rotates with gental back preasure it's a go..if not i will abort.
I wish you the best Falcon! Good luck tomorrow.
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Old Jun 10, 2012, 10:19 PM
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A10pilot's Avatar
United States, TX, Schertz
Joined Mar 2006
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Andy:

Best of luck.

Ed
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Old Jun 10, 2012, 10:22 PM
deltas are cool
AIR SALLY's Avatar
Tehachapi ,CA.
Joined Apr 2006
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do you have a wall between the inlets of the fans ? could be you need a bit of a wall to seperate them .seems to have a lot of rolling drag too
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Old Jun 10, 2012, 10:43 PM
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United States, CO, Hotchkiss
Joined Oct 2006
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Good testing, Andy. Maybe when she gets some ram pressure, she'll open up and give you some thrust.
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Old Jun 11, 2012, 02:48 AM
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Joined Jan 2010
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Full credit to you Falcon for beautiful build but just looking at that model it is wrong contender for an EDF. With your intakes and those tiny wings being a foamy it would probably fly well if it was bellow 12kg (26lb) AUW. At 18kg take off weight I would expect minimum static pull on flat surface 13-14kg, (which I doubt you are getting) otherwise I wouldn't waste my time to atemp to fly it, because it still will be bit of a flying brick.
You are probably much better off installing 160 size turbine and keep AUW to minimum.
Sorry for being negative but trying to be realistic. Another thing I would do is to build new wings at least 50% bigger area (its only a model, who gives a "fak" about scale) and number of grills in fuse not to starve turbine of air. Joe.
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Old Jun 11, 2012, 03:06 AM
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United States, NV, Reno
Joined Mar 2000
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Turbines don't need so much air, that's what the jet fuel and fire is for, it makes the thrust not the air from the inlet. A P-160 probably has an inlet of about the same size as a single 90mm EDF, this thing has plenty of excess inlet air if he goes to a turbine.

But really let's give the man some space to make his own evaluations for the EDF. He's in the only reliable place to make a valid observation - in front of the actual airplane.
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Old Jun 11, 2012, 03:45 AM
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MaHö's Avatar
Deutschland, BW, Friedrichshafen
Joined Dec 2001
876 Posts
Keep on going Falcon!
It will fly.
My Mig 29 with twin 120 flies on 10kW @ 14kg really nice. 18kg is also a good weight.

Could you perhaps go up to 11 or 12S with your 100er Stumax?!
The 8000mAh packs can handle for sure more current.....

We always say: With turbine everyone can do it, with EDF not
Good luck with your testing.
regards Martin
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Old Jun 11, 2012, 07:11 AM
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alexandermh's Avatar
Fairborn, OH
Joined Nov 2009
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Quote:
Originally Posted by AIR SALLY View Post
do you have a wall between the inlets of the fans ? could be you need a bit of a wall to seperate them .seems to have a lot of rolling drag too
+1 on the inlet separator wall. Without it, you are robbing each fan of efficient inlet air (like two kids fighting in the back seat for the same toy). Good luck Monday morning. Mark
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Old Jun 11, 2012, 12:06 PM
DELTAS RULE
corsair nut's Avatar
tehachapi, CA
Joined Jan 2006
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should be getting a report soon! cant wait to hear how it went!
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Old Jun 11, 2012, 12:41 PM
Capt. Z
falcon5's Avatar
United States, NV, Las Vegas
Joined Dec 2004
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Quote:
Originally Posted by AIR SALLY View Post
do you have a wall between the inlets of the fans ? could be you need a bit of a wall to seperate them
Quote:
Originally Posted by alexandermh View Post
+1 on the inlet separator wall. Without it, you are robbing each fan of efficient inlet air (like two kids fighting in the back seat for the same toy). Good luck Monday morning. Mark


Today's test went much better with the 1.5" x 2" rectangle cheater holes added. She had much more get up and go and appeared would have flown but I kept her on the ground due to what I found out with a little more testing I did with the fans prior to the high speed runs and more thurogh test after the high speed runs.

OK here are the numbers I got after the test runs with batts around 3.95V per cell after about 5 high speed runs. It would appear I need a longer spliter plate to separate the fans. Interesting indeed as one fan seems to get better with the other one running while the other fan does better alone and has worse numbers when both fans are running.

I only have a 4" splitter separating the fans, and the jet is back in the shop to get that corrected. But what has me a little baffled is there must be some interesting aerodynamics going on in there for one fan to compliment the other while degrading itself.


Fan 1
Alone= 3500W , 99A 39volts
Both = 3800W ,107A 39 Volts


Fan 2
Alone= 3300W , 93A 39 Volts
Both= 2600W 74A 39 Volts

So the high speed test in this latest video is with one fan 1000watts short on power. I feel when I get that corrected she should fly beautifly.

What I learned, First after I mounted the fans I really didn't do a thorough enough test and I just put them on the meter and took a quick look. I really should have dug a little deeper and tested things better. Live and learn.
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Old Jun 11, 2012, 12:44 PM
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United States, NV, Las Vegas
Joined Dec 2004
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Pass 3 and 4 if you look close I am able to lift the nose off the ground with about 3/4 elevator. These passes are with fan 2 running 1000Watts short so once corrected and with a grand of watts more i think she will fly


T 38 high speed run test 2 (1 min 21 sec)
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