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Old Jan 18, 2009, 01:03 PM
I can fly anything..... Once!
FL62's Avatar
United States, AZ, Queen Creek
Joined Feb 2004
1,143 Posts
Damon,

If you DO decide to go the EDF route - please let me know - I have been in the EDF scene for over 5 years - all the way from brushed motors to my current 96" Mig-29 Twin EDF project....

<-------- Just look at my avatar - that is a 7 foot wingspan, swing-wing BAE Tornado that weighs 28 pounds and is twin EDF (with my ugly mug sitting next to it)

I can give you some solid data and pros & cons of each system - I've had most all of them!

Mike
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Old Jan 18, 2009, 01:13 PM
It only takes one good idea
dag214's Avatar
Fishers, Indiana
Joined Oct 2004
6,006 Posts
Quote:
Originally Posted by FL62
Damon,

If you DO decide to go the EDF route - please let me know - I have been in the EDF scene for over 5 years - all the way from brushed motors to my current 96" Mig-29 Twin EDF project....

<-------- Just look at my avatar - that is a 7 foot wingspan, swing-wing BAE Tornado that weighs 28 pounds and is twin EDF (with my ugly mug sitting next to it)

I can give you some solid data and pros & cons of each system - I've had most all of them!

Mike
Thanks Mike,
If I go that direction I will call you.

Damon
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Old Jan 18, 2009, 01:14 PM
It only takes one good idea
dag214's Avatar
Fishers, Indiana
Joined Oct 2004
6,006 Posts
Quote:
Originally Posted by Thekid3418
That is very true jfetter. Although, would 30 lbs do much with this monster? Maybe it would help it "glide with style" instead of just gliding (taken from a classic movie ). Im sure you could get fans really cheap at HC. Or I've heard good things about the HET 9305. And i think they are pretty cheap at about 60 each.

If you were only going to use them for a little bit per flight, you could have small batteries. I would bet you could set up a motor fan and ESC from HC for 100 bucks per set. Batteries might only be 30 dollars per system, so thats 550-575 bucks after shipping. More then i would spend on an entire plane but a fairly small portion of your expenses
Believe it or not 30 pounds of thrust would keep this plane in level flight, that is if it were a true 30 pounds at over 25 mph true airspeed.

Thanks, DAG
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Old Jan 18, 2009, 01:18 PM
It only takes one good idea
dag214's Avatar
Fishers, Indiana
Joined Oct 2004
6,006 Posts
Here is what I got done today, and I have to work for my real job the rest of the day.
I am hoping to have my full main r-gear mock-up done by next Saturday. This is going to be a heavy work week for me so I may not get much done in the evenings. If this mock-up works perfect then it will be my r-main gear.

Thanks all,
DAG
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Old Jan 18, 2009, 03:39 PM
The Kid
Thekid3418's Avatar
Detroit, MI
Joined Dec 2007
2,586 Posts
I think most 90mm fans run around 9 lbs of thrust static each. So that would be 36 lbs between 4 of them, at speed it might be JUST enough.
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Old Jan 18, 2009, 05:28 PM
It only takes one good idea
dag214's Avatar
Fishers, Indiana
Joined Oct 2004
6,006 Posts
Here is something to think about.
Actually just think of the B-36 setting at the end of the runway ready for taking off. On radio #1 I set the brakes, I call to my copilot on radio#2 set flaps for take off, then I take the six Hacker up to take off power and the brakes are holding her, then I call to the copilot for jets at 100%, he (or she) takes the throttle on the #2 radio and slowly take the 4 EDF to 100%, then I release the brakes and she starts rolling, after about 150' I pull her into the air and then call to my copilot gear up, then flaps up, then jets to idle. Get the picture? Just something to think about.

DAG
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Old Jan 18, 2009, 05:32 PM
The Kid
Thekid3418's Avatar
Detroit, MI
Joined Dec 2007
2,586 Posts
Sounds to me like it won't be complete without a leather flight jacket! And perhaps an old big band album playing
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Old Jan 18, 2009, 05:40 PM
War Eagle!
sneasle's Avatar
United States, AL, Huntsville
Joined Sep 2006
2,902 Posts
Quote:
Originally Posted by dag214
Here is something to think about.
Actually just think of the B-36 setting at the end of the runway ready for taking off. On radio #1 I set the brakes, I call to my copilot on radio#2 set flaps for take off, then I take the six Hacker up to take off power and the brakes are holding her, then I call to the copilot for jets at 100%, he (or she) takes the throttle on the #2 radio and slowly take the 4 EDF to 100%, then I release the brakes and she starts rolling, after about 150' I pull her into the air and then call to my copilot gear up, then flaps up, then jets to idle. Get the picture? Just something to think about.

DAG

That sounds good to me!
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Old Jan 18, 2009, 06:04 PM
It only takes one good idea
dag214's Avatar
Fishers, Indiana
Joined Oct 2004
6,006 Posts
Hey all,
Been doing some math.

If I go with EDF's in the jet nacelles here is what I have to consider with the engineering of it:
1. What will it weigh and can I get my CG correct.
2. What type of thrust to pick, one that helps the plane, or one that just helps enough and makes sound so we know they are there, the reason this is a question is 2 EDF's pulling on the nacelle pylon will need to stay on the aircraft. This may be a huge load out on the wing.
3. Can I fit the ESC and the batteries out that far in the wing.
4. What will it weigh and can I get my CG correct.

This would be very cool, but I have a bunch of engineering to do to see how this could all work. Anyone have a ball park on the weight of a 65mm type EDF. I know that size will fit with zero problems.

Thanks, DAG
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Old Jan 18, 2009, 06:17 PM
It only takes one good idea
dag214's Avatar
Fishers, Indiana
Joined Oct 2004
6,006 Posts
FYI,
This is the jet nacelle with a 1" cube drawn beside it.

This is draw with a 90mm tube in it. Look too tight. If there was a 85mm fan, that would be better.

Looks like I am going to be calling Mike.

Thanks all,

DAG
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Old Jan 18, 2009, 06:24 PM
HAL... Open the damn doors!
jfetter's Avatar
Miramar, Florida
Joined Jul 2007
8,504 Posts
Quote:
Originally Posted by dag214
Hey all,
Been doing some math.

If I go with EDF's in the jet nacelles here is what I have to consider with the engineering of it:
1. What will it weigh and can I get my CG correct.
2. What type of thrust to pick, one that helps the plane, or one that just helps enough and makes sound so we know they are there, the reason this is a question is 2 EDF's pulling on the nacelle pylon will need to stay on the aircraft. This may be a huge load out on the wing.
3. Can I fit the ESC and the batteries out that far in the wing.
4. What will it weigh and can I get my CG correct.

This would be very cool, but I have a bunch of engineering to do to see how this could all work. Anyone have a ball park on the weight of a 65mm type EDF. I know that size will fit with zero problems.

Thanks, DAG
Too small! Go 90mm, you already have it sized for it @ 3.6" ID...

90mm EDF - 3.7oz
Mega 22/30/3 Motor - 7.7oz
Spin 55 ESC - 2.6oz
8S 5400 (1 batt for 2 motors) - 34oz

Jack
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Old Jan 18, 2009, 06:31 PM
War Eagle!
sneasle's Avatar
United States, AL, Huntsville
Joined Sep 2006
2,902 Posts
That drawing looks doable, but I would get Mikes input. If you really want to make good use of them, then intake and exhaust area has to be taken into consideration, so going down to 70mm may be a good idea.

Call Mike!
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Old Jan 18, 2009, 06:45 PM
HAL... Open the damn doors!
jfetter's Avatar
Miramar, Florida
Joined Jul 2007
8,504 Posts
Guys, 70mm fans seem too small, 90mm will fit, if they don't you can sand 1mm from around the inside and create 2mm more clearance. If you really have 3.6" clearance though, you should be golden.

My opinion after re-thinking all of this is to buy 4 x 90mm fans for $300, mount them and allow them to free-wheel. Build a hatch for adding ESC's and a shared battery per pod so you have the option later.

This is the equivalent of adding frosted flowers to a 3-layer cake that already has icing and powdered sugar, perhaps not necessary. Besides, you're on a roll now, keep trucking!

Jack
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Old Jan 18, 2009, 07:15 PM
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Angelo's Avatar
Chicago, IL
Joined Nov 1999
2,058 Posts
Stirring the pot further...

Forget about the edfs for THIS plane, just put some mock turbines in to freewheel, you don't need the thrust (you could always use smoke to simulate jets engines on takeoff).

Plan on edfs for your next plane, the YB-60! It's a natural, the full size YB-60 used 70% of it's parts from the B-36. You could do the same thing, and come up with a unique and very different scale subject. You've already done most of the engineering, all you would need on the fuselage is a new nose cone and tail feathers. The wing would also be mostly the same, just swept back and with new ribs where the piston nacelles were. 8 90mm fans, or 4 turbines, if you want to go all out, would probably do the trick. I'll bet CG would be easier to achieve, too.

Just a thought...
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Old Jan 18, 2009, 08:28 PM
Team 3DHS
BoneDoc's Avatar
San Antonio, TX
Joined Sep 2004
15,632 Posts
Angelo is right.

IMHO, EDF is such a waste of energy from its inefficiency. You're better off not putting anything in them. They dont' even generate turbine-like sounds
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