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Old Apr 14, 2014, 05:23 AM
Tony Audsley Retired Locksmith
Lockey's Avatar
Australia, WA, Perth
Joined Sep 2011
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Mig 15

I am looking for advice, ideas or comments on this project

I have designed a MIG 15 and would like to put a std out-runner motor with a 6" (maximum) prop in its guts

Has anyone seen this done or have any advice, or suggestions on motor etc

I an thinking (to keep it reasonably scale looking) the wing span would have to be 1200 mm and the fuselage is about 7 inch outside diameter at the widest part

I was thinking

Motor: D2826-6 2200kv Outrunner Motor (or similar) http://www.hobbyking.com/hobbyking/s...dproduct=12919
ESC: TURNIGY Plush 40amp Speed Controller (or similar)
Prop: 6x4E or 5 x 5 propeller

Will these be powerful enough ??

I have designed a prototype and had the plans printed and, I will commence building soon, I am hoping for a slide on grass takeoff

Look forward to your comments and ideas

Lockey
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Last edited by Lockey; Apr 14, 2014 at 05:29 AM.
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Old Apr 14, 2014, 07:06 AM
FPV Proximity is FUN!
fOaMmaSh87's Avatar
Australia, WA, York
Joined May 2012
700 Posts
That motor is bloody powerful I don't doubt it will fly it. Looks nice are you going to paint it red ?

-Ben
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Old Apr 14, 2014, 07:08 AM
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United States, MO, Stockton
Joined Oct 2013
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mig 15

why not a edf unit for it or build your own
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Old Apr 14, 2014, 07:30 AM
Using foam in moderation
newguy2012's Avatar
United States, IL, Aviston
Joined Sep 2012
586 Posts
That Sparks fellow did something similar. He is the one that has all those great toon planes. I know he did an F86 saber. Not sure on the Mig

http://www.rcgroups.com/forums/showt...ighlight=spark
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Old Apr 14, 2014, 08:10 AM
CNC Cutter
birdofplay's Avatar
United States, IN, Indianapolis
Joined Dec 2005
8,291 Posts
Wow Tony !
I was thinking about an F-86 a couple of yrs back.
I thought about doing a Square Sabre like in the pix but never quite
put it into action.

I like the idea of the Prop inside.
I use that motor on my smaller Slide On Ground series of Fighters.
F-15, F-22 and Mig29 zooom zoom !


I was going to try a ROLLED TUBE of MPF inside with an EDF.
My 1st attempt at rolling did not inspire confidence in the project. :-(

I'll be watching this one fer sure.

Bob
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Old Apr 14, 2014, 08:37 AM
"Some do, some don't"
old_coastie's Avatar
United States, MI, Grand Rapids
Joined Jul 2013
283 Posts
My 2 Cents

Have used this exact motor and ESC combo, plenty of power but needs big well to draw from, think 3S 2200 mah 25C, in order to maintain peak output....

Used it on WMPF Mako, with an AUW of 24 oz so thrust to weight should be ok..

In essence your thinking of creating a "whole fuse EDF" right?

Need some input from some guys with more prop science than I, but was thinking that you might want a "modded" prop, something that will take advantage of the ducted enviorment, maybe something like a 12 X 6 cut down to match as closely as possible the I.D. of the thrust chamber???

Ok so maybe more than 2 cents, but just some thoughts, like I said I have this exact motor and ESC if you would like some bench tests done just let me know, prob have most props from 6" to 12"...

Mark R.
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Old Apr 14, 2014, 09:02 AM
Tony Audsley Retired Locksmith
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Australia, WA, Perth
Joined Sep 2011
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WOW, thanks for the input guys

I too have used this motor, prop ESC combo in a lot of my models and I think is is more powerful than a 64 /70 EDF ... Slam, I am not really a fan (excuse the pun) of edf's


Mark, thats an interesting suggestion to use a cut down larger prop, wonder if the motor would handle it? ... Please if you have some time, do a few bench tests and let me know what you come up with

This is why I threw it open to you guys, I know there are a lot of clever guys out there ... a lot cleverer than me when it comes to the electrics side of things

I have little doubt that the Mig will fly, it all a mater of how much power it will need.

It looks like taking about one and a half sheets of Depron and about 1 sheet (Depron size 1000 x 700) of MPF (MPF is easier to roll)

I have the preliminary plans printed and ready to cut out the parts, I haven't gone to lots of trouble with the plans until I see what works and what doesn't

Look forward to any more ideas or comments

Lockey
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Old Apr 14, 2014, 09:17 AM
Geez That's A Big Fly
Banjofrog's Avatar
Australia, WA, Parkerville
Joined Sep 2011
1,333 Posts
Hi Tony,

That motor won't handle 4s and if you plan to run 2 or 3s then the kv is not high enough for the size you are planning, realistically you are planning on building a 90mm or bigger EDF equivalent, I was going to surgest this one on 4s with a 6x4 speed prop http://www.hobbyking.com/hobbyking/s...er_2350kv.html but maybe the 3200kv of the same maybe better, but for me it does start to get harder to guess and remember the noise factor where you fly.

Shaun,

Just to add I am using the 2350kv above in a Sky Fun Jet on 3s which does get along at a nice pace and on 4s it will go over 160kph, but AUW is less than 1kg.
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Old Apr 14, 2014, 12:52 PM
Allways the hard way!
georgy's Avatar
South Africa, GP, Germiston
Joined Jan 2012
358 Posts
You definately got my attention now! Love the Mig-15...

A few things i learned with my slot-jet Mig..

That T-tail is BIG and heavy.. Flat wing did not work for me as expected in this case.. KFm2 improved matters a good deal. I used scale size horisontal stab which wasnt a good plan.. ended up enlarging a good deal after 1st few flights to make it work...

Mine was a profile, so maybe none of the above will be valid for yours

Cant wait to see your new plane go..

George
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Old Apr 14, 2014, 02:22 PM
59 years of RC flying
Daedalus66's Avatar
Canada, ON, Ottawa
Joined Feb 2006
15,753 Posts
Hi Lockey

Let's be clear that using a prop inside the fuselage is not an alternative to EDF, it IS EDF, but with two blade fan. Generally EDFs use a multi-blade fan to absorb more power from the motor, given the restriction on diameter. (Remember that Italian full size DF with regular engine and two blade prop inside that flew about 1939. It had a huge tubular fuselage to allow the necessary volume of air to be moved at relatively low speed http://en.wikipedia.org/wiki/Stipa-Caproni )

Normal size EDFs need to move air through at higher speed and are inherently less efficient when it come to generating thrust at moderate air speed, typically requiring 50% or more power to fly a given model, especially when you consider the increase in weight due to the bigger motor and battery needed.

By the way, to maximize efficiency, it's important to have minimal clearance between the blade tips (which should be square) and the walls of the duct. This pretty much requires that there be a rigid metal, plywood or plastic ring with struts supporting the motor. In other words, you really need to think in terms of an EDF unit, whether purchased or home made.

To give a concrete example, the AquaCat is Polaris sized, uses the same motor as mentioned above and an 1800-2200 3s 20C battery. It flies for 6-8 minutes with lots of reserve. It weighs about 22 oz ready to fly and pulls about 20A for takeoff.

The AquaJet is essentially the same model with a Lander EDF unit instead of the motor and prop. It needs a 2800-3000 3s 30C battery and ready to fly weighs about 32-34oz. At takeoff it uses about 40A and throttled back it flies for about 4 minutes. What I like about it most is the sound, which always draws attention. What I like least are the short flights, but that's typical of EDF.

In short, it's entirely feasible to do a fairly light EDF MIG 15, but not with the same motor and prop as you'd use for an out-in-the-open setup. What you need is a regular EDF unit. The alternative, of course, is to stick the motor on the tail end with a normal prop pushing.
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Old Apr 14, 2014, 08:43 PM
Registered User
Canada
Joined Nov 2000
6,644 Posts
An... amazing to me, pattern of trying previously 'successful/proven' models with 'less'
success.
Search.. IS our friend
Read this perhaps ?
http://www.rcgroups.com/forums/showt...cartoon+mig+15
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Old Apr 14, 2014, 11:14 PM
"Some do, some don't"
old_coastie's Avatar
United States, MI, Grand Rapids
Joined Jul 2013
283 Posts
Would you believe

Turnigy D2826/6 2200 Kv Brushless

Max I = 34A
Max Thrust (Theoretical) 960 g
Max Power = 342 Watts

As posted in various places on RCG....

Test Setup

Turnigy Plush 40A Esc
Venom 2100 mah 20C 3S Lipo
Watts Up Watt/Volt Meter


All props set for pusher config, thrust measured via electronic scale with tare set just before power up...

Base Line APC 6X4E

Initial volt 12.49 (Watts Up)
24.01 Amps Peak, 273 Watts, 26 oz / 735 gr thrust


MA 6X4X3
Initial Volt 12.43
Greater than 32 Amps before "shutdown", test config failure, must have been a whole lot of power.... would have exceeded "safe" operation limits

Cox LH 5X3.5X3
(Change rotation on motor)
Initial Volt 12.34
24 Amps Peak, 260 Watts, 24 oz / 679 gr thrust
(Not as good as base line 6X4E)

But look what happens next....

Cox LH (5X3.5X3)X2
(Peak Charge Batt)
Initial Volt 12.43
Amps Peak 31.4, 344 Watts, 29 oz / 820 gr Thrust


Mark R.
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Old Apr 14, 2014, 11:17 PM
"Some do, some don't"
old_coastie's Avatar
United States, MI, Grand Rapids
Joined Jul 2013
283 Posts
Was somebody saying something about square tips and multi-bladed??????

Mark R.
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Old Apr 15, 2014, 01:05 AM
Tony Audsley Retired Locksmith
Lockey's Avatar
Australia, WA, Perth
Joined Sep 2011
2,062 Posts
Thanks for the comments guys and I have been right through the link you gave me on the cartoon Mig and Sabre … although I haven’t read every post in the thread, I have got a general idea of what he set out to do and what he accomplished … very well done Sparks, I can see you are a very talented guy.

Thank you Nigel, as usual my friend your comment have given me food for thought

Hey Shaun, thanks for the suggested motor mate, I will look at that too

Lockey
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Old Apr 15, 2014, 02:14 AM
Registered User
GermanTigger's Avatar
Germany
Joined Oct 2004
315 Posts
Quote:
Originally Posted by Daedalus66 View Post
Let's be clear that using a prop inside the fuselage is not an alternative to EDF, it IS EDF, but with two blade fan.
Not quite correct! As EDF uses a Rotor (multiple blades) to get the air in rotation! the Stator deflects the air.
A Regualar Propeller does not have those Stators.

Quote:
Originally Posted by Daedalus66 View Post
In short, it's entirely feasible to do a fairly light EDF MIG 15, but not with the same motor and prop as you'd use for an out-in-the-open setup. What you need is a regular EDF unit.
I also would say that you we need more power than a in-the-open setup. But not as much power as a regular EDF !

Toby
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