Scale E-Powered Aircraft Discuss electric powered scale models here.

KMP/EMS DC 3 103,9" span Electric conversion?

Old 01-22-2009, 01:59 PM
  #1  
KnutK
Oldflyer
Thread Starter
 
KnutK's Avatar
 
Join Date: Dec 2008
Location: Vest coast of Norway
Posts: 13
Question KMP/EMS DC 3 103,9" span Electric conversion?

Hi!
I have just got my EMS/KMP DC 3 box into my workshop, it was a really huge box, I had problems get it in my shop because it was the same hight as the door!Data of the DC3:

This is what the instruction manual says about the airplane:

Length : 1790 mm (70,5")
Wing Span : 2640 mm (103,9")
Wing area : 77,39 sq.dm (8,33sq.ft.)
Wing loading : 116,3 g/sq.dm (38,1 oz/sq. ft.)
Flying weight : 9 Kg. (19,8 lbs)
Radio : 6ch&12 servos
Engine : 70-2 cycle, 91-4 cycle

I have 2 electric engines:
TURNIGY AerodriveXp SK Series (HobbyCity)
AerodriveXP SK Series motors are designed for those who want the very best in outrunner technology for their R/C plane. Typically an efficiency improvement of around 8-10% can be seen over similar classed motors. This is in part due to the following;
Stator Laminations: .2mm
Magnet Type: N45SH
Bearings: Dual oversize (Japanese)


Model: SK50-55-580
Kv: 580rpm/v
Turns: 5
Resistance: 16
Idle Current: 1.5A
Shaft: 8mm
Weight: 329g
Rated Power: 1580w
ESC: 80A
Cell count: 4~8 Lipoly
Suggested Prop: 12*6, 13*8, 14*7, 15*9
Power equivalent : .61+ glow engine

I intend to use these engines on this bird, and I wonder if any one have done this before. I am going to need some advice on this one, I have been building smaller electric airplanes before, and some of them are twin engine setup. I intend to use these two engines with two 80 amp. ESC and one or four 2200 25C ZIPPY lipos on one engine, two in paralel and two packs in seriel to get 22,2v 4,4 amp. lipo.
My qestion is: Do you think this configuration will take to the air? I need some advice about what propeller to use on this big flying mass too
I have to say, I am an old fuel engine flyer, but it is about 30 yers since I have been flying F3A models, and taken up the old hobby, whitout the scaring engine sound, therefore electric, and I find it facinating to see if it will fly. And I really like the DC 3 from my childhood. We have the DC 3 of Norway still flying, a really shiny thing!!
Regards from Norway,
KnutK
KnutK is offline  
Old 01-23-2009, 03:51 AM
  #2  
haze_b
Member
 
haze_b's Avatar
 
Join Date: Jun 2007
Location: Honolulu, HI
Posts: 110
Default

KnutK,

A big old DC-3 sounds like a great model. I'm sure it'll look great in the air.

In general, if you can get @100w / lb out of your power system, it should fly well.

You also might want to consider downloading "motocalc" or a simialr program to help verify your setup.

Post some pics!!

Good Luck.
haze_b is offline  
Old 01-23-2009, 07:22 AM
  #3  
Slowjohn
Passed on
 
Slowjohn's Avatar
 
Join Date: Jan 2006
Location: Mid Coastal TX.
Posts: 2,100
Default

Howdy KnutK and welcome to WattFlyer

That's a heck of a plane to jump back into the hobby with and I wish you all the good luck you'll need building it. I'm sure you've probably noticed a lot of the changes that have occurred while you were away from the hobby. I was out of it for about the same amount of time as you were myself and the advancements & changes stunned me. I guess the one that got me the most though was what was "cutting edge" back when I'd stopped flying were now called "Vintage"

I hope you'll do a build thread here of you huge DC-3. You'll find lots of good folks here with some great experience to share and help you with should you need it.
Good Luck with the build and Stay Safe

Standing By,
SJ
Slowjohn is offline  
Old 01-23-2009, 09:05 PM
  #4  
KnutK
Oldflyer
Thread Starter
 
KnutK's Avatar
 
Join Date: Dec 2008
Location: Vest coast of Norway
Posts: 13
Thumbs up KMP/EMS DC 3 103,9" span Electric conversion?

I will keep you updated as the build goes forward, I intend to start building when I retire this year. I intend to get all the stuff I need for the building, and then start building. I have a little one from Great Planes to crash first, and a lot of other planes too The west coast of Norway is wet, cold and windy at this time of the year, I'm waiting for the spring to start flying. I agree, it has been a huge step forward since last time i did fly these little ones, and I did fall in love with the electric setup at once.
And I am sure I will need your advice, so thank you for this forum, it is a place where we beginners can get the help we need.Thanks!

Regards,
KnutK
KnutK is offline  
Old 01-23-2009, 10:07 PM
  #5  
Slowjohn
Passed on
 
Slowjohn's Avatar
 
Join Date: Jan 2006
Location: Mid Coastal TX.
Posts: 2,100
Talking Standing By

Hope your not retiring next Dec.

Anyway we'll be here waiting for your call

So until then or when ever...

Standing By,
SJ
Slowjohn is offline  
Old 01-24-2009, 12:52 AM
  #6  
CHELLIE
Super Contributor
 
CHELLIE's Avatar
 
Join Date: Oct 2006
Location: Hesperia, So. Calif
Posts: 19,269
Default

Originally Posted by KnutK View Post
I will keep you updated as the build goes forward, I intend to start building when I retire this year. I intend to get all the stuff I need for the building, and then start building. I have a little one from Great Planes to crash first, and a lot of other planes too The west coast of Norway is wet, cold and windy at this time of the year, I'm waiting for the spring to start flying. I agree, it has been a huge step forward since last time i did fly these little ones, and I did fall in love with the electric setup at once.
And I am sure I will need your advice, so thank you for this forum, it is a place where we beginners can get the help we need.Thanks!

Regards,
KnutK
Hi KnutK Wow thats a big undertaking I would stay away from trying to use a bunch of small lipos and hooking them all up in parallel and series, your asking for Big trouble I Always use K.I.S.S. , buy 1 lipo for each motor, and buy 1 flight battery, to control your servos & receiver with a 10 amp UBEC from Castle Creation, you will need to disconnect the red wire from the ESC,s going to the receiver, the Rhino Lipos have been working great for me and my RC club, very powerful and work great, Hope that helps, Chellie
http://www.hobbycity.com/hobbycity/s...5C_Lipoly_Pack
Motor Power lipo

http://www.hobbycity.com/hobbycity/s...0C_Lipoly_Pack
flight lipo

http://www.castlecreations.com/products/cc_bec.html
UBEC

http://www.hobbycity.com/hobbycity/s...eed_Controller
ESC
CHELLIE is offline  
Old 01-24-2009, 01:09 AM
  #7  
CHELLIE
Super Contributor
 
CHELLIE's Avatar
 
Join Date: Oct 2006
Location: Hesperia, So. Calif
Posts: 19,269
Default

I think I would use the turnigy 50-65A motor on your plane, a 50-55 might not be enough power, and your plane requires a 70 to 91 motor/enging, hope that helps, Chellie

http://www.hobbycity.com/hobbycity/s..._(Eq:_4030_AXi)



Model : TR50-65A-400
Input Voltage : 14.8V~29.6V (4~8S Li-po)
Kv : 400 rpm/V } within 10%
Current capacity : 60A/60s
Dimensions : 50mm X 65mm / 1.97in X 2.68in
Shaft diameter : 8mm / 0.31in
Weight with cables : 414g / 14.60oz
Number of poles/magnets : 14
Recommended model weight : 3000~4500g / 100~200oz
Power equivalent : .50 to .72 glow engine
Suggested Propeller Size: 6S: 16x10 / 7S: 14x10
CHELLIE is offline  
Old 01-24-2009, 01:15 AM
  #8  
CHELLIE
Super Contributor
 
CHELLIE's Avatar
 
Join Date: Oct 2006
Location: Hesperia, So. Calif
Posts: 19,269
Default

with motors getting this big, its ok to use a nitro prop, i like the Zinger Wood props,

http://www.atsrcplanes.com/zingerprops.htm
CHELLIE is offline  
Old 01-27-2009, 09:27 PM
  #9  
KnutK
Oldflyer
Thread Starter
 
KnutK's Avatar
 
Join Date: Dec 2008
Location: Vest coast of Norway
Posts: 13
Thumbs up

Hi! Thanks for quick response, I really think the help and good advice I get here is helping me out.....
I did use some time to study different motors, but the DC 3 has a very narrow space between the nacelles and the fuselage, the largest propeller have to be no longer than 13 1/2" (14" will hit the fuselage!), so I had to get a motor that could give me the nessesary power with a propeller this size. I did use motocalc, and it seems that this motor can do the job with a 13*8" propeller, but I will be thinking of a way to lead an airflow from the nacell to the battery compartment in the midwing for cooling the batterys.... they will get warm without any cooling. I will purchase a 6S4000 Rhino pack for each engine as you suggested, I follow the K.I.S.S. theory Chellie , I don't want to make a expensive firecracker!
I will start building this bird sometimes after summer, I don't have the time for it yet, I have to work for living, and try out all the other models during spring and summertime. I will try to post some pictures of the plane as soon as possible, my be this weeken when I am returning home from where I'm working just now. As I mention earlyer I will retire the 1. of april, then I will use more time with my grandchildren, my wife and my airplanes. I'm also building and flying ultralights in my speartime with my brother, so I hav'nt any problem with finding somting to do!!
For now,
Have a nice day.
Regards
KnutK
KnutK is offline  
Old 01-28-2009, 04:17 AM
  #10  
CHELLIE
Super Contributor
 
CHELLIE's Avatar
 
Join Date: Oct 2006
Location: Hesperia, So. Calif
Posts: 19,269
Default

Nitro planes seem to be built a little heavier than Electric planes are, if there is some ways that you can shave some weight off the plane, with out making it weak, you may want to do that, Just my 2 cents worth Take care, Chellie
CHELLIE is offline  
Old 02-06-2009, 11:33 AM
  #11  
KnutK
Oldflyer
Thread Starter
 
KnutK's Avatar
 
Join Date: Dec 2008
Location: Vest coast of Norway
Posts: 13
Talking Thanks everybody for your interest in my prodject!

Hi!
At last I got time to testrun my new TGY, and the result I got was:

1450 watts
75 Amps
Battery temp: Handwarm with with different rpm, 2-3 minutes at full power........

Prop: 13x8", will try a 13x7" when I get the new 6 cell 5000 25C and propellers from HobbyCity, I think this will take the DC 3 into the air.

When I start building, I will certainly look into reduce the weight of the airplane, and I think I've got a soulution on the cooling problem for accu compartment, whithout cutting big holes in my butiful plane...... I will start a building tread as soon as I start building, for now I am just collecting hardware
Pictures will soon be available.
Take care,
KnutK
KnutK is offline  
Old 02-07-2009, 03:32 PM
  #12  
KnutK
Oldflyer
Thread Starter
 
KnutK's Avatar
 
Join Date: Dec 2008
Location: Vest coast of Norway
Posts: 13
Default Pictures of the project

Found some pictures..........
Attached Thumbnails Click image for larger version

Name:	12253.jpg
Views:	437
Size:	14.0 KB
ID:	92837  
Attached Images    
KnutK is offline  
Old 04-28-2009, 10:21 PM
  #13  
electricfly2002
New Member
 
Join Date: Aug 2005
Posts: 8
Default KMP DC3

Hi.

have you started on the build yet? Will be starting with my electric version within the next two weeks. Ordered two Hyperion ZS 4025 (505 Kv) motors for the plane
electricfly2002 is offline  
Old 04-28-2009, 10:35 PM
  #14  
rcers
Super Contributor
 
rcers's Avatar
 
Join Date: Jul 2005
Location: Trophy Club TX
Posts: 6,314
Default

KnutK - you can also use 3 blade props - and they will look much better too. That will increase the load dramatically.

KMP stuff looks great - but it is typically HEAVY - so do all possible to keep your power system and batteries LIGHT. Do not underpower this - you will want 125w/lb or so.

Don't want to scare you but this will be very much the opposite of a parkflyer. With a near 40in/oz loading flight characteristics are flat serious. You must fly this dude all the time. I would strongly recommend some stick time on a 30in/oz airplane BEFORE you fly this bird!

I have done about 10 twins now - happy to help you with questions or issues!

I would really love to do their BF-110!

Mike
rcers is offline  
Old 04-29-2009, 08:09 AM
  #15  
electricfly2002
New Member
 
Join Date: Aug 2005
Posts: 8
Default

Mike,

I will be using 12x8 3-bladed props as suggested, and although I would prefer to use 4035 (i.e. stator dia 40mm, 35mm thick) which is the normal .90 glow replacement, but I am going for the smaller motors with 6S packs to keep the weight down. If I find that the amp draw on the 12x8 props are too low, I will consider the 13x8 props.

We are "hot and high" in Pretoria in South Africa, so 100w/lb may be a bit low, but I am counting on motor efficiency and good batteries (new G3 Hyperions) to carry me through. We also weighed completed plane with two .90 OS morors, which came out at about 11kg dry! My aim is thus about 1200w per motor, which I can push to 1500w if needed to get the suggested 125w/lb (which I suspect will be over-powered!).

Not sure why, but it seems that very little info is available on the internet on this plane. Would love to know the AUW of the planes that the other guys built!

Regards,

Andre
electricfly2002 is offline  
Old 04-29-2009, 03:44 PM
  #16  
rcers
Super Contributor
 
rcers's Avatar
 
Join Date: Jul 2005
Location: Trophy Club TX
Posts: 6,314
Default

Little info - as the KMP stuff is remarkably expensive and many don't care for their stuff much. I have heard complaints about paint issues, and there is always the weight. They simply are VERY heavy. So much so that they are for expert pilots only and misbehave when you have any sort of situation.

That said - they are VERY well detailed and scale. I have seen their P-38 fly and it was one impressive ship.

One suggestion on props - keep the pitch as high as possible and these will cause more load:
http://www3.towerhobbies.com/cgi-bin...?&I=LX1633&P=7

Graupner:
http://www.hobby-lobby.com/g-sonic_3...18512_prd1.htm
http://www.hobby-lobby.com/g-sonic_3...18513_prd1.htm

The Graupner props I have run suck amps like no tomorrow. So they might be a really good choice for a low KV motor and less cells.

Mike
rcers is offline  
Old 05-02-2009, 08:39 AM
  #17  
electricfly2002
New Member
 
Join Date: Aug 2005
Posts: 8
Default

Hi,

thanks for info and links. Changed my mind and ordered two of the new Hyperion ZS 4020 12 motors. They are about 100g lighter than the 4025 motors, and are rated at 1800w each.

Will check the amp draw as soon as the arrive!

Regards,

Andre
electricfly2002 is offline  
Old 05-07-2009, 10:14 PM
  #18  
KnutK
Oldflyer
Thread Starter
 
KnutK's Avatar
 
Join Date: Dec 2008
Location: Vest coast of Norway
Posts: 13
Thumbs up Progress on DC 3 prodject EMS/KMP

Originally Posted by electricfly2002 View Post
Hi.

have you started on the build yet? Will be starting with my electric version within the next two weeks. Ordered two Hyperion ZS 4025 (505 Kv) motors for the plane
Hi all!
Report from the far north.......
I haven't got to the point of starting to build yet, it's going against summer in my country now, and my house, garden and other things I own need attention and care.
I will also take some time out on two weels(Suzuki Burgman), this I can only do during spring, summer and autumn here in the west coast of Norway.
Rest of my spare time I will fly my other aeroplanes, all electric of course.
I've testrun my engines with a better battery, and found these data from the testrun of TURNEGY SK 5055-580, FlightMax 5000 25 C, 80 A ESC and a MASTER 13X8" propeller: 1450 w, 60-65 amp, battry volt never under 20v.
I had to stop the test because the drum get loose on the motor, I've heard about this, so I stoopped at once when i the engine dropped in revs. I will secure the drum lock tite on both of the motors before I test them next time.
I did a weight test of the entire plane with all equipment, and find AUW around 19 lb, so I do think these engines will give me the trust I need, it is a guy (Bokis I think he call him self on the net, there is some rather good videos on the net) in Sweden who flies the KMP/EMS with two rather lazy 90 4T Chinese, and he says it will fly easely with two 70 4t. I have read that there are two different models of this airplane, mine is that one with balsa wings outside the engines.
I will start building when the bad wether starts again next winter, so stay on, I will follow you trough the summer as well..........
Have a nice flying season,
Regards,
KnutK
KnutK is offline  
Old 05-08-2009, 07:31 AM
  #19  
electricfly2002
New Member
 
Join Date: Aug 2005
Posts: 8
Default

Hi,

Thanks for info - the 19lb seems very light. Does that include your motors, batteries etc? Bought myself a second plane, as I got the new plane with the undercarriage from a friend for about the same price as the undercarriage in the shops The undercarriage will aslo add abot 3lbs to the all up weight ;-(

I have a friend at our local club (www.whitehills.co.za) that was using a turnigy motor in a 1/3 scale Sukhoy, and the magnets on the case also came loose. We suspect that Turnigy motors are not using high temperature epoxy on their motors, and as soon as the motors heat up the magnets come loose. Motor was fine at 50A, problems at 65A (on 12S pack).

Waiting for my motors, but I will probably start building over the week end. I also have the balso wing versions. What servos do you intend using?

Regards,

Andre in a misty Johannesburg


Also wigh
electricfly2002 is offline  
Old 06-01-2009, 09:56 PM
  #20  
electricfly2002
New Member
 
Join Date: Aug 2005
Posts: 8
Default

Tested my motors recently - the Hyperion ZS 4020 motors swing a 12x8 3-blader at 9500 rpm at about 52A on a 6S pack. Busy building the wing - mid section just about complete
electricfly2002 is offline  
Old 07-09-2009, 05:48 AM
  #21  
KnutK
Oldflyer
Thread Starter
 
KnutK's Avatar
 
Join Date: Dec 2008
Location: Vest coast of Norway
Posts: 13
Default Summer has came to Norway :-)

Hello to you all! It has been a bysy time for me, so I had to set aside the prodject until dark winter evnings, but I have not stop thinking of it. I plan to do a jig for testing out the engine/esc and batery set up during the summer. Just now I have been traveling a lot, at the time staying in Orlando Florida, until july 16.
In the meantime, have anyone of you done a modification on the wing, I would like to modificate them, so I could take off the outher part of each wing for more easy transportation. I have not studied this yet, but I am willing to listen to the experience of the comunity...........instead of use too much time solving this on my own.

Until next time,
Happy flying
Regards
Knut
KnutK is offline  
Old 07-09-2009, 10:11 PM
  #22  
electricfly2002
New Member
 
Join Date: Aug 2005
Posts: 8
Default

Knut,

The instructions are confusing, but basically you use the same method as attaching the stabs. Use the provided template to drill and insert the outer locating dowels, and then use a blind nut to attach the outer wing panel to the mid section. Can send you a pic of my setup, which will clarify the setup. Was just a challenge to set the correct incidences, as I found that my wing mid-section had a warp of about .75 degrees.

I will be running two of the new Hyperion ZS 4020 motors, draws about 52 amps on a 6S pack and swings a wooden 12x8 3-bladed prop at about 10200 rpm.

Just about finished with my plane - just completed the battery box, received my 2S A123 receiver pack today and will be checking CG over weekend.

Regards,

Andre
electricfly2002 is offline  
Old 07-19-2009, 08:12 PM
  #23  
KnutK
Oldflyer
Thread Starter
 
KnutK's Avatar
 
Join Date: Dec 2008
Location: Vest coast of Norway
Posts: 13
Default

Originally Posted by electricfly2002 View Post
Knut,

The instructions are confusing, but basically you use the same method as attaching the stabs. Use the provided template to drill and insert the outer locating dowels, and then use a blind nut to attach the outer wing panel to the mid section. Can send you a pic of my setup, which will clarify the setup. Was just a challenge to set the correct incidences, as I found that my wing mid-section had a warp of about .75 degrees.

I will be running two of the new Hyperion ZS 4020 motors, draws about 52 amps on a 6S pack and swings a wooden 12x8 3-bladed prop at about 10200 rpm.

Just about finished with my plane - just completed the battery box, received my 2S A123 receiver pack today and will be checking CG over weekend.

Regards,

Andre
That seems just the same set-up like the one I'm workin' on........I look foreward to see/read the result of flying your plane when finished.........
I can't find anything in my instruction about mounting the stab or the outher parts of the wing without gluing them, but if you have some pictures that show a way to do it, it will be fine.
The wing does not fit in my Audi, so if I can take them in 3 parts, I would be a happy gay One more question: Do you intend to mount a retract system on your plane? I intend to mount the original system, but it will add a 500g to the total weight...........
Regards,
KnutK
KnutK is offline  
Old 07-21-2009, 12:48 PM
  #24  
KnutK
Oldflyer
Thread Starter
 
KnutK's Avatar
 
Join Date: Dec 2008
Location: Vest coast of Norway
Posts: 13
Thumbs up Tested the Turnigy motors

Hi!
I have done a testrun on my motors, it looks like I vill get enough power out of them to get airborne............
I have made a jig with a fishing scale, and a wattmeter/voltmeter, and the measuring result was as follow:

Pull: 5 Kg
Watt: 1425
Amp:63
Volt: 20.9
All at full trotle and 13x 7" propeller, and Flightpower 5000 6 cell........

This is the first time I tested, and the battery, engine and ESC was only handwarm.......
The whole plane will be around 10 Kg, so this should be plenty power I think, I will do some further testing later, to measure time and volt/amp/watt at difrent power setting.
KnutK is offline  
Old 07-23-2009, 10:58 AM
  #25  
KnutK
Oldflyer
Thread Starter
 
KnutK's Avatar
 
Join Date: Dec 2008
Location: Vest coast of Norway
Posts: 13
Build Review

Hi!
I have started to test engines and other mechanics of the project. I have searched some on the web to find out how much power I need pr. kg. or pr. lb, but there are many different suggestions.... Based on what I have read on different forumse, I will need at least 100watt pr. lb., the model ends up around 19-20 lb. I've read all the suggestions in this and other forums, and found that I will need minimum 2000Watt total in this type of model. It need not to climb straight up by the propeller, it is, after all a scale project...... Therefore, I think the need for power will be around 1ooo watt pr. motor, so with 1425 watt I will have a power reserve. My concern is more that I end up with not getting the best efficiency out of engines/batterypackages, got two 25C/5000/6cells intended for use in the DC 3.
I found sulution for the wing in another forum, a guy named Boris had done it this way:
"One ting that could be worth thinking about is how to make the wing attatchement,I glued the wing spars with the wing sections and use blind nuts in the wing(one at each side)and normal plastic bolts screwed from the wheel wells,works perfect for me..
Easy to do also,just used a wooden screw from the well and screwed together the center section with the wing ,voilį.the holes will be perfectly aligned..
This makes the aircraft very easy to assemble at the field and nice size to transport.. "
//Bokis

It is raining to day, so I can't do any pictures of testing rig and tests, so I will do this tests another day........my wife do not like me too much if do tests in the living room I think........
So, until next time,
Regards
KnutK
KnutK is offline  

Quick Reply: KMP/EMS DC 3 103,9" span Electric conversion?


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.

Page generated in 0.16285 seconds with 16 queries