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

[knutk]

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!
I have 2 electric engines at 2000W that I intend to use 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 2000W (chinese brand) with two 80 amp. ESC and one or two 22,2v 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

[3Deranged]

Sounds like a great conversion. Didn't see any specs on the weight on Chief Aircraft site. Any idea of the AUW? 100 watts/lb would be a good scale starting point. Any more power only adds to the fun. Might even have some payload capacity for a speaker system with real radial sounds=cool! You'll have to check on the KV rating on your motors and see whats the recommended prop/pack sizes. You'll have to post some video when you're done. Do a search and see if anyone else has done this project. RCGroups has a lot of knowlegdeable folks that might be able to steer you in the right direction. Also Wattflyer.com is a site to check out too. Good luck on your project. Who needs a couple of messy engines to ruin your nice new airframe? If you've got about 4kw on tap then you should could top out at 40lbs AUW and have nice scale like flight. Converting the prop sizes(usually 2 blade figures) to 3 blade shouldn't be too hard, if you want to use 3 bladers that is.

[knutk]

Thank you for the response, I certainly need help whith this project. I will try to post some pictures when I start at this one:-) I have in the meantime built a GreatPlanes DC3, this is a smaller one of the same. I haven't flown it yet, waiting for a new receiver.
I'm sorry for late respons, but I'am travelling a lot in my job. This is a project for my retirement in april, so I intend to use the time I need for getting a nice flying DC3 just for fun:-)

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

The engine and battery configuration is a bit heavyer than the combustion engines I think, but it should be a handful of power to lean on I think.

[Goinav8n]

I know your motors say 2000 watts per but what prop ? What size prop does the nitro model have on it? I am not sure of the scale size of the prop but it should be a great conversion. If your motors are similar to say a AXI 4130/16 you will have more than enough power. With the CC-80 ESC's 6s is all you can use. Listen to the motors you are going to use. They have become very good but sometimes the bearings are not as good as some of the more expensive models. Just listen and when they start to squel replace the bearings.

Hobby city has 6s 4000-5000 mil packs by Zippy. They seem to hold voltage very well and some of my friends have been using them with very good luck. YOU have to have 3 bladed props on a DC-3. It just has to.

Keep us updated as this will be a great conversion

Jeff

[knutk]

	Quote: Originally Posted by Goinav8n
	I know your motors say 2000 watts per but what prop ? What size prop does the nitro model have on it? I am not sure of the scale size of the prop but it should be a great conversion. If your motors are similar to say a AXI 4130/16 you will have more than enough power. With the CC-80 ESC's 6s is all you can use. Listen to the motors you are going to use. They have become very good but sometimes the bearings are not as good as some of the more expensive models. Just listen and when they start to squel replace the bearings. Hobby city has 6s 4000-5000 mil packs by Zippy. They seem to hold voltage very well and some of my friends have been using them with very good luck. YOU have to have 3 bladed props on a DC-3. It just has to. Keep us updated as this will be a great conversion Jeff

I've test run one of the engines, with a 18"-6" propeller.
My battery was'nt quite up to amp-drain, and drop a lot in volts under the test, I manage to get about 850 w and 37 Amp. before I had to stop running. (I could fried eggs on the lipo , and throw it out in the yard until it went cold enogh to handle!).
I will try to get another LiPo with better data, my be a ZIPPY 5000 6 cell.......and try it again. In the meantime I will run the engines with two batteries in paralell, just to find out the quality of the engines, and listen to the bearings like you suggested.
I will likely use a 3-blade propeller on the model, and i think a 16"-8 or 10?" will give the right impression.
As you understand, I am trying out different config. on this one at the time.
AUW seems to end up at 8500g (ca. 19 lb), engines is 480 Kv/v, max. 70A 2000Watt on top, 50A running.
If these engines do'nt seem good enogh, and I'm not have faith in them, I have been thinking of this one : HXT 63-64-A 280Kv 65A Brushless Outrunner (52-30) as an aternative engine for the aircraft. May be an overkill, if anyone have a suggestion, just stay foreward!


Here is some pictures, the little one is an DC 3 from GreatPlanes, wingspan 1510mm (59-3/8") just for trying out flying a DC 3

[knutk]

I've been away for a while, but now I'm on it again. Did purchase ZIPPY lipo's suggested, only 2200MA 2 in paralell and 2 packs in serial, 11.1 volts, and testrun the chinese junk again, the lipo stood up against the amp flow, they where handwarm only whith 22.2 volts and 67 amp draw. But not so with the chinese engine, it quiet an smoke and therefore I went the same way (HobbyCity), and purcahased new engines, they are more up to what i need I think.
They will take a more suitable propeller 13" 3 blade, this will look great on the DC 3.
Data on the new motors are as follow:
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

As soon as I am starting building this bird, I will provide some fotos, my be some video too........
Regards,
KnutK

[gator8287]

I just recieved mine and have problems in dry fitting. and some other questions ? Have yoou assembled yours yet. And have you found any issues in fit

[knutk]

Hi!
I hav'nt started building yet, but I will start on the project soon, as the winter is on its way here in Norway.
There are a tread in wattflyer.com on this, I have used the summer well and gathered information and solutions on asambeling the kit, it is'nt too well described in the description following the kit..........
There are a couple of videos in YouTube and Viddler.com on this model, mostly with normal model engines, not electric.
The most importent thing i have get solutions for, is to make the wing in tree parts, not in one huge one. I cold not find anything about this in the kit description, but found a description in one of the forums, described by one swedish guy, calls him self Bokis in the forums. I think you can google his nick name and find it.
Regards,
KnutK

[gator8287]

My instructions show the use of a blind nut and screw to make it a three piece wing. Look closely at the exploded view of the wing . You should have a picture of the wood block and screw, plus its placement. My instructions show a template for the wing to drill wing alignment holes for the dowels and the wing blind nut. Although on mine the template does not exsist but the wing root is marked with an x for location.