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Old Jul 23, 2011, 09:46 AM
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United States, WI, Fond du Lac
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Quote:
Originally Posted by Beltpilot View Post
Very nice build!

Your CG outcome helps a lot with my new project: converting a small foam Guanli/Lanyu Do335 to brushless. I was also concerned about the CG as I want to use two similar motors for front and back, but reading now that your's came out nose heavy, I'll go for it...


Best wishes for your maiden,
Bernhard
Thanks Bernhard,

Do you know of a source that gives the RGB or CYMK values for the various colors? The local paint shop can mix acrylic or enamel to match if they have the values.

You might want to use weights or blobs of clay that weight the same as the motors you want to use, and battery to check things before you commit to particular motors. I was obsessive about keeping the tail light after J Morgans experience with his Do-335. The ratio of the weight of the power system to the AUW will also affect what will work. The power system on mine for example was 33% of AUW.

Pat
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Old Jul 23, 2011, 11:12 AM
Wilde Sau
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Germany
Joined Sep 2009
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Hi Pat,

I know there is a list like that, need time to find it, don't know where I saw it.

Thanks for the hint with the weights, will do that definately...

You mean, the weight of both motors, ESCs &props is 33% of the AUW? Or the thrust of the power system is 33% of the AUW?

Cheers,
Bernhard
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Old Jul 23, 2011, 02:20 PM
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Quote:
Originally Posted by Beltpilot View Post
Hi Pat,

You mean, the weight of both motors, ESCs &props is 33% of the AUW? Or the thrust of the power system is 33% of the AUW?

Cheers,
Bernhard
33% is just the batteries and motors. If I include the wires, ESC's, Props and spinners it's over 40% of AUW. The thrust is better than 1:1. It will easily lift it's weight in static testing.

Pat
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Old Jul 24, 2011, 04:07 AM
Wilde Sau
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Germany
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Thanks Pat!

33% for motors and batts does not sound like much. I bet that on my foam bird, the batt will be of a higher percentage of the AUW. Makes it easy to balance the plane with the batt in the nose...

I'll have to measure RPMs once the power system is up... then I can say what kind of thrust I get. Will be plainly sufficient, that's for sure as others have already built the bird with smaller motors than the ones I intend to use.

Anyway, concerning those colors... when typing in "RLM RGB" or "RLM CMYK" into Google, one finds loads of those tables... however, quite a few of them are not very good.

There is a German site where a guy compared 7 of those tables next to each other:
http://kg.fliegerkorps.de/html/lackierungen.htm
As you don't need to understand German to read the list, that is one of the best sources for RGB-values.

Obviously, a lot of the colors are quite off from each other... in my opinion, the way to go here is to choose an option that is not gaudy... but still distinguished colors.

I have some color chips from the Merrick/Kiroff book that pretty much represent what those RLM colors did look like. Their sources are official and reliable (as much as a late war German source can be reliable ).

I can give a recommendation based on that, however it has to be considered that my monitor is not calibrated and also, I don't have perfect daylight to determine the exact tone on the paintchips.

That said I would recommend the following:

Use RLM 65 for the underside. My best guess is 65v.2, third column (48SM)
RGB 133 182 222 (#85B6DE)
That is still a little too bright though, at least it appears like it on my screen.
I therefor recommend to tone down Blue just a little, with 200 being a good value (#85B6C8)

For the topside camo scheme, use RLM 81 and RLM 82.

RLM 81 is the darker, brownish tone and is the one that is used on the nose and then go from there. My best guess is 81v.3, fourth column (XS)
RGB 35 30 24 (#231E18)
Hard to tell, but should workout fine... not too brown and quite dark, at least on my screen.

RLM 82 is the lighter, olive-green color. My best guess is 82v.2 third column (48SM)
RGB 61 72 55 (#3D4837)
Looks a little too olive on my screen and could use a bit more green... 85 would be a good value for green with this combination (#3D5537)


Ok, that is what my screen tells me
I went to the window to get better light for watching the original color chips from that book. If my screen as any reasonably near calibration, these 3 colors should look good on your bird.
Enjoy the paintjob

Cheers,
Bernhard
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Old Jul 24, 2011, 07:32 AM
olivier
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Dinan ,Brittany ,France
Joined Jun 2007
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Whaoh!

CONGRATULATIONS!

cheers!
olivier
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Old Jul 24, 2011, 09:23 AM
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United States, WI, Fond du Lac
Joined Sep 2008
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Quote:
Originally Posted by Beltpilot View Post
Thanks Pat!

33% for motors and batts does not sound like much. I bet that on my foam bird, the batt will be of a higher percentage of the AUW. Makes it easy to balance the plane with the batt in the nose...

I'll have to measure RPMs once the power system is up... then I can say what kind of thrust I get. Will be plainly sufficient, that's for sure as others have already built the bird with smaller motors than the ones I intend to use.

Anyway, concerning those colors... when typing in "RLM RGB" or "RLM CMYK" into Google, one finds loads of those tables... however, quite a few of them are not very good.

There is a German site where a guy compared 7 of those tables next to each other:
http://kg.fliegerkorps.de/html/lackierungen.htm
As you don't need to understand German to read the list, that is one of the best sources for RGB-values.

Obviously, a lot of the colors are quite off from each other... in my opinion, the way to go here is to choose an option that is not gaudy... but still distinguished colors.

I have some color chips from the Merrick/Kiroff book that pretty much represent what those RLM colors did look like. Their sources are official and reliable (as much as a late war German source can be reliable ).

I can give a recommendation based on that, however it has to be considered that my monitor is not calibrated and also, I don't have perfect daylight to determine the exact tone on the paintchips.

That said I would recommend the following:

Use RLM 65 for the underside. My best guess is 65v.2, third column (48SM)
RGB 133 182 222 (#85B6DE)
That is still a little too bright though, at least it appears like it on my screen.
I therefor recommend to tone down Blue just a little, with 200 being a good value (#85B6C8)

For the topside camo scheme, use RLM 81 and RLM 82.

RLM 81 is the darker, brownish tone and is the one that is used on the nose and then go from there. My best guess is 81v.3, fourth column (XS)
RGB 35 30 24 (#231E18)
Hard to tell, but should workout fine... not too brown and quite dark, at least on my screen.

RLM 82 is the lighter, olive-green color. My best guess is 82v.2 third column (48SM)
RGB 61 72 55 (#3D4837)
Looks a little too olive on my screen and could use a bit more green... 85 would be a good value for green with this combination (#3D5537)


Ok, that is what my screen tells me
I went to the window to get better light for watching the original color chips from that book. If my screen as any reasonably near calibration, these 3 colors should look good on your bird.
Enjoy the paintjob

Cheers,
Bernhard
Great, thanks!

That should get me close enough. I suspect there was a certain amount of variation in batches of paint during the war, not to mention fading and discoloration once the aircraft were in the field.

Pat
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Old Jul 24, 2011, 10:45 AM
Wilde Sau
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Germany
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Quote:
Originally Posted by pmullen503 View Post
Great, thanks!

That should get me close enough. I suspect there was a certain amount of variation in batches of paint during the war, not to mention fading and discoloration once the aircraft were in the field.

Pat
Exactly!
You just need two things:
- colors to start from (the "official" RLM-colors)
- put the colors you have on the scheme together so as to create a convincing appearance

I hope those colors I proposed look good... the disadvantage of modern TFT screens is that a color may look quite different on another display...

Cheers,
Bernhard
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Old Jul 24, 2011, 04:15 PM
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United States, WI, Fond du Lac
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It Flies!

I flew the Do335 today with a single 2200 mAh battery (54 oz AUW, just under 16oz/sqft wing load). The first bungee launch almost did her in. I didn't have enough tension and by the time the hook was off it was about a foot above the weeds. I should have let it land but I hit the throttle and made the ugliest bungee launch in history. I swear I cut some alfalfa on the way up. It was either tail heavy or the elevator is very effective being just in front of the rear prop because it was just about vertical in an instant. It climbed right out though. A few clicks of trim and soon it was flying well. To avoid stressing the battery I slowed down to a cruising speed at about 1/2 throttle where it flies well if I keep the turns large. From there, I just did nice level circuits until my 2 minute timer went off. I had plenty of altitude so I cut throttle to see how well it glides and it glides beautifully. In fact, for all three flights I'd cut throttle at about 100 ft. and glide it in. The battery came down cold with only about 800 mAh used.

Second flight I moved the battery forward a bit and I increased the bungee tension to it's limit. Launch was still marginal but much better than the first. This time I tried some full throttle runs and it's quick but not extremely fast. I did a few rolls and they are much quicker in one direction than the other. I expected rolls to be very similar in both directions with the push-pull counter rotating props.

Third flight I started to feed in throttle before it was off the hook and I got a pretty good looking launch though I was worried about catching the tow line with the rear prop. I moved the battery forward a bit more and the CG now feels about right. Based on the power used in the first two flights, I flew it faster and longer; 3 minutes. Tried some verticals and it goes up nice and straight. With the higher speed, it grooves nicely in the turns. I only had the upper rudder on and it's still very effective.

I fly over farm field and because of the wind direction today and obstacles on the approach, I was landing far out into the field. I'd level it out close to the ground and let it drop on it's own. There is a low hill in the middle of the field and I wasn't able to get it to land before the hill. So I actually didn't see any of my landings. Well, the last flight must have been a little hotter than the previous two because when I got to the hill the plane was no where to be found. I took me 30 minutes of wandering in the alfalfa to find it. My camouflage paint may not be correct but it's very effective!

Unfortunately, there's no video. My @&%# keychain camera's battery is shot. It only holds a charge for about thirty seconds. Normally, I clip it to my cap to record the flight including the notes I mumble to myself. So, until I get a new one, no video.
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Old Jul 24, 2011, 08:17 PM
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Crystal River Fl.
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Congrats Pat! hope to see some vid soon. An awesome plane. w.
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Old Jul 25, 2011, 02:32 AM
Wilde Sau
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Germany
Joined Sep 2009
3,604 Posts
Congrats!

I am just trying to picture those "blind" landings you did
Why didn't you fly the plane from that hill?
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Old Jul 25, 2011, 05:10 AM
Now in TN!
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Chapel Hill, TN USA
Joined Apr 2001
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Congrats Pat. It will fly w/o the bottom rudder, in fact w/o the bottom fin. Mine tore the bottom fin off on the first failed bungee launch. We launched again w/o the bottom fin and she flew fine w/o it.
Great job on the build.

J
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Old Jul 25, 2011, 09:57 AM
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United States, WI, Fond du Lac
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Quote:
Originally Posted by Beltpilot View Post
Congrats!

I am just trying to picture those "blind" landings you did
Why didn't you fly the plane from that hill?
The field is about a foot tall alfalfa. You really can't bungee launch through it. It'll grab the line as it lifts up through it. I usually use the lane between the fields but we have corn growing upwind. Don't know if you've ever lost a plane in a corn field but trust me it's bad. I had one go down a couple years ago and had to walk every row and nearly stepped on it before I saw it. So I had to stay well away from the corn. My neighbor was cutting hay so I didn't want an untested plane flying anywhere near him. If I could have hand launched I'd have been in a much better place.

The blind landings weren't so bad: the plane was skimming the alfalfa and just dropped below the horizon. The ground effect glide is pretty substantial. Once I get used to the plane I'll know just how much speed I can bleed off and not stall and I should be able land it where I want.

Today, if the wind is good I'll have a much better environment to fly in. I took my keychain cam apart and charged the battery with a proper charger and it looks like it might run for 20 minutes or so. So I might get some video. I really missed not having the verbal notes during the first few flights. It's hard to remember all the observations about the flights.
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Old Jul 25, 2011, 10:04 AM
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Originally Posted by J Morgan View Post
Congrats Pat. It will fly w/o the bottom rudder, in fact w/o the bottom fin. Mine tore the bottom fin off on the first failed bungee launch. We launched again w/o the bottom fin and she flew fine w/o it.
Great job on the build.

J
Of course, I remembered your experience so I had no doubts about flying without the lower fin. Mine is removable, held with pins and magnets and will (hopefully) release undamaged on landing.

Working on the scoops and exhaust pipes now. The scoops I carved from foam but I'll try to slosh mold the exhausts like you did since I'll need four copies.
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Old Jul 25, 2011, 02:02 PM
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Some short video. Pieces of the two flights I was able to video before the camera died. The end shows a couple (pretty ugly) landings. In the second one you can hear what I thought was an AT-6 flying by (I was busy at the time and didn't get a good look at it). EAA Airventure is going on so there are all sorts of airplanes flying overhead.

do335.wmv (2 min 6 sec)
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Old Jul 26, 2011, 07:11 AM
Now in TN!
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Chapel Hill, TN USA
Joined Apr 2001
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Yeah, you need a runway. That alfalfa really grabs it. Nice, flies just like an Arrow.

J
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