Official Black Horse 1724mm Dornier DO335 Pfeil ("Arrow") Thread

[Aros]

[Gilatrout]

The packages and specs seem to only list one motor? Does this model not use 2 motors?

[Twowingtj]

The packages and specs seem to only list one motor? Does this model not use 2 motors?

It does indeed require two motors. Something in the .46 to .60 equiv range should be good. Haven't fully decided on my choices yet.

[CF-105]

I had a feeling it was a copy/paste fail ;)

[handyman220]

I don't know how many DO-335s Motion brought in but they are going fast. Website is showing only 7 left. As much as I want one my finances right now can't justify another plane.

[Oxotnik]

It does indeed require two motors. Something in the .46 to .60 equiv range should be good. Haven't fully decided on my choices yet.

I think that I'm going to go with Aerodrive SK3 5055-480kv motors (which are roughly Power 60 size). I'm running these motors, with MAS 14x8x3 props, in my 91" Phoenix A-26 and love it. In a plane that weighs about 1/3 less, I bet that they'd give the Pfeil a real kick in the pants. The 335 is supposed to be a speed demon after all. :-)

I'm not sure if there'll be enough room to hold two 6Sx5AH batteries though.

[Terminater007]

Don't think u will fit 2 x 6s 5000 in the front , u might be able to get 2 x 5s 5000 ….. I ran 1 x 6s5000 and it gave about a 4 min flight.... believe it or not theirs's not a lot of room in the front for the batteries and the hatch further back is where the servos also thats where i put the 2nd ESC..

Motors I used were sk3 5045 500kv with a apc props 14 x 7 front and 14 x 8.5 rear.

Also if u open up the scoop under the fuselage be prepared to get grass around the rear motor :) hehehe

reg the number on the tail, in my opinion font is too big and would of preferred it wasn't there..

[OV10]

I think that I'm going to go with Aerodrive SK3 5055-480kv motors (which are roughly Power 60 size). I'm running these motors, with MAS 14x8x3 props, in my 91" Phoenix A-26 and love it. In a plane that weighs about 1/3 less, I bet that they'd give the Pfeil a real kick in the pants. The 335 is supposed to be a speed demon after all. :-)

I'm not sure if there'll be enough room to hold two 6Sx5AH batteries though.

So why are you not considering the recommended 17" more scale diameter prop?. Price of the recommended power system.?
The powerplant that I used on my 93" ASM A-26 was the FL 5055-390kV from the Spitfire using MAS 16x10x3 CW/CCW props.
eCalc spec'd out the mixed flight time @ 7 min using 2 4000 6S. They developed almost 3000W of power combined.
This looks to be my approach for the Pfeil.
The price tag for the FL motor @ $60 is a lot more palatable than the recommended Admiral @ $130

[Oxotnik]

So why are you not considering the recommended 17" more scale diameter prop?. Price of the recommended power system.?
The powerplant that I used on my 93" ASM A-26 was the FL 5055-390kV from the Spitfire using MAS 16x10x3 CW/CCW props.
eCalc spec'd out the mixed flight time @ 7 min using 2 4000 6S. They developed almost 3000W of power combined.
This looks to be my approach for the Pfeil.
The price tag for the FL motor @ $60 is a lot more palatable than the recommended Admiral @ $130

WC,
I’d failed to write down all of my thoughts. I’m am thinking 16x9x3 or 16x10x3. Might even try a 17” 3-blader, to see how what that power draw is. The SK3 5055-430 and14x8x3 only pulls about 60A, static; so, the 5055 is definitely capable of swinging a bigger prop.

I checked HK last night, and the SK 5055s are out of stock, of course. The recommended Admiral motor seems huge. I think that I want to stay in the Power 60 region. I did see a couple FMS motors that looked interesting. I could go with EFlite or Rimfire Power 60s, but I like the price point of the SK3 5055 better.

I’m very interested in some more details about your ASM A-26 and its power train. If it’s okay, I’ll PM you, to keep from going too far off topic this early in the thread.

[OV10]

Ox...….. PM away

[WAYNE888]

I have been waiting for this bird.....even got the Cessna O2 to play with the push/pull thing...…..wasn't expecting it NOW. I am not really in a position to get yet another 400 buck bird, that is a grand by the time it is airborne.....but I love it Even got a Revell 1/48 model as a mule.
7 left.....that IS what credit is for I suppose....my wife wants to buy it for me as early xmas…..bless her heart. Have yet to fly my HE111 ! only 7.....will t6hey get a second batch pretty soon? What to do what to do....damn..... **she just got a 4 grand bonus....but that is hers....I feel bad taking any of it....I am retired.
7 left...…..coin flip? hahahahahahahahaha

[WAYNE888]

FINE! I did it......thank you Paypal....thank you Brigetta my wife…..there is now one less Do335 available for purchase

[Twowingtj]

FINE! I did it......thank you Paypal....thank you Brigetta my wife…..there is now one less Do335 available for purchase

Well, as the Borg say "resistance is futile".

[TwistedGrin]

Gents, landing this aircraft looks like it has to be flat panned three pointers....pancakes.....no flare. Long take offs only on the wing of course too....anybody have comments of flight performance of this model?

[Alpha]

TwistedGrin I've flown it several times and can comment on its flight performance. As with balsa in general, these ARFs can be configured in different ways. 6s or 8s, 17" 2B props or 16" or down to even 14", it all depends on user preference for amps/rpm/consumption. In general, OV-10's approach may prove a good one for most pilots. One thing I'll say is that for any of models of 60A or 80A ESCs you choose, there's a good chance you'll need to extend the wires. ZTW ESCs are my Go To for this configuration. We're updating the website today with more accurate electronics component information to give pilots a clearer head start, but anyone building an ARF at this level probably already knows what to look for.

A few highlights to consider based on my observations when operating this bird:

1) Battery space is sufficient but not excessive. 6s 5000-6000 can CG, and 8s 4000 also, depending on the pack dimensions. Don't plan on 6s 8000 or something like that --it likely won't fit and/or CG.

2) Motor can diameter should be observed. We're tweaking our recommendations on the website today to ensure easier fit and clearance. There are so many possible motor configurations that we're trying to spec a reasonable middle ground with reasonably wide props. I tend to prefer lower amp, higher voltage setups, but that's mostly driven by my field types.

3) Ground clearance is obviously something every Do-335 must be mindful of. Flat rotations and approaches are advised. Don't yank the elevator during takeoff. I haven't had any issues off of grass, yet, because the model doesn't suddenly leap off the ground. It's sedate. The ventral fin does not break-away, and it is part of the fuselage, so you really must avoid landing on it. Thankfully, the Do-335 rotates predictably and lands easily when flat. Use flaps to keep power on and wings level and fuselage flat with a minimal flare at ankle height. This bird rewards throttle management throughout the descent instead of yanking the elevator.

4) In the air, the Do-335 is a pattern flyer. It's really quite a straightforward operator. I attribute this to the contra-rotating prop setup and the overall layout of the aircraft including its wing shape and position. Cruise on a ~1500w setup is about 65% throttle. It penetrates well through wind, and flies closer to an electric jet than an electric warbird. Its overall wing loading is right where you'd want it for sport flying. I would not call it a fast flyer, but it's not slow or "sluggish" at all. The rudder doesn't have much authority, but I don't feel like I'm reaching for more rudder, anyway. One thing it won't do very well is extended slow rolls, but barrel rolls are easy. Loops to 300' are achievable if entered into properly but airspeed will bleed rapidly near the top. Successive loops are achievable if the first is entered into from a dive. Not that I recommend such things for general flying.

5) Due to the Contra-R setup, I would not recommend purposely deadsticking during flight. Keep airflow moving over the surfaces, like the AL37 airliner. In fact, it's helpful to think of the Do-335 as an EDF airliner in terms of throttle management and energy management --keep it moving, but it doesn't need to be going fast to fly stably. Keep energy up in a turn, and limit your bank angle to <30 degrees if your airspeed is less than double your stall speed.

6) Stalls are typically down forward and slightly to the right. You'll see wing rock as the airspeed drops, so power up soon after otherwise you'll risk a stall. Stall recovery is relaxed elevator and power to maximum (another benefit of the contra-R configuration).

7) I don't recall a flap to elevator mix. Technically the model lands fine without flaps, a bit like the Freewing 80mm A-10.

8) Landings are also straightforward, as you would fly a large EDF. Longer approach, flatter angle, managing descent with throttle, power off at shin height if you're too fast, tiny flare at shin height. Once the mains are down, I push forward elevator to pin the nose to the ground throughout the rollout. This increases friction to slow the plane, while also increasing the nose's steering authority while importantly reducing the risk of the rear prop striking any grass or debris. If you're landing with more than a third power, you're probably way too fast, even with full flaps. I set a conservative 30 degree flaps.

9) I ditched the stock pilot, but I kept the stock wheels. I happen to like the wheel material for the surfaces I fly on in Vietnam and China. The nose wheel is small, they do the job plowing through grass, which is probably why I prefer their level of firmness.

10) The model can be scaled out with a more accurate spinner and other bits. But we'll leave that to Elbee and Dirty Dee and Co.

[Oxotnik]

So, it sounds like my bad habits of landing too fast with almost no flare are fortuitous for flying the Pfeil. :-)

Alpha, thanks for your thoughts on the flight characteristics.

[TwistedGrin]

Excellent as usual sir....landing like an EDF is great analogy sir!

TwistedGrin

[Oxotnik]

Alpha,
I'm still curious about your thoughts on options for retracts.

It sounds like there's room for only one 6S battery. So, both motors will have to be from from one 6S 5AH (or so) battery? Two Power 60 [ish] motors, pulling 70 or 80A each, pulling off of one battery, doesn't seem like it's going to get a very long flight. What flight times were you getting?

[Twowingtj]

For retracts, I went for the XWave RM400-90 called for on the Motion site. I've used them on another larger bird and like them. Pretty solid unit and they run smooth. Only two sets left.

[WAYNE888]

For retracts, I went for the XWave RM400-90 called for on the Motion site. I've used them on another larger bird and like them. Pretty solid unit and they run smooth. Only two sets left.

this one needs to be shelf cured for a bit.....I am sure something will turn up by the time it has ripened