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

[ghethco]

Hi guys,

Getting mine ready to maiden... Have not been able to find any reference to flap -> elevator mixing. I've modified my flaps with offset hinges made from G-10, so full 60-70 deg deflection is possible. I'd like to take the guesswork out of flap -> elevator mixing if possible. Or did people find it isn't necessary?

Post edit -- found (on a different thread) the following worked for two people, one of whom also did offset hinges to allow more flap deflection: 6% down elevator mix for 1/2 flaps, 11% for full flaps.

Gary

[Twowingtj]

TwistedGrin Nice video and great flight! I might go with the A-10 trailing link nose gear as well. Eases the stress on the nose retract. I haven't had issues with mine yet, but others have.

[TwistedGrin]

Got in another flight tonight....nearly dead calm but clouds were blocking the sun so it was getting dark super fast.....perfect flight, loops, aileron rolls, tight figure eights about 20ft flat even....ya it's an arrow....perfect landing. Cool bird!!

TwistedGrin

[TwistedGrin]

I got in four flights on my Dornier 335 Arrow this Sunday........the right wing retract always needs an extra cycle while in flight to bring it down....thinking it may be binding up in the wheel well. I will be checking it separately later this week on the bench.

I am still amazed this aircraft is able to loop and turn on a dime. It's just a cool bird - LOVE it. However it is tender on the retracts.

My nose gear retract is just fine with the trailing link axle Oleo strut from a Freewing A10 80mm nose gear (MotionRC FJ311110811) / Have to insert a longer spring stopper inside the strut cylinder - stops the travel short of the prop striking the ground and compresses the spring spring

https://youtu.be/BLBWVqSAtIY

TwistedGrin

[Twowingtj]

MrSmoothie On your mains stalling, check to see if the gear pins have gotten bent backwards some. I'm running Robart wheels on the mains as well. My wheels compress a bit with the weight of the model and tend to be a bit draggy in the grass. The gear pins supplied with the struts are soft and do bend rearward easily, causing the wheel to contact the backside of the wheelwell when retracting.

I've wanted to change out the gear pins to a standard hardened pin, but the strut grub screws are not drilled at 90degrees. They seem to be drilled wherever the maker wants to put a hole. Hence the non-flatted pin going into the struts. If the struts were drilled with grub screws at 90 and 180 degrees, we could change pins easily.

Luckily, knock on wood, I haven't had an issue with breaking nose gear retracts. And I'm carrying a 6S 8Ah pack up front.

[MrSmoothie]

Hey Guys, been a while since I posted here. I'm still flying my Do335, but not very often, as I've decided the Xwave retracts are marginal for the mains, and inadequate for the nose, at least at my increased flight weight. The problem is that the trunnion forks snap off (nose retract) as they carry the landing stresses. I'm lucky if I get even 2 or 3 flights sometimes, with landings that I thought were pretty darn good, landing on Geotex. But then you consider that above the nose gear is a 6000 or larger lipo, maybe 7 oz. of nose weight, two Talon 90 ESC's, 5055 motor, and large prop, and maybe not so hard to believe. On the mains, the stress is carried by the trunnion bearings, and they hold up fine. But with the weight of a Robart Scale Wheel (and gear door resistance), one or the other main typically stalls before fully retracting.

I think the Xwaves could easily be improved -- it appears that the trunnion is machined. Simply machine away less between the forks, and there'd still be plenty of clearance for the worm gear. The forks could be at least 1mm wider, and it wouldn't cost a thing to make them stronger. I don't know much about the grades of aluminum, but I suspect a different grade could help as well.

All that said, my Do335 is grounded for the time being -- I've gone through at least 3 or 4 nose retracts.

So, are there any options? I've never seen an Eflite, so don't know if it's any beefier than the Xwave. I believe it (their steerable nose gear) is made for a 4mm strut, so I'd have to drill out the trunnion. I've looked at Robarts, but I'm hesitant to spend more on retracts than the model costs. I know Hobbyking has some large retracts, but they are pretty much out of stock or "global" when you need another.

MotionRC: If you are going to get into large ARFs, I think you should consider an upgrade model of the Xwave for models 15+ pounds. I think they're find for 10-12 lbs. and have standardized on them for several of my other models -- makes it convenient to keep a spare or two on hand when you use the same unit in multiple models. They're priced right and MRC keeps them in stock -- two strong points in their favor. I just don't think they're best suited to the Do335.

[paladin]

very nice tony!

Joe

[Twowingtj]

I had a chance to fly the Do-335 at the Warbirds over Chenango Bridge event this last weekend. My wife was able to get a pretty good video.

As I mentioned before, this plane has a very unique sound. Most of it is generated by the rear prop positioned behind four flying surfaces.

We were dealing with a fairly stiff crosswind. I wound up with a bit more of a flare than planned. Luckily, I had reinforced the lower rear fin. No damage.

https://youtu.be/zCYN_KHHbdc

[SanExup]

That looks amazing!

[Twowingtj]

After a lengthy pause, while other projects took priority, the 335 finally had it's maiden.

The CG was spot on the recommended 175mm with a 6S 8Ah lipo about an inch back in the front hatch. She came in at 15.3lbs AUW.

The bird lifted off with ease using take-off flaps and felt real good on the sticks. There were no quirky tendencies at all. Just a nice heavy metal warbird feel. Two clicks of left aileron is all she needed.

Being a twin, with the rear motor behind four full tail surfaces, it has a sound unlike any other warbird. It's like a swarm of huge angry bees on steroids! Not what you want to hear coming up behind you if you're tooling along in your P-51.

It has a good, eye catching presence in the air.

Landing is just a matter of dropping take-off flaps(30 deg), keeping it pretty flat and controlling decent with throttle.

Didn't get vid or in flight shots.

[edfen]

The number on the tail should be 102 to match the letter code VG PH

[edfen]

The numbers on the tail should be 102 to match letter code VG PH

[Alpha]

Alert to all you Pfeil owners, before we put it on the website, I wanted to post here on Hobby Squawk that we have a Pfeil that is new in the box except it's missing the plastic canopy. If anyone wants to save $100, PM me.

[TwistedGrin]

Yep, CG at 163mm. I tried to make some "minimal" repairs to the wings main landing gear mounts....the 1st flight of the repair trials the right main gear would not deploy. I landed on the left main and the nose gear with a full run out without issue..... My nose gear is perfect and holding up just fine....I flew three more sorties with the mains down flying dirty. Still did all the requisite loops, rolls, figure eights without any problem....landing softly. I will set up the new set of wings and carry on. Open up the original wings for drastic repairs as needed.

Love this bird

TwistedGrin

[Twowingtj]

Congratulations! Always good to hear when things go well.

Is the the nose weight correct? Seems like a lot with an 8000mah battery up front.

[TwistedGrin]

WOW!
Maiden plus three flights today 03-27-21

The maiden was a breeze.....10-12mph headwinds with brief strong puffs of 15mph crosswinds. This airframe acted like nothing happened in the air. I was amazed that is simply lifted off the runway (Grass field) at about 25yards of run up. The rotation was nearly flat and once airborne....ya it was an arrow. Not real fast (counter rotating 3blade props) but very respectable pace. It is super stable and exhibited no vile traits. Turns, rolls, loops, figure eights were all done with ease. The landing was a bit awkward as the winds lifted it back up about 5ft, I had to blip the throttle and flatten it back out then merely landed again..no flare but a gentle flat three point landing.

I was able to make three other spirited flights cruising at or near 50% throttle with shallow dive runway passes at full tilt. The sound of the props is really neat...the galley enjoyed the sound and the looks of this strange airframe. Flight duration on the 6s 100C 8000mAh LiPo was 6:00min landing at 3.80v per cell.

The fourth flight I pancaked a little too hard on the rain soaked soft grass which popped the retract mounts in both wings.....the plywood retract mounts have split open and cracked the wings....but this will be an easy fix.

The airframe flies on rails, has an excellent resonance sound from the props, looks wickedly odd in the air, tight axial rolls, huge gargantuan loops, tight figure eights all day....easy to land.

If I prang this one up beyond repair - I will order another...it's that fun for me.

Special Note: My build deviated from earlier post ...deployed off the shelf prop spinners and customized the nose gear. More information can be found at the other webthread for this model (https://www.rcgroups.com/forums/show...-Models/page35)

Motors: Flight Line 5055 390Kv
Props: MAS 16x10x3 Pull/Push props (Counter rotating)
Spinners: Extreme Flight FW-190
Nose Gear: Freewing A10 80mm nose gear (MotionRC FJ311110811) / Have to insert a longer spring stopper inside the strut cylinder - shorter travel, compressed spring
Battery: RCJuice Hobby Star 6s 100c 8000mAh LiPo (901grams)
Flight Battery: Spektrum LiFe 2s 6.6v mounted in front of the forward battery tray
Lead weight: 105ounces mounted on the nose rear firewall and in front of the forward battery tray
ESC: (2) Castle Talon 90
Receiver: Spektrum AR8010
Stabilizer: Hobby Eagle A3-L
CG for flight: 163mm

All good

TwistedGrin

[TwistedGrin]

I have made great progress on my DO 335....I have opened up the manual...and C.A.'d the Ailerons and Flaps...should be finished by February perhaps.

TwistedGrin

[TwistedGrin]

10:4 Thank you MrSmoothie.....I over looked the post somehow.....thanks for sharing your excellence sir!

TwistedGrin

[MrSmoothie]

I uploaded a zip file containing all of the 3D files I created for my Dornier on my RCG built log -- on one of the later pages somewhere:

https://www.rcgroups.com/forums/showthread.php?3565749-Dornier-Do335-Pfeil-Black-Horse-Models

[TwistedGrin]

Mr. Smoothie - You are on target....I have NOT drilled my props yet. My spinner back plate fits perfectly flat onto the original FlightLine propshaft adapter. However I am second guessing my strategies:

A. Use the original FlightLine motor propshaft adapter (I have four of them at the ready)
1. Score or groove the prop shaft adapter face to provide positive surface friction with the spinner back plate surface
2. Drill and pin the spinner back plate to the prop shaft adapter
3. Counter sink the propeller hub to expose more thread for the prop-nut
i. Mill down the propshaft adapter face to allow more threads exposed

2. Use the FlightLine 1600mm Corsair propshaft adapter (I have two of them at the ready)
A. Use your 3D Print files on somebody's machine
B. Ream the prop for larger prop shaft diameter

If I choose option 2 I need to know and order the correct material for someone's 3D printer and get your files.....and settings for all of it. There are several pilots I know of in Fort Worth Tx who have 3D printers....but I don't understand enough about them to know what questions to ask......I am assuming there are settings, granularity, heat, speed, size capabilities variables to deal with?

TwistedGrin