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

[Ah's Availble]

Hello,

I just bought this model. Looking for tips on build and alternative landing gear options. What works well? What didn't?

[tommysev]

See Post exponential

I attached a trailing axle R/C Jet Oleo strut to the XWave front retract....then added a stopper to compress the Oleo Spring and prevent it from compressing 100%.....otherwise it was too weak and caused prop strike.....Fly from well manicured grass field....no issues at all.

TwistedGrin

Hello, I'm just starting my build... May I ask for specifics about the strut you added to the front retract? I'm starting to order components now. Many thanks!

Tom

[TwistedGrin]

10-22-2024 Flew my BH Dornier 335 yesterday for the first time in over a year....the retracts would not operate at the field. I was able to get the mains down just to fly with all three landing gear down. Flew (4) flights in swirly 13-15mph winds. No issues with take off or landings on our grass runway. Retracts operating smoothly after applying some Liquid Wrench Silicon Lubricant back at the hanger.

Currently running 6s 100c 8000mAh LiPo via Flight Line Spitfire 5055 390Kv motors with CR Push/Pull 3blade props. The aircraft has loads of power but is a little slow. Cuts figure eights, loops, rolls with ease and ubra smooth. Windy conditions don't tend to bother this airframe at all.

Thinking of changing to (2) blade props for more top speed and possibly longer flight time, but also considering the breaking affect the (3) blade props have on landings....for for now are really easy executing slow flat wing 3point landings.

The upgraded struts I deployed on the X-Wave retracts are holding up just fine.

TwistedGrin

[TwistedGrin]

The XWave retracts do fit but are not a good choice. The nose retract is no where near strong enough and will not last.

See Post exponential

I attached a trailing axle R/C Jet Oleo strut to the XWave front retract....then added a stopper to compress the Oleo Spring and prevent it from compressing 100%.....otherwise it was too weak and caused prop strike.....Fly from well manicured grass field....no issues at all.

TwistedGrin

[Arkx400]

It does not come with retracts. The XWave retracts that Motion RC sells are a good fit and work well.
The stock struts fit in the XWave retracts.

The XWave retracts do fit but are not a good choice. The nose retract is no where near strong enough and will not last.

[Twowingtj]

Well done!

[Spinnetti]

Like I did with their He-111, I've been making my own landing gear, though I'm first making them in 1/6 scale, maybe scaled down for this later. Nose is done, assembling the mains now. Cool bird regardless.

[Skavage]

Perfect. Thank you!

[Twowingtj]

It does not come with retracts. The XWave retracts that Motion RC sells are a good fit and work well.
The stock struts fit in the XWave retracts.

[Skavage]

Does this come with electric retracts or are they an upgrade item to purchase separate? I ask because the description doesn't mention them, yet the "Spare Parts" link lists them and the "Upgrades" don't. I don't want to order them if it comes with them, but if not I'll order a set.

Also, do the stock struts fit the electric retracts?

Thanks!

[James]

My modified 335 to 435 (turbine version). Xicoy X45 in the back.

https://youtu.be/-OaGbNbDmUo

Great video. Really cool twist on the subject

[Twowingtj]

Propan Welcome to Hobby Squawk!

Great mod on the 335.

[Propan]

My modified 335 to 435 (turbine version). Xicoy X45 in the back.

https://youtu.be/-OaGbNbDmUo

[TwistedGrin]

Nose gear modificaton of 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. The A-10 80mm nose gear is short so it needs a spacer....I had a fixed gear strut mount from some other model and cut it to the length 15.5mm to match the same length of the original strut. I honestly can't remember if the original strut pin was used or I made a longer one. I do know that I use the bottom slot of the pin to use the set screw to hold the strut on instead of the spring....the slot needs widening sometimes to allow the strut to pivot freely. I use washers to fill the gap between the retract trunion and the steerin arm as it has to clear the retract to pivot correctly....the washers help the pin from bending too much. I may have had to drill into the retract trunion to allow the strut pind to get down into the the first grub screw.....I have had to do this on some other planes too (Maybe the Nexa OV-10?) The strut pin must be slotted so the grub screws can keep the alignment. I just use what I have in the bins and try to fabricate a solution....this is what I wound up doing.

TwistedGrin

[paladin]

the xpower with no slippage can achieve 73.6 mph with that prop.
the 5055-390 with no slippage can achieve 98.4 mph with that prop.


in my case:

(2x) 5060-380 on 8s turning a 15x8 APC-e (((3.7*8)*380)*8)/1056= 85.2mph

(1x)5060-380 on 8s turning a 15x8 APC-e = 85.2mph (+) (1x) xpwr -22cc on 6s turning a 15x8 APC-e = 84.1mph

prop wt factor published by AMA in the 90's = p*d(squared)

15x8x2 = 8*15*15= 1800
15x8x3 = 8*15*15*1.5= 2700 <= this means more of battery going to heat and shortening flight life

APC-e does make a pusher 15x8x2.

i would like to stay with standard bat size of 5000mah or 5amp.

Joe

[Twowingtj]

paladin On the xpwr, I'm running a MAS 15x7x3 pusher. I think is is producing a bit more thrust than the Spitfire motor up from turning a MAS 16x10x3. The rear motor is turning ~2400rmp faster as well.

The MAS 3-blades are not the most efficient props. APC 2-blades would be better, although not look as good.

I'm using a 6S *K lipo all the way up front and it needs the weight to balance. The rear compartment is pretty much full with the receiver, servos etc.

For flaps, using none on take-off and full deflection allowed mechanically, on landing.

[paladin]

paladin Interesting find on the 105deg retract. The Xpwr motor is what I'm running on the rear of mine.

very interesting!

how well does the xpwr push. i'm thinking a 5060-380 on 8s up front and the xpwr aft on 6s. 8s all the way forward and the 6s between servo bay and cockpit.

how much flap do you use?

Joe

[Twowingtj]

paladin Interesting find on the 105deg retract. The Xpwr motor is what I'm running on the rear of mine.

[paladin]

I've made some progress on the purchased parts for mine. retracts:

mains:
Xwave RM400-90 Electronic Retract Multi-Pack (2 Retracts) [XWA6015-004] Motion RC

nose gear:
#558RSE 105 deg Electric Nose Retract RoboStrut Ready – Robart Manufacturing

as for motors i am still ????

if i go with our std power it would be turnagy NTM 5060-380 turning 15x8x2 on 8s.

other 6s options being:
Xpwr 22CC Motor (extremeflightrc.com)

E-flite 60-Size Brushless Outrunner Motor: 500Kv | Horizon Hobby

any thoughts?

Joe

[Twowingtj]

ghethco nice work on the hinges. Mine are still stock. It could use a few more degrees of deflection.

My elevator mixes are 2% less on each.

Looking forward to seeing your progress.