Official Dynam 1500mm B-26 Marauder Thread

[warbirdbob]

It's a shame we've had to go through all these problems to get this plane in the air! I flew my F7F out of the box and it was the most stable, predictable, solid plane I've flown. With this bird, it's like having to rebuild the thing to get it to even fly half decent. BTW, I renamed mine "The Beast"----wrote it right on the side of the fuse-- pilot side! Trying flight #4 this weekend---at least it's a thrill every time it goes up. Anything can happen!!!

[warbirdbob]

PS----I've noticed the PNP version is still on B/O

[warbirdbob]

OOOPS---I meant RTF

[Mad Baron]

Trying for the maiden flight (take 2) this coming weekend. I am going through the plane and readjusting the stab so maybe I will get a successful flight! :Cool:

[rifleman_btx]

Yes it will be a success! :)

[Mad Baron]

:Cool:I'll keep thinking fly, fly, fly!!!

[Bearcat]

I used 2mm balsa tonight to shim the stab so that was taken care of, now waiting on MRC as we send email and pictures to show how this is fitted together.
the bottom of the wing is flush..the top have has the gap from Hades.. sucks since the other side is perfect.

[rifleman_btx]

Yikes!

[Mad Baron]

Got the stab adjusted just need to set the elevator throw. Rebalanced with the 3600 & 4000 Admiral battery just slightly nose down attitude and with the gear deployed its nearly level. Cant wait to get that first flight in!

[rifleman_btx]

Heck yeah should be fun!

[xviper]

Flew the B-26 again today and once again, retract failure while in the air. First, only one retract came down, then after cycling, none came down. I had to land it in the tall grass. Belly flopped it with no damage. I read in the other forum that Dynam retracts may not work below 60F. I think this may be the key to the whole situation. I was flying near freezing temps. Right out of the warm car, the retracts cycled no problem. About 1/2 way into the flight, I tried the retracts and that's when the problems started. As I got further into the flight and the more it flew through the cold air, none of them worked. This is a real bummer. I like to fly all winter long, so unless I replace these retracts with a suitable non-Dynam gear, this thing is done till next spring.
I think Dynam needs to re-think their choice in retracts and use something from the FMS or Freewing bin. Those things have worked for me to well below freezing temps. No matter how interesting the next Dynam product may be, I will buy it with the notion that the retracts will have to be replaced immediately.

[OV10]

Unfortunately that low temp idiosyncrasy of the Dynam etracts has been more real rather than being fake news.

[CFIT rob]

That is indeed troubling. Did they work ok at home after warming up? Do you have stock wheels? I too fly year-round. Hate to keep her grounded from something like that. Mine might be the first variant with skis. Reperpose my skymule skis. B26 mulerauder? B26-SM? Maraudski?

[xviper]

That is indeed troubling. Did they work ok at home after warming up? Do you have stock wheels? I too fly year-round. Hate to keep her grounded from something like that. Mine might be the first variant with skis. Reperpose my skymule skis. B26 mulerauder? B26-SM? Maraudski?

They have always worked in the house where it's warm. Yes, I have the stock wheels. I thought at first that the non-functioning wheel was catching, so I cut some of the plastic to make sure. Unfortunately, they stop working after it's had time in the cold air.
I tried the SkyMule with the skis last winter. Unless the snow is very hard and crusty, the plane sinks the skis into the snow and the plane won't get up enough speed to skim on top. Besides, the props just beat the snow like a blender. The B-26, being a heavier plane, may sink even easier. Ice would be fine.

[themudduck]

Hey there Mad Baron - I promised earlier that I would share the settings I use on my radio for the B26. I'm not saying that these settings are required or perfect, they're just what works for me. A lot of this is personal preference.
The only thing that is particularly important is to limit the elevator throw.

I'm using a DX9.

Travel Sub-trim: 90% on aileron and 60% on elevator, 100% everything else
Dual Rate/Expo - I don't have two different rates, I just use one setting. The expo means that the amount of travel is buffered until you move the stick all the way, this results in smoother flight and I don't have to worry about getting full travel until I really want it
Aileron: 100% rate, 30% expo. I am measuring 1" throw each way (which is probably too much for a lot of guys but I like the model to be responsive when I want it.)
Elevator: 70% rate, 40% expo. I am measuring 3/8" throw each way, at maximum. (using the middle hole on the elevator horn) I do still have a bit of up trim, maybe 1.5mm to fly level.
Rudder: 100% rate, 45% expo. (the expo on the rudder is for smoother steering)
Flap settings: 100% up, 40% mid, -55% down. No elevator mix.
Aileron to Rudder mix: 35% (switchable on/off) - this is so the rudder works with the ailerons. I find the B26 drags its butt through aileron turns, so this is quite helpful and I usually fly with the mix on.


And just because I'm typing I may as well include a list of all the modifications I've done to the model out of the box:
epoxied the wing mount fittings into the fuselage
fixed the wing hatch to be flush (mostly magnet repositioning, but some trimming at the front of the wing saddle to get the wing to lay flat on the back side)
replaced the wheels with "scale" wheels. The nose wheel is slightly larger (a slightly nose-high stance helps with takeoffs on grass, plus it looks more scale)
removed and re-glued the flap hinges (because they were loose)
lowered the LE of the stab by about 1mm and raised the TE of the stab by 2mm
trimmed the center part of the stab so it doesn't hit the rudder
removed and re-glued all of the guns because they were loose or installed poorly
installed TI's bombardier's decal
painted the anti-glare panel and the inside of the cockpit OD, repainted the pilots
painted the bare parts of the flaps that are exposed when deployed
painted the servos
repainted some of the invasion stripes to fix some misalignment of the lines... the lines on the flaps didn't line up (picky, picky)
removed the tail weights, which were loose
tested at 65mm but final balance is at 57mm with a 3600mah battery towards the front of the tray

[rifleman_btx]

Just an idea, I wonder if you could place some hand heaters in the retract pockets to keep them above the magic 60°temp. https://www.walmart.com/ip/Hot-Hands...&wl13=&veh=sem

[xviper]

Just an idea, I wonder if you could place some hand heaters in the retract pockets to keep them above the magic 60°temp. https://www.walmart.com/ip/Hot-Hands...&wl13=&veh=sem

Interesting concept but I think they'd interfere with the full movement of the strut. I'm going to see if the old retracts out of my Nemesis or Pilatus will work.

[Mad Baron]

Hey there Mad Baron - I promised earlier that I would share the settings I use on my radio for the B26. I'm not saying that these settings are required or perfect, they're just what works for me. A lot of this is personal preference.
The only thing that is particularly important is to limit the elevator throw.

I'm using a DX9.

Travel Sub-trim: 90% on aileron and 60% on elevator, 100% everything else
Dual Rate/Expo - I don't have two different rates, I just use one setting. The expo means that the amount of travel is buffered until you move the stick all the way, this results in smoother flight and I don't have to worry about getting full travel until I really want it
Aileron: 100% rate, 30% expo. I am measuring 1" throw each way (which is probably too much for a lot of guys but I like the model to be responsive when I want it.)
Elevator: 70% rate, 40% expo. I am measuring 3/8" throw each way, at maximum. (using the middle hole on the elevator horn) I do still have a bit of up trim, maybe 1.5mm to fly level.
Rudder: 100% rate, 45% expo. (the expo on the rudder is for smoother steering)
Flap settings: 100% up, 40% mid, -55% down. No elevator mix.
Aileron to Rudder mix: 35% (switchable on/off) - this is so the rudder works with the ailerons. I find the B26 drags its butt through aileron turns, so this is quite helpful and I usually fly with the mix on.


And just because I'm typing I may as well include a list of all the modifications I've done to the model out of the box:
epoxied the wing mount fittings into the fuselage
fixed the wing hatch to be flush (mostly magnet repositioning, but some trimming at the front of the wing saddle to get the wing to lay flat on the back side)
replaced the wheels with "scale" wheels. The nose wheel is slightly larger (a slightly nose-high stance helps with takeoffs on grass, plus it looks more scale)
removed and re-glued the flap hinges (because they were loose)
lowered the LE of the stab by about 1mm and raised the TE of the stab by 2mm
trimmed the center part of the stab so it doesn't hit the rudder
removed and re-glued all of the guns because they were loose or installed poorly
installed TI's bombardier's decal
painted the anti-glare panel and the inside of the cockpit OD, repainted the pilots
painted the bare parts of the flaps that are exposed when deployed
painted the servos
repainted some of the invasion stripes to fix some misalignment of the lines... the lines on the flaps didn't line up (picky, picky)
removed the tail weights, which were loose
tested at 65mm but final balance is at 57mm with a 3600mah battery towards the front of the tray

Good info I've got my expo rates close to what you have yours set at. I have performed a lot of the mods and repairs that is listed here on the squawk now I have to figure out how to set up the mix on the aileron to rudder mix yet I got a Gavin 8 channel radio for it and the programing the trans is different than my Futaba. Just 3 more days until the maiden flight!

[themudduck]

Good info I've got my expo rates close to what you have yours set at. I have performed a lot of the mods and repairs that is listed here on the squawk now I have to figure out how to set up the mix on the aileron to rudder mix yet I got a Gavin 8 channel radio for it and the programing the trans is different than my Futaba. Just 3 more days until the maiden flight!

Good luck to you! I'm looking forward to your comments after this weekend!

Despite all the grumbling, I really like the way mine flies. I have some other scale planes that need to be handled carefully (Me110 and P51 that like to screw themselves into the ground on takeoff due to prop torque (so they need a firm hand on the rudder during takeoff), and a P47 that has to be landed absolutely perfectly of it will tip over) and these tendencies just remind me that I'm flying a scale plane and not a trainer and I enjoy the challenge.

We all know that the full-size B-26 had a steep learning curve and required particular attention to avoid disaster, and the fact that the model also needs to be flown correctly just seems appropriate to me, if you know what I mean, the fact that it requires some skill makes it more gratifying in my opinion (although its not so friendly to beginners). Its very sensitive to elevator and it needs flaps at low speed. If you pay attention you should have great results!

[NoDirt!]

Hey guys, I am really close to clicking the buy button on this one but I would like to ask if anyone here is able / willing to 3D print the cockpit, guns and site that WW2 Wing Nut created.

I know I can try GrabCAD but I trust you all a bit more.

If you can do it send me a message or post here please. Thanks!