Official Dynam 1500mm B-26 Marauder Thread

[rifleman_btx]

Yeah I'm gonna look at throwing some balsa under the anchor points

[borntoolate]

The top wing cover did not fit well on my bomber. The magnets were not glued in properly. I removed the magnets and the cover still did not fit very well. To fix that, I trimmed the aft side of the cover slightly and also the back portion of the wing, I took off a small portion with a new blade held at about a 45 degree angle. The cover now fits flush. I will work on the bomb bay later today. On the first B-26, I am going to use a conventional type door - like on the B-17. It will not look as cool on the ground as the bi-fold doors, but in the air, on a bomb run, you probably won't be able to see it.

Bob

[themudduck]

Back at home charging after flying... got in two nice flights today and found something very important. If your elevator has too much throw, you will snap-roll this model. I discovered this while doing some tests 2-mistakes high. When I yanked back on the stick the model did a "departure from controlled flight" - into a very fast and nasty 1 & 1/2 snap roll. No aileron or rudder, just elevator. The guys were saying "your elevators must not be adjusted" but that isn't it. It was a classic high-speed stall.

I dialed back the throw and it solved the problem for the second flight. I started with 75% elevator travel on my DX9 and ended up with 55%. This model is short-coupled and reacts strongly to elevator. If you keep the elevator movement low you will have good results. Mine is set now at 1/2" maximum throw each way, and I am not using full up most of the time.

Neutral flight requires a bit of up elevator trim, mine has about 1/8" up. But I don't think its nose heavy. Later on maybe I'll adjust the stab incidence, I bet lowering the LE of the stab by just a bit will fix it.
Balanced at about where the manual says. The battery isn't all the way back - if I push the battery all the way to the back the front Velcro won't hold it... so its about an inch away from the backstop. I put a piece of foam there as a spacer.

I found that the B26 isn't very fast. When you go to full power it doesn't speed up much - but that's OK, I like a plane that flies realistically.
My 4000mah 4S Admiral battery showed 3.8 volts after a 5 minute flight (3.9 when I got home)

I used a little flap for takeoff (maybe 10-12% down) - takeoff was uneventful. Retracting the gear had no affect on trim. I used full flaps for landing. I didn't use any elevator trim at all with the flaps, and I'm not sure it's necessary. With full flaps it handles really, really nice and flares nicely. I really love the way it lands with flaps..

All in all it was really nice flying plane. You just need to be careful with the elevator. Try a loop and pull out too sharply and "pow" it will snap and you'll see why it was called it the "Baltimore *****".
Fly it like a lady and it will reward you.

[TiredIronGRB]

Callie graphics applied, some more weathering and I'll be through.

[hellcat716]

Was so disappointed with the B-26 today when I opened the box I am going to return it tomorrow. Nothing packed right, top wing hatch was warped and magnets loose. Nothing taped down in the box. Hope Motion RC get's better quality control in the future. Could be a good model with a lot of work that I am not interested in doing.

[ruffneckx1]

TIGRB......your effort is OUTSTANDING. :Cool:

When you get a chance could you detail your gear door mod ??


Woody

[rifleman_btx]

Just for grins what way did it snap over?

[TiredIronGRB]

Just for grins what way did it snap over?

It drops to the left just a tad which I don't usually see on twins, quads.

[rifleman_btx]

Interesting, I'll have to check my throw rate again. But I don't remember it being much, but it was at least 5/8 inch.

[rifleman_btx]

I did have those anchors pull up on the left. So I still think I had a flaw in my fuselage. It flew perfect through 2 packs and the 3rd pack was the snap of death with nothing changed. I feel the weight in my plane broke free on impact with the ground

[TiredIronGRB]

Rifleman, check the clearance on the ailerons where they meet the flap...mine was rubbing some.

[rifleman_btx]

Copy that

[rifleman_btx]

Looked like a slight rub at high deflection. But higher than what I used in my flap settings. Otherwise it looks like it was ok

[xviper]

It drops to the left just a tad which I don't usually see on twins, quads.

I had the HobbyKing C-47 - another twin, 4 cell plane. It had a terrible tendency to drop a wing when stalling if airspeed wasn't kept up. Had to do very wide, fast, near flat turns. My old FMS B-25 Mitchell was similar. Fly it slowish only when going straight, not in a turn and don't climb too fast. I plan to fly this one fast until I am familiar with its stall characteristics up high.

[themudduck]

I had the HobbyKing C-47 - another twin, 4 cell plane. It had a terrible tendency to drop a wing when stalling if airspeed wasn't kept up. Had to do very wide, fast, near flat turns. My old FMS B-25 Mitchell was similar. Fly it slowish only when going straight, not in a turn and don't climb too fast. I plan to fly this one fast until I am familiar with its stall characteristics up high.

Hey guys,

I did some more flying this evening and went through several stall tests (up high). My elevator throw is 1/2" and it will still snap, if full elevator is applied at speed. When its allowed to slow down, it will snap to the left rather hard. But I found that if I had the flaps set down about 10 degrees, it didn't stall as suddenly and I could slow it down more. With full flaps, it is much harder to stall and will fly with full up elevator.

My conclusion is that its important to limit the elevator throw and in the clean configuration (flaps up), one needs to keep the speed up.

[rifleman_btx]

That's what I was doing, I was close to 300' up and it snapped then recovered then when I tried to level it off it snapped still in the dive. At that point all Hope was lost

[TiredIronGRB]

I had the HobbyKing C-47 - another twin, 4 cell plane. It had a terrible tendency to drop a wing when stalling if airspeed wasn't kept up. Had to do very wide, fast, near flat turns. My old FMS B-25 Mitchell was similar. Fly it slowish only when going straight, not in a turn and don't climb too fast. I plan to fly this one fast until I am familiar with its stall characteristics up high.

Exactly, I have two of the HK C-47s and they will tip stall in a heartbeat...the B-26 doesn't seem like it's near as bad but any plane with the narrow tipped wings should be flown flat as possible with some speed in the turns and a long runout on takeoff.

[themudduck]

Hey I also wanted to mention that after a 6-minute flight with my 4000mah pack, it was at 3.92 volts per cell. So I'm going to try the 3600 pack from my Tigercat next weekend and see if it makes a difference to the flying. Its likely that a little less weight should be helpful. And I'll probably still have more than 5 minutes of flying.

[TiredIronGRB]

My conclusion is that its important to limit the elevator throw and in the clean configuration (flaps up), one needs to keep the speed up.

I think this is sound advice.

[ryramZ]

Dynam Twin ESC Calibration