Official Dynam 1500mm B-26 Marauder Thread

[Bigrc2]

Also don't forget to adjust the tail incidence as discussed above, work like that must be preserved

Thanks, Rifleman. Will add the 1/8" elevator shim tomorrow.

[Bigrc2]

Here are the spacers and the adjustments to the horizontal stab... Need to sand a little more on the leading edge bottom of the stab to get it smoother and a better transition to the new angle.

Good job, Hardway. The pic will be a great hope.

[ryramZ]

She's ready for her maiden. I'm planning on Friday for the big event. Unfortunity, the Robart diamond threaded wheels I ordered won't arrive until then, so I'll go with the 'Fat Boys' for the first couple of flights. My first attempt at doing weathering with the salt and water method worked out pretty well. And putting the Flak Bait nose art on took some patience. The bombs had a tendency to lift off the backing. Still have the landing lights to sub out for white ones and to repostions the green/red to the wing tips.

That looks great! I was worried about the decals sticking so I put a coat of wbpu on first. I'm sure it helped.

On the matter of incidence I recommend saving that for later. Cg on the lines I show in the video and give it 2-3 mm up trim to start. If you removed the tailweights you may need more. The Hoosier racing slicks will work fine. They are light and you won't see a pitch change when you work the gear up or down. Low throw on elevator and mind the flare with some throttle.

Calibration required to sync motors and your good.

Looking good!

[rifleman_btx]

Or just do the mod have a flatter flight surface reduce the drag and gain the speed

[themudduck]

The incidence of the tailplane is what seems to be causing this weird situation:

Original incidence = tendency to pitch down, hence the feeling its nose heavy and the need for tail weights and about 1/8" up trim. Limit the elevator throw.
Corrected incidence = plane doesn't need up trim to fly level, and balances the same or slightly forward. Still limit the elevator throw.

In other words, it isn't nose heavy. Mine was tail heavy. So I removed the tail weights and I moved the balance point forward a bit.
I'm recommending using a smaller battery. I'm using a 3600 (with no tail weights) and the battery sits further forward to balance at 57mm (the 4000 was way back)

I'd really like to see some more flight reports from guys who have done the mod, so we can get a few more opinions about how it affects the flying and also get some more opinions on the best balance point (noting the flying characteristics) before we recommend that everyone do these things.

[rifleman_btx]

I should be able to fly mine Thursday. So far, 2 have noted the mod to be very successful. I'm positive mine will be as well.

[themudduck]

Rifleman, I'm confident the stab mod will eliminate the need for up elevator trim. But I'm still worried about your balance point. I know you're experienced, so do some tests to see if its tail-heavy or not.
I have a feeling you'll see that it is tail heavy at 65. I'll be anxiously awaiting your report! Time for me to crash... :Sleeping:

[Hardway]

Mud!!! Dang! Don't say crash! How about time for a long nap!! HA!! Night guys! :-)

[rifleman_btx]

Rifleman, I'm confident the stab mod will eliminate the need for up elevator trim. But I'm still worried about your balance point. I know you're experienced, so do some tests to see if its tail-heavy or not.
I have a feeling you'll see that it is tail heavy at 65. I'll be anxiously awaiting your report! Time for me to crash... :Sleeping:

Copy that, I'll definitely let y'all all know what happens

[Tony617]

Hey Tony, yeah the numbered wires were a bit of a pain to figure out. I hooked mine up to a servo tester and then relabeled most of them (there are a few that were self-evident like the retract and nose steering/rudder.)
So you're telling me that the instructions showed what those numbers meant? Wait... Ah - HAH! :Dizzy: (I just glanced at the instructions, but I did watch Pilot Ryan's build video!!) :Silly:

The only other Dynam RC airplane I have is the F6F Hellcat V1 which does not have flaps. It was easy to set the Hellcat up since the battery hatch opens up and I can see the throttle wires since it comes out of the ESC directly. The B26 not so much. I did use my servo tester to test all of the servos but I did not take the four screws out and remove the B26 wing. Now I just need to work on the hatch that covers the wings.

Tony

[themudduck]

Hey Tony, yeah that B26 has a giant pile of wires in there doesn't it. Fortunately sorting them out went pretty smoothly and once that's done you don't have to deal with it any longer. I used some wire ties to bundle it all up into a neat pile of spaghetti.

I'm still working (obsessing) on my hatch.

You probably saw the previous posts - the wing mounting anchors (in the fuselage) are a problem. I pulled mine out and re-glued them so they're sitting flat on the bottom of the socket instead of at the top (see post# 457). In the original position at the top edge of the fuselage, they simply pull up and get crammed into the bottom of the wing.... and as a result the wing doesn't want to be pulled down in the saddle all the way when you tighten the 4 bolts. That had to be fixed just for structural strength of course - but we were also thinking that if the wing wasn't sitting down properly then maybe that was why the hatch wouldn't fit correctly.

We've also found that the front magnet on the hatch is too low, it needs to be pried off and re-glued in a little higher so that it's the same level as the fuselage magnet.
After I fixed the magnet at the front of the hatch, the hatch fits absolutely perfectly when the wing isn't there.

And after fixing the four wing mounting bolts, the wing pulls down and lays in the saddle correctly. All good so far...
But with the wing installed, the hatch is STILL about 1/8" too high at the back end. It can't go down any farther. Aaaargh. :Angry:

With all the discussion about the incidence of the stab, now I am looking very carefully at the incidence of the wing. Looking at my plane, it appears that the nacelles aren't perfectly parallel to the fuselage - they seem to be tilting down just a bit at the front. I was looking at this last night and I think if I lower the rear part of the wing saddle about 1/8 of an inch, the wing will be aligned correctly (the nacelles will be correct) and the top hatch will fit. And that slight change to the wing will provide a little more lift - and THAT would mean that the "up-trim" and/or the shim for the stabilizer would NOT be needed. See, if the TE of the wing is lowered, affectively you're raising the tail. Something to think about.

:Thinking: I want that hatch to fit! If I can make the plane fly better in the process than that's a bonus.

Maybe I'll work on this tonight, I'll post some pictures.

[Tony617]

Hey Tony, yeah that B26 has a giant pile of wires in there doesn't it. Fortunately sorting them out went pretty smoothly and once that's done you don't have to deal with it any longer. I used some wire ties to bundle it all up into a neat pile of spaghetti.

I'm still working (obsessing) on my hatch.

You probably saw the previous posts - the wing mounting anchors (in the fuselage) are a problem. I pulled mine out and re-glued them so they're sitting flat on the bottom of the socket instead of at the top (see post# 457). In the original position at the top edge of the fuselage, they simply pull up and get crammed into the bottom of the wing.... and as a result the wing doesn't want to be pulled down in the saddle all the way when you tighten the 4 bolts. That had to be fixed just for structural strength of course - but we were also thinking that if the wing wasn't sitting down properly then maybe that was why the hatch wouldn't fit correctly.

We've also found that the front magnet on the hatch is too low, it needs to be pried off and re-glued in a little higher so that it's the same level as the fuselage magnet.
After I fixed the magnet at the front of the hatch, the hatch fits absolutely perfectly when the wing isn't there.

And after fixing the four wing mounting bolts, the wing pulls down and lays in the saddle correctly. All good so far...
But with the wing installed, the hatch is STILL about 1/8" too high at the back end. It can't go down any farther. Aaaargh. :Angry:

With all the discussion about the incidence of the stab, now I am looking very carefully at the incidence of the wing. Looking at my plane, it appears that the nacelles aren't perfectly parallel to the fuselage - they seem to be tilting down just a bit at the front. I was looking at this last night and I think if I lower the rear part of the wing saddle about 1/8 of an inch, the wing will be aligned correctly (the nacelles will be correct) and the top hatch will fit. And that slight change to the wing will provide a little more lift - and THAT would mean that the "up-trim" and/or the shim for the stabilizer would NOT be needed. See, if the TE of the wing is lowered, affectively you're raising the tail. Something to think about.

:Thinking: I want that hatch to fit! If I can make the plane fly better in the process than that's a bonus.

Maybe I'll work on this tonight, I'll post some pictures.

I will look at my nacelles and see as well since I did not check of they are parallel to the fuselage or not. I too used wire ties to fasten the bundle of wires from the servos and put to the right of the LiPO.

Tony

[borntoolate]

Here are some pictures of my progress. I posted these on RCG. Still not finished with the bomb bay and new decals are on order.

Bob

[ruffneckx1]

borntoolate...your photos are not coming thru. :Confused:


Woody

[Tony617]

Here are some pictures of my progress. I posted these on RCG. Still not finished with the bomb bay and new decals are on order.

Bob

I don't see any pictures.

[borntoolate]

I see them. Maybe they are too large. I will re-send them smaller.

Bob

[borntoolate]

Smaller versions.

[ruffneckx1]

Ok, That did it. :)


Woody

[rifleman_btx]

Very nice!

[rifleman_btx]

Hey Tony, yeah that B26 has a giant pile of wires in there doesn't it. Fortunately sorting them out went pretty smoothly and once that's done you don't have to deal with it any longer. I used some wire ties to bundle it all up into a neat pile of spaghetti.

I'm still working (obsessing) on my hatch.

You probably saw the previous posts - the wing mounting anchors (in the fuselage) are a problem. I pulled mine out and re-glued them so they're sitting flat on the bottom of the socket instead of at the top (see post# 457). In the original position at the top edge of the fuselage, they simply pull up and get crammed into the bottom of the wing.... and as a result the wing doesn't want to be pulled down in the saddle all the way when you tighten the 4 bolts. That had to be fixed just for structural strength of course - but we were also thinking that if the wing wasn't sitting down properly then maybe that was why the hatch wouldn't fit correctly.

We've also found that the front magnet on the hatch is too low, it needs to be pried off and re-glued in a little higher so that it's the same level as the fuselage magnet.
After I fixed the magnet at the front of the hatch, the hatch fits absolutely perfectly when the wing isn't there.

And after fixing the four wing mounting bolts, the wing pulls down and lays in the saddle correctly. All good so far...
But with the wing installed, the hatch is STILL about 1/8" too high at the back end. It can't go down any farther. Aaaargh. :Angry:

With all the discussion about the incidence of the stab, now I am looking very carefully at the incidence of the wing. Looking at my plane, it appears that the nacelles aren't perfectly parallel to the fuselage - they seem to be tilting down just a bit at the front. I was looking at this last night and I think if I lower the rear part of the wing saddle about 1/8 of an inch, the wing will be aligned correctly (the nacelles will be correct) and the top hatch will fit. And that slight change to the wing will provide a little more lift - and THAT would mean that the "up-trim" and/or the shim for the stabilizer would NOT be needed. See, if the TE of the wing is lowered, affectively you're raising the tail. Something to think about.

:Thinking: I want that hatch to fit! If I can make the plane fly better in the process than that's a bonus.

Maybe I'll work on this tonight, I'll post some pictures.

Just be careful with that, you do want a slight amount of down thrust. Fortunately since it's counter rotating you don't need the right angle thrust. But just keep that in mind when/if you mod that.