Official Dynam 1500mm B-26 Marauder Thread

[Ted7rns]

Welcome to Hobby Squawk Ted, I think you'll really like it here :)

Thanks ;)

[Bearcat]

A Tale of Two B-26 Shims.

We flew two B-26's today one with the Shim on the Horizontal Stabilizer (Klink's Tanks) and the other shim the motors up some, then just trim the elevators (Bird Dog Special). Both flew great and we had some fun today. Thanks for the video Kenny.

Our Squadron is growing, we are up to 4 B-26s.

I noticed that Klink's Tanks has the same issue with the wing as mine.. it's not flush with the wing where the halves screw together.

[Ted7rns]

I noticed that Klink's Tanks has the same issue with the wing as mine.. it's not flush with the wing where the halves screw together.

Yeah I know... Don't know how to fix it... Maybe the wires not tuck away enough.

[Ted7rns]

Here's another video we did as well... Same flight as above, just a different view.

We like this new forum site. We love Motions, we have bough 60-70 warbirds from Motion. Everyone of our Squadron mates buying the same aircraft so we can fly formations together.

[themudduck]

Yeah I know... Don't know how to fix it... Maybe the wires not tuck away enough.

Bearcat, Ted7ms, check the wing mounting pads (inside the fuselage) - many of us have found that they are not glued in very well, and can pull out. This will make it so the wing won't seat properly (and the whole wing can pull out).

That's some nice flying Ted! Great video!

[rifleman_btx]

Love the videos! They look great!

[Bearcat]

Yeah I know... Don't know how to fix it... Maybe the wires not tuck away enough.

I opened a ticket with Motion RC and sent in the pictures I have posted here, they said this is the first time they seen this, but now this is the second case of it we have seen.
I have checked everything and even measured the thickness of the wing and the inner wing thickness and checked for loose parts, everything is tight - and the wires are not outside of the tracks so there is no pinching going on there. If I can get somebody to measure the thickness of the inner wing where it bolts to the wing and then compare it with mine then it can help find the problem.

But Klink's tank flew fine like this correct?

[Bearcat]

Bearcat, Ted7ms, check the wing mounting pads (inside the fuselage) - many of us have found that they are not glued in very well, and can pull out. This will make it so the wing won't seat properly (and the whole wing can pull out).

That's some nice flying Ted! Great video!

It's the outer wing we are talking about and where it bolts on to the main wing..

[themudduck]

It's the outer wing we are talking about and where it bolts on to the main wing..

OK gotcha. I remember that from a previous post. Its a flush fit on the bottom but there's a gap at the top. Of course the wing mounts are on the bottom side. Do you think that its the wingtip that is causing the problem, or the wing center section? Just curious. I remember when I assembled mine, there was no place to put the wires and cramming them into the small pocket was the only way to do it. I commented back at the beginning that they could have left more room in the design...

[Bearcat]

If I can get somebody to measure their outer wing thickness and then the main wing thickness so I can do a comparison that would answer that $250 question. :-)

[Bearcat]

What is the best advice for the first flight of the B-26 compared to the B-25 I own? Do they fly the same or do I just need to watch the elevator throw on the B-26?
Would a flight stabilizer help with the snap roll issue?

[quitcherbitchen]

I watched X-plane fly Brent's and He mentioned it could benefit from a gyro. It doesn't seem to like wind very much. I have an eagle tree ready to go once I get mine ready for action.

[Ted7rns]

I opened a ticket with Motion RC and sent in the pictures I have posted here, they said this is the first time they seen this, but now this is the second case of it we have seen.
I have checked everything and even measured the thickness of the wing and the inner wing thickness and checked for loose parts, everything is tight - and the wires are not outside of the tracks so there is no pinching going on there. If I can get somebody to measure the thickness of the inner wing where it bolts to the wing and then compare it with mine then it can help find the problem.

But Klink's tank flew fine like this correct?

Kink's Tank flew fine. I will look at more this weekend.

Ted

[CFIT rob]

Bearcat..I cant speak on the b25/b26 comparison. My first 6 or so flights were without stabilizer. It flew ok in a moderate wind(10ish),pitch was stable but roll was not. I installed an a3L and it tamed the wing rock considerably. She stays grounded on a gusty day or 20ish winds(thats avanti time). I dont think a stabilizer will do anything to prevent a snaproll or a tip stall. I believe a rearward CG or large ELE deflections cause the snap. Limit ELE to 1/2 inch and dont go big on the expo so you dont get a sudden rush of ELE( 20% for me) It does drag its tail thru a turn so co-ordinate some rudder to make it look right.

[Ted7rns]

This is the Gap. I really only have it on my Right Wing... I need to take it a part and look at the wires. I believe they are pushing it up. Anyone else know?

[themudduck]

I believe a rearward CG or large ELE deflections cause the snap. Limit ELE to 1/2 inch and dont go big on the expo so you dont get a sudden rush of ELE( 20% for me) It does drag its tail thru a turn so co-ordinate some rudder to make it look right.

Bearcat - I agree with CFIT, what he wrote is the best advice for your first flight. So:
- forward CG position
- limit elevator throw to 1/2 inch or less, with some expo
- coordinate turns with rudder

[Veltro]

Bearcat - I agree with CFIT, what he wrote is the best advice for your first flight. So:
- forward CG position
- limit elevator throw to 1/2 inch or less, with some expo
- coordinate turns with rudder

In addition to the above, I would add that it prefers calm weather, likes 3/4 throttle, and has no pitch up problems with flaps. In fact, it likes half flaps. Just make sure you check that the hinges are properly glued, Re-glue as needed,

[Veltro]

Veltro, I agree with the rudder suggestion - I've been using a 35% mix since the beginning and find it very helpful for the same reason. ...

Thanks for the recommendation. I'll give it a try. Unfortunately we are supposed to have high winds this weekend.

[Veltro]

So what seemed better the shims or the thrust angle? Interesting ideas :)

The two of us with the horizontal stab shims are really happy with them. We aren't sure if we will do the engine shims.

If I understand it correctly, the reason for the engine shims was that the plane would start to climb when he was on short final. He likes to use throttle-only to control decent for landing.

I believe he was running into a situation where he had the plane trimmed for normal flight, The up trim is compensation for the engine down thrust. As the plane slows to land, there isn't as much thrust and consequently the up trim makes it start climbing. Taking out a little down thrust eliminated the impact on his elevator trim setting.

I get the feeling either modification will do, although I don't know if he is still carrying a little up trim, which a lot of people on the forums didn't want to do.

[themudduck]

The two of us with the horizontal stab shims are really happy with them. We aren't sure if we will do the engine shims.

If I understand it correctly, the reason for the engine shims was that the plane would start to climb when he was on short final. He likes to use throttle-only to control decent for landing.

I believe he was running into a situation where he had the plane trimmed for normal flight, The up trim is compensation for the engine down thrust. As the plane slows to land, there isn't as much thrust and consequently the up trim makes it start climbing. Taking out a little down thrust eliminated the impact on his elevator trim setting.

I get the feeling either modification will do, although I don't know if he is still carrying a little up trim, which a lot of people on the forums didn't want to do.

Earlier in the thread (way back, in the stone ages) another modeler determined that the horizontal stab didn't have the correct incidence in relation to the wing. The shim corrects the incidence. Without the shim, a lot of up-elevator trim is needed for level flight, and the plane just isn't flying correctly. With the shim, everything is balanced and happy. ommmmmmmmm.