Official Dynam 1500mm B-26 Marauder Thread

[terrygrau]

Broken Props??
No one mentioned the flex of the nacelles or haven't noticed it. I even drove bamboo skewers thru the nacelles into the wing but the flex remains and is enough to eliminate the prop clearance at touchdown

[themudduck]

TerryGrau, I haven't noticed this problem in my experience, but I am sure that its possible. The landing gear is mounted on the nacelle, so how are they flexing? Just the foam bending?
I can't imagine this happening unless you are coming in fast and slamming into the ground pretty darn hard. I bring mine in with full flaps and it slows down and lands like a feather. Its one of the nicest-landing planes that I have. I do want to note that I am using full flaps for landing, with about a 60-degree deflection.

As Rifleman says in the next post, you could also try a slightly larger nose wheel. The full-size B26 stood on the ground with a positive angle of incidence so this helps with the scale look as well as helping with takeoff performance. I've done this on my plane, forgot to mention that.

[rifleman_btx]

Nope can't say I have on landings at all. You have to keep alittle speed in it so you can control the touchdown. I did change the nose wheel to the flightline P38 wheel. That did change the angle of the motors up a touch. Might try that if you're having these strike issues on landings.

[xviper]

In this post ........................... https://www.hobbysquawk.com/forum/rc...3426#post93426 , you can see in my video that my landing was a pretty hard "plop" on a very rough field. The props never touched the ground and remained intact. The key is to keep some UP ELE at touch down, which means you must flare just about right (near stall) when landing. You need to whack the ground very hard to mash the props into the dirt.

[Hippie 64]

I have not had it happen either . You can float this plane in so soft and just kiss the ground . Almost any prop slap will be caused by a hard slap landing . Even if it were into taller grass not sure if the props would break but I guess they could



Bryan

[terrygrau]

Not my imagination. Flew yesterday and watched the nacelles move up and down just during fast taxi. Mine was one from the first shipment to MRC so maybe there is a change along the production run.
I'll look into the larger nosewheel

[xviper]

Not my imagination. Flew yesterday and watched the nacelles move up and down just during fast taxi. Mine was one from the first shipment to MRC so maybe there is a change along the production run.
I'll look into the larger nosewheel

I would suggest you inspect those nacelles closely. You might consider gluing them onto the wings in addition to using some FoamTac on the screw threads when you tighten them. As said earlier, the landing gear is attached to the nacelles and should keep the distance between the ground and the nacelle fairly constant. The only time I can see a prop hit causing breakage is if the tire(s) hit a depression in the ground, then plowing into the higher ground in front of the divot. My field is one of the lumpiest ones I've seen and I've never hit the ground with a prop on my B-26. I've cut grass lots of times but that has never broken a prop.

[NoDirt!]

Oh the engineering...
My first flights have been a bit less than graceful at liftoff with the plane popping up more than lifting off. Our grass has been pretty thick and a bit tall but I still want to raise the AOA.
I decided I would add a spacer under the front retract as I don't have a larger wheel at the moment.
So I remove the retract and what do I find? Spacers of course. Nuts!
Ummm, nuts used as spacers I mean. 1/4 x about 3/32 thick. I found it pretty funny. Use whatcha got I guess!
I made a spacer out of 1/4" ply and will see if that helps.

[xviper]

The business about these spacer nuts was first posted about months ago ......................

https://www.hobbysquawk.com/forum/rc-airplanes/propeller-airplanes/72587-official-dynam-1500mm-b-26-marauder-thread?p=123456#post123456

It was a surprise then and I guess it's still surprising owners today.

[NoDirt!]

D'oh! I even posted on that page! Guess my CRS is kicking in :Silly:

[quitcherbitchen]

The larger wheel solved mine, but the spacer nut is the cheap solution. Actually the bigger wheel doesn't look that scale as the scale front wheel is small. I might go back to using spacers.

[Bearcat]

Broken props??
Admittedly not all my landings are textbook, but I have been going thru a few props. between flexible cowlings/motor mounts and lowering a wing on landing.
I have even shorten prop diameter by 1 inch with limited success. Unless it's a soft landing the cantilever nacelles flex the wing and dip down enough to hit blades.
Anyone else experiencing this have a recommendation?

I run into this way too often, I went with larger tires even and I still bust a prop..

[NoDirt!]

Adding the plywood under the front retract seems to have helped. It rotated and lifted off easier today.

AND, three successful bombing runs! Munitions were armed (with flour) and impacted on target on the runway.
I'm glad it worked as well as it did and the guys got a kick out of it.

[quitcherbitchen]

Send me some pictures for my website.

[NoDirt!]

Yea, I need to get some photos or better video. So far all I have is a not so great video.
Maybe next week.

Hers a pic of the new stance after adding the spacer under the front retract.

[quitcherbitchen]

Good bomb videos are actually rare. Many times( I mean many) I will ask my friends or someone nearby to video the drop. Guess what? They flub the perfect hit on target. Either film the drop or film the target. Better yet, film both with two cameras. I want to place a camera on the target one of these days. I never get around to it.

[themudduck]

Hey, no posts for a while here! I hope everyone's enjoying flying their widowmakers.
I have another flight video taken from my B26 if anyone's interested. At one point I did a spin...actually SEVEN. This plane spins like crazy!

[quitcherbitchen]

No kidding it spins like crazy. I try my best not to do that.

[quitcherbitchen]

So I received my sonictronic spring hinges to do my landing gear door mod. I am a little worried the Dynam retracts won't be able to overcome the spring tension in the hinge. Those little springs are stiff.

I also got my bomb bay doors to close without making the servo buzz by lengthening the control rod on one side. Must have been a geometry error on the servo placement on one side. Now they work perfect. The bombs still come out of the plane much more scattered then with my B-17. I think the bomb bay is quite narrow on the B-26 and the bombs must bump into each other on exit. Or the plane is flying faster then my B-17 and the bomb tails have more bite. Any angle off and they go further in that direction before stabilizing.

[quitcherbitchen]

The Sonictronic spring hinges for the gear doors worked, but they really put a load on the retracts. I am not going to use them. I even tried lightening the spring tension by uncoiling one wrap off the hinge. No luck. Instead I will use an FMS 3 second sequencer from the old 1450mm P-51 and servos. I bench tested and it works. I buried the Dymond 2.2 gram servo half way into the wall.