Official Dynam 1500mm B-26 Marauder Thread

[NoDirt!]

Yes, on my second flight last week I bounced the landing a bit on our grass runway and removed one blade. Thankfully I live close, went home and retrieved my spares.

Aside from working on our landings and keeping spares on hand I don't have any great advice.

[xviper]

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'm still on my original props. I've got a very rough, lumpy, bumpy grass strip and I've even landed on one main gear and belly landed on a couple of occasions when the stock gear failed in the cold. You need to learn to chop the throttle when the plane gets within a few inches off the ground. Driving the props into the ground will break them easily. Now that I've changed all the retracts to a different brand, landings are never an issue. The props don't come close to a ground strike, especially once you've mastered the "main gear touch down first" technique.

PS. You can try some stronger MAS props but if you drive them under power into the ground, you'll either still break them or break something in the motor mount or nacelle.

[terrygrau]

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?

[NoDirt!]

Did you hit your target? :)

Bob

Strictly training runs yesterday. Probably need a few more prior to the fist mission.

[borntoolate]

Finally got some good flights in yesterday (for the most part - bent a main a little on the 7th grass landing)
BUT the first bomb drop was successful! Woo Hoo! I think that's going to get fun!

Did you hit your target? :)

Bob

[NoDirt!]

Finally got some good flights in yesterday (for the most part - bent a main a little on the 7th grass landing)
BUT the first bomb drop was successful! Woo Hoo! I think that's going to get fun!

[rifleman_btx]

The only reason I kept the mains was due to the field I land on. As it is very choppy

[borntoolate]

I swapped out the wheels for Robart diamond tread - 3" mains and 2.25 nose. The Dynam retracts were replaced with Freewing MiG-21 retracts and oleo struts. Still awaiting calmer winds for maiden for both B-26s.

[xviper]

The fat wheels do give the plane a bit of a cartoon flavor. Just not sure that's what I want for this one.

[rifleman_btx]

The only one I swapped was the nose wheel. I might do the mains this year, maybe

[xviper]

Flew mine this morning after having it hang from the ceiling all winter. It reminded me of how wonderful this thing looks in the air. Greased every landing. I can't say that about most of my other planes.
I must admit, however, that those big, fat wheels are somewhat goofy looking. May have to mod them up later with skinnier ones.

[borntoolate]

This one has a bomb bay added. That may account for the wire mess, or the former wire mess!

Bob

[rifleman_btx]

All I did was run the reciever under the wing, that really cleaned up mine.

[borntoolate]

Since it is so windy today, I had time to work on the B-26s. The battery compartment was a mess with the wiring. so I made a simple cardboard divider to clean it up. Installing/removing the battery is quick and easy now. Cost - nothing. Time to mod - 5 minutes.

Bob

[quitcherbitchen]

So I didn’t go vertical, but I did use a ramp. Really easy to load the battery now

[fhhuber]

moving cg vertically changes the axis of the roll and how much you have to work to hold straight knife edge.

distribution of the weight side-side or up-down affects roll rate (how crisply it can do 4 or 8 point rolls). More weight out toward the tips means its harder to start rolling and to stop rolling. The closer the heavy stuff is to the CG the sharper your points and corners will be when trying precision maneuvers.

Some planes this matters more than others. Scale bombers never were meant for precision aerobatics.

[quitcherbitchen]

Good point FH, but I am doing it for three reasons. One, I hate the velcro straps, they were too far forward for me as I moved my servos to the rear bay and got rid of the tail weights. Two, the rats nest of wires always had to be moved in order to strap the battery. I think if I put in a foam battery bay I can route the wire thru the foam thus making any constant shuffling of wire almost unnecessary. Three, getting the weight in a more vertical plane will make the models vertical CG more centered. Less pendulum being down low. Might effect the roll rate and aileron throws. Right now, the rates seem kind of mushy, but that may just be my expo setting. I figure it is worth a try to make loading the battery easier.

[fhhuber]

What do you guys think if I change the battery to sit like this?

Any way the battery fits that does not throw CG off is fine. (note that CG is a point in 3D space, not a line or plane through the model. It can be off up-down or side-side as well as fore-aft.)

If you moved it to aid getting correct CG without adding "dead lead" (or to reduce useless ballast) then you are doing exactly the right thing.

I commonly trim some foam to get the battery where I want it or to fit a larger battery. I'd much rather carry a larger battery than useless ballast.

[quitcherbitchen]

What do you guys think if I change the battery to sit like this?

[rifleman_btx]

Ouch! yes whole heartedly agree with that.