Official Dynam 1500mm B-26 Marauder Thread

[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.

[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.

[rifleman_btx]

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

[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!

[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!]

Did you hit your target? :)

Bob

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

[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?

[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.

[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.

[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.