Official Dynam 1500mm B-26 Marauder Thread

[rifleman_btx]

HahahaLOL, naw, she just floats forever and I jerked the stick back to hard and it just stalled on me. Luckly not high enough to really screw the pooch, but yeah, not the prettiest. Lol

[themudduck]

Hey Rifleman, looks like you really avoided "something bad" on that landing! Your model slows down well.

Hey, was there an earthquake going on during your flight? ;)

[rifleman_btx]

Well that makes since now

[xviper]

Heres where I put my battery packs, with it there the cg is at 65mm

This explains a lot. You are using a Zippy 20C 4000mah, 4s. It weighs 399g. Zippy batteries are some of the lightest batteries in any given mah and cell count. By comparison, my Gravity weighs 428g. A 20C - 50C NanoTech is 430g. A Turnigy 20C is 437g. A Turnigy 30C is 452g. A Turnigy Heavy Duty is whopping 480g. If one where to use the HD, it would have to go as far back as possible AND you may even need to add more weight to the tail.

[rifleman_btx]

Heres where I put my battery packs, with it there the cg is at 65mm

[rifleman_btx]

It's weird with takeoff flaps it has a really long rollout. that was with no flaps at all. I have a 4000mah pack almost as far forward as I can get it.

[NoDirt!]

Nice flight, and nice save!
Yours lifted off fairly quick. Mine seems to need a long roll out. Do you know where your CG is?

[rifleman_btx]

Here was my B26 today, flew good, but I just about cartwheeled it on the landing... flared waaaaay early. Oops

[rifleman_btx]

Pulling for good things brother

[Mad Baron]

Well the B-26 is 99% complete just a few parts need put back on. I took it outside to my front yard (away from any powerlines) and range checked with the motors on and off no unusual servo movement so hopefully it will fly with no issues.

[rifleman_btx]

That's freaking awesome :Cool: very impressive

[quitcherbitchen]

I use 3300 40c China Hobby batteries and no weights in the tail. I did move the servos back one bay. My 3300 is shoved as far back as it can go. I weighed mine and I was under 6.3 lbs with battery. Get 9mins flight time

[themudduck]

I can't see a difference of 225 grams between a 4000mah and a 3600mah (and those weights). Besides, I'm quite happy with the way mine flies as is.

Hey Xviper, let me point out that back on post 437 you wrote that you took out the tail weights and you said "I'd rather move the battery back or use smaller batteries to make it balance".

There are variances between planes of course. Mine balances with the 3600 battery propped forward about 1.5 inches from the back of the battery bay (I used a piece of foam for a spacer) with no tail weights. But if you guys are flying noseheavy with a 3600, then I guess the tail weight may be needed. IDK, personally I would try an even smaller battery before I would add weight.

[rifleman_btx]

Yeah I think it does, weird thing is mine still looked like it was dragging its butt in the air. It flys ok but it's just leaving a large W in the sky where its ass drags...:Confused:

[Mad Baron]

I use the 3600 and it balances out just right. I tried balancing it with no weights and it was too nose heavy. I can live with a couple of ounces if it helps the plane fly well.

[xviper]

I can't see a difference of 225 grams between a 4000mah and a 3600mah (and those weights). Besides, I 'm quite happy with the way mine flies as is.

[themudduck]

This plane needs the weight it doesn't want to balance without them it was too nose heavy without the weight

Too nose heavy without the tail weights? Have you tried using a smaller battery (as I have been suggesting for like since forever?) You'll end up with a lighter model overall, which is always a good thing when you're talking about this kind of plane.

The weights were talked about from the beginning of this thread (see post 537 for example). Someone at the factory noticed how nose-heavy the model is... and added the weights. Its better to use a smaller battery! With a 4000 mah battery (and the tail weights) your plane will weigh about 6 pounds. With a 3600 and no weights it will weigh about 5.5lbs.

Besides correcting the balance issue, with a lighter plane the motors don't have to work quite as hard (they draw less amps) and so flight times with the smaller battery are just as good.

[rifleman_btx]

Wow it's really strange as my 4000 almost touched the front of the canopy hatch :Confused:

[borntoolate]

I had to put my weights back in as I had put larger motors and ESCs in, plus I replaced the Dynam gear with a mix of Freewing (mains) and FMS (nose gear). With the weight it is still a tad nose heavy. Next flight I will adjust with a bit of weight, or move my BEC battery (s@ 1300) further aft. She sure sccots around nicely with the 11Hobby Bearcat motors!


Bob

[xviper]

There are 2 weights in the tail cone. On mine, one was just rattling around. I hot glued it back in place and put more hot glue on the other one. I think it'll fly pretty the same with or without the weight. Without the weights, you'd need a little more elevator UP to compensate but once trimmed, the plane shouldn't know the difference. My 4000mah, 4s is pushed as far back into that bulkhead as it will go. The front velcro isn't even used. It doesn't touch the battery.
The true test is flying it inverted. It's been a long time since I flew it that way, so I can't remember what the outcome was. Obviously, it wasn't shocking enough that I would remember anything bad about it.