Official Dynam 1500mm B-26 Marauder Thread

[rifleman_btx]

I never understood the logic in using those. Doesn't seem like they would be saving much in that vs using screws

[RRHandy]

Easier and faster to assemble.

[xviper]

Interestingly enough, I bought a bag of these horns, backing plate and screws from HobbyKing some years ago. They were a few bucks but I could fit them onto several planes, estimating each one would take about 1/2 dozen sets. Oddly, HobbyKing no longer sell these in favor of the ones Dynam uses on this plane. Looking at them closely, they aren't a simple flush glued piece. Each horn has 2 pins that go all the way through the control surface and I notice that they've pushed glue into the holes where the pins go. I've put my plane through some pretty aggressive maneuvers and none of the horns seem to be prying loose. However, I use quite a bit of expo on mine, especially when I haven't dialed down the rates. I can imagine that if someone were to use high rates and little to no expo, those horns would take quite a bit of yanking around and could work loose.
On planes that come with the screw type horns, they usually aren't installed. That's left up to the end user to do, so they aren't saving any time do it at the factory.
I've attached a couple of close up shots of the "other" side of those control horns and you can see where the glue has come through. On those ones that didn't seem to have enough, I leached in some foam safe CA as added insurance.

[Kloverzero]

Whats happening guys!! Thought I would share my B-26, and where it has been, and what I have done.

So, out of the box, everything worked just fine. Of course it has an XT60 connector, and all of my high end 4S batteries have an EC5 on them, so I changed it out. No big deal right? It wouldn't have been if I had not put the negative bullet in the positive hole accidentally!! I get to the field for the maiden, and BANG!!! The wires instantly fused and exploded. A shard landed on top of the wing and melted a nice hole in it. Of course, it fried an ESC in the process.

Anyone who has done any work on the plane knows the ESCs are buried in the nacelle, and you can't access them. I had to cut the nacelles off. I did this by running my Exacto through all of the glue seams that I could reach, and then rocking and pulling the nacelles until they came free. Fortunately, this did not result in any visible damage, and I was able to access the ESCs. I have a ton of spare parts laying around, so instead of ordering new Tomcat ESCs, I replaced both of them with the 40A Hobbywing ESCs from my ill fated Freewing 64mm A-10. These worked great, as I had no desire to put the ESCs back in the nacelles, and they had very long motor wires. This allowed me to mount them in the bottom of the wing in the forward wire trough. I cut the center out of the covering foam, and left the heat sink open to the airflow.



Once this was done, I also added a very long Y connector in the mix to run up into the nacelles so that if I ever needed to change out the main gear, the connection would be right there, and I wouldn't need to fish anything through the wing and nacelle. With all of this in place, I was ready to put the nacelles back on the wing. This is one nacelle back on, showing the connector in the wheel well, and the exposure of the ESC.



Okay, all of this done, it was time to finally get the maiden done. I had not looked on here to see what anyone had said, I wanted a clean maiden. There were no modifications done to any flying surface, the throws for all of the control surfaces were at 100% in the transmitter, and anyone who knows me, knows I am old school, and do not use expo or dual rates. Takeoff from my grass field was smooth, but it quickly became apparent that a lot of up trim was needed. By the time I had it level, I had every click of up trim available in it. I was also using a 4S 5000 mAh Admiral PRO 60C so there was considerable nose weight in it. But, other than the incidence issue with the horizontal stab, the plane flew very nicely, and had decent speed and maneuverability for a bomber. I flew the plane two more times with no changes.

LET THE FUN BEGIN!!

Time for some mods for this bird. In this case, a bomb bay, paint job, and a wheel change!!

I cut the bomb bay doors off the bottom of the plane, and of course, the elevator and rudder servos are right there. I cut the entire tray out, clipped the z bends off the pushrods, and pulled them back out the end of the model. This left me with a nice open cavity. I then cut out the panel lines directly behind the bomb bay to move the radio equipment to. I didn't want to move it forward, so back was the ticket. I found a nice, clean open bay, that even has a nice shelf to mount the servos to. Clipped the guide tubes for the pushrods back, and re routed all of the wires from the nose to the new radio bay. Then I added a few Robart hinge point pinned hinges for the doors.



Then, I separated the doors, drilled the holes in them and prepared them for mounting. This is as far as I have gotten on this part of the modification, as I need an Admiral 10 channel receiver, and a GT Power electronic switch before I finalize the door servo position and control horns on the doors. The finished product will incorporate an electromagnet on each side of the bomb bay made from two 16 penny nails (one on each side), that will magnetize thin sheet metal strips that will be on the inside of the bay walls. Then, I will fashion some foam bombs, with a little lead shot in the nose of them for ballast, and a thin metal strip on the side to "stick" to the metal strips while the magnets are energized via the electronic switch with power from the flight battery.







PAINTING AND WEATHERING

The finish is Testors OD Green sprayed directly over the factory finish, with no additional work being done to it. I replicated the invasion stripes using the "Blue Paper Towel" method of masking, and it worked very well, as usual. I used Rust-O-Leum Profession enamel in Flat white and Flat Black for the stripes. The bulk of the weathering has been done using a "Generals" charcoal slab (Available at Michael and ACMoore) as well as "Generals" pastel chalk for the leading edge distress and some brown mixed in to simulate rust here and there. I use the slab to apply the charcoal to the panel lines, and then use a paper towel to fade it out in the direction of airflow









So, this is where I am at. Since these photos were taken, I have painted the OD bar through the fuse invasion stripes in anticipation of decal application. I have Callie making me the "Little Pink Panties" nose art. I will just use the stock decals for the rest of it, as there are no liveries that I really care for in the OD color. So, it will not be a "scale" livery, but that's okay, it will still look really good, and outside of a few aficionados, no one will ever be the wiser. I will post more as I get it done. I will be ordering the receiver on Wednesday, so I am hoping to have her complete by our Event of The Year November 11th.

Happy Landings guys!!

[warbirdbob]

Horns are OK---Nothing came loose---Just a "Bitchy" airplane----rifleman, you're welcome to the nose cone---and all "glass" parts are OK---check pictures.

[warbirdbob]

Kloverzero---Your plane is beautiful---hope with all your efforts, it flies as well as it looks. Good luck

[xviper]

It wouldn't have been if I had not put the negative bullet in the positive hole accidentally!! I get to the field for the maiden, and BANG!!! The wires instantly fused and exploded. A shard landed on top of the wing and melted a nice hole in it. Of course, it fried an ESC in the process.

Anyone who has done any work on the plane knows the ESCs are buried in the nacelle, and you can't access them. I had to cut the nacelles off. I did this by running my Exacto through all of the glue seams that I could reach, and then rocking and pulling the nacelles until they came free.

I was also using a 4S 5000 mAh Admiral PRO 60C so there was considerable nose weight in it. But, other than the incidence issue with the horizontal stab, the plane flew very nicely, and had decent speed and maneuverability for a bomber. I flew the plane two more times with no changes.

Reversing the power leads - been there, done that and I've seen others do it, too. Sorry it had to happen to you but if anything came out of it, it allowed you to show us how the engine nacelles are attached. So for that, thanks.
I'm flying with a 3000mah, 4s all the way back and it's still a little nose heavy. A 5000mah is huge and I'm not surprised you need so much UP elevator trim.

[Kloverzero]

Reversing the power leads - been there, done that and I've seen others do it, too. Sorry it had to happen to you but if anything came out of it, it allowed you to show us how the engine nacelles are attached. So for that, thanks.
I'm flying with a 3000mah, 4s all the way back and it's still a little nose heavy. A 5000mah is huge and I'm not surprised you need so much UP elevator trim.

It was my own stupidity. I always check, and then double check the polarity markers. I was just in a hurry to get to the field for the maiden as the days are growing shorter. All I have are 2200 and 5000 in 4S, and I didn't think 2200 would quite cut the mustard, so to speak. (Though, they do have the XT60s on them, LOL) As I said, I also did no mods, so there was no shim in it, or anything, it was straight stock. While I haven't flown it on anything else, it seemed to like the weight. In doing the paint and mods, I also found two rather large chunks of lead in the tail. Since I am moving all of the electronics rear of the cg, I took them out for now. I am also going to add another servo for the elevator, and run each side on a separate servo, so that will add a little more "usable" weight aft. Using the 10 channel receiver on my DX9, I will be able to adjust the elevator halves independently to aid in lateral trim. I will be running 8 channels with the bomb bay doors, and electromagnet control.

[Kloverzero]

Kloverzero---Your plane is beautiful---hope with all your efforts, it flies as well as it looks. Good luck

I put three good flights on it before the starting the mods, so hopefully there is no change in the characteristics, because it flew very nice previously!! Thanks as well, I am putting some time and effort into the finish!! I think a nice bomber is worth that (and it helps with re-sale value, LOL)

[NoDirt!]

Kloverzero the plane looks great. I have one on the way. Still haven't decided on a livery. I hope some day to do a bomb bay but will see.
Would you mind a short explanation of the Blue paper towel masking?

[quitcherbitchen]

Looks good Kloverzero. My only suggestion would be to forget the magnets and go with servos on the bomb bay. That way you can close them.

[Kloverzero]

For the blue paper towel masking technique, I have developed a photo tutorial, as I get asked about it quite a bit. I first saw it here on the squawk, but I do not know what the post was now, it was over a year ago. But here you go.

These are what you need:

Blue Shop Towels (Lowes or Home Depot)
Roller Cutter (Walmart sewing/crafts section)
Rattle can paint
A tupperware bowl for water.
A metal straightedge (optional)



Using the roller cutter, cut the towel into 1/4 inch wide strips, then make larger strips to back up the skinny ones.



Dip the strip into water to soak it, then use your fingers to "squeegee" off the excess water, and put it on the surface to be painted.





Take your finger and run it along the edge to be painted, to seal the towel to the surface. Then use an excess piece of towel to blot the water away. Back up the strip with a wider piece of towel. Once you have a sufficient distance, you can use an old dish rag or bath towel to cover the rest of the part to avaoid overspray.



When you spray the paint, start from over the towel and spray away from the seam to be painted, to avoid leaching of the paint under the towel. If the situation will not allow this, hold the can as far from the surface as possible, so the spray stream is not strong enough to lift the towel.



Unmask the area immediately. Do not allow the wet towel to dry on the surface, or you will have a mess on your hands. That's it. Easy Peasy, no adhesive masking technique!!

[Kloverzero]

Looks good Kloverzero. My only suggestion would be to forget the magnets and go with servos on the bomb bay. That way you can close them.

Servos for the doors, the electromagnets will hold the bombs until I want to release them, rather than them just falling out when the doors are opened.

[Kloverzero]

Kloverzero the plane looks great. I have one on the way. Still haven't decided on a livery. I hope some day to do a bomb bay but will see.
Would you mind a short explanation of the Blue paper towel masking?

Sorry, I forgot to quote you in the blue paper towel post, check it out above.

[themudduck]

Kloverzero, your bird really looks terrific, I love the OD paintjob. I guess to save some time you could have masked off the original invasion stripes instead of painting over them and re-doing them... did you do it that way because you wanted to have brand-new stripes? They look great! The bomb-bay mod looks really good as well. Moving the servos out to the next bay rearward is genius. And I like the idea to drop the bombs via an electromagnetic actuator. That's good stuff.

We've had a great deal of discussion here about some important mods/fixes and I don't understand why you would purposely overlook all of it... just for the thrill of discovering these things on your own. For example, the tail weights. Anyway I wish you all the best, and I'm really glad that you had three good maiden flights! We sure don't want to hear that you've had a bad accident.

Please check your wing mounting pads (inside the fuselage) and the flap hinges... these can easily pull out.

[Kloverzero]

TMD, Even if I had come on here and looked, as an agent of the company, it is my responsibility to fly the model bone stock to give my feedback for the manufacturers benefit, to help move forward. I would not have done any of the mods before the maiden regardless of knowing about them or not. I did have a loose flap hinge out of the box, and I have pulled and re glued them all with Foam Tac to ensure they do not come loose again!! The mounting blocks for the wing seemed to be pretty secure, and I did some pretty aggressive flying on the second and third flights, so I think they are okay.

The factory invasion stripes were pretty weak, and they were glossy, I wanted them flat, and it is not that big a deal to paint them. (It also gave me an excuse to go get some more spray paint!!) As the stripes were painted in the field mostly with mops, or whatever they had on hand that could spread paint, I wanted to "imperfect" them some.

[rifleman_btx]

You dang sure hit that nail dead on... Dang good work. Oh and thanks for the conversation about the plane parts and what not. And as I finish that other project I'll have it posted in this section.. my n9mb is almost ready for testing. Just have to install the control surfaces. Anyway enough on the other projects. When you fly this bird. Give us the video! I'm looking forward to seeing it :)

[themudduck]

TMD, Even if I had come on here and looked, as an agent of the company, it is my responsibility to fly the model bone stock to give my feedback for the manufacturers benefit, to help move forward. I would not have done any of the mods before the maiden regardless of knowing about them or not. I did have a loose flap hinge out of the box, and I have pulled and re glued them all with Foam Tac to ensure they do not come loose again!! The mounting blocks for the wing seemed to be pretty secure, and I did some pretty aggressive flying on the second and third flights, so I think they are okay.

The factory invasion stripes were pretty weak, and they were glossy, I wanted them flat, and it is not that big a deal to paint them. (It also gave me an excuse to go get some more spray paint!!) As the stripes were painted in the field mostly with mops, or whatever they had on hand that could spread paint, I wanted to "imperfect" them some.

OK gotcha, I understand. Everything makes sense. And I love your paint job even with the imperfect stripes!!
I've used your paper towel technique using newspaper.

We found that the wing blocks were glued to the top edge of the foam, instead of on the bottom surface. The top edge is really thin and so the blocks pull upwards right into the bottom of the wing when you tighten the bolts. If you take the wing off you'll see.

See Post# 787 with a picture on page 40

[rifleman_btx]

Yeah and them pulling up wasn't planned by factory design I'm sure. And up pulling a fare amount of gs pull them loose pretty quick

[Bearcat]

PS---Anybody want parts?? Send me a Postage prepaid box and I'll fill it.

The cowlings I would take if they are in good shape!!!

send me a message..