Official Dynam 1500mm B-26 Marauder Thread

[Mark 2]

Rifleman, take off each retract and loosen the screws by 1 turn and give it a try, I got this advice 5 years ago from the Dynam A-10 forum and it goes help until you get around 50 degree..

Is this for the screws that hold the retract into the wing or the screws that hold the two halves of the retract unit’s case together?

[CFIT rob]

Its was warm(80s) when i had my failures, no flights under 70 F. Been unusally warm till now ,now below normal (think my ex wife must have returned to the state. Yup... so cold she made the furnace kick on.) Im going to experiment myth buster style with a spare main and my glitching main, see what it takes to make 'em fail.

[Dewey H Lee]

Also check and see if your end points on your tx does anything. This helped with a bird that i had trouble with that XVioer suggested to me. I thought that once it was activated it went through the cycle unless it binds up but strangely enough it made a difference. Mine was not Dynam and was not working at all and then change what Xviper told me to and they were good and then started doing almost the samething later as yours. Fiddled with the end points again and was good to go. Only 8 flights since though. Long shot but maybe. Not the expert these guys are. THERE GURU'S. :) . If it wasn't for them id be lost:Confused: halve the time.

[Bearcat]

Is this for the screws that hold the retract into the wing or the screws that hold the two halves of the retract unit’s case together?

That holds the halves together

[Alpha]

CFIT Rob, we conducted similar cold temperature tests on these new V2 retracts when they were redesigned. Granted it was the summer outside, but we controlled for temperature and humidity down to freezer temps. The V2 retracts were noticeably less prone to stalls than the original Dynam retracts in these tests, due in part to a couple key redesigns:

For one, the PCB elements are less exposed, and the microswitches are pyramids. The older flat style microswitches required precise alignment otherwise they wouldn't depress. The new V2 microswitch's pyramid shape accepts a wider range of leadscrew position in order to depress or release the switch. The margin for error literally multiplied by a factor of five. Importantly, the V2 switch is SMT soldered by machine for consistency compared to the hand soldered V1 microswitch, making failures due to alignment almost a thing of the past according to our Service Center data collected since the V2s were rolled out earlier this year. The PCB layout also requires less lubricant, which was also prone to fouling the mechanism in colder conditions. They were using the wrong viscosity and amount.

Please post your results here! I expect they will match what our tests found.

[CFIT rob]

Alpha...when do you sleep? Your devotion should be a model for every american business. Im starting to picture your company a bit like wonka's chocolate factory. All the wonderful toys. The R&D. The committed staff. I would love to see pilot ryan dressed as an oompa-loompa. Ive been around boat/engine mfgrs as a shop owner/mechanic for 30 years, if there is a V2 of a problamatic part, that usually adresses the problem. Temps are returning to normal so it may be a few weeks to get real world results. "Lab" testing this weekend. Testing will be true to my mythbuster heros.

[Bearcat]

Better yet I would love to work for them...

[rifleman_btx]

Rifleman, take off each retract and loosen the screws by 1 turn and give it a try, I got this advice 5 years ago from the Dynam A-10 forum and it goes help until you get around 50 degree..

Copy that, will give that a go

[themudduck]

So, its on sale now for $209. That's a nice price! Just buying the retracts, motors, escs, props and hubs separately costs almost $150. I'm tempted to get one just for all the spare parts.

Its the pilots, that's where the money is. I bet they sell a lot of those spare pilots.

[TSHobbies]

realll tempted to get one now lol

[NoDirt!]

So, its on sale now for $209. That's a nice price! Just buying the retracts, motors, escs, props and hubs separately costs almost $150. I'm tempted to get one just for all the spare parts.

Of course! I just got one :Silly:

[rifleman_btx]

So, its on sale now for $209. That's a nice price! Just buying the retracts, motors, escs, props and hubs separately costs almost $150. I'm tempted to get one just for all the spare parts.

Its the pilots, that's where the money is. I bet they sell a lot of those spare pilots.

A lot of daughters/grand daughters with tiny horse farms lol

[Bearcat]

This morning a did a huge test with the B-26 and honestly I knew this could have ended badly on landing but I flew with the temps being 44 degree and foggy as hell. This test answered the retracts answer and I have answers for everybody so I will break this down from start to finish.
*44 degree tempature
* retracts will raise and lower but if they don't wiggle the rudder stick and they will drop 100% of tries.
B-26 flew great with some windy but man with silver paint it blends in the fog too fast!!!
Elevator I was able to bring flush but the plane is too nose heavy at 55mm for CG so I will move the battery back to 58-60 mm range next flight.
Both flights were conducted with an Admiral 4000
First flight it was noticed she was pitching nose up when you let the sticks go, I was forcing down elevator to keep her from stalling, I did manage to take her to the edge of a stall twice before giving her down elevator and lower power, landing was done in the grass with purrfection.
Second flight I changed the elevator from 3mm up to even ZERO..this gave me a stable flight with no tip stalling but let go of the stick and she dives even at full power so this tell me to move the battery back 3-5 mm or the elevator might need a slight up or maybe use a lighter 3600 4s battery..
Also the right cowl came loose again which caused the angle to point down and I kept noticing a pull to the right so I will epoxy this down and that should take of that issue.

Has anybody shimmed the front landing gear to raise the nose alittle?

[xviper]

* retracts will raise and lower but if they don't wiggle the rudder stick and they will drop 100% of tries.

Very interesting observation. I wonder why this makes a difference. I've flown around circuits trying to lower the gear while moving the ailerons and elevator but not the rudder. Last time I flew in the cold, it was one main that didn't come down. Trying some more, it was one main and the nose that wouldn't come down. Then again and none of them came down. Belly flopped it in the tall grass with no damage. It doesn't matter now that I've replaced them all with other brands of gear.

[Bearcat]

I'm using Du-Bro 2.75" treaded for the mains, and a Dave Brown 2 3/8 wheel for the nose. Your suggestions would work well too. I used an extra collar on the inside and cut the protruding end of the axle off using a Dremel..

Do you mean 2 3/4 or 2 1/2 or 2 1/4, Tower Hobbies is not showing a 2 3/8 wheel of that brand.. ( which is made in Hamilton Ohio near me!)

[Hardway]

Its the pilots, that's where the money is. I bet they sell a lot of those spare pilots.

Bro, you gave away the secret!!!! Now the price will go up just because of the intrinsic value of those pilots!!!!!!! ;)

[Bearcat]

Two more flights this evening and I am happy to say I have where the battery should be for both 4000 and 3600 batteries.
Landings have been good and I glued down the cowling so the prop does not bounce on landing as it has in the past and bust a prop both times.

[themudduck]

Do you mean 2 3/4 or 2 1/2 or 2 1/4, Tower Hobbies is not showing a 2 3/8 wheel of that brand.. ( which is made in Hamilton Ohio near me!)

Hi there,

By the way, yeah I installed a slightly larger nose wheel. This helps the model take off a bit easier. But the REAL reason I did it is because the full-size B26 sat on the ground like that (picture below) and I wanted it to have that look. Its just a silly anal-thing I like to do, I like my planes to look scale. Well at least I try. Sigh. The main wheels aren't correct either.

Well I'm pretty sure its a DaveBrown. The wheel doesn't have the size printed on it - I just measured it the best I could, using a ruler. It's bigger than 2-1/4. Maybe its a 2-1/2? I was shooting for a wheel that was slightly bigger than the original one.
I guess what you can do is take the nose wheel off yours, and measure the distance from the axle to the point where the wheel will touch the strut... that's the maximum size (multiply by 2). My wheel is just clears the strut. Here's a picture of the nose wheel on my B26.

By the way, Motion has these. This is the "treaded lite flight" type. Here's a link to the 2.5" size. Here's a link to the 2.25 size.
I just measured again just now. I swear to God, it's exactly between 2-1/4 and 2-1/2. So I don't know what the hell is going on.... :Thinking:

[NoDirt!]

A little hacking and painting of the cockpit:

[rifleman_btx]

Sweet!