Official Nexa 1630mm Junkers JU-52 Transport (Balsa ARF) Discussion Thread

[Oxotnik]

I'd managed to lose one of the nylon straps that hold the strut supports in place. I shaped a chunk of balsa as a replacement. I like the tie-wrap solution better. I'll probably swap out my ugly balsa block for a less-conspicuous piece of tie-wrap.

Edit (7 hours later): Found the missing nylon strut strap. Merry Christmas to me.

[airotroy]

Maidened my Ju-52 today. It flew very nicely. It was a bit squirrely on the ground; it took me several attempts to get her running straight enough to take off. She flew really well. I love the sound of the 3 motors running.

Very nice maiden. She sure flys nice once off the ground. Hopefully you can get that worked out. Iv been promised the correct motor mount and the missing gear straps from Motion several days ago. They want the bad mount back. Waiting for ESC"S and Motion before I can do much but your flight gives me something to look forward too.
Russ

[OV10]

Tony, I don't know. As you know, the tailwheel is mechanically linked to the rudder, and, visually, the tailwheel is well aligned with the rudder. I've got pretty good take-off technique for tail-draggers, where I ease into the throttle, get her running straight, get the tail up, then pour on the power. The Ju was weird. It felt like it was yawing one way with the tailwheel planted, but then yawed the other way when the tail wheel came up. The Mains are straight. Maybe the suspension in one of the Main Struts is compressing during the takeoff run, inducing a yaw. I have a full throw on my rudder (I always like a lot of rudder) and have expo set at 30%. Maybe, I need to run the rudder expo up another 20%, to see if that damps out the overcorrection. I'm still puzzled. On the second flight yesterday, I had to abort the first takeoff run, but successfully got her in the air on second run. I'm still pretty baffled about what's going on during the takeoff run. In the air, though, she's flies like a dream. 4S with these 2836-1000kv motors has plenty of power. After a 5 minute flight, I was still around 50% battery, and I'd mostly kept the throttle around 75% for the flight.
Charlie's recommendation for these motors was really good.

I certainly do remember that trimotor sound including an initial faux radial rub like you had. My 3 blade MAS's had a little more growl than your 2 blades.
The rudder is VERY effective and as such I used rates......high(30 degree) for taxiing and low(15 degree) for takeoff/flight.

[Oxotnik]

Thanks, Charlie. I'm only running full rates right now. I'll set up low rates for rudder for takeoff. First, though, I think that I'll try cranking up the expo on the rudder and see how that does. I'd debated about putting 3-bladed props on my Ju, but I only saw one or two photos of the Ju with 3-bladed props.

[airotroy]

Well, Murphy struck. again. No nylon straps for the Landing gear attachment, both antennas are missing, and horn supplied with the tail wheel doesn’t match the instructions. In fact, it’s the typical horn you use on the vertical pushrods for ailerons. I’ve already contacted Motion about this. First Nexa Model I’ve owned. Not impressed so far.

One minor item. Cut away the film for the rudder. NOTE - the slot is MUCH longer than the actual rudder. Now I’ve got to put a wood filler to fill the gap

BTW - motion actually contacted me regarding the screwed up motor mount. They said they checked stock and I must have gotten a bad one. I’d recommend you submit a problem report so they know I’m not the only one who got a bad one.

Did Motion ever make the motor mount problem right ? Their supposedly sending me a correct mount along with the missing nylon gear straps and want the wrong mount returned to them. Still waiting after 3 weeks.

[Rmawer]

Did Motion ever make the motor mount problem right ? Their supposedly sending me a correct mount along with the missing nylon gear straps and want the wrong mount returned to them. Still waiting after 3 weeks.

When I wrote to them, I just told them the issue, what I had to do to fix it, didn't need a replacement (was sure they would have to get it from the factory and didn't want to wait), and that they should check their inventory. The fix was simple since the glue joints are of a poor quality (easy to break that center piece out and flip it 180 degrees). They thanked me for the notification and said I had a fluke as all the others were fine (Lt and Rt mounts). The difference is so subtle, it's easy to overlook. Seeing as you had the same issue, this appears to be a problem and not a fluke.

I'm almost thru my build and have 2 pages of issues I've uncovered (have you discovered the wrong position of one of the flap horns yet? - Unless you cut a new slot, you have to A) use a reverse servo, B) get a reverser for one of them, or C) put the second servo on another channel, mix, and reverse that specific channel). It's funny. I bought the twin Otter (same company) at the same time and have so real issues (a few inconveniences but nothing that can't be fixed).

[airotroy]

When I wrote to them, I just told them the issue, what I had to do to fix it, didn't need a replacement (was sure they would have to get it from the factory and didn't want to wait), and that they should check their inventory. The fix was simple since the glue joints are of a poor quality (easy to break that center piece out and flip it 180 degrees). They thanked me for the notification and said I had a fluke as all the others were fine (Lt and Rt mounts). The difference is so subtle, it's easy to overlook. Seeing as you had the same issue, this appears to be a problem and not a fluke.

I'm almost thru my build and have 2 pages of issues I've uncovered (have you discovered the wrong position of one of the flap horns yet? - Unless you cut a new slot, you have to A) use a reverse servo, B) get a reverser for one of them, or C) put the second servo on another channel, mix, and reverse that specific channel). It's funny. I bought the twin Otter (same company) at the same time and have so real issues (a few inconveniences but nothing that can't be fixed).

My replacement motor mount for the right side arrived and I sent them back the other wrong one that they wanted back. They sent some metal (not nylon) gear straps that look ok and should work. Just ordered a 4000 4s battery, some extension motor to esc cables, a esc to battery splitter cable and the servos so Im a ways off from where you are. How are you going to mount the rear elev and rudder servos - in the tail or mid fuse ? Appears to be 4 possible cut outs in the rear for servos, havnt assembled the elev or rudder yet so I'm not sure which pair of openings to use. Appreciate the info on the flap horn. Did you just cut a new slot ? Any other problems or photos that you can share would be appreciated as well.

[Rmawer]

My replacement motor mount for the right side arrived and I sent them back the other wrong one that they wanted back. They sent some metal (not nylon) gear straps that look ok and should work. Just ordered a 4000 4s battery, some extension motor to esc cables, a esc to battery splitter cable and the servos so Im a ways off from where you are. How are you going to mount the rear elev and rudder servos - in the tail or mid fuse ? Appears to be 4 possible cut outs in the rear for servos, haven't assembled the elev or rudder yet so I'm not sure which pair of openings to use. Appreciate the info on the flap horn. Did you just cut a new slot ? Any other problems or photos that you can share would be appreciated as well.

My servos are installed in the forward most openings and as it turns out, that is the better place (and it was dumb luck that I didn't use the rearmost openings). Even though the fuselage is wider there, the small servos still bottomed out against each other (if you see the picture of the elevator servo, you'll see a second shim in the other side of the servo). Thanks to Oxotnik , I saw the fix he used for the excessively wide servo opening (just have to paint mine silver).


As for the flap servo, there are a few options:

The easiest way - buy a servo reverser or buy a servo already modified from Servo City (the reversers I've seen run from around $10 to $20; Servo City has a standard fee of $10 to have the reverse option done in the actual servo)

The cheaper technical way - "IF" you are VERY comfortable soldering and very comfortable doing it with small components, the servo mod is really easy and involves swapping just two pairs of wires; motor and potentiometer. If you are not comfortable doing it, either find a buddy who is (a 6-pack is a recommended payment 😊 ) or do the above. I am pretty comfortable doing that kind of close work so I reversed my own servo.

The least frustrating method - install the servo with the pushrod and mark on the flap where you want the horn. Now you have a decision to make. The area the horn is installed appears to be a plywood material. If you elect to use the supplied horns, you will need to cut a rectangular slot. It will be time consuming to do as you don't want an oversize slot. Two drilled holes and an X-Acto keyhole saw should do it. An easier way might to just use the classic 3-screw horn.

Hope this helps

[Rmawer]

My replacement motor mount for the right side arrived and I sent them back the other wrong one that they wanted back. They sent some metal (not nylon) gear straps that look ok and should work. Just ordered a 4000 4s battery, some extension motor to esc cables, a esc to battery splitter cable and the servos so Im a ways off from where you are. How are you going to mount the rear elev and rudder servos - in the tail or mid fuse ? Appears to be 4 possible cut outs in the rear for servos, haven't assembled the elev or rudder yet so I'm not sure which pair of openings to use. Appreciate the info on the flap horn. Did you just cut a new slot ? Any other problems or photos that you can share would be appreciated as well.

One more item that is worthy mentioning and that is the attachment of the tailwheel rod to the rudder. The parts they supplied I was not comfortable using as the tab was, in my opinion, way too wide. I had an old strip aileron bearing on my box of misc parts which I cut in half and trilled the overhang (see picture). The tab is only about 0.025" thick which makes it an ideal fit (simple X-Axto slit in the rudder material, a little CA to hold it in place - Done).

[airotroy]

Both my wing flaps have two slots cut into them for the horn - I assume to position the servo arm to go either side. Different than yours ? Pretty sure my servos will bottom out as well in the rear and I'll have to modify as you have. Thanks for the pics and help.

[Rmawer]

Both my wing flaps have two slots cut into them for the horn - I assume to position the servo arm to go either side. Different than yours ? Pretty sure my servos will bottom out as well in the rear and I'll have to modify as you have. Thanks for the pics and help.

That's hilarious. My wings only had one set of horn slots. I'm guessing you got the fixed version 😎. Horns for the flaps are installed on the same relative sides of the servo (unlike the layout for the ailerons). Glad it worked out for you.

My Rx's came today so I'll be hooking up Iron Annie tonight, Wont get my servos for the Twin Otter until the end of the month

[JayDog]

Thanks for all the information Charlie, it was very helpful during my build. Got mine 95% complete. The manual is pretty vague with regard to the CG location. Yes, 90MM from the LE but at what point on the wing? The manual says "Wing Center Section" so is the CG half way between the wing root and wing tip, about 15" or taken at the root like most other planes?

[OV10]

Thanks for all the information Charlie, it was very helpful during my build. Got mine 95% complete. The manual is pretty vague with regard to the CG location. Yes, 90MM from the LE but at what point on the wing? The manual says "Wing Center Section" so is the CG half way between the wing root and wing tip, about 15" or taken at the root like most other planes?

JayDog CG would be at the root and welcome to the Squawk

[JayDog]

Thanks Charlie

[Oxotnik]

Ah, another enlightened Iron Annie flyer has joined our ranks. Welcome, JayDog. I've flown mine with the CG at the recommended location (measured at the wing root), and she feels very well balanced in the air.

[airotroy]

That's hilarious. My wings only had one set of horn slots. I'm guessing you got the fixed version 😎. Horns for the flaps are installed on the same relative sides of the servo (unlike the layout for the ailerons). Glad it worked out for you.

My Rx's came today so I'll be hooking up Iron Annie tonight, Wont get my servos for the Twin Otter until the end of the month

Well - any progress ? Pics when ya can. Finally got my 4 wing servos in and cables pulled. Motors are somewhat mounted ( that nose motor was a mind bender ) Will leave everything somewhat loose but yet wired for length so I can test everything before the final button up. Still waitin on parts.

[JayDog]

Hi OxotniK, thanks for the welcome. I really looking forward to flying this aircraft. It has some sentimental memories for me. The full scale aircraft, D-AQUI, now owned by Lufthansa has a colored history. Among being an Airliner, a German world war two transport. sunk once when on floats and a stint in South America, it was previously owned by Martin Caden and flown in many air shows here in the USA and Florida. When it was to be sent to back Germany, I along with a few others prepared her and modified the fuel system so she could make the long trip from Opa Locka Fl. over to Europe. The guy on the far right is me. Iron Annie is now D-AQUI. Flying in her was a fantastic experience.

[Twowingtj]

JayDog Welcome to Hobby Squawk. Interesting history. Very cool that you had actual hands on time with her.

[Oxotnik]

JayDog , Speaking on behalf of EVERYONE in this thread, we'd love to hear some of your inside stories on the restoration of D-AQUI! :-)

[Alpha]

JayDog Where is the popcorn emoji? We're all eager to hear your stories restoring and flying a Ju-52!