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

[Oxotnik]

My Tante Ju is still down. On the last flight, both of the outboard motors broke their motor mounts (Propdrive V2 2836-1000kv), and I can't find these motor mounts, nor the motors, in stock on HK and can't find any other 2836 class ~1000kv motors for replacements. Am kinda frustrated not being able to fly to fly my new Trimotor. :-/

[airotroy]

A little more progress on the JU-52. Proud to say, all the wiring is finally complete (and everything actually works; smoke test proved it), Bought a Admiral Rx with telemetry (my first Rx with telemetry). Because I'm using XT-90 connectors on dual 4-cell batteries (dual in parallel to get double the mAh), I had to replace the XT-60 connectors on the voltage unit with XT-90's. Bit of a pain but successful as it avoids having to use adapters. Also a first is using 6-pin MPX connectors to make field assembly of the wings easier and less of a chance of screwing up what effector (servo) goes to what channel. The last things to do now are to install the wing fairings for the cowls and the engine cowls. After that, it's "weight and balance certification." Still need to test the motor/ESC for the best prop. Definitely will be using a 3 blade. The question is for the motors I have. 9-6 or 10-5. It all depends on how many amps the motor sucks up.

One last thing. I replaced those horrible 45mm plastic wing attachment screws with steel 30mm hex bolts. I 3-D printed some short serrated knobs for them and they are a lot easier to screw in with the limited hand space available.

Progress ? How or what did you do to get some cooling to the ESC's ? Found a Co. that makes connectors for just about any RC application. Very satisfied and saved me the aggravation of bad connections which I'm known for. Have all my parts now - ready to do some testing. 3 blade prop test to follow.

[Oxotnik]

I would really like to have a Ju-52. This one looks good in a lot of ways, but they omitted one of the key design details that makes the real one unique, the “double wing”, the Junkers term for the separate flap and aileron control surface that was mounted below the wing at the trailing edge.

I would be an instant buyer if it had that feature. (Would prefer the military scheme, though) The “double wing” could probably be added by me, but with the special covering, would be tough to make it match.

Good thing I have too many airplanes already...:)

I was planning to get a Nexa Lufthansa Ju, although I wanted the splinter version more. Then VQ dropped the price of their splinter camo Ju-52 and I snagged it instead. I would've preferred to have gotten one from Motion, but I really wanted the Luftwaffe version. I love mine. Three motors is just cool! :-)

[tab28682]

I would really like to have a Ju-52. This one looks good in a lot of ways, but they omitted one of the key design details that makes the real one unique, the “double wing”, the Junkers term for the separate flap and aileron control surface that was mounted below the wing at the trailing edge.

I would be an instant buyer if it had that feature. (Would prefer the military scheme, though) The “double wing” could probably be added by me, but with the special covering, would be tough to make it match.

Good thing I have too many airplanes already...:)

[Rmawer]

A little more progress on the JU-52. Proud to say, all the wiring is finally complete (and everything actually works; smoke test proved it), Bought a Admiral Rx with telemetry (my first Rx with telemetry). Because I'm using XT-90 connectors on dual 4-cell batteries (dual in parallel to get double the mAh), I had to replace the XT-60 connectors on the voltage unit with XT-90's. Bit of a pain but successful as it avoids having to use adapters. Also a first is using 6-pin MPX connectors to make field assembly of the wings easier and less of a chance of screwing up what effector (servo) goes to what channel. The last things to do now are to install the wing fairings for the cowls and the engine cowls. After that, it's "weight and balance certification." Still need to test the motor/ESC for the best prop. Definitely will be using a 3 blade. The question is for the motors I have. 9-6 or 10-5. It all depends on how many amps the motor sucks up.

One last thing. I replaced those horrible 45mm plastic wing attachment screws with steel 30mm hex bolts. I 3-D printed some short serrated knobs for them and they are a lot easier to screw in with the limited hand space available.

[Rmawer]

Just now getting the wing servos set and all the little pieces put together for linkage. Like you trying to figure out how to keep the esc's cool. Will prob cut out openings in the dummy engine insert to keep motors cool. Of course I'm missing some of those 3mm set screws for the gear material. Not looking forward to the soldering job for the 3 ESC's to 1 battery plug. By now you should have yours pretty much done and maybe maidened ?

My consultant job has been keeping me pretty busy and we are renovating our air museum in Camarillo (I'm a volunteer there 2 days a week). Over the last several weeks, very little got done on the JU52, not to mention the Twin Otter that I bought at the sane time (still waiting for aileron servos for that one). So much for my issues. Here's a simple solution for wiring the ESCs.

Get a piece of brass tubing, approx 1/2" to 5/8" long. The diameter should be just big enough to fit the stripped ends of all three ESC red leads. File a notch in the center of the tube, approx 1/3 to 1/2 way thru the diameter. This notch is where you will feed solder. Thoroughly clean the ID. Slip the three red ESC leads in one end and your single red lead that will go to the battery in the other. If you don't have a jig to hold everything, make one as there is a lot of wire and you will need a fairly high power soldering iron (I used my Weller soldering gun - 140 Watts) and things will get very warm. Heat the center and feed the solder in the notch until you see it flow at each end. Cover with heat shrink sleeving. Repeat for the black lead.

I've used this method many times and it does make a clean junction.

[airotroy]

I'd say i'm about 80% there. Got the receivers yesterday and finally got all three motors talking to each other. Bit of a challenge with these ZDT Mantis ESCs. Did exactly what the manual said to do for calibrating the throttle. No action at all. Had to do a full factory reset on each one. Once I did that, each one came to life and when I ran all three, perfect synchronization (meaning they all started and stopped at the same time). Not many new pictures; just a few of the power set-up. Using triple connectors for motor disconnects and fabricated the triple power cable complete with a Castle 10A UBEC.

I see you had the same challenge I had with the center motor. Thank the maker for magnets and needle nose pliers (and self locking nuts). Now that I have the motors installed, it's time to tackle the cowls. Have you cut out the spaces in the faux pax cylinder inserts for motor cooling? If not, the trick is use a new X Acto blade for each one. It's time consuming but since summer is here, I don't want to risk overheating the motor. I'm still wrestling with how I'm going to keep the three ESC's cool in the enclosed fuselage. Would like to have the wing ESCs in the nacelles but there just wasn't enough room.

Just now getting the wing servos set and all the little pieces put together for linkage. Like you trying to figure out how to keep the esc's cool. Will prob cut out openings in the dummy engine insert to keep motors cool. Of course I'm missing some of those 3mm set screws for the gear material. Not looking forward to the soldering job for the 3 ESC's to 1 battery plug. By now you should have yours pretty much done and maybe maidened ?

[Rmawer]

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.

I'd say i'm about 80% there. Got the receivers yesterday and finally got all three motors talking to each other. Bit of a challenge with these ZDT Mantis ESCs. Did exactly what the manual said to do for calibrating the throttle. No action at all. Had to do a full factory reset on each one. Once I did that, each one came to life and when I ran all three, perfect synchronization (meaning they all started and stopped at the same time). Not many new pictures; just a few of the power set-up. Using triple connectors for motor disconnects and fabricated the triple power cable complete with a Castle 10A UBEC.

I see you had the same challenge I had with the center motor. Thank the maker for magnets and needle nose pliers (and self locking nuts). Now that I have the motors installed, it's time to tackle the cowls. Have you cut out the spaces in the faux pax cylinder inserts for motor cooling? If not, the trick is use a new X Acto blade for each one. It's time consuming but since summer is here, I don't want to risk overheating the motor. I'm still wrestling with how I'm going to keep the three ESC's cool in the enclosed fuselage. Would like to have the wing ESCs in the nacelles but there just wasn't enough room.

[Alpha]

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

[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! :-)

[Twowingtj]

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

[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.

[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.

[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.

[JayDog]

Thanks Charlie

[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 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?

[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

[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]

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).