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

[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.

[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]

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.

[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.

[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...:)

[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! :-)

[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]

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. :-/

[Twowingtj]

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. :-/

Where and how did the motor mounts break? We've got the same motors for my wife's JU.

We're moving, so won't get it on the bench for a while. Just looking for preventive measures if any.

[Oxotnik]

Where and how did the motor mounts break? We've got the same motors for my wife's JU.

We're moving, so won't get it on the bench for a while. Just looking for preventive measures if any.

Tony,
A page or two back, I think that I posted the crash video. During flight, the right motor quit. I was okay, until I made a right bank to get into the landing pattern. She death-rolled to the right, and amazingly was caught in the loving arms of a bush at the treeline before she hit the ground. Only damage to the airframe was superficial. The right motor was dangling from the nacelle by the motor wire. The left motor was loose to the touch. When I got her home and on the bench, and pulled the motors, both of the motor mounts had broken between at stress risers near screw holes. I don't know if that happened in flight (it was only my third flight) or if the motor mounts broke during the bush recovery.

I'd balanced all three props, but with three motors running, I could hear the vibration and dissidence. I'd used Vibra-tite on the motor mount screws, but I think that the vibrations worked the screws loose. Next time, I'll use a stronger loctite, since the screws don't have much thread length.

[Twowingtj]

Oxotnik Thanks Chuck. I must have missed that video. Ouch.

[OV10]

Tony,
A page or two back,I think that I posted the crash video.No vid During flight, the right motor quit. I was okay, until I made a right bank to get into the landing pattern. Never bank a multi into the dead power side She death-rolled to the right, and amazingly was caught in the loving arms of a bush at the treeline before she hit the ground. Only damage to the airframe was superficial. The right motor was dangling from the nacelle by the motor wire. The left motor was loose to the touch. When I got her home and on the bench, and pulled the motors, both of the motor mounts had broken between at stress risers near screw holes. I don't know if that happened in flight (it was only my third flight) or if the motor mounts broke during the bush recovery. I would be pretty sure that it was the latter

I'd balanced all three props, but with three motors running, I could hear the vibration and dissidence. I'd used Vibra-tite on the motor mount screws, but I think that the vibrations worked the screws loose. Next time, I'll use a stronger loctite, since the screws don't have much thread length.

Sorry to hear Chuck that you had a momentary mental lapse during the emergency recovery. Thankfully these emergencies don't occur that frequently with multi electrics.

[Oxotnik]

Sorry to hear Chuck that you had a momentary mental lapse during the emergency recovery. Thankfully these emergencies don't occur that frequently with multi electrics.

Yep, I totally screwed up the emergency landing. During the climbout, I heard a loud SNAP and could tell that I'd lost some power. I'd banked left, to bring it down the runway for a low pass, to put eyes on the plane, and spotted the non-turning right prop. It was definitely a major screw up to do a right turn with a dead right engine. I was thinking ahead of how I was planning to get into the pattern for landing and didn't think tactically how I needed to fly the plane with a dead right engine. I was very lucky to walk away from that mental lapse with only broken motor mounts and some very superficial damage to airframe.

Here's the video. I don't think that I actually posted it. I was pretty mad at myself for mis-managing the engine-out recovery.

[Twowingtj]

Oxotnik That was one ugly spiral in there Chuck. I wonder, if you were able to add some toe in to the gear, if that might help with your take-off roll tracking?

[OV10]

Where and how did the motor mounts break? We've got the same motors for my wife's JU.

We're moving, so won't get it on the bench for a while . Just looking for preventive measures if any.

I read this statement this morning when I responded to Chuck but it just didn't click. Not out of the area I hope

[Twowingtj]

OV10 Nope, even closer to the field. Just off River Rd. Needed a bigger house for all the new birds in our future. That's when you know that you are seriously addicted. .

[Oxotnik]

Tony, Charlie, would love to catch up with you guys at a fly-in sometime. We definitely share common interests in warbirds.

[Grantham Kid]

I had a couple of planes that were squirrely on take-off. I fitted gyros to the rudder and it cured the problem.

[Oxotnik]

My Tante Ju is kinda weird. It's like she yaws one way way with the tail wheel planted, then yaws the other way when the tailwheel comes up. The rudder and tail wheel seem to be aligned pretty closely and the Mains seem to have be tracking straight. After I get new motors in her, I'll try to figure out why she's so difficult to get running straight. I like a lot of rudder throw. Maybe, I just need to dial in some more expo, to keep from over-correcting.

[OV10]

Tony, Charlie, would love to catch up with you guys at a fly-in sometime. We definitely share common interests in warbirds.

Hopefully a vaccine will get the year 2021 back into a more normal lifestyle and me and my newly retired sweetie can hit Fall Nall with the bigger Rollin Hangar/Bunkhouse, that should be an easy drive for you Chuck