Official Nexa 1870mm DHC-6 Twin Otter Canadian Yellow (Balsa ARF) Discussion Thread

[Rmawer]

Rmawer Thanks for sharing that tip, Rmawer! I too have had good success with Sullivan pushrods in the right places.

Do you have a target date for maiden?

If I can get my act together, and pending the condition of the field where I usually fly the bigger birds, I'm targeting the end of the month

[Twowingtj]

We've flown my wife's Twin Otter a couple of times before our move started. This is a really nice flying twin! Both motors are running CCW APC 3-blades with no real ill tendencies. Lands nice and slow too.

This is pre-Nexa, but made at the same factory. Maybe the Nature Air livery will be offered in Nexa at Motion RC.

[Alpha]

Rmawer Thanks for sharing that tip, Rmawer! I too have had good success with Sullivan pushrods in the right places.

Do you have a target date for maiden?

[Rmawer]

Never have I taken so long to complete a build. Funny thing about retirement; I've had less time to do things but at least I'm not bored.

Finally got back working on my Twin Otter. Did a first full check of all the avionics (OK - Servos). Discovered two issues with the right elevator servo (yes, I'm using dual servos).
First, I had an intermittent in the Y cable so that had to be replaced.
Second, I noticed the right servo wasn't centering so I thought the servo was going bad so I pulled it. then I tried to remove the push-rod. I was amazed with how much force I needed to pull it out. No wonder the servo wasn't centering. When I looked inside, right where the rear most window is, the push-rod tube makes approximately a 5 or 10 degree bend. The supplied 0.070" push-rod didn't like that bend and started binding in the sheath right around the rearmost window.
All wasn't lost. I replaced the steel rods (two elevators so both push-rods needed to be the same) with my trusted yellow Sullivan push-rods. Yes, I know that is not the ideal fix and a lot of builders hate them but 1) it was the simplest fix and 2) I've been using these rods for years and as long as I had them secured properly, even with gas models, they were very reliable.

[Rmawer]

Perfect! They will actually be able to "Take off, eh!"

Yes b'y

[uscanuck1xa]

I found my pilots for my Twin Otter. Being Canadian by birth and to honor our recent Space X astronauts, it only seemed fitting Bob and Doug McKenzie be my flight crew for the Twin Otter.

Perfect! They will actually be able to "Take off, eh!"

[Rmawer]

I found my pilots for my Twin Otter. Being Canadian by birth and to honor our recent Space X astronauts, it only seemed fitting Bob and Doug McKenzie be my flight crew for the Twin Otter.

[USAairlines]

I am using 2x3000mah, 4s, Turnigy Graphene. These graphenes tend to be a bit heavier and bigger than a non-graphene battery, so I would guess that both of them total more closely to about just under 7000mah. Since I had to shove one of them under the pilot's seat to balance, I would say that this plane would balance fine in the space allotted with 8000mah, 4s, maybe more.
By comparison, I've noticed that Eflite's smart batteries tend to be on the lighter, smaller size than other equivalent LiPos. I don't know how they do it, packing 100C in some of their batteries and still be smaller and lighter than anything else on the market with much less "C". And cheaper than their non-smart batteries. If you ever use one is an EDF, I'd be interested to know how they perform.

Yeah, I actually use them for my freewing AL37. They work pretty well. I am using smart ESCs for the twin otter, because I want to see battery voltage, RPM, etc.

[Twowingtj]

What battery are y’all using. I am using 2 Smart 4s 3200MAH batteries.

We are using two Turnigy Nano 4S 3000mah placed back as close to the servos as they can go. Balances perfect and flys great.

[xviper]

What battery are y’all using. I am using 2 Smart 4s 3200MAH batteries.

I am using 2x3000mah, 4s, Turnigy Graphene. These graphenes tend to be a bit heavier and bigger than a non-graphene battery, so I would guess that both of them total more closely to about just under 7000mah. Since I had to shove one of them under the pilot's seat to balance, I would say that this plane would balance fine in the space allotted with 8000mah, 4s, maybe more.
By comparison, I've noticed that Eflite's smart batteries tend to be on the lighter, smaller size than other equivalent LiPos. I don't know how they do it, packing 100C in some of their batteries and still be smaller and lighter than anything else on the market with much less "C". And cheaper than their non-smart batteries. If you ever use one is an EDF, I'd be interested to know how they perform.

[USAairlines]

What battery are y’all using. I am using 2 Smart 4s 3200MAH batteries.

[xviper]

I think these hardware kits they provide for ARF planes are fairly generic. VQ Models made several planes in their lineup and I'll bet all the hardware kits are the same for certain "class" of plane. People who build these things will use what's provided and what they already have on hand and each person will build a plane in their own way based on previous experience. When I finished mine, there were lots of left over parts. As for the wires for control rods, I cut them down and put my own Z-bend in them. The Z end went on the horn and on the servo end I put what you see in the picture. I also didn't use those spindly little tires that came with it, except for one of the mains, which I put on the nose strut. I find most ARFs to be an adventure.
PS. I'm using a reprogrammed AR636 out of an old Radian XL, with 3 gyro settings. The highest gain setting is the one I fly this TO with and it's stable as a rock. The two lower ones were experiments in caution.

[Rmawer]

Not so much a “tip” but a note: When you get to the point where you fit the wings on and you use those two thumb screws to secure the wings in place, My problem is compounded by the fact that I built a small wooden tray to set the receiver onto. This impeded my easy access to the thumb screws. I found that there was no way I could get my hands in there to turn those screws - just too tight and awkward. Before you get too far into the build, give that aspect a good look and think about a better way to do it. If you put your receiver in a different place, you may not have the same sort of problem getting those plastic thumb screws tightened, so you may not have a whole lot of head scratching to do. I used an old AS3X receiver and it needs to be level and centered to work properly.

Glad you brought up the thumbscrew issue as I had the same concern. I'm thinking about changing out those horrible injection molded screws (think they're M6 X 1.0) to plain vanilla alloy screws and adding a 3-D printed knob to increase the finger grip area. Still, getting your hand in that cramped area is going to be tough. I'll advise as to what I come up with (still thinking on this).

[Rmawer]

Evening all. I'm another one that joined the Twin Otter club. I've had my eye on this plane for several years and finally pulled out the Visa card to get it. My build is under way and made a few mods to mine in the process. First, I'm using dual elevator servos as I've never trusted the dual fork design (three set screws securing one of the most important control surfaces - on a smaller plane maybe, but not on this beast). Second, I moved the nose gear push rod to the right side. When I dry fitted the steering horn, I found where they ground the flat on the strut, the arm was just about bottomed out on the firewall resulting in very little left turn. With the move plus filing a notch in the strut mounting plate, the arm is about 30 degrees from the horizontal and swings rearward with plenty of room to turn both directions. Lastly, as a result of lessons learned, I'm using a separate servo (metal gear) for the steering (too many stripped gears in the past). The move also gave me more room to do this and still keeps the center clear for a receiver and a battery(ies).

Now, a question for those who've built theirs. In the package of hardware, in addition to the long push rods, there are three short ones with Z bends and three with clevises. Now, I see one of the shorties with the Z bend is supposed to be used with the elevator fork linkage. That leaves two Z bends and three push rods with metal clevises for the ailerons and flaps. Any idea why Nexa wants you to use two different styles of push rods for the flaps and ailerons? Personally, I plan to use Z bends at the servo and clevises at the control horns for all the wing controls (old habit). Just curious to see if I'm the only one that got this mix or if this a normal packaging set.

[USAairlines]

Not so much a “tip” but a note: When you get to the point where you fit the wings on and you use those two thumb screws to secure the wings in place, My problem is compounded by the fact that I built a small wooden tray to set the receiver onto. This impeded my easy access to the thumb screws. I found that there was no way I could get my hands in there to turn those screws - just too tight and awkward. Before you get too far into the build, give that aspect a good look and think about a better way to do it. If you put your receiver in a different place, you may not have the same sort of problem getting those plastic thumb screws tightened, so you may not have a whole lot of head scratching to do. I used an old AS3X receiver and it needs to be level and centered to work properly.

Dont worry, I have a way to get those in.😊. I am going to use the AR637t with AS3X. Shouldn’t be a problem.

[xviper]

Not so much a “tip” but a note: When you get to the point where you fit the wings on and you use those two thumb screws to secure the wings in place, My problem is compounded by the fact that I built a small wooden tray to set the receiver onto. This impeded my easy access to the thumb screws. I found that there was no way I could get my hands in there to turn those screws - just too tight and awkward. Before you get too far into the build, give that aspect a good look and think about a better way to do it. If you put your receiver in a different place, you may not have the same sort of problem getting those plastic thumb screws tightened, so you may not have a whole lot of head scratching to do. I used an old AS3X receiver and it needs to be level and centered to work properly.

[USAairlines]

This plane is beautiful. I am currently working on it, but does anyone have any tips on building?

[Twowingtj]

Maidened, plus two, my wife's Twin Otter yesterday. These are excellent flying planes. No take off flaps needed. With full flaps and about 1/4 throttle it comes in on a nice glide path with no elevator mix needed.

With the Nexa Twin Otter being the same airframe from the same factory, and at a better price point, it's a lot of fun for the $.

d.

,

[KC Air]

Anyone planning on running 4s 4000 batteries in this plane? Looks like the Admiral motors and the ZTW Mantis will support it.

I will maiden with 3S, then decide if I want to try 4S. I just tried to buy the recommended motors and esc's for this plane and neither are in stock at Motion. That is a little stinky.. new plane for sale, no electronics for it.

[xviper]

Stupid question time, or more appropriately question from a stupid person time.. switching the wires on one motor will make them counter-rotating, true?

Switching any 2 wires of the 3 will reverse the motor rotation.