NX4 build

[ultrataco]

Originally Posted by jiminator

Make sure to put a filter into the fuel line from the tank to the carb. Align makes a nice 3 way filter which functions as a fueling port and a line clamp. If you aren't using some sort of glow plug ignitor try using one of these.

http://grandrc.com/Nitro-Accessories...duct_info.html

align filter:

http://www.aligntrexstore.com/3-Way-...22-_p_445.html

On second thought that Align filter is pretty long and might not work well. EDIT I just checked my heli and that Align filter will work fine.

Thanks. I've already ordered a switchglo pro (on it's way now). I assume that 3-way filter is for use with a header tank. I may get the 2-way version unless I can find a header tank. (edit: never mind, I see the 3rd end is for fueling up.) I see everybody uses a header tank but I can't find one in stock. The only one I know about is that rjx one.

would this work?
https://www.amainhobbies.com/dubro-2...-dub402/p29329

[D22597]

Not easily. Something like this would be best. http://www.rjxhobby.com/rjx-up013a-s

As an alternative, one of these in your main tank would reduce the need/benefit of a header tank. I run both, but it's likely overkill.

https://www.amainhobbies.com/lynx-he...yx1832/p519312

[jbobb1]

I run both as well, but my header tank has the red holder.

[ultrataco]

Originally Posted by D22597

Not easily. Something like this would be best. http://www.rjxhobby.com/rjx-up013a-s

As an alternative, one of these in your main tank would reduce the need/benefit of a header tank. I run both, but it's likely overkill.

https://www.amainhobbies.com/lynx-he...yx1832/p519312

yeah I almost ordered that tank but shipping from rjx is $20. I'll wait for somebody else to stock it or just do without.

jbobb is sending me a moas, but before I knew that I ordered the OS bubbleless clunk, which was probably a mistake. too late to cancel it now. Not sure if I'll return it or hang on to it. I also ordered an Align 3-way filter, some fuel tubing, and fuel tube plugs.

So I've got lots of little bits and pieces coming to me this week.

[ultrataco]

Should the head spin freely in either direction? The clutch is catching in both directions and there seems to be resistance in the one way.

Also the starter shaft. It turns smoothly but won't spin.

[Raleighcopter]

Originally Posted by ultrataco

Thanks. I've already ordered a switchglo pro (on it's way now). I assume that 3-way filter is for use with a header tank. I may get the 2-way version unless I can find a header tank. (edit: never mind, I see the 3rd end is for fueling up.) I see everybody uses a header tank but I can't find one in stock. The only one I know about is that rjx one.

would this work?
https://www.amainhobbies.com/dubro-2...-dub402/p29329

I use that for my header. Zip tie it on and glue it with e6000 (I think) and it works fine.

[D22597]

Looks like this one is available and a little cheaper than the RJX.

http://www.heli-world.com/century-2o...o-cn2137a.html

[ultrataco]

I've been busy this week so haven't had much time to work on the build. But now it's the weekend and I should make some good progress.

All I've done since my last build update was installed pitch links and tail servo:








Yesterday I received some stuff: Lynx nipple and MOAS from jbobb1 (thanks ), red dampers which I didn't need because a pair came in the kit (you can see them in the background with the white skid bumper things), extra clutch liners (because... ) and fuel line, which I don't need (I think it was supposed to be for clunk line).




Just got this in the mail today.

[ultrataco]

Well I was hoping to get more done tonight but I had some issues with the throttle setup. Long story short, I'll have to wait until the new pipe comes in before I can really figure out what sort of clearance I have and how things are going to fit together and line up.

I broke 2 links and roughed up a third (it's ok) because it turned out the throttle pushrod was a longer than I needed. I thought they were just tight, but actually I was tightening the links farther then they could go on the rod. Once I realized this, I cut the pushrod and then it was ok. The manual says 56.2mm link-to-link, but I had to go to about 54.5mm to get the arms parallel.

The screw I had for the engine throttle arm is shorter than I was comfortable with. (see pic below) Fortunately I found a longer screw that fit. (from another kit). Also, an arm would hit the fan shroud at low or high throttle, so I cut one off. I'll likely have to cut off another one or two later. The ball was too tight so I switched it with an extra ball in the kit. I'm not sure yet if it should go on the inside or outside. I'll have to wait for the pipe.

The short screw. also, I think I'm missing a grip washer that goes here, judging by the marks.



I had to cut this screw so it would clear the servo:

[2slow2g]

http://www.anythingheli.com/search.p...r+tank&x=0&y=0

[ultrataco]

Originally Posted by 2slow2g

http://www.anythingheli.com/search.p...r+tank&x=0&y=0

thanks. looks like it's back in stock now. I ordered one.

[ultrataco]

Just got the mail.

various fuel line plugs because I wasn't sure which would work best.
Align 3-way fuel filter.
Some tubing and an overpriced clunk, neither of which I need now. I guess I'll put them to use in the header tank.

[ultrataco]

How about an actual build update.

I didn't have as much time as I hoped today, but I made good progress.

I mostly improved the one-way/main gear issue. I loosened the main shaft collar and bolt at the bottom of the main shaft and fiddled with those. I re-tightened the collar without pulling up so hard on the head this time. It's not quite free-spinning, but it's much much better than before. I think it will be fine.

A lot of the tail parts are pre-assembled so it went pretty quick.
















And we have a helicopter... mostly



I think I'm going to install 2 of those white skid bumpers near the back of the skids to try to raise the tail a little.

I like the narrow frame. It seems like it will be easy to access stuff.




Tomorrow I plan to do the electronics and wiring and maybe some of the fbl setup.

[billy bob]

I'm lovin watchin ya build.
Building one myself at the moment.
You missed the little red washers on the tail fin.
I'll be interested to see how you mount the header tank.

[ultrataco]

Originally Posted by billy bob

I'm lovin watchin ya build.
Building one myself at the moment.
You missed the little red washers on the tail fin.
I'll be interested to see how you mount the header tank.

Thanks. and oops you're right, I will install those when I get home.


I actually did all the wiring yesterday, but by the time I finished it was late and I didn't feel like taking a bunch of pics and posting. I will do that this evening. I think it turned out well.

The new pipe and main tank are scheduled to arrive today . I should have time to install them and hopefully get the throttle set up so it doesn't bump or rub anywhere.

[ultrataco]

Well apparently Gaui requires a signature for everything and I wasn't home to sign for it, so I'll have to wait till tomorrow for the pipe and tank.

Anyway, here are some pics of the wiring. I used lots of zip-ties, heat-shrink, rubber edge-protector (from Mikado), super glue, some 3m tape (4011), electrical tape, and even a bit of duct tape. Maybe a bit overkill in places, but I don't think I'll have to worry about any wires getting cut.






It's difficult to get to the usb port on the back of the ikon and I had an extra msh usb thing, so I stuck that on the front (next to the switchglo).










This is where the battery plugs in. It's a servo extension running up to the ikon.




I thought I was going to have to go to a hardware store to find a way to mount the align rpm sensor, but I ended up using a couple spare lower main shaft bolts for a 450x and some left over servo arm ball spacers from the NX4 kit. (I haven't tested it yet so it may need adjusting.)




I cut a bit from the canopy so one of the spektrum sats coud stick out where I wanted it. It's not pretty, but I didn't want to bend the antenna too much.








The canopy is a very tight fit, but I guess that's ok. The throttle servo ball rubs so I'll have to re-think my setup there.

[Ramflames]

Like how you tiddy up all the wiring.

[ultrataco]

Originally Posted by Ramflames

Like how you tiddy up all the wiring.

Thanks. I don't want wires flopping around.

[bgymr]

Thanks for the build thread. It has pushed me to fix my Nx4s.

A few comments:
-don't set your throttle linkage up until you put the pipe on. You will have to modify it to fit the pipe. At least I did.
-Nice wiring job, just the shrink tubing makes it look more messy than it is. What i used is the red Gaui Velcro straps. I cut them into 1cm strips and fold them over, then zip tie them down. Plus the red goes well with the heli. It's just a preference thing.
-I'd keep an eye on that plastic fan. I upgraded both of mine to the red Gaui one, and i balance them. Really helped the heli be smoooof. The trex 600n one is identical and interchangeable as well. If you can find a lynx one made for the 600n they are nice too.

Can't wait to hear about your maiden.
Looks great, and awesome pictures.

[ultrataco]

Originally Posted by bgymr

Thanks for the build thread. It has pushed me to fix my Nx4s.

A few comments:
-don't set your throttle linkage up until you put the pipe on. You will have to modify it to fit the pipe. At least I did.
-Nice wiring job, just the shrink tubing makes it look more messy than it is. What i used is the red Gaui Velcro straps. I cut them into 1cm strips and fold them over, then zip tie them down. Plus the red goes well with the heli. It's just a preference thing.
-I'd keep an eye on that plastic fan. I upgraded both of mine to the red Gaui one, and i balance them. Really helped the heli be smoooof. The trex 600n one is identical and interchangeable as well. If you can find a lynx one made for the 600n they are nice too.

Can't wait to hear about your maiden.
Looks great, and awesome pictures.

thanks

yeah the throttle is not set up yet. It definitely won't work as it is now.

I did not think about cutting the velcro strips. that's a good idea.

What is the benefit of a metal fan? It's a lot more expensive than the plastic one. How do you attach the magnets to the metal? green loctite?