Video Tutorial-Building the EXI 450 Squadron (Trex450 Clone)

[Merlin]

Thanks for the reply. I wasnt aware that the heli needed to be unpluged to make these adjustments. Is that the case even if you make the adjustments at the tx?.

[Nuttcaze]

yeah

[Merlin]

As it turns out, the guides for the rudder servo push rod were causing a slight bind, and ultimately the erratic tail. I removed the guides, and it hovers rock steady.

[Nuttcaze]

oh, yeah, I had that same problem, but mine was simply because I forgot to make sure they are tight, just need to slide the tip of a zip tie under the guide rings and trim off the excess

[akent]

I don't know if this is the best place for newbee setup questions or not, but here goes.
I have a few!

I just finished everything on the Squadron. This thing is a BEAST! This is my first CP (other than a .60 sized nitro 20 years ago -edit: that I never could fly). I have everything balanced and tracking, and I'm surprised at how smooth it is.

Anyway on to the questions:
1. What is normally the best setting for the Esky gyro? I have the gyro switch set to 0=60% 1=85% in gyro mode. The gyro itself has all settings maxed. Sorry if you went over it in the videos. I may have missed something, but I watched them maybe 20 times!
2. What is a good headspeed for these plastic grips and wood blades in normal mode? This one hits about 2500 rpm when it comes up off the ground. I haven't tried idle up yet. Edit: I have a tach from my planes that I set on the ground under it.
3. What is the max headspeed for these heads? With wooden blades? With CF blades?
4. What does the timing function in the ESC do? I have mine set to 'normal' like in your video.

Oh, and this is the Xheli deal with the B parts, like what you used in the vids. I am also using a DX6i and AR6200.

One comment: I was a bit flabbergasted when I figured out that in order to setup the ESC with the transmitter, you must have a motor attached! I am REALLY nervous turning everything on with FULL THROTTLE!!! I thought it was bad at first.

Is this exciting or what! I can't wait to get better on the HB so I can actually fly this monster around!
Thanks,
Kent

[Nuttcaze]

1 - you're prob going to want to turn your gain for rate mode down, it should be under 50%, but best setting are acheived by lots of testing and ends up with personal preference, I still don't have mine fully adjusted but thats just becasue it doesn't matter to me if the tail is slightly loose, I'll still fly it the same 

2 - Not sure about the headspeed, I don't have a tach yet

3 - Not sure, but I'd at least upgrade the grips and blades. Those would be the first and prob only things that need upgrading, besides adding more *Bling-Bling* - aka CNC parts 

4 - Because not all brushless motors are the same, the timing gives you more options for adding motors, not sure what the real function is, but if its not set right the motor won't run right.

One comment: I was a bit flabbergasted when I figured out that in order to setup the ESC with the transmitter, you must have a motor attached! I am REALLY nervous turning everything on with FULL THROTTLE!!! I thought it was bad at first.

You're not using a program card      I've never set up an ESC with out one, I tried to figure out how to do it through the transmitter but it was too hard for me to understand. Now I'm really glad I have the program card. With it you don't need the motor plugged in, much safer. 

[Prell]

I was a bit flabbergasted when I figured out that in order to setup the ESC with the transmitter, you must have a motor attached! I am REALLY nervous turning everything on with FULL THROTTLE!!! I thought it was bad at first.

If your worried about programing with the motor connected, remove the pinion

[akent]

Thanks for the info, Nuttcaze.
The plastic blade holders do make me nervous. I did also order some CF blades. I'll order a CNC blade holder set, too.

With the gyro gain set to 50%, the gyro doesn't seem to want to lock. It doesn't do anything. At 55% it will lock. I'll play around with the settings.

Prell, when I learned that about setting up the ESC, I just backed the motor away from the gear. This is an outrunner, so setting the ESC on the bench might be a bad idea...
Kent

[akent]

Tail problems now.
When I went out today, and hit the idle mode switch, the tail went nuts with a vibration and sent the center tail holding screw away and the whole tail sitting at a 45 degree angle to the ground.

I saw that screw missing in your vids, Nuttcase.

Did you all of a sudden hear a bzzzt with the tail and then that screw flew away and the tail was sitting at a 45 degree angle?

Is this a problem with the tail belt tension? I adjusted mine according to the Trex manual. But that is rather vague.

Any insight?
Thanks,
Kent

[Nuttcaze]

lol  , sorry to hear about the tail problem but I fought with that on mine for a while, it would always go 45 while I was in flight, had a few very interesting landing because of it. But now that I have the CNC tail (and I sanded the ends of my boom) my tail hold fine, no rotating.

[akent]

That's really interesting that it happened to you too!!!

I've been playing with this all day.
What I found out:
The tail blades were balanced fine.
I took off all of the blades and flybar and spun her up to over 3,000 rpm and no vibration. I put the tail rotors back on and there it was. I swapped the blades and same. You can see the tail shaft start to go invisible from the vibration.

The bad vibration seems to start at over 2400 rpm headspeed. This equates to almost 10,000 rpm on the tail.
I even added pieces of tape to the tail blades one at a time to see if something else might be out of balance, and nothing made it better here.
What helped was to remove the idler pulley in the tail for the belt. This tamed it some, but not enough. I saw this as common practice on a Trex site. Seems that the idler puts the belt closer together and if there is vibration it can make the belt hit in the middle of the boom. I think that was the 'brrrt' sound I heard before. It doesn't do that any more.

I really think that the top headspeed possible with these plastic tail parts is 2200 rpm or so. The plastic just gives too much in the tail.
I kept it there and it is so far ok. At least it doesn't come apart! Oh, and I sanded the boom, too. That helps a lot with things moving.

Once I get the throttle and pitch curves figured out, I'll post them here. Those need to be toned down.

By the way, with your curves as in the video, you must be at 3,000+ rpm. That's what this one turns at zero pitch in idle up. I hope noone uses that with the stock Squadron.

I also ordered a CNC head and tail now!
Kent

[Nuttcaze]

my throttle curves are just starting points for others, but I still have mine set like that  , I don't get overly in depth with perfect set-up on my helis, I can't remember the last time I actually checked my CG on any of my helis, its really all the same to me, I just get them flight ready and fly the heck out of them. Its more fun that way, its also how I got over my fear of crashing (which is the biggest reasons people have problems, they're afraid to crash and crash because of it  )

[akent]

I have been playing with rpm and throttle/pitch settings.

On this heli with the 'B' parts package, 60% on the throttle with 0 pitch is about 2500 rpm headspeed. This is about the max the stock tail can handle, at least on mine.

I even took the new tail from another kit (yes, I bought two when they were on sale) and it behaves exactly the same. It starts the major vibration at between 2800 and 3000 rpm headspeed. I was wrong in my last post with the RPM's. I wrote them down today...

If anyone sees this problem like Nuttcaze and I have, it might be prudent to set the rpms at 55-60% with 0 pitch. On a Trex forum, I saw where most with plastic parts were running between 2100 and 2500 headspeed, so this is on the higher end for the plastic tail.

BTW, this heli hovers beautifully! It's actually easier to hover than the HB, and a little wind doesn't bother it much at all! But man oh man if you touch the throttle it is a ROCKET!

BTW, I stopped by yesterday at the LHS where they sell the Trex. The $200 Trex 450 has more plastic parts than the EXI! I like the EXI better!

I love it!
Kent

[Nuttcaze]

BTW, this heli hovers beautifully! It's actually easier to hover than the HB, and a little wind doesn't bother it much at all! But man oh man if you touch the throttle it is a ROCKET!

thats always my point when I tell people to start on the HBFP, if you can hover it then go to a bigger CP, it will be much easier as the bigger helis are easier to fly, it just takes some time to get used to the heli. I also used to fly my HBFP before flying anything else, gets the fingers working before taking out something more expensive 

[akent]

I figured out the vibration issues with the tail!

After upgrading to a CNC tail, it seemed smooth for a while, but I guess after things loosened up a little, the vibration started to come back at high rpm. Of course, the CNC tail isn't going to twist!

I went through everything, and then went and bought some Align plastic tail blades for the SE V2. The problem is now GONE!

When changing the tail blades, I noticed that one Exi blade was marked 'A' and one 'B'. All of the Align blades that I bought were marked 'C'. These markings are for different weights I found out.

Just for fun, I reinstalled the original plastic tail and it's smooth too!!!!

So, if anyone has a bad tail vibration, just get some Align tail blades!!!
Worked for me!
Kent