EXI T450 FES

[9sec240]

As you might know, I removed the GU365 from my 200 FES and converted it to flybarred. I couldn't be happier. I have many flights on it now and really need some more powerful batteries to keep up with what I throw at it. Anyway........

So I have this GU365 laying around and I am kind of disappointed that I never really got to play with it. I did some searching around a while back and found a used Gaui 400 / 450 flybarless head for cheap and scooped it up. The last thing I needed to complete this project was a suitable heli to install it on. I took a look at my 450s and just could not see me doing the conversion on any of them. I decided to pick up a new heli and after looking around at clones, I decided on an EXI T450 Carbon Edition. I have an EXI head and tail combo on my Trex 450S and I really like it.

The helicopter arrived today and I am very pleased with what I got. I will keep you updated on the progress of the build and how things turn out.

Attachments:

[dunkonu23]

Cool. Thanks for sharing, Ivan. I don't know if you've ever talked with "Noobflyer01" over on RCU, but he's got an EXI as well. Good luck and we'll be watching! LOL!

Scott

[9sec240]

Step 1. Remove flybarred head and replace with flybarless head.

I think head looks at home on the EXI. The colors even jive.

Attachments:

[Jerrymac]

That's interesting. There are a lot of EXI owners over at RCU , but, I don't think any of them have converted theirs to flybarless.

And besides, you REALLY DO need another 450 sized heli. ;D

[9sec240]

UPDATE... I worked on the EXI T450 FES yesterday and have it nearly complete. I disassembled the frame to make servo install much easier and so I could check for loctite. The EXI is metal EVERYTHING so loctite is very important. I decided on Hyperion DS11-SCB servos on cyclic and a Hyperion DS09-GMD on the tail. I was going to use a Tower Pro 2415-6T 4400kv motor but the bolt pattern did not jive with the motor mount so I ended up installing an Align 430X motor instead. I used a Tower Pro TP H40A ESC and AR 6110e RX to complete the electronics. After setting up the head for +/- 11° collective and 8° cyclic using the RX only, I installed the GU365 and initialized it. I used the dip switches to set cyclic compensation to the correct direction and then worked on setting up the tail. Limits are set using a pot on the gyro and compensation direction using a dip switch.

I have a bit more work to do on it but I should be able to maiden it today.

Attachments:

[dunkonu23]

Very cool, Ivan. I'm anxious to know how the Gaui FES works out on this helicopter and how it compares to other FBL systems. I have to admit after reading so much about FBL it's intriguing. Good job, sir!

Scott

[9sec240]

Well I got her done... I have been working on dialing it in. I started with a pretty low throttle curve to begin with. 0-75-80 with an 11T pinion on a 3550kv motor is pretty slow. With the slow head speed and the swash mix turned down to 50% (25 on AIL and 29 on ELE) cyclic was very slow. The heli wobbled a bit so I started turning the gain down on the tail. The tail adjustments did not make much difference to the wobble and I was not comfortable with the way it was flying enough to do any punchouts so I figured I would turn down AIL and ELE gain on the gyro. It got a bit better but still had a bit of wobble. Turned it down more and it settled down to an acceptable level but the tail was a bit sloppy. I did a few take offs and landings and felt comfortable enough to make some more adjustments. First thing was cyclic response.... it was really slow and kind of hard to fly. I turned up the swash mix up 10% to 30 on AIL and 35 on ELE and it felt much better. I did a couple of punchouts and it did not have much pop. I turned the head speed up to 0-85-90 and it felt better at that head speed. The tail was kicking out a bit but there was no wag so I turned the tail gain up a bit and added more head speed by turning up the the curve to 0-95-100. The tail started to react better with the increase in speed so I dialed in the tail gain.

At this point, I have one battery through it and it is flying OK but it is a bit uncomfortable still. The tail is OK but not acceptable at this point. It wanders and wags a bit and just does not feel locked. I may change the tail servo to see if it helps. I need weight towards the rear so I may try a 9257 to see if that helps. It does not have the cyclic stability I am used to with a flybarred heli yet. It is somewhat windy today which might be part of the issue but it just does not feel stable enough to even do a piro yet. I am not 100% sure but it seems to have a drift to it. I am going to work on dialing it in a bit more on the next battery. I might put a 12T pinion on and see if the added head speed helps.


A bit later today...........


Tried the 12T pinion and it was not happy. Initially it had a constant cyclic chatter and as I dropped the gains, it became more of a cyclic wag. I had ELE gain nearly turned all the way down and started experimenting with dropping the throttle curve from 0-95-100 all the way down to 0-75-80 and could not get rid of the cyclic wag. I went back to the 11T pinion.

Cyclic is not as stable as I would like. I have to constantly be on the sticks making corrections. It pulls slightly in random directions. I am not sure if the servos are not centering well or if it is the gyro doing this.

I played with the tail servo ball position and got the tail feeling a bit better but still not ideal. It has a bit of a hunt but holds decent in punchouts. Piro rates are disproportionate probably due to me doing a centered slider setup. I suppose I could do a rate mode setup and see how if that helps. Right now I have RUD end points set to 100% right and 90% left with 15% expo and it is a bit better. Piro attempts end up with a bunch of cyclic movement. A single piro is enough to get out of whack... I doubt I could do two in a row.

I got one more flight in for pictures and a bit of video and I am not too sure about this thing. I really need to get it out in an open area and see how it flies.

Attachments:

[dunkonu23]

You'll get it Ivan! You're the pilot who can make this work. I know it. The progress you've made so far with it is astounding. It looks like it flies really well--I know from RCU you wrote it was hard to fly, but it didn't look that way at all!

Scott

[Jerrymac]

Sorry I can't be of much help as I really don't have any experience with flybarless, but I am sure you will get it dialed in.

Other than the unstable piros it looked as though it flew ok considering the confined area.