Trex 500X

[ACITceva]

Originally Posted by joanpeca

I'm running my electronics at 8.4V too, but, does DS535 servo support 333Hz? According to Microbeast servo list, they just support up to 277Hz...

Originally Posted by ic-racer

I'm running Spirit FBL and on the Spirit servo list for that servo they recommend 333Hz.

Any way of knowing for sure whether 333 is a safe value on the DS535/DS535M?

I notice the Enterprise Hobby specs also show 333. https://enterprisehobby.com/faqs/servo-specs

[dj_rpr]

Wow another model, TT version of the 500X and the 470 too...

[kenstick]

I think this shows you the belt drive is a failure. I bought the XT Now I wish I bought the tt.
I wonder if you can convert to a TT.

[Relisys190]

Originally Posted by kenstick

I think this shows you the belt drive is a failure. I bought the XT Now I wish I bought the tt.
I wonder if you can convert to a TT.

Im sure you can convert.

I think they are smart for releasing both. Gives us the option. options bring them more money. Kudos to Align.

[soviet911]

Originally Posted by kenstick

I think this shows you the belt drive is a failure. I bought the XT Now I wish I bought the tt.
I wonder if you can convert to a TT.

On the 470L I find the belt design to be perfectly fine ( handles take offs in grass just fine and so far had zero skipping issues) why do you say its a failure on the 500x?. The only issue is low tail ratio which the TT does not seem to address (on the box it says that it is 3.7 for 470 and 3.8 for 500 same as the belt)

[kenstick]

Maybe not a failure. I would like the TT at the beginning. Seems like all the problems we are having is with the belt.
Or are there a lot of happy people with the belt and we don't here from them.
It would be nice to have a upgrade to speed the tail up on the belt version that would be a plus.
TT is hassle free from my experience.

[Krea]

Glad to see they are adding more options. Im sticking with the belt I love mine and tail is locked in. I suppose you could always go to 80mm tail blades if needed.

[TR450ZS]

This is great news. You read the 500X thread and its mostly about guys battling to get the belt right.

[joanpeca]

I wonder if this is the way Align says "oppps! we screwed it with the belt!"...

I'm very busy in the last days so couldn't report on what's going on with my 500X. Just an advance, is in the trash. I give my money for lost. I'll tell the detail in next days.

[ACITceva]

Originally Posted by joanpeca

I wonder if this is the way Align says "oppps! we screwed it with the belt!"...

I can't imagine they would been able to develop a TT model this quickly but maybe I'm wrong about that. Still it seems more likely that it was always part of their plan.

[soviet911]

I am rather curious, I have not read the whole 500x thread (as I do not own one) but since the belt desing of 500x and 470l are so similar, I would love if some one could list reasons the belt is not well behaved on the 500x?

On the 470L there seems only two issue, the auto-rotation hub slipping, and of course the poor tail gear ratio.
It seems that the gear ratio is not solved on the torque tube and its even likely that the hub is the same leaving two biggest problems still unsolved. (at least on the 470 L torque tube version tail ratio is same)

[joanpeca]

Originally Posted by soviet911

I am rather curious, I have not read the whole 500x thread (as I do not own one) but since the belt desing of 500x and 470l are so similar, I would love if some one could list reasons the belt is not well behaved on the 500x?

On the 470L there seems only two issue, the auto-rotation hub slipping, and of course the poor tail gear ratio.
It seems that the gear ratio is not solved on the torque tube and its even likely that the hub is the same leaving two biggest problems still unsolved. (at least on the 470 L torque tube version tail ratio is same)

The main issue in fact is the main gear case slipping. That's what spoiled my heli. In addition, I have noticed another issue that can lead to premature belt wearing and even maybe belt breaking too. I've documented this new issue with pictures, I'll try to post the details tomorrow in the afternoon if I have enough time. Sorry for the brevity, I'm at work now.

[d3relict]

actually, in my experience the issue is that the tail ratio is too low, so the tail blades need to be at a very steep angle to give enough thrust, which raises the aerodynamic resistance to a level, that the belt will slip. i tried my heli with 90mm blades, and they just held the tail fine.

anyone has experience with 80 or 85mm blades?

[soviet911]

Originally Posted by joanpeca

The main issue in fact is the main gear case slipping. That's what spoiled my heli. In addition, I have noticed another issue that can lead to premature belt wearing and even maybe belt breaking too. I've documented this new issue with pictures, I'll try to post the details tomorrow in the afternoon if I have enough time. Sorry for the brevity, I'm at work now.

Thanks. This will be an interesting read. I really doubt align will change gear case assembly just swap the pulley for a gear. Luckily my 470 did not show that issue...yet

[ic-racer]

Interesting to see the TT option. I'm keeping the belt for now and I'm happy with the way it is performing. My new belt and boom are not as tight as the original pair. My new belt actually needs the tensioners moved in some. I have it set so I can just make it skip if I force the tail blades to rotate.

That build-up of aluminum that occured on the tight belt/boom pair is not evident on this belt/boom pair.

[sprokkel]

Originally Posted by d3relict

actually, in my experience the issue is that the tail ratio is too low, so the tail blades need to be at a very steep angle to give enough thrust, which raises the aerodynamic resistance to a level, that the belt will slip. i tried my heli with 90mm blades, and they just held the tail fine.

anyone has experience with 80 or 85mm blades?

i am running 80.6 mm rail blades they hold fine in my opinion.

Cheers,
Dennis

[AllanNg]

TT or belt is optional, but that tail ratio is a serious problem. Come on Align, fix it so I can buy another 500x.

[joanpeca]

Ok guys, I have some minutes now so I can share with everyone my last experiences with the 500X.

After my disappointing maiden flight, this was the last issue I had to address:

Originally Posted by joanpeca

Another update: I have already assembled it and noticed that if I spin the main rotor by hand I can hear an intermittent metallic noise, such as metal parts gazing or something like that. After a thorough inspection I noticed that it comes from one of the belt tensor pulleys, to be exact, from the one which bolt came apart. For some reason, that pulley sometimes gets stuck and is when it spins when makes that noise. While it spins, I can feel how the main rotor spins smoother. Something's going wrong there, so I'll have to disassemble half the heli again

Well, I completely took apart the tail boom mount and I found that the pulley getting stuck had a slight up/down play. Ok, if we watch the pulley on its basement against a backlight...



... we can see that the there is a gap of some millimeter tenths between the pulley and its basement. The pulley that got stuck, since it has that slight slope, could graze its basement. That was what caused the metallic noise I could hear when the pulley managed to spun, allowing the belt to run smoothly... And when the pulley got stuck, it didn't emit any noise but it grazed the belt, holding it back so I felt more resistance when I spun by hand the main rotor.

I suppose that this could lead to abnormal and premature belt wearing, and I wonder if this may have something to do with the belt breaking that @ic-racer experienced:

Originally Posted by ic-racer

Nasty 500X crash today. It started spinning around with a long string out the tail end....
I knew right away, the belt broke.

The belt teeth looked like new. Why did it break??

On my stripdown investigation I found one of the tensioners cranked all the way in!!! I know I did not build it that way, and my suspicion is that it may have twisted in on its own. I'm using loctite when I re-build it.

Once I removed the screw that hold the pulley in its basement, I noticed that the bearings inside it had come loose (in fact they felt out of the pulley, when I pulled the screw). So I carefully poured some R48 retainer inside the pulley, placed the bearings at their right positions, let the R48 dry and voila! Issue solved. According to the manual, this part comes ready to use and no need to put retainer is stated. So we can consider it as another faulty part.

Well, I then rebuild the boom, adjusted the belt tensors (six turns of every belt tensor screw), secured the tensors screws with double-sided tape since I didn't trust they could get loose during the flight, and I went to the flying field.

I flied a first pack just hovering and doing pitch pumps just to see to it that the belt doesn't slip and everything is ok. Then a second pack, doing some loopings and rolls, tail seems to hold well. And, in the third pack, just when I began to feel a bit more confident with the helicopter, the tail suddenly blew out and began to spin so fast that before I could hit throttle hold, it did a boom strike and the helicopter disintegrated in the air.

The culprit, as you guess, once again is...

Align TREX500X Main Gear Case slipping - defective part in many kits (0 min 12 sec)

I wondered why this part get loose so easily while for example, the one way bearing which is assembled in a similar manner doesn't. I think I have figured out: the metal surfaces in contact are too small to secure their join with retainer. The one way bearing has a larger radius as well as a larger height. But this part put in contact much smaller metal surfaces. It should be secured in a mechanical way, such as a slot, for example. In fact, searching youtube, I came across this workaround from another user:

Align Trex 500x : main gear case defective ! (partie 2) (0 min 53 sec)

Regarding with my 500X, the bill of materials for the rebuild sums up to about 450€. Just the parts of the kit damaged, destroyed or lost sums about 300€ if purchased in Europe (about 200€ if purchased from the vendor in Taiwan, Helipross), and also the battery and the ESC came unusable, which sums about 150€ more. I made a detailed report of the many flaws found in this helicopter and raised a paypal dispute to the vendor, but as I expected, nor the vendor (Helipross) neither Align wanted to take any kind of responsibility. They claim that the helicopter is perfect and that everything that happened is my fault. So, I'm done with Align, I'm done with Helipross and since I consider I have wasted too much money and time with this crappy helicopter, I saved the servos and the motor which seems to be ok for future projects, and trashed the rest of the heli, giving my money for lost.

So here finishes my experience with the 500X.

[Krea]

This also got posted in main forum. https://www.helifreak.com/showthread.php?t=782664

Looks like a major issue now with so many reports. I guess I will ground mine and try and contact align for a fix.

[kenstick]

Yea. The fix is TT version. LOL.