250 heli build help - copterx 250

[bazsound]

Ive been flying micros for a little bit now and wanted something i could see a little bit easier.


I know a 450 would have been much better and copterx is just asking for trouble (ive read alot of problems people have with these helis)

The copter was bought as a kit without electronics, it came part built so i removed every screw 1 at a time and applied loctite (there was very few screws that were actually loctited)

The tail belt puller was notchy out of the box but smoothed out once under turned a little (this will be getting replaced with the align partr including housing)

Well i finished puitting the electronics in yesterday and today have been trying to get it setup...

Im using the stock copterx parts for now to get it going and then upgrading as i go, i already have align feathering shafts and tail belts ready to fit. the servos will get replaced also (i have use for the copterx ones for another plane build)

the problem im having is that just before lift off it was wobbling pretty bad, i had managed to lift it off a few inches of the ground but it wobbled bad.

I adjusted the copterx gyro gains until i found it was no longer wobblying bad but the tail just wants to spin now which is wierd because it wasnt doing it baddly;

Now once it spools up so far it wobbles and the tail lets go, spinning uncontrollable.

getting frustrated i went through the gyro, maybe something is reversed, looking at another guide on how to setup the direction of your tail, it said to fold one blade up and check its direction, it should follow the stick, which m ine didnt, ok reverse it in gyro.

Now heli turns opposite it should, ok reverse channel on tx.

still didnt help......

then the heli suddenly flipped over. boke the feathering shaft (luckilly i have 2 spare) lost 2 links and a bearing.

Now heres my gripe with align parts, that every part i have looked at doesnt tell you what the part is for, just the part number etc. so what bearings do i need for the blade grips? therse like 6 different size of bearings.

what about links? what size of links, is it so hard to say , these are for servo to swash, these are for swash to blade grips, these are main blade bearings, these are tail blade bearings.

So, i need new blades (1 got bent) new bearings for main blade grips and links.


somethings terribly wrong in teh setup somewhere and i cant figure out where.

I even moved the gyro from the not so sturdy gyro plate (which has some play in it) to the side which is solid.

the guro is set for 120 degree CCPM swash, servo directions have been set, all servos go up with positive collective pitch and vice versa. Swash plate tilts in correct direction according to stick movements. tail before reversing it would push heli in right direction 9just not hold as heli would suddenly 180 just before lift off)


I fly a v977 micro heli, so obviously this is quite a bit different being much more powerfull. i can comfartbly fly hover in all orientations, do flips and rolls, do brief periods of inverted hovers etc so its not like im complelty new to flying CP so id expect to atleast get it light on its skids.

The best i got was a brief few inches by popping it off the ground and it death wobbled, after that i havnt dared because the tail just death piros..


HELP...

I need some detailed setup guide.

and also waht parts i need (align ofcoarse) to get back up, mainly the bearings and links, i know what main blades i need.

oh i have the USB programming cable coming, as im sure it really needs the most recent firmware which cures the over sensitivity to vibration and allow programming via USB but im assuming this isnt my problem since i cant even get it off the ground.


Edit:

Just did some testing without the blades on to see what the tail does.

Doesnt seem to be any excessive vibration, though the tail fin is fibrating back and forth quickly (seen this when the blades were on aswell)

once spun up to full speed, fine (obviously no blades to produce toorque for it to counteract)

rudder inputs work as espected though very sensitive .

there was no reaction to me rotating the heli, adjusted the rudder pot on the gyro, now it started to reac, the more i turn up the more it resists me trying to rotate the heli.

im confused about the gyro, i have gyro control on my TX i know it switches it between normal and ACVS so what about the pot on the gyro? does that limit how much you can have ?

Edit 2:

Found the manual for the FBL version of the trex 250.

then found align UK website which ctually tells you what each part is.

so i have the bearings, plus main blades, dampers and links coming.

care to place bets on how many original parts will remain once this gets in the air? shame really as i have come across people who have had great success with it all stock and only had something fail after many flights.

[Toocool4]

Best advice stop throwing good money after bad, just go out and get the real thing.

[bazsound]

Originally Posted by Toocool4

Best advice stop throwing good money after bad, just go out and get the real thing.

i agree probably would have been better getting the align kit. But i have the kit so might aswell solder on and get it in the air. Im in no hurry to have it flying At worst it will end up with being mostly align with the copterx motor and esc.

The servos i never planned to keep in it.

The gyro is questionable, but ill update the firmware when i get the programming cable. i may open it up and put dampening on the board . The cable will help set it up aswell. I will end up replacing it with something better, i was trying to find a futaba gy401 gyro

I think it was partially my fault for not atleast replacing the copterx feathering shaft with the align feathering shaft which i already had as i knew they were a concern (with people having them shear in flight, not let go but actually break)

And i should have checked the blade balance aswell.

I just compared the copterx feathering shaft spacers to the align ones, copterx spacer is 1-2mm thick, align is 0.2mm thick.

[yakky]

Originally Posted by Toocool4

Best advice stop throwing good money after bad, just go out and get the real thing.

Huh? He would have crashed that too.

OP, sounds like you need to take a bit of a chill. Your ambitiousness has made you crash. If things don't seem right, don't try to fly the thing, things are not going to magically get better once it lifts off.

Don't blame the kit, the CopterX is a solid kit, but you do need to take care assembling it. Really the first issue that caused the crash seems like unbalanced blades and vibes. The tail is likely letting go because of extreme vibration. The problem with the copterx FBL is no vibration logging. You'll want to make sure the rotor button hole on your head looks crisp when the blades are up to speed, if there is even a hint of blur, you have vibes. Debugging tail vibes on the 250 (real and clones) should probably have its own forum, lol.

[bazsound]

Originally Posted by yakky

Huh? He would have crashed that too.

OP, sounds like you need to take a bit of a chill. Your ambitiousness has made you crash. If things don't seem right, don't try to fly the thing, things are not going to magically get better once it lifts off.

Don't blame the kit, the CopterX is a solid kit, but you do need to take care assembling it. Really the first issue that caused the crash seems like unbalanced blades and vibes. The tail is likely letting go because of extreme vibration. The problem with the copterx FBL is no vibration logging. You'll want to make sure the rotor button hole on your head looks crisp when the blades are up to speed, if there is even a hint of blur, you have vibes. Debugging tail vibes on the 250 (real and clones) should probably have its own forum, lol.

i wouldnt have called it a crash, more like a tip over. which i now know was caused by vibration, which wasnt showing up until the rotor was at the right speed.

I dont doubt the kits are decent for the money. There wasnt much to assemble since it was already part build, the frame was already together with bearing blocks etc fited, it was litterly just sliding in the main shaft, tail assembly and main gear to complete.

I did loctite every screw before putting electrnonics in.

Blades were not balanced, really should have done that (that itself may have been a big problem).

I had issues with the washout arms, which were fine and free, but when i removed the screws and loctited them, were stiff until i backed the screw out a touch (and it wasnt overtightened) like there was meant to be a washer there. I removed them and checked for loctite on the bearings but bearings were spotless.

Also had issue with the tail belt pulley being a tad notchy until i ran it under load by hand for a minute.

2 of the screws were stripped out of the box.

But im definatly right in thinking that in good working order, it should spool up and get light on the skids without starting to death wobble or suddenly start pioeing.

Ill update the thread next week once ive got the new parts and fitted them plus balanced the blades. Im also going to fit an extra spacer between the main gear and bottom bearing block, i had an issue that if the colar was too tight it would grind against the bearing block (also main gear doesnt quite line up 100% with the tail gear)

To be honest ill probably replace the tail belt pulley and housing to align aswell as i just dont like how it came slightly notchy (like a brushless motor)


The good thing is ill learn quickly how to work out whats wrong and know how to fix it. might take me longer to get in the air, but once its in the air ill be really carefull flying it and practice at the right pace. I spent all this time getting it flying im not going to go beyond my abilitys. ( 250 may look small but they are still dangerous!)

[yakky]

Originally Posted by bazsound

i wouldnt have called it a crash, more like a tip over. which i now know was caused by vibration, which wasnt showing up until the rotor was at the right speed.

I dont doubt the kits are decent for the money. There wasnt much to assemble since it was already part build, the frame was already together with bearing blocks etc fited, it was litterly just sliding in the main shaft, tail assembly and main gear to complete.

I did loctite every screw before putting electrnonics in.

Blades were not balanced, really should have done that (that itself may have been a big problem).

I had issues with the washout arms, which were fine and free, but when i removed the screws and loctited them, were stiff until i backed the screw out a touch (and it wasnt overtightened) like there was meant to be a washer there. I removed them and checked for loctite on the bearings but bearings were spotless.

Also had issue with the tail belt pulley being a tad notchy until i ran it under load by hand for a minute.

2 of the screws were stripped out of the box.

But im definatly right in thinking that in good working order, it should spool up and get light on the skids without starting to death wobble or suddenly start pioeing.

Ill update the thread next week once ive got the new parts and fitted them plus balanced the blades. Im also going to fit an extra spacer between the main gear and bottom bearing block, i had an issue that if the colar was too tight it would grind against the bearing block (also main gear doesnt quite line up 100% with the tail gear)

To be honest ill probably replace the tail belt pulley and housing to align aswell as i just dont like how it came slightly notchy (like a brushless motor)


The good thing is ill learn quickly how to work out whats wrong and know how to fix it. might take me longer to get in the air, but once its in the air ill be really carefull flying it and practice at the right pace. I spent all this time getting it flying im not going to go beyond my abilitys. ( 250 may look small but they are still dangerous!)

Yeah, a 250 will teach you more about heli mechanics than any other size. Sounds like you know where to fix things. I'd think about picking up an FBL that has vibe analysis, your next vibe related "incident" is going to hurt that much more.

[Toocool4]

Originally Posted by yakky

Huh? He would have crashed that too.

I am sure he would have crashed some time down the line. Everybody crashes at some point, due to mistakes or equipment faults.

With regard to the kit, buy cheap, buy twice. Still each to his / her own.

[yakky]

Originally Posted by Toocool4

I am sure he would have crashed some time down the line. Everybody crashes at some point, due to mistakes or equipment faults.

With regard to the kit, buy cheap, buy twice. Still each to his / her own.

I believe the issue here is vibes, even the genuine Align 250 is plagued with vibes. The OP didn't do the wrong thing by buying the CopterX, he simply shouldn't have taken off if he had vibes. I'll concede the Align CF blades are well balanced, but if he bought one of the sports that come with plastic blades, he would have likely had the same issues. In reality, I have not purchased a single kit that didn't need some sort of fiddling with, even the famed Oxy 3. I also have several genuine Align 250s that people sold dirt cheap because they were fed up with issues. I happen to own a couple of CopterXs as well. None of them is perfect out of the box.

[nflanagin]

If he's discussing a gy401 and AVCS mode - this must be a flybarred heli. Therefore, the head problems were all mechanical setup and balancing.

[bazsound]

the gyro is the cx-3x2000.

which now after reading 88 pages over on rcgroups has been plagued with problems and very ffew peoople have actually gotten trouble free light from, soom fly but is unpredictable andmost justunflyable.

you need the usb cabe as there is settings you dont have acces without, lus you need the most recent firrmware,


after updating the firmware the gyro was way less sensitive to vibration, before theh update, simply taping the gyro or eve hgelo frame would cause servos too twitch, cantt get servos to twitch even with tapping gyro hard.

my copter x is the FBL version, itss labels copterx 250se which the equivelent trex is flabarred, but this has the fbl head.


yes i will crash, im still very much a novice and make mistakes, i have my micro that i can make mistakes that are very forgiving. the 250 is not.

ive just fitted the new align feathering shaft. despite the thinner spacers?waashers it fits perfect and is smooth as butter, i also fitted the align beareigsaswewll whwich probably helped.

the links i ordered are the wrong size, made the mistake of nott seeing the fbl section on aligns site, i may cut the links down as there is tons of thread and can bee trimmed down.


with the links, theres so much positive pitch the blades hit the tail boom so obviousy far too long.

the problmme is that o where that sells the cx20000 gyro say you need the usb cable to properly set it up, and after much reserach even then very few people actually get it flying.


i thinnk i need to replace the tail belt puylly, without the blades theress tons of vibration throough the tail boom, its like szzzzzzzzzzzzzzzzzz and you can see the vertical tail fin vibrating back and forth. even in my ineperience this seems tooo much.

i orrered the wrong blades, thought i rdrred main bades but there actually tail blades. but no probem because i should replace them too, they hit the floor multiple times.

so its more time in the sim, and o my v977 which i crashes multiple times today . o damage apart from cracked canopy ( servo saver mod, best thing every)

my v977 i ccan be sillywith, it usually dooes not break. the 250 is more serious. oce it gets in the air. this thig will spend alot of tiime just hovering and slow movementt.

Im planning o replacing the gyro verry soon probaby with a kbar. even after the firmware update depsite it being way less sensitive to vibration. i waa getting servvo twitches randmly at 30s intervals

[yakky]

You'll love the kbar, the vibe analysis is worth it's weight in gold. Plan on mods though, it will not fit in the frame. You can file the kbar case down until the sides are almost gone and it will barely slide in. Or you can mount it on its side but that looks rough.

[bazsound]

Originally Posted by yakky

You'll love the kbar, the vibe analysis is worth it's weight in gold. Plan on mods though, it will not fit in the frame. You can file the kbar case down until the sides are almost gone and it will barely slide in. Or you can mount it on its side but that looks rough.

i think its definatly theewayto go. this copterx 250 gyro is so damn uppredictabe.

beffore iupdaed it i had death wobles but te tail seemed to be holding.

now no death woble, but waants t tip over and the tail swings round as it gets light o skids.

is vibration issue, gott new main blades coming and new main gear plus shaft as i think ive bnt the main shaft.


i need to balance the taail blades aswell.

one thing i dont understand is how to i set the tail pitch, the gyro setup says to give 8 dgrees pitch in he diection to correct for toque of main motor. hw do i even measaure pitch f the ttail blades

[yakky]

Originally Posted by bazsound

i think its definatly theewayto go. this copterx 250 gyro is so damn uppredictabe.

beffore iupdaed it i had death wobles but te tail seemed to be holding.

now no death woble, but waants t tip over and the tail swings round as it gets light o skids.

is vibration issue, gott new main blades coming and new main gear plus shaft as i think ive bnt the main shaft.


i need to balance the taail blades aswell.

one thing i dont understand is how to i set the tail pitch, the gyro setup says to give 8 dgrees pitch in he diection to correct for toque of main motor. hw do i even measaure pitch f the ttail blades

Use trigonometry to calculate the tail blade angles.

[Krager]

That's one problem with an Align 250 or clone, the frame is narrow so FBL units don't fit inside the frame more often than they do. I run a BeastX on on my Trex 250, well actually an AR7200BX. I removed it from the case and mounted only the circuit board with 3M mounting tape. It's located face down under the tail boom mount. It won't fit there otherwise. Removing the case on that particular unit actually works out for the best because it weights about 10g and a 250 is more sensitive to small additions of weight. It's a much lighter heli to start, about a third the weight of a 450.

Vibes will play hell with any FBL controller so that's the first place to start. It's a big help in troubleshooting to have a flybarless controller with vibration logging. The BeastX on my 250 does not. I just picked up an MSH Brain for another heli which does. If you had a tip over, be sure to check the main shaft is still true. If it's bent even a tiny amount it will cause a huge increase in vibration. It's pretty obvious when the spindle is bent, but not always for the main shaft.

The 250 can be more sensitive to settings in tail gain so it can be more tricky to get it working right. I've had to spend more time with that compared to other settings. Also head speed on the 250 has a big effect. When I first set mine up, the tail would not hold well even with gains up higher. I was actually running head speed too low at first. I increased head speed a good amount and then the tail became much more sensitive to gains.

[Krager]

Originally Posted by yakky

Use trigonometry to calculate the tail blade angles.

I actually use trig to set all my pitch angles. I find it more accurate and resolution greatly finer than a basic pitch gauge. Just need a scientific calculator that provides sine and inverse sine functions

Once the heli is leveled on a good flat table, I use a ruler to get distances off the deck with the blades folded 90 degrees. Neutral point for reference can be measured at the blade base with the blades in flight position. It's also easy to compensate for slop in the system which a pitch gauge can't do easily. I usually get around 8mm of play at the blade tips when they're folded so I add half that to target measurements in each direction. Though the blades have to be folded toward rotation for positive pitch, against for negative pitch. That's so the weight of the blades takes up slop in the correct direction.

Setting up my centers and throws that way I've not yet had to do any trimming. The helis fly true and level right out of the gate. It's actually kind of amazing how well it works in that respect.

[yakky]

Oh, I never thought to factor in the slop like that, great idea! And they said algebra was all you needed in school.

[Krager]

Originally Posted by yakky

Oh, I never thought to factor in the slop like that, great idea! And they said algebra was all you needed in school.

Well yeah, if all a person does is sit around and watch TV. For a lot of hobbies, especially this one, higher math is handy now and then. Though trig is not really higher math, it is a level above algebra.

[yakky]

Originally Posted by CraigHB

Well yeah, if all a person does is sit around and watch TV. For a lot of hobbies, especially this one, higher math is handy now and then. Though trig is not really higher math, it is a level above algebra.

I don't even think half the population of the US can even do algebra. I remember going nuts with trigonometry when I was in high school and building subwoofer enclosures. I loved math until differential calc.

[Krager]

Yeah differential calc gets out there, actually took some electives in college beyond that into theoretical math which is really crazy. You get far enough into and it can become pretty abstract. The differential stuff is used a lot in engineering, but now there's simulators for everything so it's still not really used in the classic sense even when actually engineering stuff. In any case that was years ago for me and I've forgot more than I learned. I often have to go back and review stuff when getting into math where my memory has faded. I even had to do a quick review on trig when I went to use it for heli setup. Just like a language you lose it if you don't use it.

[bazsound]

copterx 250 first flight (1 min 17 sec)

After much perceverence and watching videos on how to setup a tail for an FBL setup i finally got this thing in the air.

I had several problems which were making getting the gyro setup to correct in the right direction impossible to set.

I also had my tail spinning the wrong way, but even after correctrring that i still had problems.

So i removed the gyro, mounted it on the side with 2 pieces of foam tape and a 2 pence piece inbetween.

I adjusted the tail in rate mode lits bits at a time until it was no longer spinning on the ground.

Then i slowly tried to take off, was getting head wobbles, ok adjusted gains, went to the extreme to verify which way was more gain and which way is less gain.

Still getting wobbles and bouncing. my tail was bouncing off the floor, this obviously really upsets the gyro so started putting forward cyclic in to stop it bouncing on the ground and what do you know suddenly its not wobblying but instead sliding around the floor. Tail still not locked in complelty but minor adjustments to keep control of the tail.

Then i got it in the air! and successfull kept it a few inches of the ground for 30 seconds.

I kept slowly getting it in the air and adjusting the tail gain, i got some pretty violent wag as can be seen in the video. so i backed of the gain, its still ever so slightly wagging. Theres some vibration i need to try and reduce.

Blades were balanced they wernt actually that far off, just 1 piece of tape. the tracking was way off. I fixed that , didnt seem like there was any less vibration though with better tracking.

I need a btter way of mounting the gyro, because of the frame the tape isnt contacting much of the frame and theres the risk the gyro may become unstuck.

Maybe i should take it out the case and get it mounted on the gyro tray inside the frame.

I still had plenty of battery left but decided it would be a very wise decision to stop and have a rest . Will take the v977 out for some fun and come back to the copterx tomorrow when my mainshaft carbon fibre blades and main gear come.


Fit those and then give all screws a good checkover to make sure nothing has gotten loose.

so all in a very good day.