Micro 180CFX Msiden and crash

[leedude1]

I really really like mine but Im still trying to figure out the cause of the bobble after the 3 pointer with the gymnasium floor "a la " no throttle hold ...... I finally got the straight blades on and the bobble got noticeably worse. Put back on the bullets and its barely noticeable, but there.

Its bugging me because I know something's off but I cant figure out what. the head at this stage is new except for new dampners which ive order on a whim,... but I'd be surprised if that could be it.




BTW: Agreed nice looking bird .

 

[murankar]

Sometimes worn out dampers will cause a bobble.

 

[leedude1]

So you think the hard blade strike in the crash may have damaged the dampers? makes sense... then well see with the new ones once received and installed..would the bullet blades you think also reduce this effect due to centrifugal force?

 

[Tony]

Yes, it pulls the blades out more since there is more weight spinning around. Are you 100% sure your main shaft and feathering shaft is straight? Have you rolled them on a piece of glass or a mirror? How are your bearing blocks and bearings?

 

[murankar]

If the spindle bolts are tight and there is play in the grips its either a shimming issue or the dampers are to compressed (permanently)

 

[leedude1]

Yeah Ive swapped them out

So far I have replaced:

Feathering shaft (bent)
hub and even the main grips
main gear
main shaft (bent)
tail shaft

Not sure about the bearing blocks but they look ok its tough to tell and I dont really feel any play there...but that would be my next after the dampners swap out.

- - - Updated - - -

No play in the grips from what I can tell though. I guessed at the dampers because its all thats still original in the head at this stage.

 

[Tony]

Take the shafts and roll them on glass. piece of glass out of a picture works well. I have seen brand new shafts with a bend in them. And measure from the outside of the head block to the tip of the blade. Is it exactly the same on both sides? Might have a shim or something missing on one side of the head assembly. And finally, have you completely balanced the blades? Meaning weight and cog?

 

[leedude1]

Ok Tony, Ill give er the once over one more time and report back once I get through it probably this weekend.

 

[Tony]

Right on. Keep us posted.

 

[Smoggie]

The blade grip bolts aren't too tight are they?.. They need to be pretty loose on a micro. If the heli is held on it's side with the blades horizontal and the heli is given a slight 'jerk' they should begin to drop under their own weight.

 

[Smoggie]

PS.. the other possibility if it's worse when you change blades is that the blades themselves are out of balance.

 

[leedude1]

Well got the new dampers in and shimmed to zero play still a bobbing.
Checked the feathering shaft while I was there again to see if it was bend out of the bag...its fine.
checked blades COG and weight, they are are spot on were actually better on the straight Lynx blades than the bullets, yet I get a more noticeable bob with the straight blades

Just got the new bearing blocks and will give that go as I think I notice a little for and aft play when I apply lateral pressure to the head..but its really hard to tell for sure because something is always giving a little also like the LG or ...

In any case gonna swap em out and see what happens. I double check the main at the same time.

Once I get this figured out im going to apply for my detective badge and tell the wife to call me Colombo.

 

[leedude1]

blades balanced... new bearing blocks installed... still bouncing ... I noticed some play in one of the servos... you think that could be it?:

 

[murankar]

IF everything else is new then yes. Thats an 85% yes not a 100%. If you have play in the servo then the servo never finds the same center. Ask tony about that.

 

[leedude1]

Makes sense M,

This has been a good over all learning in any case. There's always a positive. Love to wrench anyway so got to know my bird a little better from a guts perspective... I discovered a few new things on the way as well.
But missing that throttle hold really cost me some time (and a few bucks) well Ill order the servo and see whats shaking after that..no pun intended.
Thanks Murankar

 

[murankar]

All throttle hold is going to do on that bird is save the main gear and maybe the blades. Its just a fragile heli all around. you can buy some of the hop ups to improve it like the servo gears. Even then its still not going to be as durable as a 360 or 500 class. As long as you look at it as beater leaning platform your golden. That's all it really is for most of us. Thats why I bought one.

 

[leedude1]

It was a next step up from my others and like you said and good mid ground from my 450...I like how it handles though, much better than the 130 . Don't think Ill get past a 500 size honestly and its going to be my next build once I budget for it...I may get there for my upcoming 50th or maybe next year once I get more air time on the 450.
I fly indoors with the nano the gym gets the 150 and the 180 (as I found out runs out of gym real estate real quick)
The 180 when running smooth, is a great flying bird at least in my opinion,,Ill keep you posted on the result of the servo swap out once its in M.

 

[murankar]

If your going to go 500 I would suggest going 550. They can still be ran on 6S and takes the same electrics. Advantage is a better flight envelope.

 

[Admiral]

My 180 has been on the shelf for a couple of months due to the fact that it kept burning out Tail Servo motors, three or four flights and all of a sudden there goes another servo at A$26 they were expensive flights. Recently with a re-jig of a 450 I ended up with an align DS420 Tail servos so as it is the same size as the DS76TJ decided to see if it would work, I know it's a bit slower .8 Sec compared to .3 sec but the metal gears were a bonus although the weight went up from 7.6g to 12.7g.

I had to make up an adapter using one of the leads off a burnt out servo and a standard FM plug, the motor itself had to have the edges ground off the mounting on one end to get it into the body other than that it slipped straight in. (NOTE when making up the adapter take careful note of the Pos wire in the small plug it is not in the center like standard plugs.)

Once fitted the only thing I had to change was turn the servo arm 180 Deg and add a slight bent to the tail push rod, as the DS420 turns in the opposite direction you can reverse the servo but not the gyro.

The flying characteristics are the same the difference in weight and speed do not make a noticeable difference, about 10 flights up and going strong, the 180 is back in the flying box on weekends.
Only issue that I had was shaking back and forward, one of the cyclic servo linkages had slipped over the ball onto the shaft, easy fix.

 

[Smoggie]

More 180 woes today. It was flying fine, then on the third flight for no reason I lose the tail and it starts spinning. i hit throttle hold which stopped the spin but micros auto like a bunch of keys, so down it came with quite a thump. It landed tail first so the boom and tail shaft took the impact.

Turns out the cause was that th head of the tiny screw that retains the tail blade grips to the tail feathering shaft broke off and the tail blade and grip had been thrown off. i eventually found the missing grip and blade 40yds from the crash site... So that's another £40 ($60)... this 180 has cost me more in repairs than all of my big helis put together!