Beam pitch in flight issue...

[jiberjaber]

Well I have been trying to solve a problem I have had for a few weeks now.

I can measure the pitch on the heli on the deck, +/- 11 degrees. As soon as it is in the air, it feels like it is just getting over hovering pitch. As you can imagine, this is very fustrating.

No problems with negative pitch.

So I have been through the heli with a fine tooth combe.

I have relocktited all bearings on mixing arms.
Replaced blade grips
Replaced swash spaces
Swapped ESC between Kontronix and Scorpion
Swapperd Motors -8 and -6 tried, same effect.
Swapped blades - radix and align
Replaced main mast bearings etc
Replaced one-way bearing
Replaced main shaft and feathering
Replaced dampers
Checked the TX settings, usual suspects of knobs and switches which might effect pitch and headspeed etc.

As you can imagine, it gets a bit wearing going to the field to try out each change!

Today was the last straw, it took off, still soggy and then something exploded off mid air, second time this has happened!

So when it landed, I proceeded with a run up and a hoof across the field... it went a good 20m.... not the brightest of things as I now have a black toe and a substantial repair bill!

However it dawned on me when I was looking at the heli in bits on the table tonight... I havent looked closely but it looks like the washout pins might not be straight... hard to tell... but would these effect the pitch in flight but not on the deck?

I am not sure what to do now, do I splash the cash, about 70 quid, on parts to fix including a new head part to test the issue with these pins, or do I call it a day and get something else?

I certainly will be very unimpressed with it if I do get a new head block and the issue remains!

Anyone any ideas ?

[acwman]

If the washout pins are bent, it will be more than likely that they are binding washout, which might effect the pitch.. you maybe able to pull the washout pins out and replace them rather than buying the complete rotor hub.

[cupracing]

get something else, I had no end of problems with my beam. sold it and bought a trex 450 pro and have been a happy chappy since. no regrets here

[electricsceadu]

buy a football it doesn't hurt the toe as much

[acwman]

get something else, I had no end of problems with my beam. sold it and bought a trex 450 pro and have been a happy chappy since. no regrets here

....maybe a little harsh there!? I have had no problems with my beam. Hit the deck a few times, and nothing more than a bit of a bashed up canopy, and the usual main shaft, feathering spindle, tail output shaft, and the blades.

Use this machine to chuck around, and it takes everything in its stride... and it is not a machine that I just do figure 8s, and circuits on

[derrick]

Had no real problems with my Beam, A tracking issue was the biggest problem i have had.
Del.

[cupracing]

....maybe a little harsh there!? I have had no problems with my beam. Hit the deck a few times, and nothing more than a bit of a bashed up canopy, and the usual main shaft, feathering spindle, tail output shaft, and the blades.

Use this machine to chuck around, and it takes everything in its stride... and it is not a machine that I just do figure 8s, and circuits on

maybe your right, I guess I was unlucky. just a bit bitter as I spent so much money on it

[acwman]

maybe your right, I guess I was unlucky. just a bit bitter as I spent so much money on it

I can understand where you are coming from though.. I'm having no end of problems with a MA Furion I just got. Only just got it, and already put loads of money into it to try and get it flying right.. Smoked a 60a Castle Creations esc on it.. tried several gyros but have not managed to get the tail to hold solid, have the tail fail on me twice...basically the retaining bold holding the grip snapped mid flight..just to name a few

In the process of changing the grips/slider mech with a Beam one...

[acwman]

something exploded off mid air, second time this has happened!

So when it landed, I proceeded with a run up and a hoof across the field... it went a good 20m.... not the brightest of things as I now have a black toe and a substantial repair bill!

You mention that something exploded off mid air.. did you find out what it was?

[Paulice]

What swash servos are you using?
I had it on a heli before the same problem and it came down to the servo. but that was on a H1 setup, and this is a 120 deg 3 servo right, But if they are stalling under load it would cause the problem!

[jiberjaber]

The servos are 5065mg's not had a problem with them so far until now.

[scallybert]

The servos are 5065mg's not had a problem with them so far until now.

These are the digital vesrion of the HS65MG (?) so should be pretty decent; and unless all three were misbhaving identically, you'd get a significant cyclic input.

The only idea I have (which is a bit random), is that your mainshaft is moving up and down. Under rest conditions, or -ve collective, it's 'down'; and you're getting the intended +/- 11 deg (IIRC). When generating +ve lift, the shaft moves upwards, reducing the collective input, as the swash plate stays where it is.

I managed something like this on a GAUI 100, when I replaced a tail belt.

[jiberjaber]

Definatly not the main shaft moving in flight as it is held by both the lower jesus bolt in the gear and the collar lock below the upper bearing.

[scallybert]

Definatly not the main shaft moving in flight as it is held by both the lower jesus bolt in the gear and the collar lock below the upper bearing.

Obviously it ought to be immobile.

However, if it were able to move it would give these symptoms - though I'd expect other problems too.

Anyway, just a wild guess.

[acwman]

Looking at your other build/repair thread, I see the image below


It looks as though that you have put the thrust bearing on the outermost of the blade grip, when in the Beam manual, page 12, it should go in the middle of the two bearings.


..also looking at it, the tiny brass washer on the right hand of the picture should be between the bearing(the bearing being the outermost on the blade grip) and the thrust race(being the first to go into the blade grip). The larger washer you have pictured between the bearing and thrust bearing at the moment.. can't see that pictured in the build manual.. and maybe should not be there at all.

Could it be because of this, the blades are stalling, and not going to full positive when the blades wind up to speed?


You also mention the following when you did the repairs..
When doing up the nyloc nuts on the feathering shaft, when they are tight, the blades are very notchy and almost too compressed. This was with just one thread showing out of the nyloc nut.

You should be able to tighten the nyloc nuts fully on the spindle, and the grips should still be free..