Problem with blade 120 banking left

[Jasper68]

I am having a problem with hard left banking from start to flight, started after I out micro heli main rotor hub on, it also has xtreme blade holder, anti rotation collar and metal swash, so I put blade hub back on and it still does it, replaced 5 in 1 with a spare, put new main shaft on, new blade anti rotation collar, new blades and grips, I even put a nail tool boom on, still doing it, how can I set swash and servos? Any ideas? I'll post video

[Imzzaudae]

When you had the helicopter apart did you have the push-rods from the servos to the swash off ?

If so check that they are in the proper hole on the servo sliders.
If I remember correctly its the middle home on 120SR

Then look up level the swash with zip tie on youtube.

[dcarboni]

I haven't had a 120 in a long time but I seem to recall that the flybar can be installed 180 out it will have the effect you describe look at that don't remember if you flip it over been a long time look in manual

[Jasper68]

Thank you for the replies; I am pretty sure the flybar is on correct; although it is the one thing I have not replaced. The servo's seem to be the issue and I will try to ck swash level and reset servos's; if anyone has a link or information on setting the servo's that would be great. Here is the link to a video of how the heli starts off; I don't have attachment privileges yet so its a you tube link.

IMG 0126 (0 min 9 sec)

[Jasper68]

I should mention that when I push aileron to the right I can see servo and linkage move down; flybar moves but even with full right aileron it still goes left. This is puzzling me and I am sure it'll be simple fi but I am stumped...

[Imzzaudae]

It is obvious that the swash is not level.
You need to check the links are in the correct holes as I described above.
Then level the swash manually.

Then trim for flight

[Pfloyd]

Check (if you haven't) that the swash pin is inbetween the goal posts on the frame.

[Jasper68]

Originally Posted by Imzzaudae

It is obvious that the swash is not level.
You need to check the links are in the correct holes as I described above.
Then level the swash manually.

Then trim for flight

Link is between, I made sure of that, there are only two holes for awash links on servo, I have had them in both but keep them in upper now. I will try to level swash and see what happens. The swash however looks good eyeballing but when I use full aileron to the right and forward I can see the change in swash level and flybar. I will try the zip tie level and report back, thanks for all your advice, fixing is almost as much fun as learning to fly

[Pfloyd]

You have to manually trim out the heli.

[Jasper68]

I levelled the swash, I noticed that I had wrapped the wire for tail boom poorly and it was interfering with swash. As hopeful as I was it still banks right, I have taken it to local shop for them to fix, it certainly seems like a swash issue, I'll update this thread as to the fix..... I did get to learn my heli intimately lol

[Jasper68]

Still nfg! Hobby shop guy said it was a waste of my money he could spend hours with it and still have no success, he thought maybe 5 in 1 or all the bling, I explained i had swapped out 5 in 1 and also replaced all bling back to factory, he spent time on it with no success. The swash is level, and moves appropriately. I will post some videos of the heli spooling up and also swash plate moving.... I could buy another 120 but I have 2 180's, and now I need to figure this out for my sanity!!!! Lol

[Jasper68]

Here is a link to the heli showing the swash... any suggestions?

https://www.youtube.com/watch?v=2KBr...ature=youtu.be

robin

[Imzzaudae]

Stick the thing in a box and ship it to me. Snail mail.
Ron Box 1427 Petrolia Ontario. I will sort it out for you.

What transmitter are you flying it with?

[Jasper68]

Ron, I am using a 6dxi, I will send it out over the next week with a bunch of extra parts. Thanks I hope you can figure it out.

robin

[Imzzaudae]

Hello Robin.
Can you post your DX6i settings for me.

Consider deleting the model in your DX6i create a new one.
You may have some sub trim or some other silly thing.

I

[Merhlyn]

I'm new to heli's, this is my first post.
I had the same problem with my 120sr, sliding hard left on the wooden floor. I tried trimming it, but as soon as it moved UP an inch, it went hard right. I spent two days tring to trim it out while on the floor and finally said the hell with it. I centered the trims on the aileron and the rudder and gave it more throttle, it went up straight, not hard left or right. And I hit the ceiling. I think the SR is too light to slide around the floor. The ground effect from the rotors is just too much for it. So I spent a couple of days getting it trimmed out, but I was actually having fun flying it, even it it was only seconds at a time.
I have a DX6i and use the settings that John Salt gives in his E-book on the 120sr

[ridge-runner]

Originally Posted by Merhlyn

I'm new to heli's, this is my first post.
I had the same problem with my 120sr, sliding hard left on the wooden floor. I tried trimming it, but as soon as it moved UP an inch, it went hard right. I spent two days tring to trim it out while on the floor and finally said the hell with it. I centered the trims on the aileron and the rudder and gave it more throttle, it went up straight, not hard left or right. And I hit the ceiling. I think the SR is too light to slide around the floor. The ground effect from the rotors is just too much for it. So I spent a couple of days getting it trimmed out, but I was actually having fun flying it, even it it was only seconds at a time.
I have a DX6i and use the settings that John Salt gives in his E-book on the 120sr

It is normal for a perfectly trimmed heli to want to slide to the left when it is still on the ground. When taking off, you need to apply a lot of right cyclic to keep it in one place on a slippery surface. Once hovering up in the air balanced in one place, you will notice that the heli leans to the right (as viewed from behind). This is perfectly normal! (and all single rotor helis do this.)

Why does it do this?

Its because of the physics involved with a single rotor helicopter. Whats happening is that the motor is applying a torque on the main rotor to turn it, (clockwise as viewed from above), but the air is pushing back on the rotor trying to rotate the heli in the opposite direction (counter-clockwise as viewed from above). This is because of Newton's Law: "Every action has an equal and opposite reaction". This is the reason for the tail rotor - it balances out this tendency to rotate by pushing the tail of the boom to the left (as viewed from the rear), which applies a clockwise torque on the heli as a whole. This balances out the torque from the main rotor, but it adds another unbalanced force on the heli that wants to push it to the left (and this is why it wants to scoot to the left when you are taking off). To maintain balance in a hover, this leftward force caused by the tail rotor is balanced by tilting the main rotor (and the whole heli) to the right.

Here's what you need to do:

1. Adjust the servo links so that the swash is level. (This will set the trim to a good ball-park starting point.)
2. With the heli on the slick hardwood floor, slowly increase the throttle while holding full right cyclic. As the headspeed (slowly) increases, the heli will reach a point where it wants to tip over to the right. At this point reduce the right cyclic enough to prevent it from tipping over to the right (but don't let it slide to the left either).
3. At this point (if you maintain good control), the heli will be balanced on its right hand skid and be noticeably leaning to the right. Once again - THIS IS NORMAL!
4. Increase the throttle and take off straight up.
5. Once in the air note which way it wants to drift and then trim the servo links so that it stays in one place. This will take several flights, but once you're done, the heli should hover pretty much hands off. (But it will still want to slide left while taking off!)
6. When you land try to gently set it down on the right hand skid and maintain balance just like you did prior to takeoff.

This technique teaches very precise and controlled takeoffs and landings. For extra credit, try to do a slow 360 pirouette when balanced on one skid! (This is very difficult but once you can do it you'll be well on your way to becoming a heli master. I've been practicing for 3 years and still can't quite hold it in one spot!)

[Merhlyn]

Thanks for the tips, Now I'm working on hovering.