XK K110 Issues

[tsdoubleu]

Just got my K110 and during her maiden flight I had some issues. Being my first CP, I flew in 6g mode. Got her up and she flew backwards toward her tail. Thought I hadn't put the battery in all the way but that wasn't the problem. Took her up again and did the same so I tried trimming but that didn't help much. In fact trying to go forward she didn't go very well. I then crashed her. She didn't appear to take any damage, the servos appear to be working correctly. The problem now is I can get her up once at a maximum height of 8 feet still with flying backwards at neutral stick. Then all future attempts she spins up and you can see the body lifting up but she never leaves the ground. Change battery with same result. What's happening? Why does/did she fly backward? Now, why doesn't she lift off? Did I get a dud?

[ridge-runner]

Dud? No - I bet your main gear slipped down a wee bit on the mainshaft. Happens all the time! (in most crashes).

There should be zero play in the main shaft when you try to move it vertically up and down (the main gear is designed to slip and even come off in a crash.) To fix, simply push the gear back up while holding the top of the head.

The 6G mode needs to be calibrated. Google: "XK K110 6G calibration" which requires that you perform a steady hover while in the cal mode. You'll also want to do a 3D calibration as well (which is easy and does not require a hover flight - simply make sure the thing is level.)

Unfortunately, the 6G calibration process is sort of a chicken-or-the-egg situation because you need to be able to hover steadily to do it, but beginners typically can't do that!

[HateTheDrake]

+1 on the 6g calibration, that seemed to make a notable difference. I did a few of them. There are a few posts here with the info, but you basically hold the right stick all the way down until the blue light on the circuit board blinks. Then hover for a bit as stable as you can, land, then hold the stick down again until it stops blinking.

I think someone also said to flip the dual rate switch down so it's at 100 during calibration.

[tsdoubleu]

Thanks ridge-runner. The main gear was loose. Doing the 6G calibration today was a bit tricky because when trying to do the hover she just nose dived into the ground. Took your suggestion and watched a MicroRCFiend video where he held his so I tried it. Success . I could then take her up. She pulls to the left a bit so I'm going to take HateTheDrake's suggestion and calibrate it again. Can't wait to get out again tomorrow.

I really appreciate the help. As is the case a majority of the time, it's not the fault of the equipment but the user. Should have known from the beginning . No different than my golf game.

[hoversmooth999]

Hello Guys, tonight I spent some time and several batteries through flying my 110 and I think I may have come upon another possible method to having your 110 trimmed out. I've been flying helicopters for a good number of years and I'm a stickler for having a perfect flying bird. First off, "Does the calibration process help this bird"? Well it may help a little in the stability, but to correct an out off trim heli I may have another possible solution which may help some off you. I tested the calibration process several different times but my bird still wanted to pull to the left. The only way I could get a hands off hover was by using digital trims, but of course we all know that that is not a good method on a 3D heli. So Here It Is... I took a closer look at my heli and noticed the receiver board was mounted on some ultra squishy foam. I also noticed that when on a level surface and looking from the front that the little board was not sitting level to the ground due to the servo wires pulling down on it from one side. Coincidentally, it was at an angle that would force my heli to lean to the left in flight for the board to be level! Temporary answer is that I ran the ESC wire on the opposite side around the canopy post to pull down on that side in turn pulling the board down level with the ground. Perfect flight now. Why would such foam be used? Well I would think it is the reason people can fly this helicopter crash after crash. It absorbs all the vibrations from the bent spindles, bent main shafts and chipped (nicked) out of balance blades that people are flying these with. So check that your receiver/gyro board is sitting perfectly flat on its mount...Sorry if this is late or already mentioned. Hope this helps.

[Super fly Jimmy G]

I held the elevator stick down for one full minute but neither the blue or red lights started to blink! Any ideas? Thanks.

[Thomas.Heiss]

I would say forget the 6G mode on this heli.

Or you need to use a very thick and wobbly foam pad.

Always have a pretty bad swashplate tilt (incl. new heads) to the left and backwards.
The trim flight alone is troublesome. It quickly flew past me and crashed onto the concrete and damaged the top 101 inductor.

Not one of my three K110 (not the s) with V5 or V6 boards works reliably in 6G mode.
No idea what vibration thing is going on with the different Tarot Zyx foam pads.

The original foam pad is too soft... resulting in a bad tail hold.
You can basically pull the board in all directions very easily.

What is the board version in your new K110/K110s? V7 or higher?

I say stick to the 3G mode, forget about the 6G trim flight and use a Pc Sim first.
Hovering 700-800er helis with special hover trainers, reduced physics/speeds is the correct way to get started.
Not with a squirrely micro CP.

Maybe one of the three K110 worked with the standard foam pad when it arrived and I've test flown it in 2019.
But I always had some kind of trouble either with a bad left+back (heavy) pull and the one time I think it was forcing a forward flight and I hardly couldn't stop it.

The Omp and Goosky 6G modes seem to be better working.

No idea why the trim flight doesn't save the values or why the heli goes sometimes goes amok within the trim flight by itself.

I made sure to use the top fixed linkages (bones) of similar length. They're not all the same.

Maybe blade tracking could be optimized with adjustable linkages, not sure.

But the 3G mode works pretty good (is direct on the sticks) and tail hold can be optimized with a different foam pad.

Warning:
The V6 board don't like very hard foam pads!! Then the whole Fbl flies pretty shitty. Didn't have that problem on the first V5 board (Bnf heli).

One of my K110 only came with two small stripes under the board, lol.

Xou have to make use of the double foam oad technique. 2-3mm Smd components are sticking out at the bottom. So you need to cut out several foam pad pieces and first level the board. Then use another layer and glue it onto the main frame.

If the board is not mounted with a bad angle (level on both sides) and a full thick foam pad is installed (and not only two small stripes) then you can try to fly it in the current state. But don't be surprised if the tail hold is not the greatest if the board flops around in the air.

[Thomas.Heiss]

Trimming of nick/roll is normally NOT allowed on a flybarless heli.

With a perfect level swashplate (in 3G mode) my three K110 tend to have some slight drift in two directions.
I bet the factory has adjusted the pushrods and they are NOT all the same length.
Factory also doesn't always make that the servo arms are at the same angle (two roll servos).
Basically shall be 90° to the linkage / main shaft, that's optimal.

But before you rip it apart and wanting to redo the full mechanical setup (in 3G mode) as it is not optically the same on the sides or the Elev servo arm is higher than centered I would say: First (have someone) fly it with enough Expo and reduced DualRate in 3G mode (after enough of Sim training).

If the backwards drift is gone in 3G then the servo setup and linkages are just fine and were correctly adjusted (test hovered at the factory).

You can really screw up when you restart from scratch, I did. Took me days (not as a beginner).

There are two different techniques how you can fix a drift in the 3G mode.

But make sure that you don't use the stick trims and then to reconnect the battery and that the Fbl initializes with the given trim as then the wrong mid center points from the channel are initialized as the new 0 which you really want to avoid.
If you want to use trims in 3G mode (6G requires the trim flight but not using trims on the TX) it requires further programming on a TX with a separate top switch which the Rtf X6 might not be capable of. I have done some fancy programming on the Devo10 so I can compensate the 3G drift with a perfect level swashplate. Don't want to re-adjust the linkages after every crash.

But normally you would only adjust the linkages in 3G mode that there's no drift.
That's because the Fbl has no internal swash trims. Also it doesn't allow servo centering (subtrim) for the three cyclic servos.


Here comes the problem:
Only an expert can maiden a heli and focus on level swashplate or zero drift.
That's too much for a beginner.
It will quickly get out of control (if there's drift or when the 6G mode goes amok and badly tilts the swash).

Warning:
It's not a good idea wanting to do the 6G trim flight in your living room!!!
Sure, there's no wind, but it WILL crash against plants, chairs, tables, plants or against your face.

Never fly/hover a BL heli indoors.
You need a triple gym. Go outdoors!
I can still see the cut on my finger three years later.

[Thomas.Heiss]

Originally Posted by Super fly Jimmy G

I held the elevator stick down for one full minute but neither the blue or red lights started to blink

In that case your DualRate is not set at 100.

To run the calibration, you need to bump up the rates.... when you're in that mode (blinking) you can switch the D/R switch again and only then take off.

Both sticks (throttle and elev) need the be pulled down to initiate the 6G trim mode. So your throttle needs to be at 0 (-100 on some TXes).

[Thomas.Heiss]

Oh okay, this thread is from 2017, lol.
Didn't check it on mobile when posting my first two comments in the middle of the night.

[rcbliss]

Old thread, but your post came in time to give me lots of useful info!