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        Discussion HK250GT 6Ch from a DH9116

#1 Steve_ Nov 25, 2012 06:21 PM

HK250GT 6Ch from a DH9116
 
2 Attachment(s)
My first CP heli, moving from a Double Horse 9116. It's a pretty big
jump, and thought I would share if someone is thinking of moving up.
My next heli would have been an MJX-F45 if it had not been for a
generous donation from another forum member (Thanks Balr14 !!).

I got it mostly assembled, just needed to install electronics.
I spent a ton of time getting the belt drive and tail to operate smoothly.

But now, she spools up like a dream. Smooth and silent. My 9116 sounds like
a dying lawnmower by comparison.
The one-way bearing is awesome to hear spool down, it spins for
quite a while. The belt drive took an hour to adjust, but now you don't
even know it's there.
The head speed is insane. I was scared to put it past 60%

Before I get heavy into the manuals and start setting it up, is there anything
that looks out of place?

#2 Balr14 Nov 25, 2012 08:13 PM

I would make sure the pin moves very freely up and down inside the anti-rotation bracket. I noticed a lot of the openings in the HK250GT needed some sanding and filing.

#3 Essex2visuvesi Nov 26, 2012 04:47 AM

Quote:

Originally Posted by Balr14 (Post 23362464)
I would make sure the pin moves very freely up and down inside the anti-rotation bracket. I noticed a lot of the openings in the HK250GT needed some sanding and filing.

Also I would cable tie the wiring

#4 mugen 1 Nov 27, 2012 08:26 PM

Why not use a 3s(3 cell) li-po ? Will your canopy fit with the esc mounted side-ways? It looks like you will have to remove your gyro every time you replace your tail boom.(to get to the screws) The HK tail boom is super thin and super fragile.

#5 Steve_ Nov 28, 2012 12:37 PM

First hover today. I'm so freakin' happy. Took me forever to figure out the
setup / pitch / throttle curves / and every other thing I knew nothing about. LOL.

I have a decent beginner set I made (can still go wild 3D with
idle-up mode).

When you kick that in (idle-up).... OH MY !!! Freakin AWESOME !!!
(I only did it on the ground). And with the curve, that was only 80% throttle.

This thing is wicked. Very tricky to hover, even with a super docile custom setup.
Of course, it would be easier without the 8 Mph shifting breeze...

If anybody buys a 250GT and uses a SKY-703 radio, and Skyartec head lock gyro, you are welcome to my
setup, posted here. It's a good starting point at the very least.

https://docs.google.com/open?id=0B5i...mswZUhHLW1CTHM

It took me several hours to figure all the settings out, and this might save
you some time.

#6 Steve_ Nov 28, 2012 01:12 PM

Quote:

Originally Posted by mugen 1 (Post 23381095)
Why not use a 3s(3 cell) li-po ? Will your canopy fit with the esc mounted side-ways? It looks like you will have to remove your gyro every time you replace your tail boom.(to get to the screws) The HK tail boom is super thin and super fragile.

This is a 2S setup pulled from a Wasp V3 and seems to have plenty
of power. Idle-up is scary :cool:

As far as the gyro, I have a huge roll of servo tape. No big deal if I have to
move it.

The only place the canopy is tight is at the battery, as I have it way forward
to try to balance it.

#7 karlik Nov 28, 2012 03:01 PM

Quote:

Originally Posted by Steve_ (Post 23386505)
This thing is wicked. Very tricky to hover, even with a super docile custom setup.
Of course, it would be easier without the 8 Mph shifting breeze...

But it's gotta be easier than trying to hover that 9116 in a 8 mph shifting breeze :D

#8 Balr14 Nov 28, 2012 04:03 PM

You are doing great! But, don't shift in to idle up mode on the ground. You want to be in the air at neutral throttle; much less stress on the equipment. You should probably get used to using throttle hold, rather than cutting the throttle in a crunch situation. When you cut throttle quickly you induce negative pitch, so you come down faster. There are two ways to offset this: use a pitch curve that has very little negative pitch or raise throttle trim. The downside of doing this is it reduces your ability to fight wind. But, if you use throttle trim, you can reduce it with a flick of a finger. The use of throttle trim to control flight characteristics is standard operating procedure on the Thunder Tiger Innovator. It works quite nicely on quads, too.

#9 Steve_ Nov 28, 2012 05:30 PM

Quote:

Originally Posted by Balr14 (Post 23388316)
You are doing great! But, don't shift in to idle up mode on the ground. You want to be in the air at neutral throttle; much less stress on the equipment. You should probably get used to using throttle hold, rather than cutting the throttle in a crunch situation. When you cut throttle quickly you induce negative pitch, so you come down faster. There are two ways to offset this: use a pitch curve that has very little negative pitch or raise throttle trim. The downside of doing this is it reduces your ability to fight wind. But, if you use throttle trim, you can reduce it with a flick of a finger. The use of throttle trim to control flight characteristics is standard operating procedure on the Thunder Tiger Innovator. It works quite nicely on quads, too.

Yup, I made a custom pitch curve that is all positive pitch. 1 to 6 degrees.
It doesn't get light on the skids at the curve I set until around 2 or 3 deg, so even if I completely cut the throttle it won't pancake. When I enabled idle-up mode I made sure I was at zero or very little pitch. It makes a quick 180, then sits there screaming happily :D

#10 Steve_ Nov 29, 2012 11:08 AM

Quote:

Originally Posted by karlik (Post 23387733)
But it's gotta be easier than trying to hover that 9116 in a 8 mph shifting breeze :D

Actually, the opposite is true, the 9116 is MUCH easier to fly.
Just FYI ;)

I'm sure that will change once I get used to the completely different flight behavior.
The high head speed makes gyroscopic forces 10 times greater on the 250GT.

** EDIT
The HK250GT handles wind far better than the 9116. It's just harder to fly
because I suck at it.

#11 Steve_ Nov 30, 2012 04:38 AM

Broke my first part on the 250GT today. I was sliding sideways about a foot
off the ground and a gust made it dip and catch the skid. :mad:

Only broke 1 leg, so I can still fly it. But if I had been 2 feet up all
would be good. Stupid. :o

It can get away from you SOOO FAST... just a nudge on the sticks for a split
second is all you can give it unless you want it taking off like a freakin' rocket.

I need to get a radio with programmable rates and epa's so I can tone it down a
little while I learn.

When it starts to get out of shape, you set it down NOW.
If you have to think about it, it's too late... you've already bit the dust.
All you can do is cut the throttle and hope the blades "bounce" off the blacktop.

This thing is pure evil. Devil bird from hell, I'm not kidding.

I equate it to trying to balance a marble on top of a bowling ball.
I can't believe I have not totaled it already.

But it is so satisfying to fly... the sound, the snappy movement.
The way it holds it's position if you are on the sticks right.
It is just soooo smooth.

The spin rate of this thing is completely nuts.
The tail can spin around so fast it's a blur.

#12 Balr14 Nov 30, 2012 08:10 AM

If you tipped with enough force to break a skid leg, you should check the feathering shaft. They are always the first thing to bend. When you disassemble the head, pay very close attention to the order of the bushings, bearings, rings, etc. Lots of beginners overlook this. Going from a DH9116 to a 250 clone has to be the biggest jump I've ever heard of. Ranks right up there with starting with the old Walkera 4#3B.

#13 Steve_ Nov 30, 2012 09:14 AM

Quote:

Originally Posted by Balr14 (Post 23402596)
If you tipped with enough force to break a skid leg, you should check the feathering shaft. They are always the first thing to bend. When you disassemble the head, pay very close attention to the order of the bushings, bearings, rings, etc. Lots of beginners overlook this. Going from a DH9116 to a 250 clone has to be the biggest jump I've ever heard of. Ranks right up there with starting with the old Walkera 4#3B.

It kept flying when it happened, in fact I didn't even know I broke a part off
until I went to power down. :rolleyes:

I was going sideways at a good clip and just nicked a crack in the blacktop.
If it wasn't for that crack, all would be well :mad:
The heli kept flying as if it weighed 200Lbs. Didn't even twitch.
Like I said, I didn't even know I broke anything until post flight.

I've ran a pack through since, and it seems ok, nothing different that I can
tell. Still smooth and snappy at the same time :D

I've got it sitting waiting to see if CA will bond it back together but I doubt
it, they are just too flexible.

#14 Balr14 Nov 30, 2012 09:33 AM

Glue with CA, warp the break area with dental floss or fine thread and soak with CA. Even if it doesn't hold, you have effectively created a receptacle that you can put hot glue in.

#15 Steve_ Nov 30, 2012 09:37 AM

On a different note, the 9116 is totaled... Kid was flying, got it too far away.
I took over but it was already too late, couldn't see it.

Had to throttle cut, and this time it needs battery, PCB, head, frame,
and other stuff. Not even sure I want to fix it.


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