 |  |  |  |  |
| RC Aircraft Site HORNET PAGE 4 |
lessons - that's the way I look at it. Anyway, I still love my Hornet - I just can't afford to fix it anymore.
Flying Off Grass: Unlike planes, which fare better off grass in accidents, the Hornet is subject to it's skids
catching more things on take-off and landings and tipping. On concrete, it does run ons with bad landings
after much fun, in a cracked main shaft.... Here are the syptoms....
Cracked Main Shaft:
First symptom that told me my main shaft had delaminated was what looked to be a 'wobble' in the main
gear. Now think about it - shaft runs through TWO bearings. If something is straight and runs through
two bearings, the gear (unless IT was damaged - unlikely) should run true. It didn't. Also, when the Hornet
was held in my hand and throttled up, it made a grinding noise and was full of vibration.
Upon disassembly, the CF shaft looked FINE! Could not see any cracks. Then I put a pin through one of
the holes in the shaft, held the other end and twisted. Well THAT sure showed me it was cracked. That's a
great test as any delamination will become apparent real quick. Don't, however, do it too hard to a good
shaft. A small amount of pressure will seperate any fractures for your viewing pleasure.
So I replaced with the spare CF shaft I had bought while I wait for the great Hornet philanthropist
"BOOKEND" to send me my steel shaft from the UK. Surely there is a private, indoor flying field waiting
for that guy in the afterlife.
Gluing Servos:
Whilst I was replacing the shaft, I decided that given that my tie-wrapping of the rudder servo had worked
so well to give me REAL fast piro rate, I would try something on the cyclic servos to 'firm them up' from
the double sided foam tape I had been using.
I decided to CA a small sheet of 1/16 inch, thin-CA hardened balsa directly to the mainframe and then glue
the servos to that. First I would remove the Graupner label so there wouldn't be any 'twisting' or slop, just a
direct connection of the servo. I figured the balsa base would allow me to cut it away if I didn't like it later
vs. gluing the servo directly to the carbon mainframe. This worked quite well as I found out based on what
happened next).
Put the entire thing back together better than before and went to fly......... To my surprise, I got no
response from the Roll servo.
I checked it carefully and could hear some grinding but no movement of the arm. OH SH$#! Glue in the
gears!!!!!!! Yep, took it apart and sure enough, the CA had seeped through one of the two joints in the now
exposed, de-labelled servo case and got on the gears. GOD DAMNIT HOW MANY MORE PROJECTS AM
I GOING TO HAVE? I HAVE TWO VARIO SCALE PROJECTS AND THE REPAIR OF MY XL60SE
WAITING! WHY ARE THE HELI GODS DOING THIS TO ME!!!
Then I remembered that day in my dorm room 25 years ago.... the sweet, sickly smell of cannibis rolling
through the air.... my girlfriend (now wife) listening to some bad '70's space tunes with me.... the sweet,
sickly smell of something (what was I talking about?) Oh yeah. Anyway, I mellowed out pretty
substantially and went about the micro-surgery that is working on a Graupner servo the size of a kidney
bean.
Cleaned out the glue with a #11 blade and acetone. Put the gears back together. Greased with lithium
grease. Put the case back together. Tried the servo... It now worked in one direction but not the other -
whereat it chattered. Checked everything I could find and FINALLY figured out that the glue had caused
the gears to stall and had slightly BENT the small electrical connection plate at the bottom of the main
gear/shaft and thrown off my centering. Seems that small washer/plate has to make good contact all the
way around to know where the servo is. I pushed it down all around the edges and it works great again.
Moral - put some thin tape over the seams in the servo case BEFORE you CA the thing!
I Flew the heli and loved it again, except..................
CSM GRYO STILL SUCKS:
The tighter I make everything on the controls of this machine, the more sensitive the gyro gets. It took me
1/2 hour of trying to find that HAIR of a friggin' place near 'completely turned off' that the gain wouldn't
cause the tail to wag like mad. I am convinced this thing was designed with only THREE states or
conditions - they are;
OFF - Tail feels like you are flying through maple syrup or flying after a general anesthetic.
ON - Tail wags like the tail on a virgin 5 year old labrador in a pound full of poodles in heat.
KINDOF ON, BUT SUCKS - This is a place the size of a QUARK that lurks between the first two states
above on the gain pot on the gyro. You can find it if you have the fingertip sensitivity of Ray Charles, the
patience of Job and the ability to make sub-atomic movements with a flat-head screwdriver.
P.S. - Still no word back from my buddy at Absolutehelis who has contacted the manufacturer on my behalf
asking for a CSM gyro that WORKS with this machine (if it exists).
Next, I am going to slap a Futaba GY-601 on it with an entire roll of masking tape until the heli weighs in at
about 4 lbs and try that. Now THAT'S a gyro!
MadMan
Flying Off Grass: Unlike planes, which fare better off grass in accidents, the Hornet is subject to it's skids
catching more things on take-off and landings and tipping. On concrete, it does run ons with bad landings
after much fun, in a cracked main shaft.... Here are the syptoms....
Cracked Main Shaft:
First symptom that told me my main shaft had delaminated was what looked to be a 'wobble' in the main
gear. Now think about it - shaft runs through TWO bearings. If something is straight and runs through
two bearings, the gear (unless IT was damaged - unlikely) should run true. It didn't. Also, when the Hornet
was held in my hand and throttled up, it made a grinding noise and was full of vibration.
Upon disassembly, the CF shaft looked FINE! Could not see any cracks. Then I put a pin through one of
the holes in the shaft, held the other end and twisted. Well THAT sure showed me it was cracked. That's a
great test as any delamination will become apparent real quick. Don't, however, do it too hard to a good
shaft. A small amount of pressure will seperate any fractures for your viewing pleasure.
So I replaced with the spare CF shaft I had bought while I wait for the great Hornet philanthropist
"BOOKEND" to send me my steel shaft from the UK. Surely there is a private, indoor flying field waiting
for that guy in the afterlife.
Gluing Servos:
Whilst I was replacing the shaft, I decided that given that my tie-wrapping of the rudder servo had worked
so well to give me REAL fast piro rate, I would try something on the cyclic servos to 'firm them up' from
the double sided foam tape I had been using.
I decided to CA a small sheet of 1/16 inch, thin-CA hardened balsa directly to the mainframe and then glue
the servos to that. First I would remove the Graupner label so there wouldn't be any 'twisting' or slop, just a
direct connection of the servo. I figured the balsa base would allow me to cut it away if I didn't like it later
vs. gluing the servo directly to the carbon mainframe. This worked quite well as I found out based on what
happened next).
Put the entire thing back together better than before and went to fly......... To my surprise, I got no
response from the Roll servo.
I checked it carefully and could hear some grinding but no movement of the arm. OH SH$#! Glue in the
gears!!!!!!! Yep, took it apart and sure enough, the CA had seeped through one of the two joints in the now
exposed, de-labelled servo case and got on the gears. GOD DAMNIT HOW MANY MORE PROJECTS AM
I GOING TO HAVE? I HAVE TWO VARIO SCALE PROJECTS AND THE REPAIR OF MY XL60SE
WAITING! WHY ARE THE HELI GODS DOING THIS TO ME!!!
Then I remembered that day in my dorm room 25 years ago.... the sweet, sickly smell of cannibis rolling
through the air.... my girlfriend (now wife) listening to some bad '70's space tunes with me.... the sweet,
sickly smell of something (what was I talking about?) Oh yeah. Anyway, I mellowed out pretty
substantially and went about the micro-surgery that is working on a Graupner servo the size of a kidney
bean.
Cleaned out the glue with a #11 blade and acetone. Put the gears back together. Greased with lithium
grease. Put the case back together. Tried the servo... It now worked in one direction but not the other -
whereat it chattered. Checked everything I could find and FINALLY figured out that the glue had caused
the gears to stall and had slightly BENT the small electrical connection plate at the bottom of the main
gear/shaft and thrown off my centering. Seems that small washer/plate has to make good contact all the
way around to know where the servo is. I pushed it down all around the edges and it works great again.
Moral - put some thin tape over the seams in the servo case BEFORE you CA the thing!
I Flew the heli and loved it again, except..................
CSM GRYO STILL SUCKS:
The tighter I make everything on the controls of this machine, the more sensitive the gyro gets. It took me
1/2 hour of trying to find that HAIR of a friggin' place near 'completely turned off' that the gain wouldn't
cause the tail to wag like mad. I am convinced this thing was designed with only THREE states or
conditions - they are;
OFF - Tail feels like you are flying through maple syrup or flying after a general anesthetic.
ON - Tail wags like the tail on a virgin 5 year old labrador in a pound full of poodles in heat.
KINDOF ON, BUT SUCKS - This is a place the size of a QUARK that lurks between the first two states
above on the gain pot on the gyro. You can find it if you have the fingertip sensitivity of Ray Charles, the
patience of Job and the ability to make sub-atomic movements with a flat-head screwdriver.
P.S. - Still no word back from my buddy at Absolutehelis who has contacted the manufacturer on my behalf
asking for a CSM gyro that WORKS with this machine (if it exists).
Next, I am going to slap a Futaba GY-601 on it with an entire roll of masking tape until the heli weighs in at
about 4 lbs and try that. Now THAT'S a gyro!
MadMan
