The flying monkeys got me...

Helis and fixed wing

AMA 957918
IRCHA 4345
AMA Intro Pilot Instructor

Wednesday, March 27, 2013

Move Day

 
 
It really does help having professional movers. My last move could have gone much better. This time I went with pros, using Berger Transfer and Storage Allied Van Lines of Cincinnati. A crew of three experienced movers had everything packed and on the truck within 3 hours. The lead guy had a lot of experience packing RC aircraft and crafting boxes. The pic above is all my aircraft, except the massive Sopwith Camel, which got its own tailored box. I have no doubt they will arrive fine!
 
The T shaped box holds the Ultimate: I coudn't ge thte wings off without a lot of trouble. No problem, he made a box!
 

Monday, March 25, 2013

Moving II

Reminiscent of my last move... The planes and helis are off the wall, the wings off the planes that would let me. Hope they all make it.
 
 
 
 

Monday, March 18, 2013

New Flight Modes

Recently read a thread on Helifreak that discussed flight modes, and I decided to make some changes. RDLohr suggested setting Normal as a start up mode.
 
My previous Normal mode had a throttle curve that went zero to 50% then 75 and 100%. The Normal pitch curve was 40% to 50% (zero pitch) then 75% to 100%.
 
I had only one Flight mode. Throttle curve was 100%-90%-100%, and the Pitch curve was linear 0% (max neg) - 50% (zero pitch) - 100% (max pos).
 
Here are the new curves programmed on my Spektrum DX8:
 
 
 
Normal Mode "Start Up" Pitch Curve: A slight neg pitch, around -4 to zero pitch.
Allows the heli to come up to speed without any pitch.
 
 
 
Normal mode throttle curve. brings the heli up to 90% throttle at zero pitch.
Allows a nice transition to Flight mode, no sudden jump in headspeed when
switching into Flight mode,
 
 
 
Flight mode 1 limits the pitch to around -10 to +10 degrees.
 
 
 
Flight mode 1 Throttle curve. Some like a straight 100% curve. I have done that...The idea is that when there is no pitch the throttle is down 10% to keep the headspeed more constant, That's the thought anyway,
 
 
 
Flight mode 2 Pitch curve: Full -12 to +12 degrees.
 
 
 
Same throttle curve for both flight modes.
 
Practiced these curves on the Phoenix Flight Sim and it works well. I also like that it allows me to bring the headspeed up to full without any pitch. I did this primarily for the smoother transition from Normal to Flight modes.
 

HDX500se Up


The Blade 300 bearings I needed for the tail on the HDX came in today, and just as I expected, the new design is two closed ball bearings (the Blade 300 4x8x3) and a thrust bearing from a 450 main grip, on each side, just like a main grip. Went together fine, tight on with free rotation. I doubt this 4 mm shaft will ever bend.
 
I spun everything up without blades and things looked good. Put the tail blades on and still sweet, minimal vibration. Put the main blades on, and took her to 90%. Noticed that a servo twitched, the one I didn't replace before, the aileron servo. So I replaced it, and things look pretty good now. Perfect tracking.
 
I learned how to use the continuity mode on my multimeter and checked the continuity on my tail boom to motor mount static buster and the continuity is great (thanks psylence519 for the suggestion). For good measure I lubed the tube again.
 
So... now I just need some nice weather and a chance to fly!
 

Thursday, March 14, 2013

HDX500: Yeah... its always something

On isolating vibrations troubleshooting the brown out and jittery servo problem, I found out the tail blade hub had a bent feathering shaft.
 
Parts for the HDX500se/Lepton are hard to come by. CNChelicopter carries many of the parts, so I went there and bought the last tail hub, and for good measure a couple of tail shafts (mine remains unbent).
 
Well, its not quite the same. The original (bottom smaller one) has a one stage 3mm shaft and is shorter. It uses 2-3x8x3 ball bearings on each side.
 
The new one is on top. It has a first stage that's 4mm for the ball bearings, then steps down to 3mm for thrust bearings. This arrangement is usually seen on the main rotor, I've not seen in on the tail, but the bigger the heli it makes sense. I will need 2-4x8x3 bearings on each side, and thrust bearings. I have the latter on hand, for a 450 main rotor crash stock. This will be assembled like a mini main rotor.
 
I checked with my usual bearing provider (Avid) and they are out, so I Googled and found another of my favorite sellers has them (WOWHobbies), for the Blade 300 I think. Correct bearing, comes 3 to a pack, of course, so I had to order two packs, about $6 a pop.
 
Now I wait. I expect this to go together just fine. At least that's what I tell myself. Still waiting for the HURC programming card and the back up Hobbywing ESC/BEC if that doesn't work.

Tuesday, March 12, 2013

Zapping static gremlins

In discussing my recent travails with the electrical gremlins in my HDX500 on Helifreak, Slyster offered up the notion of static discharges being responsible. This makes sense and I had given it some thought the first time I dealt with this a couple of years ago. That's when I started spraying the tail tube with lube. Random electrical parts getting zapped, and often affecting the servos, for the most part this seemed in retrospect to solve the problem. But it still happened though rarely, and as I noted zapped a servo recently. Maybe routinely spraying the tube with silicone is not enough; others have describe sparks despite the lube.
 
So I decided to up the game. I don't want to spend $50 on two G-force static wicks. So I grounded the tail boom, which acts like a van de graaf generator, hence the static problem, to the motor block using descriptions others posted on the web. Now the boom is essentially grounded to the battery (truly grounding it directly to the battery would require another wire to the neg lead of the battery, but for all intents and purposes its grounded).
 
Here you can see the entire grounding run from the screw in the tail boom peeking out on the right to where it snakes under the gyro platform and out the forward side to a bolt, then over to the top bearing block, and then down to the motor block where it ends on the aft motor bolt.
 
The metal boom is painted blocking conduction, and the block on the tail is aluminum, which is conductive. I drilled a small hole in the boom and set a screw just into the metal (avoiding the belt inside). The copper wire is wound around the screw and a dot of solder secures it. The wire runs under the gyro platform.
 
and comes up the other side. The first segment ends here, where I sanded the frame (so it also grounds to the frame) and attached the wire, the screw set into the aluminum head block. If I had planned this better I might have run one wire with spots of insulation removed to expose the wire, but, meh. So I start another wire there and ran another segment under the top bearing block...
 

and down inside the frame to come out and end attached to a motor block bolt, grounding the tail to the motor.
 
 
Hopefully this will cage the gremlins and I won't have to revist the magicla electrical mystery tour with random electrical failures!
 
UPDATE (3/13/13): I realized that I had put the screw on the boom in a place where the belt has made its turn and is in danger of rubbing. Psylence on Helifreak also pointed this out, and it convinced me to move it, so today I moved the tap to the top and out of the way of the belt. Cut a steel servo screw very short.
 
 
 

It always starts small...

And by the time you are done you've nearly disassembled the whole thing and spent hours solving a problem you didn't know you had when you started.
 
I took the HDX 500 down from the wall to see if the failsafe was set properly, after reading a couple of posts on HeliFreak. I noticed that the throttle stuttered just before mid-throttle. I am not sure, but think I have seen this before with this heli. I decided to change the ESC out for a HURC 60A opto ESC I have. I remember this HURC ESC because it works fine on my planks, but I wasn't able to program it with my Hobbywing programming card, like I can other HURC ESCs. I also am not sure I didn't recently fry my Hobbywing card... So I ordered a HURC card and its in the mail.
 
I set up the heli as it was, knowing that not having a soft start without blades wasn't a big issue, and the stutter step was gone. And then I noticed the twitching servos... I have had this problem before on the HDX and have never really sorted it out. I would change a part of the electrical harness and it would go away. This time it was the pitch servo. It was somehow shorting out the entire system, causing the other servos to twitch and browning out the receiver. It took me a day to isolate it this time. Needless to say I also have a 60A ESC-SBEC and a new receiver coming because I wasn't sure if they were the problem as I troubleshot it. I am now waiting for the HURC programming card, and if I can't program the HURC 60A I will swap the ESC and BEC out for the one coming in the mail and hope I didn't burn out the Hobbywing card.
 
Along the way I found out the tail rotor had a bent feathering "shaft" and needed to be replaced. It was subtle in flight but very obvious on examination. I was isolating any vibrations I could find. So those parts are coming.
 
As for the extra receiver... maybe I will build that HK600 or Winrc 600 after all. Wouldn't want a perfectly good receiver go to waste, now would I?