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Old Jul 17, 2013, 07:29 PM
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United Kingdom, Scotland, Chirnside
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Glide Hawk - Initial Assembly Finished.

Well I assembled my Glide Hawk today, but not without problems. Firstly, when I followed the instructions (generic and not specific for GH but that family of birds) it said to locate the servo from the Stbd side and have the output shaft forward, towards the head. By doing this I found it was too far away to operate the elevator properly so turned it 180į. Then, the servo arm protrudes so far outboard in comparison to the connecting rod that there is too much of an angle which over stresses the components. You can see from my pictures Iíve had to add 5 washers, and even with those added there is still an angle.I would be happy to hear that Iíve made a silly mistake here!

I wasnít given enough 2mm screws and was short of two for attaching the power plate to the sail material and body. Luckily, there were plenty spare in Slow Hawk kit.

All was going great, I attached the spar hinge bolts with their locking nuts. Although the instructions say that the drive con rod bolts are attached to the spars, mine came in separate packaging. So I positioned all in place with the bolt going through the spar, and all washers in place as per instructions, with two steel washers between the ball joint and the G-10 washer. The locking nut got very stiff very quickly but I persevered then thought I had cross threaded it. I removed it and tried tightening in my hand but it was getting stiff immediately. Then I looked at the Allen hex bolt and found it to be slightly different to the ones used on the hinge bolts. The thread was far finer and it only turns out to be M3 instead of ⅛Ē UNC. But the locking nuts supplied were ⅛ĒUNC and so no good. I actually damaged some of the thread so cropped one of the bolts and for now I fitted two M3 nuts (luckily I had some here). It must have been a mix up as supplied. So I need to order a couple of M3 locking nuts and I should be good to go.

The tail elevator servo is attached by the self-tapper (supposed to be supplied but was missing) and there is a little play. Even by gravity in the neutral position the servo continually buzzes. By just touching the tail and moving it up a fraction the buzzing stops, so when flying this is going to be constantly buzzing. Iíve ordered M2 nuts and bolts and will change the self-tapper. Iím not sure if this servo will take the load and suspect it will be over-torqued but we will see.

There is nowhere in the instructions that say to ensure the correct rotation of the motor, as the wrong way would come hard against the glide locking pawl devices and more than likely cause damage or stall the motor. I turned the fuselage upside down so those pawls were free from the sprocket and gave the motor a quick go by connecting two of the wires with a choc-block to test and prove direction of rotation. I was lucky so soldered them, but if it goes in the wrong direction, just swap any two wires around.

The rudder cross shaped servo arm was not perfectly vertical when fitting so have had to trim on the transmitter, +15%. I have also increased the maximum end points from 100 to 125% (most I can do on my Hitec 6 sport). Saying that, due to the neutral trim, it goes over to one side more than the other.

The elevator upper end point has been set to 95% to stop mechanical bottoming out and the lower was fine at 100%. The neutral angle is to my eye around 25į, but Iím just estimating.

The battery Iíve positioned just forward of the middle above the ESC but we will see. I cannot hang this bird up like the SH and Iím not sure where the C.G should be so it will be trial and error.

Iíve done a flap test in the kitchen and by god can this thing flap with power! It seems a lot more aggressive than the SH, actually the whole build quality is to a different level. The only thing that concerns me is the spars. Breaking them will be a lot more work than on the SH as they are glued into the G-10 ferrules and not aluminium with grub screw arrangement like SH.The fuselage body is a lot thinner than the SH and I measured it to be around 0.03Ē and at first quite flimsy, but when it is assembled itís a lot stiffer.

I noticed the 20A ESC that I bought got hot just with the flap test so I will not be surprised if this gets fried. I will have to look into a more meatier one but the unmarked one that comes with it Iíve heard is poor giving low resolution on throttle control and jerky like movements.

I think Iím good to go for a maiden test flight now, weíve had 6 days of 80 to 90į heat and low wind so hopefully this weather will continue. It is very uncharacteristic for the UK I can ensure you.

Iíve certainly learnt a lot in the last couple of weeks, thanks to you guys and JTM. Letís hope I have a bit more initial success than with SH. Iím not going to test SH until I replace the spars, it has suddenly decided to flight to the right even with full left rudder on!
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Old Jul 17, 2013, 10:10 PM
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Ft Lauderdale, FL.
Joined Jan 2007
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man that is a nice looking bird I am Jealous...
Petey....
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Old Jul 18, 2013, 03:36 AM
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United Kingdom, Scotland, Chirnside
Joined Jun 2013
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Originally Posted by Machy2k View Post
man that is a nice looking bird I am Jealous...
Petey....
Hey thanks Petey, let's hope it flies ok. Not convinced yet as it doesn't seem a whole lot of force required to overcome the elevator servo, but only one way to find out. Should I be on full throttle for launching? It seems a lot more powerful than the slow hawk. Forgot to say that the power pack is a 1000mAh so not too heavy. Cheers John
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Old Jul 18, 2013, 12:05 PM
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United States, LA, Port Allen
Joined Oct 2011
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SK Orni Elevator Servo

I received an addendum from Sean after I got my Lazy Hawk. It said to install the servo from the other side of the body. (Servo mount flanges on opposite side of the body from the output arm). At the time, I wondered why, but your problem seems to shed light on the answer to that question.
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Old Jul 18, 2013, 01:30 PM
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Ft Lauderdale, FL.
Joined Jan 2007
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Originally Posted by Papa51 View Post
I received an addendum from Sean after I got my Lazy Hawk. It said to install the servo from the other side of the body. (Servo mount flanges on opposite side of the body from the output arm). At the time, I wondered why, but your problem seems to shed light on the answer to that question.
He's right John Mount the servo from the other side..
Also, Anytime I put the cross servo arm on the rudder servo if it will not align, it usually does if rotated 180 degrees, I would center the trims and check again at least...
Petey...
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Old Jul 18, 2013, 05:13 PM
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United Kingdom, Scotland, Chirnside
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Originally Posted by Machy2k View Post
He's right John Mount the servo from the other side..
Also, Anytime I put the cross servo arm on the rudder servo if it will not align, it usually does if rotated 180 degrees, I would center the trims and check again at least...
Petey...
Thanks Papa51 and Petey. It's good to know other people have had these teething issues too. As I said, if you follow the instructions word for word they do not actually correspond the the model in question. It also says to put the output shaft towards the head; doing it this way and it barely operates the tail. I gave a quick flapping test but the nut came off and the wing came off so have not flight tested yet. I will wait until my spare M3 x 1" bolts and M3 lock nuts arrive; I will also loc-tite these to be double sure. Boy does this bird flap! I will also do what you said regarding the rudder and put back to zero on the trim!
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Old Jul 20, 2013, 05:54 PM
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Well I've now replaced the connecting rod bolts and new locking nuts. Just to confirm the threads on those are 3mm x 1inch length high tensile and require a 2.5mm hexagonal Allen wrench key. I added loc-tite even though its a locking nut just as an added precaution.

I did what was suggested and put the tail servo from the port (left) side. I then added a new 2mm bolt, with three 2mm washers then 2 nuts, one for locking on the other side of the servo arm. This has also had loc-tite 243 added.

I haven't removed the tail and turned the cross shaped arm round to see if it's more square as of yet.
There still seems to be a little play with the tail and again the servo constantly buzzes as the weight of the tail is enough to start the servo buzzing from the neutral position. Is this normal? I can't help but think that the tail is the weak point.

I'm ready for a test flight but not sure if I'll get the chance tomorrow, will let you know how I get on. Cheers John

Oh, battery is now central on the
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Old Jul 20, 2013, 07:06 PM
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Loving the colour !!
Looks good to me, and great tip on the servo mounting from papa51

COG I believe should be around where the front V green strips on your wing meet the fuselage,
Rearwards from this, on maiden flights, not an issue, it will still fly.
can anyone comment on COG please if I am wrong.

Check the tail angle, looks a bit low at neutral ?,
but trim it up anyway on launch.
(generally bigger birds need more up elevator)

My DS-939MG arrived !!!, installed it in my LH, hope this will solve it !

Go for it !
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Last edited by jtm2003; Jul 20, 2013 at 07:53 PM.
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Old Jul 22, 2013, 11:02 AM
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Originally Posted by jtm2003 View Post
Loving the colour !!
Looks good to me, and great tip on the servo mounting from papa51

COG I believe should be around where the front V green strips on your wing meet the fuselage,
Rearwards from this, on maiden flights, not an issue, it will still fly.
can anyone comment on COG please if I am wrong.

Check the tail angle, looks a bit low at neutral ?,
but trim it up anyway on launch.
(generally bigger birds need more up elevator)

My DS-939MG arrived !!!, installed it in my LH, hope this will solve it !

Go for it !
Hi Jtm,

Well maidened my GH today but with little success. aving the same problems as you, it will rise and then nose dive so unable to get the thing flying as of yet. I noticed that my elevator was not moving up after the first nose dive. I've used a 2mm bolt to attach the arm but it is too tight so need to slack off the nut so the arm can pivot freely. I will then lock that nut in position with a 2nd nut and add loc-tite. Just wish I had tiny spanners for that small size! Perhaps as you said my elevator angle in neutral is too shallow, I'm measuring the angle between the tail and the top of the fuselage which to me should be the horizontal. I do fear the servo is being overloaded like you LH though. How did you get on with the new servo? Not much time left, this heat wave is going to be ending soon, back to the normal rainy conditions! Cheers John
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Old Jul 22, 2013, 05:32 PM
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Down at flying field sunday, but too gusting to launch the LH, so we flew the discovery instead.
Work also getting in the way, early start/late finish, but I finish my current assignment this week !!!!, so more time on my hands next week ! whoo hooh !
My son will video the LH launch, from the side, so I can see what is happening.
Leave some slack in the servo pivot arm, the bolt should not be tight against the servo arm, two nuts should be fine, but why not just use one nut, with loctite (or superglue).
Spanner wise, you can get away with using needle nosed pliers if your careful, does not need to be tight.
Mine did not rise at all, straight in, nose dive from launch.
So at least yours is rising ?
Your tail servo, you mentioned earlier was also buzzing ?, not a good sign on a non digital.
Gently move the servo arm by hand when switched off, then compare it to the rudder servo.
There should be resistance, i.e. hard to turn. is it the same resistance on both servo's?
If not, you got a duff servo, that won't hold.
My elevator servo..... was so easy to turn, so I now knew something not right.
I'll strip it down and send pics.

Just got massive thunderstorm over my house, often the day after is the BEST day to go flying.

regards
John
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Old Jul 22, 2013, 06:25 PM
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Ft Lauderdale, FL.
Joined Jan 2007
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Man I cannot believe you guys are having these performance problems, I actually started to re-read the instructions posted on Kinkade's site, and I see some good troubleshooting, not too much though about launching and diving..
I find these Orni's are sort of organic and sometimes they need to flex a little before everything is seated properly, but I always double check everything anyway...
Good Luck..
Petey...
Ps: I just got my 3d printed Orni. from Shapeways and the rest of my stuff from Hobbyking, and I now have everything I need to make Kazu Kaku's Kestrel...
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