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Old Oct 19, 2012, 01:25 PM
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Originally Posted by therealthing691 View Post
post a picture where is it broken
It is in 4 pieces , not just a single break . Was gling very high , pleay with 2 inquisitive falcons when one wing spar collapsed- yes it is in 4 pieces
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Old Mar 16, 2013, 05:53 PM
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United States, CA, Morongo Valley
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Here's a few things I've been able to come up with. These apply to LH, though might apply to others, as well:

Kitebuilder.com has the slit dacron. You want the 3.9oz material. They had ripstop listed, but for some reason he said he ran out and customer service is virtually non-existent from this guy.

Adhesive transfer tape for dacron is 3M 9485PC. Most vendors sell it in bulk, but you can find individual rolls on eBay. 1-inch width seems to make the most sense to purchase.

F168ZZ Main bearings that the Ferrules ride on: http://www.rcbearings.com/individual-bearings/f168zz

10T Motor Pinion (48P 1/8"): http://www.allerc.com (type '48 Pitch' in their search box).

Plastic drive gears from servocity: 48P/84T main and 32P/64T secondaries.

For Ferrule material, SAB Goblin 700 skids are 2.5mm Carbon Fiber and work well as a base. I'll bet you could double them up and make virtually indestructible ferrules. I may do it someday, but will have to find slightly less thick spacing material.

I also suggest that you add bearings to the main pivoting screws of the ferrules (2 per ferrule). MF63ZZ bearings work well for this application: http://helidirect.com/abec-3-flange-...3zz-p-1201.hdx. You'll have to enlarge the holes with a reamer to accomodate the bearings, but it is worth it. Since upgrading to CF Ferrules and putting the bearings on, any crash damage has been absorbed by the bearings (meaning I haven't broke a ferulle or spar since doing this mod).

Goblin 700 battery trays (small or large) are 1.5mm CF, are fairly inexpensive, and work well for minor repairs. I had to do the rear most main wing support and tail anchor on my bird and this material worked awesome.

For the wire pinion (pinion gear that drives secondaries), I found it on Amazon: Boston Gear Drawn Pinion Wire, 14.5 Degree Pressure Angle, Steel, 32 Pitch, 6-Tooth. It is not cheap.

I suggest replacing the 6/32 hardware supplied with the kit with M3 hardware (preferably shouldered bolts), especially on the ferrules. Mine snapped after only a couple of flights, hence the need for replacement bearings. http://helidirect.com/t-rex-500-flyb...er-p-14304.hdx

For the rubber caps that go on the ends of the spars, any decent hardware store will have assorted sizes of what they will know as 'screw-end protector caps'.

Thanks to others that have contributed to this thread. My bird would have been dead in the water without your help!
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Old Mar 17, 2013, 01:15 AM
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I guess me trying to re-open the business is moot now....since everyone is advertising how to and what to do here.
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Old Mar 17, 2013, 01:16 AM
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That should Please Otto to no end too! Bet he's grinning from ear to ear right now.....

Thank you Gregg!!! Your full refund will arrive via USPS M.O. as soon as I get into Sean's bank account!
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Old Mar 17, 2013, 03:20 AM
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United States, CA, Morongo Valley
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I don't think offering suggestions for procurement of materials is in anyway hindering your continuing forward. It's not like I'm divulging trade secrets here. I'm saving fellow hobbyists the boatload of legwork that it took to gather this info. It's also for my future reference.

It is not economically viable for an individual to gather the material necessary to build one these birds. Let alone the workmanship required.

But, if you want to fabricate excuses instead of a deliverable product, feel free to use me as the scapegoat. All I'm doing is making it possible for people to keep their birds in the air. There hasn't been much of an alternative and we were kind of hoping that you were going to change that.
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Old Mar 17, 2013, 09:13 AM
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Originally Posted by heli-on View Post
i don't think offering suggestions for procurement of materials is in anyway hindering your continuing forward. It's not like i'm divulging trade secrets here. I'm saving fellow hobbyists the boatload of legwork that it took to gather this info. It's also for my future reference.

It is not economically viable for an individual to gather the material necessary to build one these birds. Let alone the workmanship required.

But, if you want to fabricate excuses instead of a deliverable product, feel free to use me as the scapegoat. All i'm doing is making it possible for people to keep their birds in the air. There hasn't been much of an alternative and we were kind of hoping that you were going to change that.
The tape was a trade secret as far as I knew!!!! I am not fabricating an excuse or using you as a scapegoat!
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Old Mar 18, 2013, 09:39 PM
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Originally Posted by MrsThopter View Post
The tape was a trade secret as far as I knew!!!! I am not fabricating an excuse or using you as a scapegoat!
Carol i dont think by posting this stuff anybody suffers and this has been discussed for a long time in here .This forum is about discussing and sharing idea's. It is not hard to find out what materials are used when you own one. Having the knowledge to make one is another thing.Building Ornithopters is not for all.I myself love to build things it gives you a sense of self satisfaction.That you made it with your own hands.As for the tape being a trade secret, it never was in my eyes. I have known that since i owned my sH1 in 2007 and rang a local racing sail builder and asked them where to get it. Knowing what someone is using and knowing how to use it is 2 different things for some, but not all.
kindest regards Brian
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Old May 19, 2013, 09:43 AM
Wid
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Broken Lazy Hawk

During flight of my SK Lazy Hawk I heard grinding noise and then flapping stopped. Hard landing. Inspection showed malfunction of gear shown below. The center metal gear rotates freely within the plastic gear wheel. I need to know:

Where do I obtain replacement parts?
What is the correct name and description of these parts?
Any instructions or hints on how to do this.

I did search but still need help.
Thanks
Wid
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Old May 19, 2013, 05:27 PM
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Carol, I think re-opening would be great and many people would support that very much. I do think it would not be a bad idea to also supply replacement parts as that would give some extra profit and also support your existing customers so that they are happy and return. If you find it is not feasible to do such, then I would suggest to put together a supplier's list for the parts when the birds do inevitably break. There are many here, I think, would help you if you needed such and keep Sean's dream alive too. I personally would like to reach out and offer help and support if you ever did need such. Please do re-open and I think you would do great as long as you can find a way to not only manufacture but also market and support the products. Either way, please would you keep me posted on what happens as I personally want to see Sean's designs live on and willing to help where and if I can.
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Old May 19, 2013, 05:49 PM
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Quote:
Originally Posted by Wid View Post
During flight of my SK Lazy Hawk I heard grinding noise and then flapping stopped. Hard landing. Inspection showed malfunction of gear shown below. The center metal gear rotates freely within the plastic gear wheel. I need to know:

Where do I obtain replacement parts?
What is the correct name and description of these parts?
Any instructions or hints on how to do this.

I did search but still need help.
Thanks
Wid
If you look closely at the gear you will find a set screw hole. The set screw is either loose or missing.
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Old May 19, 2013, 08:56 PM
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If you look closely at the gear you will find a set screw hole. The set screw is either loose or missing.
Thank you n553302. Yes I see it. That is way easier than I feared!
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Old May 19, 2013, 10:35 PM
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Thank you n553302. Yes I see it. That is way easier than I feared!
A carefully placed drop of slow curing CA will help hold the screw in place. Loctite is designed for metal to metal and not recommended for some plastics.
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Old May 20, 2013, 05:53 PM
Wid
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Quote:
Originally Posted by n553302 View Post
If you look closely at the gear you will find a set screw hole. The set screw is either loose or missing.
Quote:
Originally Posted by n553302 View Post
A carefully placed drop of slow curing CA will help hold the screw in place. Loctite is designed for metal to metal and not recommended for some plastics.
And be sure to not over tighten the set screw. Over tightening deforms the plastic gear. Loosening screw relieves warp.
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Old May 20, 2013, 07:17 PM
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And be sure to not over tighten the set screw. Over tightening deforms the plastic gear. Loosening screw relieves warp.
One of my birds had that screw come loose more than once, more than likely over tightened at sometime and the result was the hole became slightly off center. The screw would still hold and the bird would fly but the orbiting gear was audible under load during flight. I replaced the gear and all is well again.
Just something that comes to mind you may want to check, gear lash.
Happy flapping

Something else, if you do accidentally strip the hole, I've dealt with it two ways. Re-tap larger, works fine and I customized the tip of the set screw to mate nicely with the gear. Or just drill and tap a new hole. There is room for a few new holes.
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Old May 20, 2013, 09:14 PM
Wid
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Originally Posted by n553302 View Post
One of my birds had that screw come loose more than once, more than likely over tightened at sometime and the result was the hole became slightly off center. The screw would still hold and the bird would fly but the orbiting gear was audible under load during flight. I replaced the gear and all is well again.
Just something that comes to mind you may want to check, gear lash.
Happy flapping

Something else, if you do accidentally strip the hole, I've dealt with it two ways. Re-tap larger, works fine and I customized the tip of the set screw to mate nicely with the gear. Or just drill and tap a new hole. There is room for a few new holes.
The set screw seems secure. I'll watch it carefully.

I do have an audible gear noise since I bought the bird, a kind of chirping sound, due to the extra power needed during down stroke I imagine. There is some wear showing on the gears but certainly not excessive. I have wondered about lash and just sort of guessed at it. Just loose enough to turn freely, Tight enough to not be sloppy.

I fly enough that I expect to eventually need to replace parts. Where did you get your replacement gear? If it is a Lazy Hawk gear what are it's specifications? I wish there were an exploded diagram with part names and specs. I fly often and plan to maintain the bird for a long time.

Thanks for your help. I was able to fly today because of it.
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Last edited by Wid; May 20, 2013 at 09:20 PM.
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