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Old Feb 16, 2009, 01:59 AM   #1
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The Official HJZ-Model Predator-II Thread

HJZ-Model Predator-II DLG



Hello DLG Fans,

May I introduce the new high performance DLG, Predator-II, designed and manufactured by Mr. Hung (a.k.a HJZ) from HJZ-Model, located at Taiwan. HJZ-Model utilizes the latest material and construction techniques to build this glider. The result is a light weight, strong, affordable, and outstanding performance handlaunch glider.

In order to make a very precise leading edge (LE) of the DLG wing, HJZ-Model develops a new technique called “half molded” wing. The top part of the wing is bagged in the mold (like hollow molded wing). and then bagged the bottom of the wing. This produces a super smooth and clean leading edge.

The wing platform has 4 panels each side. The wing tip section is CNC milled which makes it very precise and avoiding the possible errors by hand sanding.







The tail-sets are bagged and weights about 11.4g (rudder and elevator)




2.4G safe pod
Wing Span: 1485mm
Length: 1130mm
Airfoil: AG455-46-47
Wing Area: 21.97dm2
AUW: ~265g (~9.34oz) (the coming new kit is going to be even lighter )


You can get this glider at HJZ-Model's official website:
http://hjz-model.idv.tw/eshop/en/index.php

Yes, you didn't read it wrong.
The price of this kit is only $200

(please refer to the website for the latest price tag)



For more detailed information of this kit, please check the the building thread here in a separate thread:
http://www.rcgroups.com/forums/showthread.php?t=1002174
This is the easiest build we have ever had for a DLG kit

For flight report, please check the flight report by Bob McGowan.

http://bayrc.com/boards/viewtopic.php?t=4809

-Kai

Last edited by Kai@UCSB; Feb 16, 2009 at 03:25 AM.
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Old Feb 16, 2009, 02:00 AM   #2
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The designer of the Predator-II DLG is a well-known glider designer, pilot, kit-producer, and builder at Taiwan.
He is not only an expert in DLG but also in F3F planes.

Here are some of his designs:

F3F: http://www.rcgroups.com/forums/showthread.php?t=781685

F3K: http://www.rcgroups.com/forums/showthread.php?t=388878 (Predator-I)




New F3K: http://hjz-model.idv.tw

-Kai

Last edited by Kai@UCSB; Feb 16, 2009 at 03:06 AM.
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Old Feb 16, 2009, 02:01 AM   #3
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Here are some more nice pictures. Enjoy it.








Last edited by Kai@UCSB; Feb 16, 2009 at 02:11 AM.
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Old Feb 16, 2009, 02:01 AM   #4
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Color Option...



Metallic Dark Green



Metallic Blue



Metallic Black



Other Colors...


Last edited by Kai@UCSB; Feb 16, 2009 at 02:16 AM.
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Old Feb 16, 2009, 02:08 AM   #5
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A Short Flight Report from Bob McGowan (http://bayrc.com/boards/viewtopic.ph...r=asc&start=15)
---------------------------------------------------------------------------

Once I got serious, this DLG went together real fast. I was skeptical of the wing alignment jig used, but it worked great allowing you to easily join the wing, set dihedral angle, and make the hold down screw holes in perfect position in one step. Thanks for the help on that step Dom. Becouse the recieving threads in the fusilage are done at the factory, that's another big building step avoided.

The pull line supplied is amazing! Very light and very low stretch. This must be why the pull-pull is working much better than the other pull-pull systems I have used.

The tails are so light that I had to add 4 grams of tail weight. I used 4 nine gram Airtronics servos up front and the Airtronics 2.4 gig receiver which is about 8 grams without case. When I saw that I was nose heavy I went to a very light single 450 mah lipo cell for power but I still was slightly nose heavy. I guess I need the new lighter and smaller receiver that Airtronics is working on. Another way around this “problem” (a very good type of problem to have by the way) would be to use lighter servos than the 9 gram ones I picked.

The thing I like about the kit the most is the quality of the wing. It is very light and appears to have a very accurate profile. The leading edge and trailing edge are excellent. The wing tips are the best I’ve ever seen on a bagged DLG. It is not really fair to call this wing bagged because the top surface is sucked down into a high quality female mold and only the bottom side is what we think of as a traditional bagged surface. The top surface is just as shinny and accurate as any hollow molded wing.

My final weight came out at 9.4 ounces. Just from the first javelin hand launch we could tell this thing was going to be a real floater as it just kept going and going. It launches strait and high. It ranges far in search of lift. It floats excellent if that is what you need to do. If the rumor of the target street price in the USA will be what I’ve heard, this will be an amazingly good value which should sell very well and hopefully allow more people to get into the hobby. Good job on the kit Mr. Hung!

Last edited by Kai@UCSB; Feb 16, 2009 at 02:18 AM.
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Old Feb 16, 2009, 01:20 PM   #6
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That's a very nice DLG.

Is there a plan to offer Kevlar, carbon or disser version wing in the near future?

Geode
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Old Feb 16, 2009, 11:28 PM   #7
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Quote:
Originally Posted by Geode
That's a very nice DLG.
Is there a plan to offer Kevlar, carbon or disser version wing in the near future?
Geode
Hello Geode,

I heard that there are several versions in the development/research pipeline in the future.
But, personally, I think the Predator-II is a very good DLG as it is now, especially for the price and performance.

I flew the Predator-II for about 3 weeks now, the glass wing works perfectly.
Not sure if I can tell the difference between the glass wing and other Kevlar wings DLG I have. But the LE shape is definitely the best among all the bagged wings I have.

PS: The Predator-I is a moldie one

-Kai
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Old Feb 17, 2009, 11:13 AM   #8
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$200 Wow

I think we all want to see the DLG sport grow. In the past this objective has been hampered when beginners would buy cheap planes with poor performance or be turned off by the high price of high performance DLGs. What do we tell the guy who shows interest in DLG? This new plane is the answer.

There are three Predators flying in the US currently. I built and am flying one of the three. This is already a well refined design that has swept the local Taiwan scene. HJZ is ready to open up sales to the US now.

HJZ has the capability of making far more complex/advanced DLGs. They are CNC and composites experts. As an example of their capability, Kai showed a picture of one of their hollow molded DLGs sold only in Taiwan. Please understand HJZ is not a fledgling garage shop operation, but a manufacturer of quality composite parts such as those for high end bicycles. The owner, CJ, just happens to have a passion for RC sailplanes so he is working these projects in with normal production.

The Predator project goal as I understand it was to make a high performance DLG and offer it to the consumer at the lowest possible rock bottom price. This would be their answer for the entry to mid level markets and future offerings would answer the high end market. The design and tooling lends itself to low cost manufacturing. Dealer markup and the extra layer of domestic shipping is avoided by direct sales only. This results in a price to your door that does not fall on the normal price/performance curve for DLGs. $200 for a sub 9.5 ounce competition level DLG is unheard of. Yes, competition level – while not an SALpeter, the Predator is competitive and a step up from many planes you see on the contest circuit today.

The quality and value of the plane will sell itself. Kai organized a group buy for the Bay Area. People liked what they saw when they inspected our three Predators in person. I am astonished that 29 people have signed up for Kai’s group buy. That is almost double the number of contestants at our last DLG contest. This is a good sign that our Bay Area DLG scene may see a big jump in participants this summer.

Bob
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Old Feb 18, 2009, 01:46 AM   #9
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Quote:
Originally Posted by Kai@UCSB
I flew the Predator-II for about 3 weeks now, the glass wing works perfectly.
If the glass wing can survive Bob and your launch, I'm quite sure it is more than enough strength for me.

Geode
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Old Feb 18, 2009, 09:19 PM   #10
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Quote:
Originally Posted by Geode
If the glass wing can survive Bob and your launch, I'm quite sure it is more than enough strength for me.
Geode
Hello Geode,

Bob and I launch this like crazy in windy day and the wing is definitely strong enough to take our launch. Hehe...

-Kai
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Old Feb 18, 2009, 09:29 PM   #11
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Now you need to put the Altimeter in you Predator II to show off how high you launch .....
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Old Feb 20, 2009, 01:39 PM   #12
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We will do the launch high test this weekend.

HJZ-Model just announced that the new wings they are making now will be 4-gram lighter on each side. Woooo!





-Kai
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Old Feb 20, 2009, 02:28 PM   #13
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can you tell me the weight of the rudder and elevator per piece??
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Old Feb 20, 2009, 02:33 PM   #14
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Kai, do you know what density of foam is being used in both the Wing and tail?
Also what glass cloth weight is being used to get this weight?
Maybe you have already stated this somewhere, but I couldn't find it...

The model looks Great!

Jeff

Last edited by Jeff Winder; Feb 20, 2009 at 03:22 PM.
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Old Feb 21, 2009, 02:52 AM   #15
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Quote:
Originally Posted by robert14
can you tell me the weight of the rudder and elevator per piece??
I post this information in the build thread and here are the numbers.
http://www.rcgroups.com/forums/showt...=1002174&pp=50

Fuselage: 43g
Right Wing: 60g
Left Wing: 60g
Rudder: 4.8g
Elevator: 5g
Boom: 16g
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