ARROW (CF-105) from HK

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Rob
Posts: 175
Joined: Fri May 06, 2011 10:13 am

Re: ARROW (CF-105) from HK

Unread post by Rob » Sat Feb 25, 2012 5:36 pm

In the front I've installed a steerable servoless retract again from Hobby King. It took a fair bit of wood and fibreglass cutting to make it fit. The steering servo is the same HK metal gear unit as used in the wings.

http://www.hobbyking.com/hobbyking/stor ... aff=442574

I'm gluing the wings on tonight and will refit the retracts when they are dry. The hard part will be trying to fit in the ESC, air reservoir and spektrum receiver into the plane and keep obtain the correct Centre of Gravity. At the moment I'm planning to have the air reservoir in the nose, and the ESC and receiver by the fan (which is approximately where the CG is located).

I've test fitted 2 x 4S 25/50C 1300 mah nanotech batteries in the battery compartment and they fit with room to spare. They will be running in parallel.
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astroflyer
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Re: ARROW (CF-105) from HK

Unread post by astroflyer » Sat Feb 25, 2012 6:30 pm

retiredVTT wrote:Looking great Rob, I wonder if it's possible to restrict the air movement to slow down the retract...I have no experience with retracts.

Bill
robart and probably spring air have tiny plastic restricters that fit into those air lines. very small hole restricts air flow and slows the retraction speed.

should be able to order those easily.

Glen
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Joined: Tue Oct 13, 2009 7:31 pm

Re: ARROW (CF-105) from HK

Unread post by Glen » Sat Feb 25, 2012 6:36 pm

I think I saw some of them at Maritime the other day.

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retiredVTT
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Location: Bedford, NS
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Re: ARROW (CF-105) from HK

Unread post by retiredVTT » Sat Feb 25, 2012 9:08 pm

See Rob...all you had to do was ask.........Jeez..!

Thanks guys..!

Rob, I read in another thread that this model is nose heavy when built "stock" as suggested....so beware when adding additional weight up front and check twice...cut once..!

Bill
Bill
HEFA #5
MAAC #13708

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yorcram
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Re: ARROW (CF-105) from HK

Unread post by yorcram » Sat Feb 25, 2012 10:28 pm

Looking good Rob. As stated there are restricted that will slow down the airflow. I have used them in the past and they do work good. Keep the restrictions dial accessible for fine tuning.
M
Plane Crazey :D

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Rob
Posts: 175
Joined: Fri May 06, 2011 10:13 am

Re: ARROW (CF-105) from HK

Unread post by Rob » Mon Feb 27, 2012 9:13 am

Thanks guys, I'll look into the restrictor.

Bigger problem at the moment is the CG as Bill suggested. The plane is extremely nose heavy even with the esc, receiver, wing retracts and heavy RC Lander motor located at almost dead center of the CG. I could replace the front electric retract with an air retract but I don't think it will make much difference, even with one of my 4S 1300 mah batteries removed from the battery compartment the CG is much too far to the front.

I think the answer is moving one of the batteries to the rear of the plane by the ducted fan. I've heard this mentioned in other forms. Luckily I bought the 1300 mah batteries as one will fit in the rear compartment with just a bit of "trimming" of the fuselage. I'll set the components on the top of the plane before I do any trimming and check the CG to see if this will work. I weighed the plane and all fitted up it's coming in at about 1850g flying weight. Very heavy so I will only have about a 1:1 thrust to weight ratio at best. Going to land and take off rather hot I suspect so the maiden will have to be on the paved runway in Beaverbank, might need more runway length ... what's the chances of using Shearwater? :?

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retiredVTT
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Re: ARROW (CF-105) from HK

Unread post by retiredVTT » Mon Feb 27, 2012 12:39 pm

quote..."what's the chances of using Shearwater? "


...might be a whole lot better than you would think, but for now be patient and stay tuned,


Bill
Bill
HEFA #5
MAAC #13708

saboo
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Re: Shearwater

Unread post by saboo » Sat Mar 03, 2012 8:53 am

No mystery. Not secret.

See this post

http://www.asrcm.ns.ca/cgi-bin/yabb2/Ya ... 1328794781
Nothing like the smell of electrons in the morning ;-)

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Rob
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Re: ARROW (CF-105) from HK

Unread post by Rob » Sun Mar 11, 2012 9:42 pm

I had two ESCs to chose from, a Hobby Wing 60A and a Dlux 55A.
The Dlux weighs in at about 85-90 g with the wiring, the Hobby Wing is about 20g lighter.
Due to the CG being extremely far forward I decided on using the heavier Dlux ESC and place it to the rear of the CG, behind the ducted fan. Also, when I tested the Dlux seemed to run cooler and as there is not great air flow back there I hope it will not overheat. I may add some vents later.

http://www.hobbyking.com/hobbyking/stor ... aff=442574

Hard to see the Dlux hidden in there but it is, not a lot of room.
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Rob
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Re: ARROW (CF-105) from HK

Unread post by Rob » Sun Mar 11, 2012 9:48 pm

I'm going to use a six channel DSM2 receiver with satellite receiver. The main receiver will be just ahead of the ducted fan in the motor bay and the satellite will be in the nose. I have get an extension for the satellite to reach the nose. It will be routed on the bottom of the plane (same as the servo wires) between the intake ducts and the bottom of the plane. I had to use a 14AWG house wire to fish the servo wires, air line and satellite extension under the ducts. The wires exit in the battery compartment and in the nose cone.

The metal gear servos, horns and control rods, have been added. I used the horns and control rods that came with the Avro.
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