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Old Apr 26, 2010, 11:57 PM
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Thanks Allan!
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Old Apr 27, 2010, 06:36 PM
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Pete Thomas's Avatar
Lakewood, Washington
Joined Sep 2008
308 Posts
I have a question regarding motor cooling. I did not install the clear acrylic baffles behind the intake grill so I have a tremendous amount of air coming into the motor/battery/ESC compartment. However there is no way for air to escape to create a cooling effect. How have you handled the airflow across your motor, battery, and ESC? If you drilled ventilation holes, could you describe where ( include photo if possible)? Do you recommend using the baffles to obtain an optimum air-in/air-out ratio?. I was entertaining the idea of trying to open up the cockpit area around the pilot.

Thanks in advance, Pete
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Old Apr 27, 2010, 06:51 PM
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Skylakes Airport
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I use a 15 X 10 electric prop on mine, also no cooling baffles and my motor runs cool.
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Old Apr 28, 2010, 07:51 AM
Gambler-AG DLG Designer
Allan Wright's Avatar
Lee, NH, USA
Joined Jun 2001
5,188 Posts
Quote:
Originally Posted by Pete Thomas View Post
I have a question regarding motor cooling. I did not install the clear acrylic baffles behind the intake grill so I have a tremendous amount of air coming into the motor/battery/ESC compartment. However there is no way for air to escape to create a cooling effect. How have you handled the airflow across your motor, battery, and ESC? If you drilled ventilation holes, could you describe where ( include photo if possible)? Do you recommend using the baffles to obtain an optimum air-in/air-out ratio?. I was entertaining the idea of trying to open up the cockpit area around the pilot.

Thanks in advance, Pete
My kit didn't come with any clear baffles. If it did I would have discarded them anyway. I cut an exit hole in the rear of the fuselage forward of the tail skid about 3"x3". Normally I like my exit hole to be larger than my entrance hole, but with this plane, the large open grill makes that impossible.

I never had a problem with battery cooling with this set up.
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Old Apr 29, 2010, 09:22 AM
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Lakewood, Washington
Joined Sep 2008
308 Posts
Thanks guys. I will leave the baffles off and will start by opening up the cockpit area around the pilot. I'll post some photos on how I do it and let you know how it works out. The weekend forecast looks flyable so far (at least or large planes) so I hope to get in 4-6 battery packs tomorrow.

Pete
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Old Apr 29, 2010, 09:28 AM
Gambler-AG DLG Designer
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Lee, NH, USA
Joined Jun 2001
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The cockpit area sounds like a clever choice. It should look good.
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Old Apr 29, 2010, 06:20 PM
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The turnigy motor I picked fits almost perfect. I will need to trim about a 1/16 of an inch or so off the cowl around the bottom prop adapter area (the turnigy has a bolt on adapter instead of a collar type so it is bigger).

The bolt pattern on the turnigy "X" mount is slightly wider spacing than the template power 60 pattern but it was easy to do and in hind sight, because of the spacers, the templates hole locations would probably work, it's that close.

In the pic I had to hold the cowl on and the camera, but when the cowl is on tight the prop clearance looks good.

There's room for the speaker too and the cowl grill is.....well a speaker grill .

The speaker weighs about 6.5 oz roughly the weight of nose lead needed to balance the model as reported.
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Old Apr 30, 2010, 09:21 AM
Gambler-AG DLG Designer
Allan Wright's Avatar
Lee, NH, USA
Joined Jun 2001
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That's a great place for the speaker. If you're going to have to add nose weight anyway, it might as well benefit you!
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Old May 01, 2010, 02:57 PM
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Yes, may as well use the weight for something.

There will be enough wiring for a VW beetle when done.
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Old May 04, 2010, 11:33 AM
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Almost all electronics and wiring is done, took some work to get it all to where it was going and to keep the battery bay clear.

Used plumbers strap to mount the speaker (2 little angled brackets on the bottom and 2 straps on top, with 4 wood screws and 4 rivets) it is nice and rigid.

cheers
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Old May 18, 2010, 04:34 PM
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Lakewood, Washington
Joined Sep 2008
308 Posts
Well, I finally have 13 flights on the DVII. I was a bit nervous on flight number 13 due to my superstition, but it went like clockwork. I am very impressed with how easy this plane is to fly and land. The last two flying days were in 2-3 mph wind which is about as dead calm as it gets around here during spring.

The DVII balances out perfectly. I’ve included a few photos showing where I located the 7 ounces of lead to obtain a CG of 3 5/8” behind the leading edge. 1 1/2 ounces of lead were added to each side of the fuselage adjacent to the motor. The remaining 4 ounces were attached to the inside of the cowl as far forward as I could get away with. I also replaced the steel rudder and elevator control rods with carbon fiber rods and attached short (3”) Z-bend connectors to each end using CA and thread. This reduced the weight aft of the cockpit thereby minimizing the amount of lead that I had to add to the nose. As you can see from one of the photos, the battery (6s 3700 mAh Rhino) is moved 5/8” forward of the mounting plate to get as much weight forward as possible.

I ended up going with 2 channel aileron control (Aileron on right aileron and and Flap1 on left aileron using Spektrum AR6200 receiver). This allowed me to precisely center the ailerons and add 35% aileron differential. Even though I fly using coordinated turns (start my turn with rudder and then add a slight bit of opposite aileron and up-elevator), there was no detectable yaw if a made a turn using just the aileron.
This plane tracks beautifully. The E-Flite 60 motor produces awesome power. As mentioned previously, I chose to go with a Castle 75 amp ESC in lieu of the 60 amp that was recommended. I also chose to go with a Vox 15 X 8 wooden E-prop because it weighs about 7 grams less than the APC prop, is perfectly balanced, and looks cool (purchased through Precision Aerobatics). I still plan to sand off the Vox logo and clear coat the prop with a satin finish.
One final modification I made for now was to create an air-exit for better ventilation/cooling of the electronics. I opened up about 3 square inches in front of the pilot in the cockpit and between the Spandau guns as seen in the attached photos. I may still open up an additional 2 square inch area behind the pilot to allow for more cooling this summer.

I also plan to remove one of the o-rings on the landing gear suspension and try it with just a single o-ring. Our field is mildly bumpy, however it would take a very hard landing to make the two o-rings move. I think the single o-ring will provide better suspension for normal landings and take-offs, knowing that I will have to replace them about once per month as a preventative measure. I’ll report on how that works out.

This Fokker DVII has quickly become my favorite plane but is definitely not a park flyer. I will only fly this at an AMA sanctioned field with plenty of room and not at our local flying site in South Tacoma. We have a nice electric-only AMA field about 30 minutes south of here in Olympia.

Till next time, Pete.
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Old May 19, 2010, 08:05 AM
Gambler-AG DLG Designer
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Lee, NH, USA
Joined Jun 2001
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Nice clean install.
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Old May 19, 2010, 01:01 PM
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Pawtucket R.I.
Joined May 2008
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Hi Guys,Ive decided to put my DV11 together,its been sitting over in the corner for about 7 mos. and I finally have the time.Ive got a question,my buddy has a couple of 5s 4000mha LiPos hes no longer using I was thinking of buying them but there 20c . Should I get 25c or will 20 cut it,Im using the 60 size 400 kv Exceede motor.Also would two 3s 4000 mha batts. be prefferable to one 6s 4000 ? Im using 4000 as a general figure. Im thinking one 6s 25c would be best. Any help would be appreciated. Thanks. Brutus
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Old May 19, 2010, 01:08 PM
Gambler-AG DLG Designer
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Lee, NH, USA
Joined Jun 2001
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4000 mah cells at 20c is 80 amps. My setup pulled a lot less than that.
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Old May 19, 2010, 01:17 PM
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Pawtucket R.I.
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Thanks,I really appreciate it.I guess thats what Ill go with. 10 min. flight time should be no problem? Im flying scale ,no full bore stuff or acro. B
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