100" Mosquito Bomber for Electric Power

100" Mosquito Bomber for Electric Power

Postby Adam » Fri Nov 09, 2012 3:26 pm

We are currently Building the Mick Reeves 100" DH-98 Mosquito Bomber.

The power will come from a pair of AXI 53/30 F3A Outrunner Brushless Motors 235 rpm/v each running on a 10 Cell 5000mah Lithium Pack through a Castle Creations 85AMP Speed controller and Spinning 3 Blade 19 x 10 Props, All up about 8kw ( near 12hp ) of Power

Control is going to be provided by the Trusty JR PCM12x using a 2.4ghz DSM-J reciever and Digital servos all around , Retracts are Modified MR Products using Robart Air control System.

A am not going to give you a step by step guide to Building the model but just an overview of the things that are different to anything i have built before.

Adam..
Attachments
eeg.jpg
eeg.jpg (78.5 KiB) Viewed 11588 times
mosquitoEGE.jpg
It will look like this , but with Invasion Stripes to Aid visability , after flying a few warbirds I know how well they Disappear
mosquitoEGE.jpg (26.51 KiB) Viewed 11598 times
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Re: 100" Mosquito Bomber for Electric Power

Postby ash » Fri Nov 09, 2012 4:25 pm

Yay, more construction content! :D

Good luck with the build.
Adrian Hamilton > CL + FF

http://ashcustomworks.com
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Re: 100" Mosquito Bomber for Electric Power

Postby Adam » Sat Nov 10, 2012 8:48 pm

The basic construction went together really well.
This kit comes with Laser cut balsa ribs but you have to supply all your own spars & sheeting etc.
Wing & Tail construction was very straight forward and we quickly had wing panels with Ailerons & flaps.
Attachments
wing panel.JPG
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Re: 100" Mosquito Bomber for Electric Power

Postby Adam » Sat Nov 10, 2012 8:50 pm

While Dad was working on the balsa built up Wing & Tails I started on the engine mounts & working out how to cool these Monster Motors. ( more on that later if i remember )
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engine mount plate.JPG
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Re: 100" Mosquito Bomber for Electric Power

Postby Adam » Sat Nov 10, 2012 8:59 pm

Once the tail is attached to the centre section it is a huge fibreglass moulding , There are 3 lasercut plywood spars ( leading edge , main spar & trailing edge ) the engine mount bearers run from the main spar through the leading edge to the front of the engine nacelle.
The Undercarriage is mounted onto the engine Bearers just behind the leading edge ( more details on this later ) then the motors will be attached to the front of these bearers using a carbon fibre reinforced plywood former ( shown previously ) this will also be epoxyed into the fibreglass moulding.
Attachments
centre section.JPG
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Re: 100" Mosquito Bomber for Electric Power

Postby Adam » Sat Nov 10, 2012 9:07 pm

The gear doors were cut from the glass shells and hinged using a figue 2 shaped hinge and a 2mm pin through a plastic tube epoxied into the inside of the wheel well.
These hinges were required to allow the doors to open wider than the cutout so the wheels dont catch the doors on the way up.
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gear doors open.JPG
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Re: 100" Mosquito Bomber for Electric Power

Postby Adam » Sat Nov 10, 2012 9:15 pm

Now the fun really started , trying to get the wing panels to fit onto the centre section , the holes cut in the plywood ribs were not in the right place , we spent hours with the Dremel & sanding drum carving slots in the endribs so we could get the wing panels to match the centre section & have the same dihedral and incedence on the left & right sides.

After much cutting the wing joiner tubes are glued in place with plywood doublers to hold them & plenty of epoxy & micro balloons to fill the gaps.

Now the wing panels are fitted its time to start thinking about the Flaps , the Inner one is easy , but the outer one needs to disconnect as the wing panel is removed and just to make it difficult the hinge line is not parallel to the wing joiner tube so i cant just use a square tube to drive the flap.
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wing on.JPG
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Re: 100" Mosquito Bomber for Electric Power

Postby Adam » Sun Nov 18, 2012 7:16 pm

A little progress on the Mosquito in the last week, the stabs & elevators are all finished , the fin & rudder are hinged and all ready to attach.
This afternoon was the first time we had all the parts together , its a big model.

The flaps are giving us stress , the inner & outer flap dont share a hinge line so they cannot be connected together, also the hinge points marked on the plan mean that the leading edge of the flap protudes above the top surface of the wing as the flap moves down , thats not right , so on to the second set of flaps with the hinge point furthur forward , so its as far back from the leading edge as it is down from the top of the flap ( remember they are bottom hinged with a nice radiused front )
Attachments
plan view.JPG
the wings and tail are trial fitted & aligned.
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Re: 100" Mosquito Bomber for Electric Power

Postby Dale » Thu Nov 22, 2012 3:56 pm

Nice work! Can't have too many Mosquitos around the place.
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Re: 100" Mosquito Bomber for Electric Power

Postby Adam » Sat Dec 01, 2012 8:03 pm

Had a bit of a milestone today , got the first retract to work under its own power with a robart air ram, it took a bit os messing around to get it all to clear the legs when they retract.
It was a bit of a bodge up job with a flexible pushrod and ball joint just jammed into the air cylinder , but it proved the geometery worked , so in the next couple of days i hope to jump on the lathe and make the proper metal fittings and install it all properly , then i think its time for another photo.

Starting to think seriously about the doors , i dont think the wheels will push them open like the real one does , its all a bit too flexible, thinking a mini servo on the back door hinge. maybe a mock up of that just to prove it.

Glad i have the JR PCM 12x this radio just makes it so easy to do gear and doors on separate channels with a programable mix and a delay between doors opening & gear coming down , then gear up and safe before the doors close.
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