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B.26 Martin Marauder build from plans,for twin electric power


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Congratulations.
 
I don't have any kids (that I know about) but having A) watched what happens when members bring their sons to the club and B) having had a father who was really into sports, don't even try to force him into being an aeromodeller. It isn't worth the hassle for either of you.
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"PS they get even worse as they get older"
 
Ha! I can concur Timbo, I have 3 girls too, didn't sleep much last night as my 18 month old thought it would be good to cry half the night in sympathy!!
 
I got my 4 blade props today, so will run some tests with my intended 750kv Hobby King motors on Thursday,I must say, they look absolutely gorgeous!

Edited By Matt Halton on 08/04/2009 16:17:45

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Ok, I installed the nosegear,same as the one used in the HL Exec Jet retract system.
Had to chop off the sliding steering arm, as it was hitting the ply mount, so will make a tiller using kevlar sheet,and this will set me up for push pull steering.

I wanted to get the noseleg angle dangle right (canted forward) but had to bury the noseleg deeper into the fuse, just under the cabin floor. Added 2 x 1/4" x 3/8" beams to screw the unit into, also made 2 wedges from the same stuff to get it tilting the right amount.

I will use an HS 85MG servo to retract if I can't get away with using a regular 9 gram servo first!

The nosewheel is from the Phase 3 P-38 kit,as I didn't use the gears,I knew it would come in useful for another project, but was oversize, so put it in the freezer and reprofiled it using fairly coarse paper with the wheel spinning in my dremel.

Added some more nose stringers from 1/8th balsa (not on the plan) in order the add strength in the nose with the balsa skin in place.

Mains next, added the mounting beams, then will add an 1/8th birch ply mounting plate for the maingear. I'm using the .40 size Hobby City gears which are very sturdy with negligible weight gain. These will be driven by 2 GWS 'Park' servos, which are kinda midway between mini and standard servos.

The servo count in this plane is 9 servos:
Flaps: 2 servos
Gears: 3 servos
Rudder 1 servo
Elevators: 1 servo
Ailerons: 2 servos

I'll isolate the ESC's and use a 4.8v nicad pack to drive the servos!

This plane should operate easily from grass with a 2 1/4" nosewheel and 3" mains,so that's good.

I put the model on my digital scales and weighs 1lb 8oz with both motors,all retracts and wheels.This will be less when the maingear wires are cut shorter.Not weighed: servos, ESC's, props,4 cell NiCad flight pack and 3S 2500 lipo.

I still think it's possible to hit my target weight of 4.5lbs

Maingear install and all retract servos tomorrow.
Cutting into the liteply to get the nosegear in.
On the scales with motors,retracts added for a quick weight check
1lb 8 oz, pluse 2.5 oz for tail parts to add, not bad so far
Hardwood maingear beams and unit for reference next to nacelle.
Angle dangle
Actuating rod exits beneath cabin floor
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Installed one retract today,what a difficult job deciding where to place the servo! That's what took longer than anything. I'm wondering,if I have 3 different servos, how can I adjust the endpoints, is this gonna be hassle?
Also, the servo speed is very fast, I need a servo slow fer sure!

Watch the attach video and see...
 
 
 

Edited By Matt Halton on 11/04/2009 16:43:18

Edited By Matt Halton on 11/04/2009 16:44:42

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Did some more today,all retract servos are in and working, but I have 2 small problems.

I have a 'Y' lead in the system, but is only good for 2 gears, but I'm guessing I can piggy back another lead into one of the 'Y' leads?
Can anyone confirm it's ok to do this before I go and screw things up please? (no spare 'Y' leads)

2nd problem,one of the gears is moving the wrong way,the other 2 are moving in the right direction. I guess my Turnigy gizmo can take care of that!

Busted a few balsa stringers whist doing the surgery, no biggie, just not a lot of room to work.
I made a kevlar plate steering arm as there was only one on the unit and I wanted push pull wires.
All worked out ok, but man, do I detest working on retracts that why I'm doing them now,so I can add the sking with all the annoying jobs taken care of.
I found another pair of nicer (scale looking) tyre diameter and shape, but they need bushing to fit right on my gear wires, but that will be a simple job.
So, here we are!
Flap and aileron servos/hinges next!

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Thanks David.
 
My build continues, flaps installed and working, just some fine tweaking to finish them.
 
I'm nearly ready to sheet the underwings!
 
Made a wheel retainer(s) with a tinned washer, and then tined axle end with solder too, finally apply heat with a heavy duty iron very quickly to avoid melting the hub plastic, works beautifully!
Used a piece of kitchen foil between the 2 'just in case'.
 
I bought a Turnigy servo speed regulator:
Obviates the need for 'Y'  leads.
 
This will slow the retracts,and can even reverse the movement of a servo, great buy!
 
More later
 
Matt









Edited By Matt Halton on 17/04/2009 11:36:40

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Love the little videos on the retracts will be very interested to see what the servo slow set up looks like in action, please could you post a video of it when its installed.
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That's ok Timbo, they are standard servos, retract dedicated as you know, won't allow for this kind of adjustment, (no EPA) so yep, was aware! Good tip though for anyone else contemplating a purchase of the Turnigy unit.
 
Yes, that is my FlyFly Hawk,alas, still unfinished, needs a hefty injection of cash I don't have just yet!
So that's 2 Hawks unfinished at my house. However,my little UF Hawk is a little speedy thing and is helping keep my Hawk lust under control, for now anyway...
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Ok, another Marauder build update.
 
I have skinned both wing undersides after carefully jigging the airframe.
 
The nacelle skinning has started also, in 1/8th balsa and the fuse in 3/32"
 
Tomorrow I will have the other nacelle completed and rear lower fuse. At this point I can remove the model from the jigs and finish the other side.
 
Re the servo slow rate reducer videos, not done yet, but will get to it as soon as this tedium of planking is out of the way.
 
I should be able to get the leading edges and wingtips on soon too





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Martilder looks very relaxed on her back, but was the acupuncture really necessary?
Looking good.
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Ah, but she musn't smoke,and acupuncture of this kind saves ESC's




 
Finished planking the other nacelle and rear fuse lower planking. Did the nose planks too.
Tomorrow, I'm onto finishing the upper rear fuse and overwing, then I'm pretty much done with the main build...progress is sweet! 

Cheers!

Matt
 

Edited By Matt Halton on 22/04/2009 23:04:43

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I'm trying really hard David, my good wife has let me use my extra leave to get her done,so am going hell forleather to get this moved on.So yes, fingers crossed she will be appearing at Bickley!
 
I'm nearly done with the fuse planking,after that, leading edges,trim up the wing skins,add tips then make masters for 'plexiglass' moulds.
 
I'm waiting for prop adapters to arrive from the US, should be here anytime soon, then I can get to the power system install.
 
Just not enough hours in a day!
 
Of course, then there's the surface detail after covering it....
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All planked now (at last!!!) some trimming and sanding to do . Leading edges are glued on, they need planing and snding. Wingtips are from 1/2" sheet balsa, not shaped or glued just yet.
 
The worst is over!
As you see here here,excluding the tail parts but including the 2 x retract servos, 2x aileron servos and 2 x flap servos (plus retracts and wheels of course) weighs in at 1lb 14oz, so I'm very pleased about that!

Edited By Matt Halton on 24/04/2009 20:04:15

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