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DB Cirrus Moth build


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I have had a think about the battery/speedo access..

I normally try to do a hatch on the top, but in this instance it would be tricky, in fact nigh on impossible, so it will be on the bottom.

As i said the 4Max power train has a 3s2600 40c lipo, the one in the pic is a 2650, so very close, the motor however will handle 4s....Both will fit in the same place the latter with a bit taken out of the engine bearers. The option is available to go on the other side of the former to aid the C of G if necessary.

The opportunity is there to make the hatch go all the way to the front, this will give access to everything. It will be held on with magnets and locating tongues, maybe even a screw. There will be a ply interface. there might have to be two hatches,

D.D.

Battery position.

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Sheet material.

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Chamfer 1

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Chamfer 2

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Chamfer 3

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Edited By Dwain Dibley. on 25/02/2017 14:29:38

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OK..So there's been a change of plan.....

The front part of the bottom sheeting is going to be glued on and any access to the speedo will be from the top. The plastic cowl looks like it will be removable so that will be the way forward.

Before I could fit the sheet I needed to fit the U/C, before I could fit that I needed to sand the front to shape and so on and on...

I laminated the 1/8th balsa with some 1/32nd ply, I then cut some 1/16th ply for the fuz sides. These ply pieces will strengthen things up and take the holes for the rare earth magnets better than balsa alone. Plus they will form a wear resistant interface (I like that word) twixt hatch and fuz.

I added some strip to help locate the hatch. I will devise a catch in a bit.

D.D.

Mock up

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Shaved. David plane is a useful tool.

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ply strips on Fuz sides.

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Ply on hatch top. With inner edge marked up,

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Locating Rails.

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Now it's time to stitch on the Under cart so it can get in the way like a right pain in the butt. I would really like to be able to cover the fuz before attaching it, but once i put the top decks on, it's all over....literally.. frown

Hey, I could add some ply cross members and...........................................Aaaaaarrrrrrrrrrrrggggggghhhhhhhhhhhhh Noooooooo.

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Spent the early hours catching water in a bucket in the workshop thanks to Doris blowing half my roof off.

you only realize how much kit you have crammed on yer shelves when you have to move it off to fit a bucket on.

So....This A.M. I have stitched on the U/C, fitted the bottom sheeting, glued in the cock pit floors. I have used Aliphatic as it sands better than CA.

It's starting to look like a plane now when it's all fitted together, and once the top decks are on that's it for the basic Fuz build. apart from the cowl fit and of course the radio and motor install.

Cheers

D.D.

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Is stitching the front of the undercarriage the way the kit is designed? It'll make it quite difficult to remove/replace the bottom wing if the undercarriage is not able to swing clear. I think I'm inclined to fit a piece of hardwood across the fuselage either in front of, or behind, the former you've stitched to and secure it with clamps as per the Tiggie.

As for battery, esc and motor access, can't you make the whole of the fuselage top in front of the cabanes removable? Then it's just a matter of fitting the battery and then connecting it and shutting the hatch (safely, behind the prop) just before you're ready to fly. I know there's an additional arm to the cabane that leans back from the hatch but I would have thought there's ample room.

Geoff

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The last two photos... I added a bit of wood to the rear of the hatch so that when it goes on it will form a bit of a fairing against the wing to fill/hide the gap you can see on the plan.

Once all these bits are assembled it's an easy job then to sand it all to shape, and in that way the hatch shouldn't be too visible on the finished model.

Like the top hatch on the Ben Buckle Great News below. Yellow is quite translucent but imagine a darker colour. That's a blade of grass that looks like a mark on the nose, before you all shout...laugh .cheeky

D.D.

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Edited By Dwain Dibley. on 26/02/2017 15:10:13

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Geoff, the front U/C wire is stitched to former two and swings freely, the rear one is screwed to the wing with saddle clamps into a hardwood block, once the wing is on. To insert wing... swing the U/C down out of the way.

I intend to fit an isolating plug between the battery and Esc/motor, this will be located in the side of the fuz and will be plugged in to arm the system. There is a commercial one available using XT60 plugs, which I use anyway.

Another Connector is made with a simple loop across the poles to make the circuit when plugged in., and can be made to look like part of the plane.

D.D.

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Edited By Dwain Dibley. on 26/02/2017 15:33:15

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Posted by Dwain Dibley. on 25/02/2017 10:44:45:

I need to come and see the progress on the SE5A john, I assume you mean the one built by D.V.

 

 

No I meant my smaller Flair one Steve. The DV Hutson one has big scale u/ c permanently fixed, it's all done with new litho cowl etc and engine in just the one wing panel to finish.

Edited By fly-navy on 26/02/2017 15:35:16

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I rounded off the front of the model after shaving the sides to profile. There will be more sanding, because no matter how careful you are , you will get dinks in the fuz sides, so invest in some balsa-lite filler.

Another test fit of the front top deck and a line was marked along the fuz, I then glued the edge of the ply along this mark with CA, in a kind of do a bit miss a bit fashion so that it didn't run off. If you allow the ply to run off, it will not line up on the other side, or on the front and rear formers. As it was I had to add 3/8th balsa to the rear former, to give enough meat to catch the rear top deck ply.

I rolled the model slowly, keeping pressure on the formers and adding glue as I went, bit by bit.

The last job was to make sure I got the other edge of the ply down good and firm, again by starting in the middle and working outwards, bit by bit.

I noticed that there were a couple of gaps around the front and rear formers, so I used thick card in layers in decreasing sizes, until I had filled the gap. Card is great as it ends up like ply, nice and stiff, when glued up with CA.

I also make the Arming plug, and mocked up the arrangement, in case anyone wanted to see it.

D.D.

There will be a couple of plugs on the ends of the harness, but I didn't have any more 12 gauge silicon wire.

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Shapely

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All done with shims in place.

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The big order went in to 4 Max last night.

Wire

Lead locks

Servos

Power train. I went for the combo, as you save a bit of cash and You cant have enough props !! can you ???indecision

That done, I emptied the bucket, and went up the wooden hills to Bedfordshire.

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This morning, I set to to move a bit more rubbish from the work shop, that hole in the roof is a good incentive to tidy up.

I then put the tail feathers together....Another niggle here was the laser must have been a bit short, as it hadn't quite gone thru the sheet, but hey !! I just used a scalpel to get the last nth of balsa.

The fit of the parts however, was 100% spot on, nice and tight, which helps when assembling. Half an hour saw 5 items assembled on the bench.

now, if you havn't done this before, don't pay too much attention to the parts matching the plan 100%.

Just pin down the longest pieces, the trailing edge etc and work from that, making sure in the case of elevator halves you make two identical pieces. make sure the "ribs" are square to T/E.

I always sand these items, to clean up joints, while they are stuck down, I find it is easier.

I nick the missus' nail files for this...wink

I am now in a position to work out the servo positions and control setup.

D.D.

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Temporary model storage. The model is a Double Diamond, that I refurbed and converted to Electric power.

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What glue do you use for construction? I tend to use PVA (Titebond usually) rather than cyano, which I restrict to places/times when a quick bond helps. Less smelly with fewer fumes, as well, which is a bonus.

You've inspired me to get my finger out so I can finish my 1/4 scale Mew Gull (also electric) and move onto my Cirrus Moth. Though I've distracted myself by buying a Dynam foamie Hurricane on eBay this morning from a seller only a very few miles from me

You're doing incredibly well to continue the build with a leaking shed roof. I'm fortunate in that my workshop is an extension off the living room I had built just before I retired so, hopefully, it should remain leak free.

Like the bike. Sadly dropped bars are beyond me now but I rode many 1000s of miles/year when I was a just a few years younger. It's just 30/35 minutes every morning on the turbo trainer these days to get half fit for the summer.

Geoff

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Well spotted Dave,,, LOL It's been up graded to shuttle 2 spec, bought off Bernard of Much-Marcle fame.

Geoff, my "shed" is also part of my house, I split the garage and made my work shop from 1/3, it is accessible from the kitchen. I now have a 1700 quid bill to replace the roof.crying work shop is about 8 X 12. Garage is now only about 16' long.

I use Aliphatic for flexibility and if I laminate stuff, or if a lot of sanding/shaping is required. C/A the rest of the time for quickness. Araldite/Epoxy for joining high stress areas Wings etc.

That is my road bike G, a giant Defy 1, I have a Crossrip 3 (cross bike come all rounder) with drops, and hydraulic disc brakes for commuting to work and a Cannondale 29'er for the hols

Chapeau

D.D.

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So I made the super bucket drainage system at work, only to find the flippin water has changed direction, and is now running down the wall behind the studding. Doh !!

Super bucket in place just in case tho..wink

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Vented thru the door !!

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After the plumbing half hour i put the arming harness together. I really should buy some more red and black heat shrink, but you can only plug XT60's in one way round so no possibility of shorting out. I used to used 4 mm bullets but XT60's are way, way better. 60 =rated for 60A. You can now get blue and black ones.

D.D.

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Edited By Dwain Dibley. on 01/03/2017 23:39:13

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This morning, I decided I would have a go at cutting out the slots for the cabane struts and the cockpits.

So starting with the cabane slots I set to with my trusty blade.

I marked a line at the point where I thought the struts would touch the the top deck, this was short of course, ( better than too long ) and then it was a case of nibbling away till it was spot on.

I used a razor saw to start the cockpit cutouts at the apex of the top deck, this gave me a good line to work to with my knife. I cut about 2mm inside my marked lines and then cleaned up by sanding.

This is one of the more tricky jobs as it can all go very pear shaped, very quickly....Patience is the name of the game here. Take your time.

There is nothing in the book to say how you fix in the struts, I'm assuming epoxy.....!?. There is an opportunity here to make some kind of cover/brackets, for the bottom of the struts.

I will cover the fuz before I attach them I think, that way i can get to the awkward bits and possibly do the cockpit surrounds and instruments/seats, etc.

Next job servos and elevator controls, and the motor mount. The speedo was not in the delivery, it is on its way though.

D.D.

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How does this guy keep getting in ???

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Is that pilot one from DB? I've got one for my Cirrus Moth and put him together but he's not painted yet - one of my favourite jobs. He looks to be a bit big to me but perhaps he need cutting down to size. I used one of Pete's men in my Tiggie (a modified WW2 chap) who's supposed to be sixth scale and he looks a trifle on the big side too even after cutting him off in a place I hope didn't hurt too much.

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Sorry to see your leaks still interfering with your workshop. You should take credit for soldiering on (piloting on?) in the circumstances.

Geoff

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Hi Geoff,

I can't remember where I got the pilot, he was one of two I bought for my Magnatilla. He is 1/6th scale but needs his Butt cut down LOL. However he is German, and probably wont be flying the Moth.

I put a pete's pilot in my Spitty, they are very good.

Tiggy Looks great BTW.

Typical, aint it . I haven't built for ages and when I do the roof blows off...!! surprise

 

D.D.

Edited By Dwain Dibley. on 02/03/2017 13:20:33

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Bored my way through "They flew alone" on iplayer earlier Steve, plenty of Moths on there.

Have you thought of modelling your plane on Amy's as a tribute to hercool

Good news about the sunny weather today give you a chance to dry out a bit, bad news got to chuck it down tomorrow. Coming along nicely mate.

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Thanks Chaps. smiley

Thanks John, build me up and then "BOOM"......laughcheeky The super bucket is still in place, waiting to prove itself....LOL

Still contemplating the scheme at the mo....

Tonight I just laminated up a bit of ply and two layers of fat balsa, with which I will make a motor mount.

I have a couple of motor boxes from ARTF's that I have built for people in the past, I used one in the Great News....unfortunately they wont fit in the front of the moth, well....it will...... but the cowl fouls on it. BAH !!

The front of the boxes is loose so you can set side and down thrust and then glue it up.

Still, I already have the Down built in, so it's just side at 2 deg. It may end up with more due to the torque of the motor.

D.D.

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Heavy Man !!

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It's a motor.

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The motor box, it's in backwards as I was just trying it, but you can see the adjustable ply plate at the back, which is really the front....surprise it's a shame it is just too wide at the top.

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