DB Cirrus Moth build

[Chris Whalley]

Hi guys, silver solartex for the wings and tail surfaces, white solartex for the fuz brush painted with humbrol no. 14 (French blue). The decals are indeed from DB S&S, they went on a lot easier than I was expecting using soapy water and a credit card to squeegy the surplus out. The engine will be a Saito 56. Speccy 6 channel radio with a servo in each wing. Just ask if you need any more info.

Regards Chris W

[Former Member]

[This posting has been removed]

[Dwain Dibley.]

Thanks for the input Tom.

D.D.

[Dwain Dibley.]

Last bit for tonight.

I have made and fitted the servo tray.

Added the last of the bulk-heads and beefed up the bases.

Made two thin ply covers to add cockpit detail to later.

Made a rudder cable arm from ply to get the position right, this may change material wise as things go forward.

D.D.

Lower wing fixing plate with m4 nuts.

[cymaz]

I did much the same thing in my Gipsy Moth for the rudder

[Dwain Dibley.]

That is the way my book of words tells me to do it Cymaz. Indeed, I could use the bits supplied for the aileron bellcrank linkage for the rudder instead, as I intend to have a servo in each wing. This would allow for a more scale like position in my fuz.

It's all interesting stuff Guys.

D.D.

[john stones 1 - Moderator]

Posted by Geoff Sleath on 22/02/2017 17:47:34:

Very nice, Chris. Are those the DB S&S decals?

This is the version I hope to build. Not sure about the scheme, but it is different. I have a Tiggie fibreglass cowl and the idea is to make a hatch at the front so I can slide the battery in under the motor to get it s far forward as possible. Hopefully, no lead will be needed.

Geoff

I reckon that colour scheme looks very classy

[Jonathan M]

I've been thinking all along that you're building the 48" (20E) version, but I've just realised you're probably doing the larger 40 version! No wonder you've got captive-nuts for the lower wing bolts. My plan shows a tongue and single bolt for the upper wing, with dowels and rubber bands for the lower one, although I'm in fact going to modify this so I've got nylon bolts all round.

Jon

PS Both Cirrus Moth examples pictured look very good!

[Dwain Dibley.]

Yes...sorry....Should have said this is the 40 size.....I was going to do the 60 size for petrol but I cant physically fit another big model in my garage or work shop.

AnyHoo, you Herberts have caused me a load of work !!!

I have had to make a new servo tray and a tray for the rudder cranks, I also broke the forward cockpit former.... so I remade that, I added the ply this time for strength. I had to move it forward a tad to get access to the crank bolts. I could have used screws from the wing opening, but I had my Anorak on again..

I can now put in the cock pit floors, or at least make them to fit later. I am gonna try and get some detail in there.

Cheers

D.D.

Whats up with some pics that want to go thru 90' and grow. ?????

Bigger servo tray

Access from the cockpit area.

Edited By Dwain Dibley. on 23/02/2017 14:43:28

[Dwain Dibley.]

So the next job was cabane building, which was quite tedious. The plane and book of words were a bit ambiguous here as well. Do you line up the top of the wire with the wooden upright, or the top of the ply plate ?

I chose the latter as there are cut outs in the plate but they don't match the uprights 100%.

Bearing in mind that this will affect the incidence of the wing there should be a bit more info.

As it turned out the wire is now extended past the bottom of the up right, so accommodation was made in the fuz sides. Also the rear plate cut outs were not sufficient to allow binding of the piano wire, so I adjusted those too.

The next job was to bind the wood to the wire, so it was wrapped in masking tape and bound with twine. Once it's all in place and squared up I will seal the binding with C.A.

After all the faff it looked O.K.

There is always the fact that the struts can be adjusted to suit if I got the height all wrong, there is probably a 16th in it.

D.D.

One down.

A balancing act.

I had two of these in the kit, but then only one wanted to stay so I had to make another. there's 20 minutes I'll never get back. Lucky I has some ply of the same thickness knocking about, a coping saw, and some patience, even after a long search.......I mean where did it go...???

Cockpit flooring.

The top wing retaining set up. A coupla hooks at the front and some M3 nuts and metal bolts (correct size this time) at the back.The piece of ply you can see goes in the wing center section.

Edited By Dwain Dibley. on 23/02/2017 21:14:39

[Geoff S]

That platform, and the quick and easy interplane strut fixings are what make my Tiggie (and I assume the Cirrus) such a great biplane. Last summer it was just about always taken to a flying session and usually flown a few times. I have other biplanes that tend to be hangar queens because of the long assembly time at the field. Not so these DB De Haviland kits.

You're making very quick progress. It's persuading to get out of my lack of interest rut (over 2 months!) and get building.

Geoff

[Dwain Dibley.]

Posted by Geoff Sleath on 23/02/2017 21:57:11:

You're making very quick progress.

If only you knew Geoff.....

I am in fact forcing myself to go slower than usual, or my mate Johnny will have my guts for garters.

I agree about the rigging times, they should be quick. I was pleased to see how the top wing goes on. I though it would be the DB wing fixing Rubbish I had on my Auster, so was devising a way to use a wing tube....Thankfully there was no need.

D.D.

[Dwain Dibley.]

Well Guys,

Despite Doris ripping the roof off my Workshop, I was able to do a bit more on the Moth.

I Glued up the "hooks" on the top support and added the screws this morning.

The next job in the book of words is to simply "check the position of the cabane struts on the top deck and glue in place" Easy right ??

So after an hour of marking out for the struts and the two cockpit hatches, allowing for edging and instrument detail, scalish shape and dimensions, I was ready to go.

I used the screen as a template.

I also took a copy of the front former before glueing it in place, so that I can make a motor mount later to accommodate the outrunner. The beauty here is that the down thrust will be built in automatically, the side thrust 2 deg, ( maybe more with leccy) can be sorted later.

I changed the rod I was using for the rudder mech, as it suddenly dawned on me, that as well as building some adjustment in, I would solve the problem of access for repairs and mantenance. Just pop the clevis off, undo two screws.............Hey Presto..................and she's out..

Credit to other people due here as I did study their pics.................a lot......!!

Edited By Dwain Dibley. on 24/02/2017 14:39:19

[Dwain Dibley.]

First off, a question....

Can I assume that we have to fix the undercart each time we rig the cirrus/tiger moth ?

The book of confusion says I can stitch and epoxy the front u/c brace but I have to make sure I can move it to fit the wing !!??

It might be worth making a couple of brackets/hinges that allow it to swivel on the former.  ??

I have fixed the sheet balsa that simulates the bottom of the fuel tank, and sanded it to shape, again, the plan is a bit sketchy as I cant really see where to finish the curve. I have taken it to both extremes, front to back just in case. There is a numbered part that I cant find, like a fairing, so I have made it from scrap. There are a number of parts listed that you make from sheet, but this is not one of them.

I know I sound quite negative re the kit, whereas in actuality its a really nice build, so don't be put off. I am just trying to be constructive in a bid to iron out any niggles that a first time builder might stall on. Also these plans have been copied and recopied over time, and even the moisture in the atmosphere can grow them. An old mate of mine, John Cross, once told me "always build both wings on the same day so they are the same size".

Prior to fitting the tank bottom, I had to stitch the cabane struts to the platform, again I used strong twine and C/A.

I set the structure while it was in the fuz to make sure it was straight.

Holes for servo wires will have to be cut later.

Cheers

D.D.

The next job is to sort the u/c, with a bit of wire wrapping and soldering.

The best way to do this is to have the thing in the model when you solder I find, that way you can't get it twisted or have to bend it to fit. To that end I will have to try and jig up the bottom wing mount..

If I cant do that I will make a jig on a piece of ply, by simply measuring to relevant distances between mounts on the plan, and squaring things up.

Edited By Dwain Dibley. on 24/02/2017 19:07:13

[Geoff S]

If it's the same as the Tiggie then you have to detach the undercarriage where it fits to the underside of the bottom wing. Just undo one screw on each clamp (2) and slacken the others and pivot the undercarriage forward out of the way. It's not really much of a problem.

I did put a bit of a fairing on the rear struts to represent the damper/spring, but that's all. I had to make my undercarriage from scratch as I didn't have one with the model I was given.

I didn't bother to add anything to the top wing platform underneath to represent the fuel tank bottom. It's almost impossible to see underneath once the model is rigged anyway. I did glue some corrugated cardboard sheet to the top of the tank to simulate the full-size. I t was red and I didn't even need to paint it as the corrugation pitch is quite scale. I got 10 sheets of A4 from an eBay supplier for next to nothing. Still have 9 sheets left so if you want red, even as a sample, let me know when the time comes - no charge

This model has a scale-like outline but can be made more scale with additional features like closed loop controls and fuel tank corrugations. I also added rib tapes but I could do more. I don't think DB S&S claim it's a true scale model with all that implies.

Geoff

Edited By Geoff Sleath on 24/02/2017 19:26:45

[Dwain Dibley.]

Thanks for the reply Geoff, sounds as if it's the same Matey,

I tend to add stuff too, I generally get ideas as the build progresses. I build a pretty scale U/C for the Baby Ace with functioning suspension, but as you intimate, some times you have to draw the line tween looks and functionality.

Thanks for the generous offer B.T.W.

Cheers

D.D.

[Former Member]

[This posting has been removed]

[fly-navy]

Nice to see you back in the workshop again Mr D. building to your usual standards I see

Nice looking model, by the sound of it is the same arrangement as the Flair Scout series undercarriage.

Give my love to Johnny.

[Dwain Dibley.]

Sounds interesting Percy, will look into that.

Good Evening John, I was wondering when you would show up, I will pass on your kind regards.

Here's the U/C.

[Geoff S]

Posted by Percy Verance on 24/02/2017 22:02:26:

There was also a mod in one of the mags a few years back showing how you left out the wing leading edge sheeting and replaced it with riblets as per full size, although most builders would probably be happy enough with the standard spec......

Not sure about the Cirrus Moth (my kit is in the loft with its drawings) but the Tiggie doesn't have l/e sheeting but has the scale riblets (2 between each full rib). I'll certainly be building my Cirrus like that.

Geoff

[fly-navy]

Yes Steve, much the same. What I did with my Pup and SE5a though was silver solder the two down legs together with the axle free and running in an inverted "U" soldered on both legs with so Mick Reeves bungy retaining it to give a nice bit of suspension.

[Jonathan M]

Although I'll be building the smaller 20E kit, I'm following this thread as "first time DB Sport&Scale builder", as there seems to be much in common in the two sizes. For example, I had the same confusion over how the U/C fixes and swivels, etc.

Posted by Dwain Dibley. on 24/02/2017 19:05:04:

I know I sound quite negative re the kit, whereas in actuality its a really nice build, so don't be put off. I am just trying to be constructive in a bid to iron out any niggles that a first time builder might stall on. Also these plans have been copied and recopied over time, and even the moisture in the atmosphere can grow them.

Without being too negative myself, I've spent much time studying the plan and instructions and agree that these can be improved. Although the lasered parts are top notch, my plan is really blurry and quite faint which makes it hard to understand. It doesn't help that components are given big numbers in a single sequence (e.g. 201, 202 etc) rather than broken down into sub-assemblies (i.e. R1, R2, F1, F2 etc). With the instructions lacking on a great many details, it all then becomes a bit of a guessing-game.

But hey-ho, that's the challenge and the fun of it!

Well done DD for your clear and well-illustrated explanations - and hope I'm not trampling on your blog.

Posted by Geoff Sleath on 25/02/2017 00:46:57:

Posted by Percy Verance on 24/02/2017 22:02:26:

There was also a mod in one of the mags a few years back showing how you left out the wing leading edge sheeting and replaced it with riblets as per full size, although most builders would probably be happy enough with the standard spec......

Not sure about the Cirrus Moth (my kit is in the loft with its drawings) but the Tiggie doesn't have l/e sheeting but has the scale riblets (2 between each full rib). I'll certainly be building my Cirrus like that.

Its a judgement call for me as to how much alteration for scale to do. Studying drawings of the full-size Moth its clear that this is something of a stand-off scale design, with speedy building and robustness as its primary aims. I'll stick with the sheeting on mine, but will add rigging (being 48" it can fit in the back of the car) and a Barbie Doll!

[Dwain Dibley.]

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

It's nice to get some input Guys, so keep it coming, it would be nice to hear from Richard B. I remember Eddie always used to have his say, which is only fair. I always had a chat at the shows with Eddie.

Those riblets look easy to replicate on top of the sheeting with strips of balsa or twine.

On the plane at the museum, G-EBLV, there is a bit of extra detail to add to the U/C in the form of the fairings and a cross brace/cable/tensioner/thingy.

A few bits and bobs on the fuz sides...steps and stuff....plenty of dents and dings if you want to add those

Cowl lines, extra decals, engine detail etc.

Cheers

D.D.

[Geoff S]

I notice that the undercarriage on G-EBLV DH60 is different from most DH60s illustrated in Stuart McKay's book. Most DH60s (and all DH82s) don't have an axle that goes right across but have a pivoted cross structure in between the 2 legs. I thought at first it was a simplification by DB to make construction easier but it seems not. Looks like I'll be scratch building my Cirrus undercarriage to make it right for a Moth Major

I used the model as a jig when soldering up my undercarriage and protected it from hot solder drips by covering it with a bit of rag. I suppose a simple jig, like yours would have been better.

Geoff

[Jonathan M]

As I understand it, G-EBLV is an early Moth, which had the full horizontal axle arrangement.

Edited By Jonathan M on 25/02/2017 11:31:21