Geoff's DB DH60 Moth

[Dwain Dibley.]

Ditto to all that Percy has said...........I will just add that I think I bolted everything up with the wires stitched on( I had the same hole probs, but used them anyway) got it all square, as PV says it is pretty accurate, then I Glued the twine with CA, this turns it to Iron. I then dismantled it all and used aliphatic on the stitching, once that was dry I added the Balsa and sanded to shape.As you say Geoff, fit it for good after all the fiddly bits.

D.D.

Edited By Dwain Dibley. on 23/02/2018 23:20:04

[Geoff S]

Thanks, Dwaine. I suppose if I don't bother too much about the wooden pieces tightly butting up to the platform cutouts then the stitching will work. I have some perfect twine for the job - thin and very, very strong. I think my wife brought a whole cone of it from work, where they made clean room overalls. Can't think what they used it for, all I know is that there must be miles of it - literally.

I notice you put the wing retaining hooks at the outside rather than towards the centre as in the drawing. I don't suppose it matters. I put mine as per the drawing partly because that's where it is on my DB Tiger Moth.

One thing I did do differently from the instructions was to fit the 0.4mm ply decking before the cabane struts. It was quite easy to cut the slots accurately as no doubt you found as well. I rolled it up and left it overnight to take shape. It worked a treat and was straightforward to fit. Sadly, when I tried the same trick on the tapered piece for the rear fuselage it split and I had to make a new piece - after ordering a sheet from SLEC

I have most of the material to make the sprung undercarriage.  I ordered some springs today.  It's this design by Gordon Whitehead.

 

Onwards and (eventually) upwards.

Geoff

Edited By Geoff Sleath on 24/02/2018 00:17:34

[Dwain Dibley.]

Yes, I found that I got a closer fit on the struts by gradually removing the ply.

Wing retainers.....just put them out of the way of the Stitching in case repairs/adjustment was needed, the added bonus being it was less wobbly.

That undercarriage will be the Mutts Mate.  

D.D.

Edited By Dwain Dibley. on 24/02/2018 09:20:49

[Geoff S]

Having seen yours, I wish I'd put mine further out. It's a better position both for keeping clear of the stitching and, being wider based for stability. I should have read your build thread more carefully

No building today. Got a load of stuff to organise for a swap meet. I keep building and I need to clear out planes and engines that I'll never use. I hope to get home with an empty car ... that's if I don't buy something myself - but Avice will be with me to keep her tight hold of the family purse strings

Geoff

[Former Member]

[This posting has been removed]

[Geoff S]

The drawing shows countersunk screws as fixings for the wing retainers but doesn't supply any in the kit so I used some servo screws instead. I must have 100s of various sized wood screws/self tappers but none the right size. The screws will be hidden by the dummy fuel tank that's glued under the platform so it doesn't matter much.

I'm in the process of sewing the cabane struts to the platform and I'm sure it will be fine. Even though the cutouts for the struts aren't quite right I'm sure it won't be noticeable.

The swap meet wasn't all that successful from my point of view because returned home with most of what I'd taken but the arduous 5 mile journey and the cost of a table was more than offset by the sales. There were a few familiar faces there including Paul Marsh but I didn't see him leave with another model so perhaps he won't be adding to his tally on the 'New Models' thread If nothing else, it was a good social event and even my wife enjoyed it.

Geoff

Edited By Geoff Sleath on 25/02/2018 15:29:59

[Jan Luethje]

Hi there, I’m a modeler from Berlin and just wanted to say thanks to everyone for the great advice I received here, while building my DB Sport & Scale Cirrus Moth 20 E. It’s a nice kit an fun to build, but obviously not very widespread in Germany, because I couldn’t find any German build thread.

I started building last november, overtaking some mods from Martyn Johnston (e.g. „fake riplets&ldquo, also developed some own mods, and now I’m more or less at the same stage like Geoff with his Cirrus Moth. It’s really interesting to see, that he and I came to pretty much the same solutions for similar problems.

Like him, I decided to attach the lower wing section with screws instead of rubbers and reinforced the lower center correspondingly. Like him, I made a new plywood front former for the electric engine, instead of building „a box in the box“ for mounting the motor.

There are still some points to be sorted out, but I’m quite confident to maiden the bird at the end of the season. And also hoping to see the original in flight at Shuttleworth Collection during the summer

[Geoff S]

My Cirrus Moth is (almost) finished and flying (over a dozen) but I'm afraid I got a bit lazy and stopped posting progress reports. However, I did take a few photos and I'll try to add a few of them in the hope it might help subsequent builders. There's a few dodges I used that may help others like installing snake outers as guides for the tail closed loops (2 for the elevator halves) and ignoring the warning of using a simple pivoted bar for the rudder control (the out of tension wire just goes slack and there's no problem).

Another dodge was to make a motor safety/arming plug in one of the motor feeds using HiFi 4mm gold sockets and a short wire with 4mm plugs. It works perfectly and has the advantage that the controls can be checked without the motor starting inadvertently. Coupled with a throttle disable switch on my transmitter there's very little danger of damaging the motor and avoids any potential problems with extended battery leads.

Geoff

However, I still have a little problem - the exhaust pipe. As you can see here, my model lacks one.

I bought some thin walled plastic pipe about 10mm diameter which would look OK but I can't think how to create the double bend where it snakes round the cabane supports. Are there any suggestions? It looks OK pipeless but I'd like to get it a bit nearer scale even though it is, at best, sport scale.

Geoff

[Former Member]

[This posting has been removed]

[PeterF]

Posted by Geoff Sleath on 23/05/2018 16:55:27:

 

However, I still have a little problem - the exhaust pipe. As you can see here, my model lacks one.

 

I bought some thin walled plastic pipe about 10mm diameter which would look OK but I can't think how to create the double bend where it snakes round the cabane supports. Are there any suggestions? It looks OK pipeless but I'd like to get it a bit nearer scale even though it is, at best, sport scale.

Geoff

 

Geoff,

On my Tiger Moth exhaust I used thin wall plastic tube for the exhaust, although that only has a single 45 degree bend at the outlet end. I bent it using a hot air gun to soften it, but first, I put a piece of thick wall silicone tube inside that was a good fit. This meant that as the tube was bent, the silicone maintained the shape and stopped the bend collapsing. In your case if you tried this, the silicone tube may end up stuck as a permanent fixture.

Peter.

PS, nice looking model, love the colourful schemes available on the Moth series.

Edited By PeterF on 23/05/2018 18:58:29

[Geoff S]

Thanks, Peter. I'll give that a try. I did a search for 10mm plastic tube on eBay and this stuff came up at about 2 quid/metre. I had thought of trying to get some Serabend from somewhere but I'll see if I can find some silicone tube in my junk drawer.

Geoff

[Martian]

Hi Geoff try blocking one end of plastic tube filling with sand then block the other end heat with heat gun bend to shape when cool open up and the sand will run out

[Gordon Whitehead 1]

Hi Geoff, I had the same problem to solve when I built my Hawker Demon. I made the zig-zagged exhaust pipes from balsa sanded round as explained on this plan in the diagram just in front of the fin :

https://outerzone.co.uk/plan_files_06/6269/Hawker_Demon_RCM_757_oz6269.pdf

I probably then sanding-sealed them and covered them in tissue doped on with the sanding sealer.

The same thing could be achieved by laminating 1/16in x3/8in balsa strip, as often used for forming the outlines of wing tips and tail surfaces.

Kind regards

Gordon

Edited By Gordon Whitehead 1 on 26/05/2018 21:49:47

[onetenor]

Posted by Geoff Sleath on 24/02/2018 11:13:39:

Having seen yours, I wish I'd put mine further out. It's a better position both for keeping clear of the stitching and, being wider based for stability. I should have read your build thread more carefully

No building today. Got a load of stuff to organise for a swap meet. I keep building and I need to clear out planes and engines that I'll never use. I hope to get home with an empty car ... that's if I don't buy something myself - but Avice will be with me to keep her tight hold of the family purse strings

Can you expand on your first paragraph. "Put mine further out" What further out.?

Geoff

[Geoff S]

Thanks Martian and Gordon. Tha's two ideas to try

OT, the plywood hooks that hold the top wing in place at the front of the support platform are shown as near the centre on the DB drawings but they could be placed near the edge of the platform which would, arguably, make them a bit more stable. In practice the wing is very secure when the DB drawing is followed.

Geoff

[Former Member]

[This posting has been removed]

[Geoff S]

PV: IIRC the latest drawing for the Moth shows wood screws as well as glue holding the the top wing hooks in place. In any case I did that and I'm quite confident the wing will stay in place in normal flight - even violent aerobatics!

Certainly Richard is keeping up the DB quality as did Eddie before him. I'm almost tempted to buy a new Gringo kit as my original one (and its builder!) are featured on the DB web site but as I have limited time I think I'll commit to building sport-scale models for anything other than very quick builds.

You seem to have a few kits in hand!

Geoff

[Former Member]

[This posting has been removed]

[Jan Luethje]

A really nice Moth that Geoff built! Mine is still far away from that point, although most of the kit-building is done. Still have to sort out all the scale details, before covering it.

Today I made the exhaust pipe you mentioned above. I went for some 6mm plastic tubes (probably PVC) from the hobby shop. Tried different, „recommended“ methods to bend it, but finally lost my patience and grabbed my blow torch. Just moved the tube with short and quick movements through the flame, and then it was really easy to bend it to shape. Ok, there were some minor kinks, but no problem to correct them with filler.

The thing will be glued to the dummy engine, I made out oft balsa, when everything is painted – and I’ll have to make a cut of course, where the cowl is ending.

Still not sure, how to fix the pipe at the fuselage. G-ELBV at Shuttleworth seems to have a kind of three-point-wire-attachment, but that looks rather flimsy for a park flyer …

Edited By Jan Luethje on 10/07/2018 23:12:09

[Geoff S]

I'm afraid my Gypsy Moth is still exhaust pipeless, partly because I'm flying it so much. I must have had around 50 or 60 9/10 minute flights since I maidened it earlier this year (6 this afternoon!). Your pipe looks good. I'll have a go with the blow lamp and see if I can do as well. I really like your dummy engine as well.

It's the only model I'm flying right now as I'm frantically practising my chosen schedule for the scale flying only competition I'm foolishly intending to enter this coming Sunday. Those flights include well over 100 landings as each 10 minute flight includes at least 1 touch and go (not always perfect! The bottom wing is a bit scuffed from contact with our hard runway)

It handles a reasonable breeze quite well but it blew over after landing on one occasion this afternoon. Which I guess would be nil point if I do the same in the competition.

On my last flight, I noticed the top wing was a bit cockeyed and not parallel to the bottom one. On inspection the forward angled cabane struts had become detached from the cabane platform. They'd been quite tricky to fix in place when I built the model. I've now (this evening) drilled 2mm holes through the struts into the plywood platform edge and used cocktail sticks as dowels to hold them firmly in place as the 30 minute epoxy cures. The cabane feels quite rigid now and the wings should align perfectly as they did when I first built the Moth.

I'm also getting good 10 minute flights with capacity to spare in the 4AH 4S LiPos which more than adequate for my purposes.

Geoff

[Jan Luethje]

Thanks Geoff, it was actually much easier to build that pipe than I had thought (not the dummy engine though: more than 40 pieces). I also figured out tonight, how to attach it to the fuselage. Just drilled three holes into the pipe, roughly where the attachments at the original are and glued hardwood dowels in. Then I drilled two 1mm holes into each dowel, so that I can fix short peaces of steel wire there. This will hopefully be solid enough and meet the look of the original sufficiently.

Regarding your cabane-experience: That’s exactly what I feared to happen in case of a nose over.

To prevent that, I glued small strips of hardwood around the corners, where the struts meet the platform and I glued wooden brackets underneath. In addition I bent thin white plastic strips (the stuff you use to seal a leaking drain) around the cabane struts and that piano wire, that is ment to stabilize the cabane and soaked the bindings with Expoxy. I hope that it looks somewhat better than the usual cord bindings after having painted it.

All that adds weight of course and isn’t very scale either. But as a wild flyer I’ll most likely have rough landings from time to time.

Good luck with your competition, that sounds really exciting! I don’t think, that we have something like that here, but regarding (historical) aviation and scale modeling, Britain seems to be a dream anyway.

My own efforts will come to a halt next week, as I’m going to travel to Farnborough – just to look, how the big boys are doing. I'm eager to visit Stow Maries and Shuttleworth as well – may be later this year.

[Martian]

Posted by Geoff Sleath on 10/07/2018 23:40:42:

I'm afraid my Gypsy Moth is still exhaust pipeless, partly because I'm flying it so much. I must have had around 50 or 60 9/10 minute flights since I maidened it earlier this year (6 this afternoon!). Your pipe looks good. I'll have a go with the blow lamp and see if I can do as well. I really like your dummy engine as well.

It's the only model I'm flying right now as I'm frantically practising my chosen schedule for the scale flying only competition I'm foolishly intending to enter this coming Sunday. Those flights include well over 100 landings as each 10 minute flight includes at least 1 touch and go (not always perfect! The bottom wing is a bit scuffed from contact with our hard runway)

It handles a reasonable breeze quite well but it blew over after landing on one occasion this afternoon. Which I guess would be nil point if I do the same in the competition.

On my last flight, I noticed the top wing was a bit cockeyed and not parallel to the bottom one. On inspection the forward angled cabane struts had become detached from the cabane platform. They'd been quite tricky to fix in place when I built the model. I've now (this evening) drilled 2mm holes through the struts into the plywood platform edge and used cocktail sticks as dowels to hold them firmly in place as the 30 minute epoxy cures. The cabane feels quite rigid now and the wings should align perfectly as they did when I first built the Moth.

I'm also getting good 10 minute flights with capacity to spare in the 4AH 4S LiPos which more than adequate for my purposes.

Geoff

Hi Geoff if you want to avoid the possibility of kinks in the plastic tube fill a longer piece than you want with silver sand or salt and cap ends then heat gently then bend uncap tip out salt or sand job should be a good un

[Jan Luethje]

Just in case, that anyone might be interested in another example: I also managed to finish my Cirrus Moth 20 E, quite a while after Geoff (and so sorry for the blurry foto).

Maiden will follow, as soon as the weather allows it. I really enjoyed building it, but some modifications were necessary, to make the plane ready for modern electronics.

My most important conclusion: Try to build as light as possible regarding the tail end of the model, but don’t hesitate to „get heavy“ at the front. Even a full-metal-dummy engine might be suitable. I had to add about 100 grams of nose weight to meet the CoG …

Edited By Jan Luethje on 22/03/2019 02:00:20

[Geoff S]

Looks very good, Jan. I was lucky and managed to avoid any extra ballast. The 4AH 4S batteries I'm using proved to be just the right weight.

Good luck with the maiden. The weather in the UK has been a bit windy mostly but there have been a few dry, light wind days. I managed afew flights with mine in the unseasonal warm spell we enjoyed last month. Let us know how you fare.

Geoff

[Jan Luethje]

Thanks for the kind words, Geoff and you’re right of course. 4S would have been the smarter way to go. I went for 3S. May be something, I gonna change after the maiden.