DH.60 Cirrus Moth (oz1794)
About this Plan
De Havilland 60 Cirrus Moth. Scale free flight model for .5 to .75cc power.
Quote: "De Havilland 60 Cirrus Moth. Full size plan feature. 31 inch Free Flight Model for 0.5cc to 0.75cc motors, by John Watters.
IN LOOKING FOR a new lightweight four cylinder engine, Captain G De Havilland used half of an existing French Renault eight cylinder engine, remodelled it and christened it 'Cirrus.' Always a glutton for work De Havilland designed the DH 60 biplane to house the new engine. Captain de Havilland also had a keen interest in moths and butterflies. As most moths fold their wings back when at rest, De Havilland arranged for his DH 60 to do the same. Putting a name to his new aeroplane was then ready made - thus the 'Cirrus Moth' was evolved.
The model is based on the aeroplane often seen with the Shuttleworth Trust Collection and has been kept as true to scale as possible, with no increase in areas. Construction techniques are straightforward, and mainly follow those described by Eric Coates in his 'Flying Scale Models' series of articles. Additional scale details can be obtained from the scale drawings in Plans Pack 2705 available from Aeromodeller Plans Service.
Wings: Make all the wing ribs and riblets from hard 1/32 sheet by the sandwich method cutting out the spar holes before shaping the ribs. The ribs are slid onto the spars to their correct position and the spars pinned down over the plan, letting the ribs into the trailing edge. The wingtips are built up from 1/32 sheet with 1/16 sq strips on either side, curving the strips by nicking the inside of the strips with a thumbnail or razor saw. The interplane strut hooks and wing dowel tubes are epoxied to the spruce spars. The ailerons should be built as separate items, then glued to the wings afterwards. The wing centre section (which is also part of the fuselage) should be constructed with care and it is important to check that the wire parts are formed accurately and assembled square.
Tail surfaces: The tail and rudder construction are from 1/32 stiff sheet (light quarter grain rather than having straight grain!) the shapes being marked off from the plan with the spars and ribs marked on both sides. The structures are then built up on both sides of the sheet and sanded to section when dry. The curved 1/16 square edges are best formed like the wingtips by nicking the inside edges with the thumbnails or razor saw.
Fuselage: The fuselage is simply a box section con-struction with longerons and spacers. First construct two identical sides by building one on top of the other. Cement formers Fl and F3 in position (the formers should already have the undercarriage, cabine wires and tubes attached) along with the engine bearers. The shaping of the engine bearers comes about from initially choosing an Allbon Dart 0.5 cc engine as the power unit, but not knowing whether this would have sufficient power, I made allowance for the fitting of a Mills 0.75cc.
The two fuselage halves can be joined at the stern post and the remaining formers and spacers added. Sheeting to sides, top and bottom can now be added and the nose area built up using sheet and block. The cowling is best built up by spot gluing the formers and block to the fuselage and shaping to fit the nose area, with the exhaust being made either from balsa or aluminium.
Finishing and flying: The fuselage should be clear doped or sealed with sanding sealer and sanded smooth. The whole model was covered in lightweight tissue and doped with thinned-down dope (1 part dope: 1 part thinner). The colour scheme was applied by spray gun as this method gives very good results for very little gain in weight, providing you give a number of light mist coats. The rigging and control wires are made from nylon fishing line and the rigging attachment points from solder tags epoxied into the fuselage and wing centre section. The lines are fixed to the tags by looping through the hole in the tag and fixing with small pieces of aluminium tubing crimped flat. Loops can be made at the interplane struts end, by the same method.
Whether by good luck or good judgement, no ballast was required to obtain the CG position. After test gliding over the pro-verbial long grass, a low powered test hop showed a slight stalling tendency under power, this was cured by a washer under the rear engine lugs. This also showed that the Dart had quite enough power. Further powered flights proved that the model did not have any hidden vices and circled naturally to the left. I hope your model provides you with as much enjoyment as I have had from mine."
Update 20/01/2014: Replaced this plan with a clearer version thanks to RogerClark.
Quote: "Here is a repaired version of J Watters' Cirrus moth, with the missing section on page 2 repaired. The only guess I had to make was that the interplane struts are 1/8in thick; but 8 is the only likely digit to fit what is left on your current version of the plan."
Supplementary file notes
Did we get something wrong with these details about this plan (especially the datafile)?
That happens sometimes. You can help us fix it.
Add a correction
DH.60 Cirrus Moth
by John Watters
Scale IC F/F Biplane Civil
all formers complete :)
got article :)
Found online 16/11/2011 at:
Format: • PDFbitmap
De_Havilland_DH.60_Moth | help
see Wikipedia | search Outerzone
ScaleType: This (oz1794) is a scale plan. Where possible we link scale plans to Wikipedia, using a text string called ScaleType.
If we got this right, you now have a couple of direct links (above) to 1. see the Wikipedia page, and 2. search Oz for more plans of this type. If we didn't, then see below.
ScaleType is formed from the last part of the Wikipedia page address, which here is https://en.wikipedia.org/wiki/De_Havilland_DH.60_Moth
Wikipedia page addresses may well change over time.
For more obscure types, there currently will be no Wiki page found. We tag these cases as ScaleType = NotFound. These will change over time.
Corrections? Use the correction form to tell us the new/better ScaleType link we should be using. Thanks.
Do you have a photo you'd like to submit for this page? Then email email@example.com
User commentsNo comments yet for this plan. Got something to say about this one?
Add a comment
* Credit field
The Credit field in the Outerzone database is designed to recognise and credit the hard work done in scanning and digitally cleaning these vintage and old timer model aircraft plans to get them into a usable format. Currently, it is also used to credit people simply for uploading the plan to a forum on the internet. Which is not quite the same thing. This will change soon. Probably.
This model plan (like all plans on Outerzone) is supposedly scaled correctly and supposedly will print out nicely at the right size. But that doesn't always happen. If you are about to start building a model plane using this free plan, you are strongly advised to check the scaling very, very carefully before cutting any balsa wood.
© Outerzone, 2011-2021.
All content is free to download for personal use.
For non-personal use and/or publication: plans, photos, excerpts, links etc may be used, provided that full and clear credit is given to Outerzone with appropriate and specific direction to the original content i.e. a direct hyperlink back to the Outerzone source page.
Unauthorized use and/or duplication of this material without express and written permission from this site's owner is strictly prohibited. If we discover that content is being stolen, we will consider filing a formal DMCA notice.