Another Parnall Elf

[wonwinglo]

Your wing folding is just spot on,and above all it is functional and practical,you just cannot beat hands on looking at the real thing to see how the designer did it,for anyone who has not attempted a biplane you just dont know what you are missing out on,once built they are very strong and great fun to fly.

Grahame dont let the lack of feedback put you off sending in this info,rest assured there are lots of people interested,it is not that they are ungrateful,think of these excellent practical contributions as assisting people who are perhaps thinking of building their first scale subject,it is all being archived for future posterity,everything that you write will appear on the search engines,so if someone is building a Parnell Elf it will lead them here ! after you have dealt with this one then you can tell us about your Albatross,now there is a tricky building subject.

[Guest]

cool dude i prefer the pics in with the text stops you getting lost

this is a really cool porject dude keep up the good work

[Greyhead]

Back to plan A, from the replies it seems that embedded photos are preferred, 3 for, 1 neutral and 0 against. As for the Albatros, that was built in 1998 before I went digital so no construction photos and as I’ve just sold it, no chance of any more. There is however quite a story to the development of the model but it will have to be 99% text. But first I'll finish this thread!!

[Greyhead]

At this stage I’d made the hinges and satisfied myself that they would work but hadn’t started the wings so the photo above is really out of sequence but it’s the only one I’ve got of a finished hinge showing the bolt.


The next job was to furnish the cockpit; one advantage of these early planes is that they were very basic in the instrumentation department. The throttle and fuel switch etc. were made from scrap aluminium or plastic tube and balsa.





As mentioned above the floor is yet to be added.





I hoped that it would be a simple job to use the photo of the full size panel but unfortunately because of parallax (hope that’s spelt correctly!) some of the dial faces are partly hidden by the bezels and whilst not obvious at first sight, perspective has made the outer dials oval.





After spending many a happy hour on Photoshop I produced acceptable dials etc. These were correctly spaced using Publisher and printed out on “Glossy Photo Paper”. The control panel itself is made from card covered with litho plate, the dial printout, a sheet of clear acetate and finally another layer of card. The bezels are cut from card and the “level flight” indicator is a length of Bowden cable outer.





The clarity possible using “cheap” technology is amazing, this photo doesn’t do the dial faces justice. I used a high-resolution setting when printing out and, although way “over the top”, it is possible to read the serial number on the rpm indicator using a magnifying glass!

[Greyhead]

Onto the cowl, my favourite part of any aircraft, they are so individual and have lots of lovely fixings, bumps, air scoops and other odd appendages to stretch our modelling imaginations.


First a photo of the finished article, it can appear a daunting task but taken step at a time it’s OK.





A decision has to be made as to whether to cut non-scale holes or use scale inspection hatches to gain access to the engine for choking and adjusting the needle valve etc. In this case the sides are hinged so the choice is fairly obvious although it does complicate the build somewhat. The first step is to make ply formers for the front and rear, with this cowl it was slightly more complex, because of the hinges there are actually 3 formers, top and left and right sides, for both front and rear. The formers are then joined with balsa “longerons” and covered with 1/16th balsa. Wetting the outer surfaces where there are tight bends helps considerably.


The next problem is the long hinge. Commercial “piano” hinges are just too big and won’t bend. You can make your own quite simply by soldering brass tube to brass strip and cutting into suitable lengths.





The hinges are glued using epoxy.





The result is a very neat joint.





That’s enough for today, next time it’s fixings, louvers and exhaust pipe.

[Guest]

can`t wait bud

[Guest]

hope to be reading the next part soon oster_ke

[wonwinglo]

Grahame once again some really useful and practical tips here,these scale details make all the difference in the world to a model,your piano hinge looks most convincing.

These are the tasks that really eat up the time but if you enjoy doing them then that is the main thing to improve the end product,the Parnall Elf just has such great character.

I was a bit alarmed last year when Shuttleworth were considering selling her off,she would have vanished Stateside never to be seen again,thankfully someone saw sense and she has been retained at Old Warden.

[Greyhead]

No time today, terrible thing having to earn a living, roll on retirement!


Just a photo of the exhaust side of the cowl.





Reading through my last post I realise that I didn’t explain how to ensure a well fitting cowl, wonderful thing hindsight.


First of all make the templates for the formers using the model not the plans, remember to remove 1/16th for the covering, mark the hinge line and partly cut. Then fit the balsa longerons with the assembly in situ using cling film to stop unwanted adhesions, only then fully cut the sections free.

[Guest]

Hello,

Your work is impressive. Your technical solutions are constructive and original.

I'm also at the the bench with a 1/3 Tipsy Junior. It's also a long time project with pauses.

Hope to read you soon on the forum.

Congratulations,

Marc.

[Greyhead]

The cowl is covered with a combination of litho plate and printer paper. Where there are compound curves use litho but for flat plates printer paper is lighter and easier to stick, it’s also a lot cheaper, if you can’t find a friendly printer. The rivet lines are embossed from the rear using a dressmaker’s pattern copying wheel, the spacing may not be correct but who knows? At least they’re evenly spaced. For individual rivets use an old “Biro”.


The louvers are a simple job on the Elf as they are separate items riveted on. They are made from strips of litho bent to shape and glued through holes cut in the side panels. Don’t be tempted to just stick them on the outside; they’ll look terrible and won’t help to keep your precious engine cool! The secret is to mark out all the holes, cut the first hole and glue the louver in before cutting the next hole. This maintains the curvature of the panel. I also strengthened the strips between the louvers with a few carbon fibre tows but this is not really necessary, it was just a bit of “belt and braces”.


The exhaust is from paper rolled around a felt tip pen. Use medium cyano and then roll the pen on the workbench adding more glue as needed. I use kitchen foil, as it appears to be about the only thing cyano won’t bond to, to stop the lot sticking to the pen. Coating with a mixture of 30min. epoxy and micro balloons produces the pitted surface if you keep dabbing it with a “suitable implement” for the first few minutes as it cures.





The “suitable implement” I used was my finger but I’m sure the Health and Safety establishment would tell me I’m storing up all manner of ills for the future, so the choice is yours!

[Guest]

Exhaust is superb ! I thought you had welded-up a miniature metal one and then put it out in the rain for a couple of years. Cant wait to see the Albatros.

[Greyhead]

The twin air scoops are made from litho and really help the cooling by directing air down over the rocker box onto the cylinder block. The other bits and pieces use litho, copper wire, brass tube and washers.


You get a good view of the cabane struts with a coat of paint in this view and can just about make out the carbon fibre "tongues" that lock the wings in place.


The Elf logo was printed onto self adhesive white paper, once again after a bit of manipulation using Photoshop.





The fasteners are not functional, the sides are held in place by magnets, very useful items these, they also hold the luggage hatch and the rear section of the lower wings which fold down to allow the main wings to fold back. There’s a thread about them on the site, they are still available from Maplin and in fact I’ve just bought a new supply today. I prefer the ones originally designed to be used as electrical connectors, they are in a metal holder with a stiff wire attached; this helps with the positioning.


Code: N51AK


Description: Magtrix Connectors


Page: 582

[Guest]

good posting dude

[Glider Guider]

The inkjet vinyl for making the logos is available from Overlander Batteries and comes in clear or white and costs £9.00 for between 8 and 10 sheets depending on the specification. On the white film I get good results using the 'Photo Quality Glossy Film' setting on my Epson printer but beware it can take a quite a while to dry so be careful not to smudge it. I have not tried clear film.