Following on from the kind comments and interest shown in my Tiger Moth and Gloster Gladiator biplanes, I thought I would share my latest project. This is a 1/6 scale Gloster Gamecock which is a 1920's British Biplane "between wars" fighter plane. I am building this from a plan by Gordon Whitehead. I have been taking photos during the building process so it can be followed and I will be describing the whole build and thought process.

First off... why this plane. Well its not exactly pretty, but its different and rarely modelled. Not too much data available.. all in all a bit of a challenge! 

Anyhow, I hope its of interest and a source of fun! Watch this space


 

nice one mate..........
I have not flown planes for years now but have the plans for a WW11 SuperMarine Walruss..
the last of the bi-planes to see service in uk forces.
used most commonly on battleships and cruisers in 1941/42
I will follow your thread with interest....
regards
don

The excitement is building  

I hope that the powers that be provide you with lots of free time to make it a quick build !

Mike,

There are some builders (and their creations) who leave you speechless with awe. I won't even bother wishing you "best of luck", as I believe your expertise does not warrant such mundane encouragement.

By the way, you set the bar too high....................

 

Warm Regards,

VC

Hey Mike,
Excellent choice, I have built two of Gordon's design from plans and am a fan of his engineering, light and sturdy models does he design!
I have the Gamecock plan from Mr. Gordon for that one day project, and couple of others too.
Had a very educative interaction with him while building his 25 size Tiggy, wherein he helped a lot.
He has mostly converted to electric now
Would wait for your build pictures to draw some inspirations
How do you intend replicating the large Al panels on the nose ?  

Gloster Gamecock


Part 1

Little history first. My association with RC planes goes back a lot  of years when as a 13 year old I built a single channel 36” Keilkraft  “Gyron” with a 1cc diesel engine, which flew but had a mind of its own!

Put off, I dabbled in Control Line… more failure.  The advent of multi channel proportional radios in the 1970’s gave the budding RC modeler half a chance of success. I built from plan (the start!!) a 3 channel “Tauri” with an Enya 19, flew a few times successfully and then wrote it off it a fit of disorientation…. ooops -  I am 16 years old.  

Football, education, marriage, kids and my unrelenting quest to be a Rock Star, all seemed to get in the way, but I never lost touch.  It wasn’t until my early twenties I joined the model club in Dubai where I built a Gangster 63 with an HP61 and under the guidance of a nice man called Barry, learned to really fly and haven’t stopped apart from a few years back.

But I love to build as well hence this little story!

I am certainly no expert but when considering building scale models from a plan there are a few things to think about!  

Is it within your building capabilities?  Skills need to be acquired and developed, starting with simpler models and working up to more complex models.  

Is it a model that you will be able to fly?  A highly loaded Spitfire or a multi engined B17 is going to be a handful compared to a Piper Cub for example.  

Is it a model of a plane you like? Sounds silly but if you are a builder half the fun is “gloating” over your pride and joy!!  

Which plan? There are many plans available for all sort of planes and all trusted designs, however, certain designers have a reputation for quality of design such as Brian Taylor, David Boddington, Duncan Hutson, Nick Ziroli to name but a few.  Doesn’t mean you are limited to such designers but there is a degree of comfort available there.







THE PLANE

Gloster Gamecock.


Developed in the period after World War One which was period of apathy as far as the Armed forces were concerned, the Gamecock evolved from the Gloster Grebe. It was based on outdated designs, wooden structures and took no advantage of any advances in technology.  

The Air Ministry ordered a total of 80 Aircraft over the period September 1925 to November 1926.  By 1933 the Aircraft had been declared obsolete.

The only remains of an example of the Gamecock are part of a fuselage in a museum in Finland. In 2009 plans to construct a full size replica were underway in Gloucestershire in England.

The plane had a reputation for being highly aerobatic, prone to spinning; aileron flutter and poor visibility on take off. Most quirks were ironed out with the ongoing development of the Gloster Gamecock II.

I bought the plans years ago ( I like to collect plans!!) and spent a few months looking at them, identifying potential problem areas seeing if I could build it etc have I got  a suitable engine, in other words “do ability”.

This plane at 1/6 scale comes in at 60” wingspan, will probably weigh 10-11lbs (4.5-5.5kg) so my trusted Saito 91FS should be ok.  It’s large enough to get some nice detail and small enough to transport easily.

The landing gear needs to be fabricated  from metal tubing and wire and will require a lot of silver soldering, I have a blowtorch so that’s not a really worry, but again if you can only soft solder it would be an issue, potential area for skill development here!

Initially the Gamecock used a 9 cylinder Bristol Jupiter Mk IV engine, fully exposed, this is a version I want to replicate. I have a choice here, build it  from Scratch… and I mean from scratch, there a few photos on the web and off you go….. or buy a plastic replica, William Bros have kits of engines available, not quite the Jupiter, but maybe they can be adapted to suit. Something else we’ll be looking at later.

OK by now you will have decided for yourself, this scale modeling is all just a pain in the neck or it could be interesting and fun… researching, thinking, creating and  making… all of which at some point in time will result in a machine which will be flying majestically right past your eyes       “…and its all my own work…”

Having worked up a list of wood and hardware needed, I ordered it all up from a company called SLEC in the UK. This plane involves a lot of spruce timber which is new to me but readily available at SLEC;  www.slecuk.co.uk

The designer emphasizes that there is a build sequence:  wings THEN fuselage, rationale being you cannot complete the fuselage strut alignment without the wings.

No excuses now!

Thanks Mike for taking the time to post in such detail.  From our conversations, I thought you were into model stuff for about 15 years.... to know that you started before I was born certainly changes the perspective (nope, don't mean to paint you "old" )

Awaiting further developments and pictures of this build, and hopefully to see it take off in our field !

As promised some photos of where I am at present, to give you an idea. I will go back to the beginning of the build and go through it all with more photos.

You can see a photo of the replica being built in UK, this is in 2009, plus one of the better profile photos of the real thing back in the 1920's

As far as the build goes, this started in September 2009, so progressing ok (actually at lightening speed for me!) Lots to think about in this build but thats part of the fun

Awesome 

One more suggestion Mike.  A lot of us could learn from information about the tools and techniques you use for the delicate balsa work.  How you cut, shape etc, and how it may be different for ply versus balsa etc.  Also, the glue you are using, how you cover the mode etc.  Basically the things that may seem obvious to someone who has been around, but can pose as questions/choices for people who are newcomers to this aspect.

Part 2

WINGS

I now have a pile of timber and piano wire staring me in the face… almost goading me …”now what?”

Let’s go for it!

Not too much to think about with building the wings just follow the plans.

The one thing I made an early decision on is how to actuate the ailerons. As per the plan the ailerons are driven by a central servo. This drives pushrods through a 90 deg bell crank to the control horn.  This involves a lot of setting up and potential areas of linkage slop, I always get frustrated setting this type of linkage up.

Good news: the advent of super slim servos that sit in the wing that makes this type of connection redundant.

So I have used the Hitec 125 servo that will be fully concealed in each bottom wing half. I did consider putting them in the top wings but the full size plane has an external bottom/top aileron connector so I am going to do that as well. Decision made.

I always make a copy of the plan to work off  and photocopy the parts that have to cut out ie wing ribs fuselage formers and glue them using a gluestick to the timber. This gives an accurate template to cut to.

Other options are tracing through the plan on to the timber using carbon paper, or using pins to “prick” the outline though the plan onto the timber.  I find the copy method easier and flexible. The paper is easily removed later and one advantage is you can easily see what the part is!! Useful for me as it could be months before I come back to that part!!

The wings are 1/16” balsa ribs and 3/8 x 1/8” spruce spars, trailing edge and  bracing. Rib web bracing are 1/32” ply and the aileron spars from 3/16” balsa.

Fortunately the wings are for the most part parallel chord so we can use the sandwich method to cut the most of the ribs. Using two 1/16 ply rib templates made as described above and 1/16 balsa blanks sandwiched between the templates, the ribs are cut and sanded to size.  You can cut out for the spars as per the plan, but I always cut these to suit the actual spar so it is accurate, in this case 3/8 x 1/8” spruce. Being a biplane there are lots of ribs… patience is virtue!!

The cut ribs can be placed over the spars on the plan, careful alignment is the key here.

I always do a dry run or two before the glue comes out, to make sure I am happy

From the pictures you can see the sequence: one bottom wing bare bones complete with ribs and spars, note the aileron still in the rib and will be cut out later to maintain the exact profile…. that’s the theory… doesn’t quite work in practice but it wasn’t too bad! You can see what I mean , the angle cut for the aileron was tricky and the ribs don’t exactly align but the rib capping strip will hide this and any misalignment will be rectified with a sanding bar.


You can also see the ribs and spars plus Trailing edge glued up. Important to  get it flat on the board to avoid warps and keep the ribs vertical. I use PVA or white glue that gives a little bit of drying time for any final adjustment.

You can use superglue or cyano but glues have different properties and, not wanting to create a debate, I believe for wood to wood joints PVA glue is the best. My only caveate here is that on high stress areas ie wing joiners, firewalls, tailplane/fin joints epoxy gives you the extra strength. 

I am aware that there are many types of cyano now available, but at the risk of being called old fashioned, I am old fashioned!!

More to come!

Pretty neat build (and building table) there Mike.
One more way to transfer plans on to timber is to make a photocopy and then put the piece of copy upside down on to woodstock you need to cut and run suitably heated iron over the paper, which transfers the printed part on to wood. This would also work with any laser printer but not with inkjet printed documents.
The only downside to photocpier method is that unless you are carefull, it may distort the print 

WINGS Part 3

Following on from last time:

The end curved sections of the wings are three lamination made up from 1/16” x 1/4” spruce.

These were formed by gluing a copy of the plan to a 18mm mdf board, nailing pins to the outline , cutting the strips and wetting them, applying glue the face of two strips and them bending them to shape and putting nails in to hold tall three strips at the same time  whilst the glue sets and timber dries.

Lots of pain here as the hammer hit my fingers instead of the nail… you can see the ends loose laid for final cutting and fixing.

You can also the servo temporarily fixed whilst I work out the pushrod angles. Lovely servo, I think “cute” is the word! 

The leading edge is added planed and sanded to rough shape. Don’t forget to add the web bracing and stiffeners or else the wing will twist. 

There is an issue where the leading edge meets the laminated wing tips, they do not line up. The wing tips are flat and the TE centerline is halfway up the rib, “never the twain shall meet”. I am going to leave this till later as I will get the solution when I have a look at the covering.

One thing not to forget is the nuts that will take the bolts that will fix the interplane struts in place. The plan show “T-nuts” but I opted to use locknuts; these have the plastic thread in part of the nut to “grip” the bolt in place. Just a little bit more secure. These were fixed by drilling a tight fit hole in a spruce doubler and epoxying the nut in place before gluing the double under the spar, a hole is then drilled through the spar for the bolt access.

I have aligned the top wing half to suit the dihedral required. Word of warning…it’s very easy when joining wings to get a twist built in. If you draw a line through the centre of the trailing edge and leading edge of each wing half at the last full rib section, when you join the wings these lines must be parallel to each other assuming the wing has no washout, which is the case here.

Way to do it: place on wing on a flat surface, place a piece of timber exact height of dihedral you require under the last rib , the timber should be full length of the rib, now in theory the two wing datum’s are parallel. Remember this timber spacer will be slightly less than the stated dihedral as you are working away from the tip.  You have to be really honest with yourself here as a twist will really affect the trim of an aircraft.

The bottom wings have the same build sequence as the top so no excuses!

As an aside, I have put a photo as an idea of the basic tools I use, working from the left: assorted needle files, rasp file, razor saw (exacto type), Scalpel knife (exacto type), box cutter, home made sanding block, steel angle, various clamps, hacksaw and steel ruler. Obviously I have for example several steel rulers up to 1 meter long and clamps tools but most of my works building planes is using these types of tools. Not exactly hi-tech!

By this time I have had enough of the wings so next time we’ll be starting the fuselage!

See you later!

Not sure if this can get anymore personal than THAT !

Please do post in detail, especially the covering part (material, tools, techniques).  Also, on the fuse, I assume to use some epoxy instead of the white glue you have been using all along so far ?

Right, so I admit that I am now bored with the wings. Cutting, fixing and pinning 60 plus 1/16 x 1/8 x12” capping strips did it for me and I need to start the fuselage to create a diversion and some light entertainment.

Decision points here:

How will the engine fit, where will the tank go, where will the radio go, how will the servos actuate the controls …..?

The original design was for a 61 size 2 stroke, I want to use my Saito 91FS which is considerably bulkier and longer.  It means a putting a separate bulkhead behind the front former. There is 4deg down thrust and 4deg right thrust required so this needs pen and paper and calculating the position of the new bulkhead plus the offset needed to achieve the thrusts.  Four strokes vibrate and I wanted to use isolation mounts.

I settled on a product from Just Engines in the UK, www.justengines.unseen.org   they ship worldwide, which are neat and easy to use. By fixing the bulkhead with down thrust built it I can adjust the isolation fittings to give me the side thrust. Has to be a careful calculation to get centerlines in the correct position to take the mounts.  Also the isolation fittings require 10mm diameter holes drilling…. not for the faint hearted!  I always work up to this size by using a 2mm, then 5mm, then 8mm drill, less stress and more accurate.

Unfortunately the downside of this is that the bulkhead eats into the tank area, but I really don’t have a choice so will have to manage that later on.  With this design the tank and servos go into the same bay and that’s a pet hate of mine. Burst fuel pipe and loads of damage.

Happened once on a trainer I have. Fuel ended up coming out of the tail!!  Fortunately, radio was ok. I stripped the plane, poured rubbing alcohol through the fuselage which did the trick, neutralized the fuel soaked timber. Plane was recovered and is still flying!! Not bad for a plane originally bought in 1986… but that’s another story!


A photocopy formers are cut and pasted (literally) onto ply or balsa and cut by hand with a scroll saw, new blades make this fairly easy.  The balsa sides are cut as well as the doublers. The plans are a bit tricky to use as lines of demarcation for the parts are not clear, so it’s awkward to see where parts start and end. This goes back to the beginning about experience and skill levels; if you had just cut all parts from the plan and tried to assemble, you would be in all sorts of trouble.  You have to remember the designer is assuming you have experience and will cope with this sort of thing.

The secret is to check, measure, recheck and remeasure, then cut!  You are not in a hurry are you???

The sides can be glued together … use impact adhesive, fiddly but gives a flexible joint as opposed to epoxy. Don’t use PVA, I did this last year on a model, against my better judgment, the water in the PVA just bends the fuselage sides and doublers like a banana but lengthways along the fuselage.. and it’s impossible to get out.  IMO

The side longerons are 3/16” spruce are cut and I epoxied these to the fuselage sides. The intermediate struts and bracing are 3/16 x 1/8” balsa fixed with PVA this type structure is very strong. You have to build two opposite sides! The spruce longerons have a curve in them and that’s a bit fiddly to maintain. Build over the plan with lots of pins to keep the correct outline.

I got a fright when I saw how short the fuselage was in real life!

Next crucial task is the front bulkhead, it has to be fixed true or the whole fuselage will be out of line.  I always use 90 minute epoxy here a) because it’s strong and b) gives me time to make any adjustments to ensure its ok.

To get the fuselage to its basic box I added to formers that take the lower wing. These have brass tubing stitched to the ply; these will receive the wing dowels built in to the lower wing panels. It’s important to get these tubes in the right position... Stitching them in is achieved by tack gluing the tube with superglue, make sure you are happy and then drill 1mm holes both sides of the tubes every 10mm and using needle and thread stitch the tube to the former. Once done coat the thread in epoxy.  By the way this should be done before you fix the former to the fuselage. Again using a set square check the fuselage is straight and level and square when fixing formers.

The next test to check the fuselage is true is to mark the centre of each former at the top or bottom, fix a pin to this mark at the front former, attach a length of thread to the pin and pull it tight to the end of the fuselage. Pull the ends together and you can now line up the thread with the centre marks along the fuselage. Are they all in line? If so … good job, if not the fuselage has a twist in it, you may have to adjust the back before final gluing or worst case redo some formers.

Again it’s not a race, so take your time.

I now add the top and bottom bracing; this is done in two stages as the fuselage in plan view has two curves, so you can’t do this in one go. This was very very tricky and accompanied by a lot of bad language... (Apologies). I admit it took three goes to get the back end of the fuselage glued before I was happy. You can see the end result at this stage.

Ok now I turn into being a little kid, I want to see the lower wings fitted, so it’s back to the wings; the alignment here is really important.  You have to drill two holes in the end two ribs of the wing to match the brass tubes, not only that but the wing section datum is approx 3 deg off the fuselage centre line. This was built in when the tubes were stitched to the formers, but the wings have to match.  To do this before I fixed the end ply rib to the wing, I temporarily fixed this rib to the fuselage and marked the hole location using a piece of wire with ink on the end poked through from the other side… holes marked and drilled…. done!

Wing ribs are fixed, piano wire dowels cut and bent to achieve the 4 deg dihedral and wings located into the fuselage - now we have the semblance of a plane!!

See ya!

Coming up nicely

Are you referring to the the "JEN Isolation Fittings" on this page http://www.justengines.unseen.org/acatalog/Engine_Mounting_Gear.html  ?

Wow!.. great build!.. All the best Mate.

Yes the JEN isolation fittings.

Mike, You are the man with patience and passion      At the end, once everything is complete, please post the average number of hours you spent building this. I really wanna know that.

Missed you at the field today (and last week too).. guess/hope you are working overtime on this build, as opposed to over time on your day job

In UK! and now STUCK in UK due to ash    anyhow chance to post some more pics!

Aaahh, that explains it !  How long more is the flight ban expected to be ? 

Do you actually see any of the ash/soot in the air in your vicinity ?

Nobody knows. As far as the ash, there is no trace whatsoever. It is actually a really beautiful day with clear blue skies!! You wouldn't believe it!

Long time no see:  :)got caught in volcanic related delays, busy at work and took ages to setup the alignment for the wing struts and interplane struts. A total of 12 pieces of metal to cut and fix.

Anyhow as you can see from the photos all done. The struts are 1mm aluminum strips faced both sides with 1.5mm balsa plus the edges too, all sanded to give the aerofoil profile.  I used the impact adhesive to fix the balsa to the aluminium, takes 10 minutes. I then stained the balsa with teak colour wood stain, a coat of sanding sealer, sanded down and then another coat of stain. It is already for a coat of varnish at the end of the build.

The interplane struts are from ¼” x ½” spruce, again sanded to shape with 1mm aluminium fixing plates let into the ends.

The whole assemble was fitted loose, jigged, unfixed, glued with slow epoxy, rechecked for alignment, re jigged etc and allowed to dry and then hopefully once dry it has all stayed in place. Actually the final result wasn’t too bad I have to say.

Next up is the tailplane and elevators which are a mix of balsa and spruce, the tailplane is in two halves which will be fixed using piano wire dowels into brass tube in the fuselage, slightly unusual but wasn’t too difficult to keep aligned. The elevators are hinged using the robart type hinge, slop free but you have to be accurate drilling the holes.

Next the fin and rudder, the rudder frame design is three laminations of 1/16” spruce with tight curves. Try as I may I couldn’t do this. Wetting the timber, steaming it, cutting nicks in the back, front, a combination of all techniques, the spruce just cracked on the first bend and there are 4 bends. Ok forget it; I made up a frame using spruce on the straight and hard 3/16” balsa to form the curves as per the photo, problem solved. Fin was straightforward.

Now we have an airplane!! Undercarriage next up!
 

Great to see the bird take shape  

The original picture has more piano wire connections between the wings, those are in the works ?

PS: Looks like the windy weather today prevented us from flying, but resulted in you getting time to update the build thread  

Well spotted!!

These are the bracing wires which I will add when the plane is covered. The designer cautions not to over tighten so obvioulsy they have an some function to keep the wings in shape. Must say it feel solid as it is.

There are two diagonal braces on the V struts above the fuselage and two anti flutter struts going from the interplane struts to the wing tips. These are not in the photos but were added as the plane evolved. Not made yet certainly will be included!

Trust the wind to come out to play of Friday, should be ok for tomorrow though!