Mick Reeves 1/3rd Scale Pup

[Jez Harris 1]

I thought it was quite pricey too initially, However I have built a couple of Balsa Usa Models for around £400, which by the time I factored in wheels at £80, metalwork and rigging wires, a proper undercarriage built by a mate at £60, nuts, bolts, hinges, they probably worked outaround the same cost - but were nowhere near as scale.

Jez

thanks for watching and commenting.

[Tony F]

Fascinating to watch Jez....but impossible to get past my wife methinks

Tony

[Jez Harris 1]

More progress made.

I added the side formers and the forward stringers..

I also added a few addtional pieces of 1/4sq balsa along the top of the fus longerons - this wil give me something a bit more beefier to atach the cockpit decking to, and also to attach the fuselage metal panels to later in the build.

I couldnt resist a cheeky trial of the cockpit decking and the instrument panel -Even the decking is supplied with the scale cutout already done for you... looks okay so far.

Until I discovered that although the formers are fitted exactly as shown on the plan - I double checked by measuring their position from the start of the top longeron..This unfortunately leaves a former showing -

Having checked a bit of reference material to make sure my cockpit cut out is correct (it Is), it was the work of a moment to move it back a few milimetres. It turns out the plans show a different cockpit cut-out pattern. Glad I checked as it would have been a pain to relocate later in the build.

Jez

[Jez Harris 1]

Next step is adding the rest of the top formers and the stringers. This was a doddle as the cut of the formers was again spot on. I didnt have to adjust any cut-outs or notches to end up with a dead straight run of stringers.

The ends of the stringers terminate in a nicely thought out set of formers that give the correct scale finish and supports the tailplane. There is a triangular re-inforcement piece that just needs a slight trim to get it to sit flush

Next step was to add a bit of colour to the woodwork visible in the cockpit - Ronseal Antique Pine. You can just make out where a bit of black paint has sorted those rigging brackets out.

Jez

[Jez Harris 1]

While the paint and varnish was drying I turned my attention to another little sub assembly job..The wheels..

You can pay over £80 for a pair of Dubro wheels but they are quite heavy and you cant do much with them to make them look 'right'

First off - lots of pieces!

Nice light foam tyres

Vac formed inner and outer covers

Construction begins bt knocking in a few captive nuts.

You then fit the 2 halves together using plastic spacers

2 Wooden discs are supplied - you epoxy these to the covers which in turn are bolted to the main plastic discs.

You end up with something that resembles the makings of an old fashioned cine projector.

Time to enhance the look a little bit..

Using wooden dowel of diferent sizes I knocked up a couple of valves - I used heatshrink to give them a rubber look.

These were then trimmed to shape and to length. To give the valve tops the right look I painted them, but before the paint fully hardened I rolled them on a file to give them a knurled look.

Next I used a couple of lengths of thin carbon rod to create spokes - I had to get the dremmel out to drop the level of the rim down a bit in order to get the valves in the right place.

I think this looks okay for now - I need to add some trim to the cut outs and around the axle - this will be done later when I get the solartex out.

Jez

[Chris Bott - Moderator]

Blimey you don't hang about do you!

It's fascinating watching too.

Something I don't think I'll ever aspire to. So, many thanks for sharing.

[Jez Harris 1]

Next up..tin bashing.

Under a pups fus is a groove where hot gasses exit the cowl. heres a full size..

I used a piece of tin plate to create the same - again using carbon rod to simolate the wires. Still got the vent pipe to add. Marked out ready for bending..

And screwed to fus...

Followed by more metal bashing to create the side cheeks - the difficult bit being the forming around the stub wings.

And a quick put together to check it all lines up..I need to find a decent way to countersink the 0.6mm plate as the screws are countersink - I think I might experiment countersinking the wood they screw into and seeing if the screws will shape the rest.

[Tony Bennett]

fantastic workmanship.

well worth watching this thread.

[Jez Harris 1]

With the metal bits removed and stored until I'm ready to have a bash at panels and various pipes, breathers, ammo chutes etc I thought it was time to torture some balsa..

Time to start the tailplane.

With the lower spar fixed to the board I packed the ribs off the board - quite a bit of packing required.

One of the first things to add is the tailplane adjustment device - it sits over the trailing edge and on the full size allows adjustment of the horizontal stab. Its just a couple of pieces of brass tube soldered together. This will eventually be soldered into the fus.

The leading edge is 3/16 dowel, the rear is 1/4". These are spaced by a mere 8 balsa ribs. Again as this structure wont be visible I'm not going all out with internal rigging wires, instead I'm simply using 1/4" square to beef it all up.You can just see the little brass adjuster at the top of this shot - I nearly forgot to fit it before glueing the ribs on...

The fit of the parts is again important - no simple butt joining the ribs to theleading/trailing edges - the ribs are shaped to take the dowels.

There are 8 bracing wires attached to the tailplane (4 top/4 bottom) - 4 bolt to the leading edge and 4 onto the spar. I have added a bit of packing to the spars to stop the covering being pushed in when the braces are fitted later.

Now - back to those tips. The wood is cut as shown, leaving a bit flapping loose - I can only guess you have the option to either glue them back in place and go with them like that or remove them and add tubing/wire. I'm ading wire to strengthen it.

So its out with the springy wire bender thingy..I find these a god send as it stops me putting kinks in the metal as it stops them from bending too much in one place.

It took me ages working a bit at a time to get the bends as I wanted them, but I got there in the end. I drilled holes in the dowels to accept the end of the wire -

- and drilled 3 holes in the wing tips - sorry about dodgy photo!

[Jez Harris 1]

I then used thread to bind the wire to the tips. I simply dipped the thread in cyano to prevent me needing a needle.
I found only 5 or 6 winds were needed to secure the metal edge. I secured the thread by locking it in place with a cocktail stick and wicking cyano into the thread.

I'm pleased with the result - super tough tips with very little weight added.

All this work and hardly any mess to clean up..

So - addition of cap strips completed and voila a finished stabiliser...

Couldnt resist a gratuitous "stick the tailplane on the fus" shot.

[Jez Harris 1]

Bit more metal work - this time with the elevators.

First, a bit more bending to get the outline sorted - all in 14 gauge wire.

This is where I am up to - a little kit of bits that need silver soldering together. The metalwork will fit to another piece of dowelling - some of the "ribs" will simply pass through holes drilled in the dowel and be supported by the 90 degree bends tied to the wood. The two ends are set into grooves, again they will be strengthened by small metal struts.

Okay - so I've now got various bits of metal to join together.

First step is to thouroughly clean the parts - I simply used wire wool followed by a wipe down with Iso alchohol.

Next bit is to wrap the joint using the wire provided - I learned a valuable lesson here - dont pull really thin wire really tight - it has a tendancy to slice into flesh..

Next is to apply flux - I just use a paint brush to apply it, then you simply heat until 2 parts go a dull red and wick in some silver solder. Let it cool then give a thorough clean with a wire brush and if necessary a file.

And so on - I'm not using any sort of jig - just a vice. I am keeping a very close eye on keeping everything in line though.

Next job is to add the control horns. One of the first things I did was number all the various brackets to make identifying them a bit easier - anything to cut down hassle!

So its 2 number 17's folded over at the ends..

Again, a simple task to solder them in place - the scruffy wire is some thick garden wire I used to hold them in place whilst doing the soldering - this just gets cut off.

The metal frame is attached by simply drilling holes through a length of dowel which becomes the elevator leading edge.

The frame is held by very thick cotton which is soaked in cyano. They are wrapped over the little 90degree brackets I added earlier.

Finally - one completed elevator.

1 1/2 hours later there are 2..

And then a rudder made in the same way..

Jez

[Willowlea]

oh wow, that is beautiful Jez. I would love to build a 1/3rd scale pup.

You mentioned using Ronseal Antique Pine, prolly a noobie question this, but does it add much to the weight or is that something you don't need to worry about as much with this size scale?

[Jez Harris 1]

Hiya, thanks for the feedback.

No - it doesnt add much weight - I'm only doing the visible bits anyway. At 1/3rd scale you can get away with a bit of weight as long as its in the right place - i.e in front of the balance point.

I recently completed a complete refurb of 1/3rd scale cub - I used 27 cans of spray paint on that one!!

Jez

[Jez Harris 1]

Next up I'm looking at the centre section..

The plans are a bit woolly here as they show very little info as to how you create this shape..the outside assembly of the centre section.


Its not helped by all of the ribs being labelled as W1 despite being all sorts of different types....

This where it pays to slow right down, move the glue away from yourself so you dont get tempted to plough on, and get all other plan sheets out that cover the approach to the wings..
By looking at how many of each different rib I had, I found that the approach Mick takes is not only substantial, but very good looking too.
The outer rib of each wing panel and the centre section is formed of a laminate of 4 parts - there is firstly a decorative rib (bottom one in picture) that even though you cant see it when you put the a/c together its fretted out as per the ful size.
Then a solid rib(middle), followed by another with cut- outs (top) to take a strengthener at 90degrees to the ribs.

After laminating the ribs together I laid them on the plan - the spars dont line up as I expected so I am going to wait until I have studied the plans side by side agian to see what I need to consider - I know what I have done re the laminating is correct as all the holes for the wing joining dowels line up.

[Jez Harris 1]

Now back to the centre section..I have had time to ponder and I need to create the brackets that hold this onto the cabane struts. Only when I can see what these look like and how they fit, can I tackle the various things in the bit that holds the top wings on..

This is the bit that fits into the top of each cabane strut - this meant more metal folding and more silver soldering..
IMportant bits though as this bracket holds the top wing on, holds the cabane strut wires and the landing wires - all these are completely functional so if any bit fails it can be disastrous.


They are only tiny bits of metal but sooo much bloomin work - firstly the holes are the wrong diameter for the supplied bolts so it was time to blunten some drill bits.
Next the supplied nuts are nyloc - its not easy trying to heat these..they tend to melt everywhere.
Then all of the bolt holes need to be countersunk.
All the initial cleaning, bending, checking, re-bending, soldering, drilling, countersinking etc meant creating the following 8 little bits has taken 3 hours.. And I've still got to give them a final clean yet..

[Jez Harris 1]

Now a few more little niggles..

Firstly the centre section is held on by 2 bolts running into blind nuts.
The brackets for these are the 4 bottom ines in the last post. The holes are pre-drilled (albeit too small).
Only when I go to fit the blind nuts in the spars do I find they are to close together making fitting 2 blind nuts impossible unless you take a hacksaw to one of them..


This is then the laminated outer rib that I was pondering over last time.
The spars simply locate into the following cut outs - same as any other rib/spar joint...



Well..er Nope..they dont 'cos those blimmin pesky blind nuts mean they dont fit without a bit of wood surgery..


Anyway - I'm off for some more head scratching. I think the easiest solution is to remove just enough from the ribs to clear the blind nut - its not close enough to cause issues when you screw a bolt through them so no worries there.

Jez

[Jez Harris 1]

Carrying on with the centre section...

The lower spars were glued in and left to dry for 12hrs+
The main bit of the centre section is built up as per most builds - just adding bits whilst building over the plans


As mentioned before - the quality of the cutting is superb - it will be a shame to cover them up!


I'm using titebond to give me time to get the position of each rib spot on - a simple set quare keeps everything err- square!


10 minutes later and the top spars are on.


Mick even goes as far as to pre cut the spar webbing to the correct depth.You get masses of it - Its all 1/32 ply so dead easy to cut to length.


The depth is spot on -a 1-2mm gap top and bottom leaves nothing sticking up above the spars

[john stones 1 - Moderator]

lovely metal work Jez

kit looks very good , love the instruments

[Jez Harris 1]

Within a few minutes the spar webbing is all on - It goes on both sides of the spar on both front and rear spars. You end up with box sections that are really strong.


The leading adge is glass fibre rod.


The nose of each rib and the 5 riblets that go into the centre section are all pre-shaped to accomodate the rod.


I wasnt sure which glue to use - I tried cyano on an offcut..looks good.


I wanted to make absolutely sure so I gave it a bit of a tug and it simply popped off.
The glue doesnt penetrate the glass so it doesnt grip at all - I tried taking the shine off with sandpaper but it was no better.

A similar test with epoxy proved much much better so I went with that.

Time to add a touch of scale stuff..There is a turnbuckle and cables visible through a small inspection window on the leading edge..


I'm making the surround from lithoplate cut to size quite easily with a scalpel. This will be glazed with the supplied acetate and held in place with screws.


The trailing edge is made from more wire so time to get bending again..


More soon..

Jez

[Jez Harris 1]

Ok - more on the centre section..

The trailing edge is again made from 14swg bent to shape -


The difference being, instead of one piece - its 2 pieces side by side..That is going to be a nightmare to accurately bend by hand!


The first piece was easy enough..


After a lot of bending, re-bending, swearing and general dog-kicking in frustration, I got close enough..
There is one kink on the left but I am going to pop some more solder between the layers and grind it level..

[Jez Harris 1]

I then got to pondering..(dangerous I know)
The method to fix the leadng edge is shown on the plan as more metal brackets which are epoxied to the ribs. Due to the narrowness of the ribs, they would actually need to be 50% longer than shown to make them really strong.


Although its not all that heavy, its additional weight in the wrong place -i.e. its behind the c.of.g. When you bear in mind the same method is due to be used on all four wings as well, the combined weight will all add up leading to the need for ballast in the nose.
I am going to try another method..
I grabbed a couple of BBQ skewers and drilled a cuple of fixing holes.
I then cyano'd the skewers in place.


I could then bind the trailing edge using thick button thread and set in place with cyano making sure there is plenty of contact between the thread and the rib. The result is a rock solid fixing. I've twisted it repeatedly, thumped it with a small hammer and thrown the completed assembly at a wall at 90% to simulate one of my better landings and it stands up to it well. A rib will break before the fixing lets go.


With the addition of a few strips of capping, the centre section is almost there.


I need to sort out the little inspection window as I'm trying to recreate this..


Mine is a bit too short - I can see it needs to extend back over the spar, so I will do another one at some point. The shape was created by annealing the lithoplate and forming the shape over a metal ruler.


More soon as its time to cut the interplane struts and trial fit the centre section- Jez

[Jez Harris 1]

Cabane struts..

First off I made 2 paper templates by tracing over the plan - You have to be really careful here as the first of the 6 plan sheets shows a side view that shows the struts in detail..Dont use these because the struts are angles by about 30 degree so you arent seeing the full length.
The proper templates are on one of the later sheets.


Next a chopped off 4 lenths of poplar onto which I copied the outlines. I then cut them out using a handsaw - my jigsaw is pants and wonders off line too easily!!


I find the easiest way to shape odd sectionned bits of wood is the draw lines at various mid points and other changes of shape - this stops me going too far - You can always remove more wod but its tricky to replace when you sand away too much!
I find a hinge slotting tool is great for this..


And other markings all just done in pencil..


And then I get to use my favourite tool - the razor plane!
Nothing is as satisfying as seeing little curly wisps appearing.


Next step means getting the monster out...

[Jez Harris 1]

Have you ever had a need followed by a flash of inspiration to achieve the need?

Well I really needed a bench sander..One day I might go out and buy one.

I've got a bench and I've got a sander - and I've got a vice. I just combined the three to create the beast!


Before very much longer I had 4 finished struts.


Four metal brackets are bent to 30 degrees and fastened to the fus.


Next the 4 brackets made the other day are fixed to the centre section.


The 4 struts are grooved top and botton to accept these brackets - this was quite a challenge as a razor saw cut was too fine causing the struts to splay open and risk splitting. I couldnt get a standard wood saw to cut the struts without tearing bits of wood off (I ended up re-making one of the struts as it just ripped apart.) I ended up using a very large cut off disc of the right thickness to gently cut the slits.
The brackets then epoxy into the struts.


I checked to see if it was square from side to side - I'll take that!

MR pup build 762.jpg (37.04 kB, 640x480 - viewed 28 times.)

[Jez Harris 1]

Checking the for-aft level is a bit harder as the centre section isnt exactly flat!

I checked the plans again, and by careful measuring I established that the wing dowels in the top and bottom wings give a zero-zero measurement.
I placed dowels into the holes in the bottom wing and lay a metal bar across them. I raised the rear of the fus until this bar was absolutely level.

A simple piece of masking tape running from the top of each of the dowel holes in the centre section gave me a line to work too.


I could then check the level of this line. Adjustment was made by raising the rear of the centre section whilst the epoxy was still wet.
A steel rule is just visible in this shot - I have clamped the centre section at the right position until it dries.


I will upload more progress soon..Wings next!!

Jez

[Jez Harris 1]

Okay - Wings..all bloomin 4 of them!

Someone remind me what it is about building WW1 bipes that interests me?

First job was to splice all 16 spars - 3/4 x 1/4 spruce. You get 16 pre cut lengths that are identical in length, You then get shorter bits of differing lengths, I got quite confused here because you end up with 16 spars whose lengths differ by up to 4 inches. There were 5 longer ones and 6 short ones that were the same length. It was only when I checked them against the plan that I found that even the shortest ones were long enough to do the longest spars of the bottom wings that I decided that the various length tips are some sort of offcut.


Whilst that lot were drying I laminated all the other required parts - thought I might as well do the bits for all 4 wings - 4 root ribs that are exactly the same as the centre section and 8 sets of wing tips and the various bits that make up the tips.


The plans are on two sheets - one for the left wings and one for the right. The odd thing is that the details you need to know - eg location and type of brackets, are spread across both so you really need to work on one sheet but have the other on hand to work to. So its down with a fresh plan, covered with some new polythene (I buy packs of polythene dust sheets from wilkinsons - £1.00 and you get loads - 1 pack will do this whole build, including several changes of plans).


The wing build is the same as the centre section - great ribs, 4 spars and pre-cut spar webbing - I was impressed with the spar webbibg for the centre section, however once I started the wings I realised not only are they cut for the correct depth, but you also get suppiled various widths depending on the rib spacing.