Many thanks indeed to Kev, Phil, Dave, Mark and Alan, gratefully received again!
A dinky little model engine is a work of art sometimes Kev, my own attempt is coming along nicely at the moment, I still have to work out those pesky copper tube doo-dahs but overall I'm very pleased with the way its going. Its probably taking a little longer than it should because I'm also trying to design it to be resin cast-able for future models (nothing like saving some work the second time around!)
Ok then, before starting the basic version, here’s a look at the real thing in
Photo 1. This is the
Le Rhone 9C 80 horsepower rotary engine. This was a French design produced by the ‘
Gnome’ Company whose main factory was ‘
Gnome et Rhone’ and so their engines were known as Le Rhones in British service. These engines were used in many of the early aircraft, they were built under licence in Britain, Belgium, Sweden and Imperial Russia and, ironically, before the war began, in Germany too, made by the
Oberursel Company. Imperial Germany saw no reason to cease production once hostilities began and so both Allied and Central Powers aircraft were flown against each other using the same engines! I’m not sure if the Germans carried on paying royalties to the French company throughout the war – stranger things have happened though! The later
Le Rhone 9J was an improved 110 horsepower version used on the Sopwith Triplanes and Camels. When an intact Triplane fell into German hands they reverse engineered the engine and produced
that one for their own machines as well. Again ironically, the most famous of the German aircraft, the Red Baron’s Fokker Triplane was a re-designed reverse engineered Sopwith ‘Tripe’ powered by the ‘bootlegged’ German copy of the captured Tripe’s engine!
Those copper tubes which I always thought were part of the exhaust system, are in fact the exact opposite – they are the intakes for the fuel/air mixture pumped into the cylinders!
Photos 2 and
3 show the main elements of the cylindrical ‘hub’ of the engine. The two big ones are the front and back of the hub, whilst the smaller one sits on the rear face. As you’ll see later on, when I get to grips on the scratch built ‘super-duper’, there’s a lot more to them than this! All three of these discs were first glued onto the 1mm card and then were cut out using the ‘nipping’ method. First a series of straight cuts with the safety razor produced the octagons shown in
Photo 3 and then each corner was further nipped off producing a more circular finish each time. Finally, medium grade sandpaper was used to finish off the edges into as round a circle as I could manage.
Photo 4 shows the long strip of paper which forms the side of the hub, joining the two discs together. The white circles mark the position of the nine cylinders coming later. (There is still some sanding to come on the discs in this shot!) The first job is to glue the ends of the strip together to form the collar for the discs. This was quite easy to do as long as you happen to have a large round paintbrush whose handle is the same diameter as the collar!
This is shown with the strip being glued around it in
Photo 5. The easiest method of gluing the first of the two discs in place was to dry fit it, sanding down the disc until it would just fit into the collar and then gently pushing it down until it was flush with the bottom edge as shown in
Photo 6 and the other side up in
Photo 7. Once it was in place I then applied the Roket glue around the inside of the collar up against the disc, locking them both together as illustrated in
Photo 8. The second disc was a little harder to fit in – since you can’t apply the glue afterwards on this one the disc has to be sanded down a little more to allow the disc to fit in with a layer of glue around the edge of the collar. And also, as that glue has much more ‘grab’ than normal PVA, the fitting has to be as quick as possible before the glue stops any further movement. With a fairly loose fit after the sanding I managed to get the second disc in as seen in
Photo 9. The smaller back disc is also in place here and this is where I nearly suffered a catastrophe! After I took this picture I decided that the little disc was about a tenth of a mm out of centre and decided to try and slide it over a touch. Unfortunately by this time the glue had already stiffened up and my attempt to move that piece caused the whole thing to concertina down to resemble a very battered top hat! After all that work I was determined to try and rescue the assembly rather than do it all again and I eventually came up with the ‘
resuscitation tool’ as seen in
Photo 10. Basically a length of 1mm brass rod, bent to the shape shown with the end ground down smooth. With this I was able to insert the short bit through the central hole and carefully prod and poke at the crumpled collar, gradually pushing it back into shape as seen here. Very little of that hub collar is seen after the cylinders go on and I’m relieved to say none of the damage is evident now that it’s completed! We now come to those self same cylinders – nine of them in total. As shown in
Photo 11,
Part 36 is a small tube with a wavy bottom edge which when glued into the tube shape accommodates the curve of the engine hub. The darker striped rectangles on the left are
Part 36a, which is a slightly larger tube which fits over the other one.
In order to make the tube construction easier, I found a nice thick brass rod, which was increased in diameter by adding masking tape as shown in
Photo 12. The thickened section is exactly the same diameter as the finished tube so the procedure was to coil the paper around the brass rod to impart the curl and then to move it down to the taped section for gluing as illustrated in
Photo 13. Once that was dry I could then glue the larger piece over the paper tube as shown in
Photo 14, ensuring that the ends started and finished at the same join as the first tube. Thanks to the clever planning of the kit designer, the join is at the back of the cylinder after it is glued to the hub as you can see (or rather, can’t see) with the first cylinder glued on in
Photo 15. Much later in
Photo 16 we have all nine of the cylinders in place and no signs at all of that disastrous crumpling from earlier!
In the next instalment the cylinder heads are fixed on together with the copper intakes and push rods but for the final photo here, we have the much easier method of cutting out those cylinder heads – by chance they were the same size as one of the larger heads on my old leather punch tool and the final
Photo 17 shows the trial punching on a set of re-print heads. If you look closely at the cylinder at the twelve o’clock position you can just make out a disc of thin plasticard – that was the first trial punch to check for the size required!
Until next time, Happy Modelling to you All!
Robin.
Plymouth57 attached the following image(s):
First wooden ship:
The Grimsby 12 Gun 'Frigate' by Constructo Second:
Bounty DelPrado Part Works Third:
HMS Victory DelPrado Part Works 1/100 scale
Diorama of the Battle of the Brandywine from the American Revolutionary War Diorama of the Battle of New Falkland (unfinished sci-fi), Great War Centenary Diorama of the Messines Ridge Assault
Index for the Victory diary is on page 1
US
