I found this photo on one of the Japanese solid modeling sites. A pair of scratch built radial engines for a Junkers Ju-88. No details given, but it looks like maybe wire wrapped around each cylinder core. I believe they are 1:48th scale.
(http://saiunkai.s261.xrea.com/cgi-main/img-box/img20090614085015.jpg)
For a larger image...
http://saiunkai.s261.xrea.com/cgi-main/img-box/img20090614085015.jpg (http://saiunkai.s261.xrea.com/cgi-main/img-box/img20090614085015.jpg)
They look great.
Lou
I have seen this same technique on some of the old plans and build articles. Only they would use string wrapped around a wooden dowel. A coil spring might work well too. Tension, not compression. In some of the same plans sewing pins were used for pushrod tubes and bolt heads. Might be an interesting group build.
A simple Radial engine, large scale say 1/32.
It might be fun to build a Clerget or Le Rhone. I assume a rotary engine can be considered a variety of radial? I'm in. :) Maybe I'll even stick an airplane to the back end of it.
A 1/32 radial would do nicely in my WACO Cabin Biplane. It has been on shelf for almost a year now. I have the wings rough cut and a block for the fuselage. I am experimenting with showing the fabric covered wings.
Lou
I have some radial engine line drawings somewhere in the basement. I will list what I have tomorrow.
I have some good Wylam drawings but you'll have to give me a week to scan and post them. It's a P&W Twin Wasp JR.
I have Wylam drawings for the Cyclone F-50, Wright Whirlwind, P & W Wasp Jr and the Clerget. I will be looking for some info on the Jacobs 750HP seven cylinder engine for my 1/32 Waco Cabin Biplane. My wings are rough cut already and I will be making a second fuselage to replace the one I screwed up this morning. You know measure twin, cut one !!!!!!! Sorry no rotary engines.
Lou
I would like to amend this too include any Air Cooled Aircraft engine. The reason being that there are so few good drawings of these subjects available and such variation in detail and technique that I believe we would be mistaken to exclude such interesting any power plans layouts that can offer a learning experience to all of us. I propose we include Rotary, Inline, Opposed and V engines in this build, as long as they are AIR cooled. This opens the field to include engines such as Liberty, Mercedes, Lycoming and Continental ect. This opens the door to include sister builds of WATER cooled and JET engines in the future.
Does any one second this?
Works for me Ray.
Lou
Found some beautiful renderings of a LeRhone 110hp:
http://www.theaerodrome.com/forum/aircraft/14397-le-rhone-oberursel-engine-blueprints.html
This build has been proposed, seconded and approved. It has been amended to include all AIR cooled aircraft engines.
This build has no expiration date.
Let the chips fly Gentlemen! :P
I always start my engines by making a cylinder locator. In this case the engines are nine cylinder so the locator has 40 degrees per sector. The crankcase is 8mm in diameter and cylinders will be 1cm in height
(http://smm.solidmodelmemories.net/Gallery/albums/userpics/thumb_Rotary_Engine_001.JPG)http://smm.solidmodelmemories.net/Gallery/displayimage.php?album=241&pos=4
Lou
(http://smm.solidmodelmemories.net/Gallery/albums/userpics/thumb_Radial_Engine_002.JPG)(http://smm.solidmodelmemories.net/Gallery/albums/userpics/thumb_Radial_Engine_003.JPG)
The cylinder location is transferred to the other end of the dowel using a strip of paper. followed by marking the location in reference to the end of the crankcase.
http://smm.solidmodelmemories.net/Gallery/displayimage.php?pos=-3414
(http://smm.solidmodelmemories.net/Gallery/albums/userpics/thumb_Radial_Engine_003.JPG)Rotate the dowel as to mark the location of the cylinders and any shaping required to form the crankcase.
(http://smm.solidmodelmemories.net/Gallery/albums/userpics/thumb_Radial_Engine_005.JPG) Locate the centre of the dowel and drill the prop shaft before shaping the crankcase
(http://smm.solidmodelmemories.net/Gallery/albums/userpics/thumb_Radial_Engine_004.JPG) Start a pilot hole and then enlarge to the diameter of the peg used to attach the cylinder. I use round toothpicks
(http://smm.solidmodelmemories.net/Gallery/albums/userpics/thumb_Radial_Engine_006.JPG)I recommend that the cylinder locations be drilled prior to shaping the crankcase. I had some problems with the wood splitting slightly when drilling on my first crankcase.
Enlarged picture can be found at http://smm.solidmodelmemories.net/Gallery/thumbnails.php?album=241
(http://smm.solidmodelmemories.net/Gallery/albums/userpics/thumb_Radial_Engine_007~0.JPG) I have two method of attaching the cylinders to the crankcase. The first is to reduce the diameter of the cylinder to fit 5/64" hole(toothpick diameter) and the other is to hollow out the cylinder to accept a round toothpick.
(http://smm.solidmodelmemories.net/Gallery/albums/userpics/thumb_Radial_Engine_008.JPG)Either way works fine.
(http://smm.solidmodelmemories.net/Gallery/albums/userpics/thumb_Radial_Engine_009.JPG)(http://smm.solidmodelmemories.net/Gallery/albums/userpics/thumb_Radial_Engine_010.JPG)
http://smm.solidmodelmemories.net/Gallery/displayimage.php?pos=-3433 In trying to resolve the simulation of the cylinder fins, I used a known method and a bit of a twist. I used telephone wiring for its size and bared 3" of wire. Wrap the wire around the cylinder and there you go. I found it was easier to wrap around a long section of dowel, cut and bore out the end and attach with a toothpick insert. This was kind of trial and error until I got the wrap nice and tight.
(http://smm.solidmodelmemories.net/Gallery/albums/userpics/thumb_Radial_Engine_011.JPG)
http://smm.solidmodelmemories.net/Gallery/displayimage.php?album=241&pos=11Note that the silver cylinder has little definition. I dipped the entire cylinder in paint and let dry before painting silver. Bad choice as the paint was way to thick and lost the fin effect. It will be replaced as it is only stuck to a toothpick. More to come
I don't finish the top of the cylinder as this will be hidden by the cowling. And 4 strand telephone cable is only $1.39 CDN at my local hardware store.
Lou
(http://smm.solidmodelmemories.net/Gallery/albums/userpics/thumb_Radial_Engine_014.JPG) Small stubs of toothpicks await the cylinders
(http://smm.solidmodelmemories.net/Gallery/albums/userpics/thumb_Radial_Engine_013.JPG)Assembly line production of cylinders
(http://smm.solidmodelmemories.net/Gallery/albums/userpics/thumb_Radial_Engine_012.JPG) The 9 cylinders are attached.
(http://smm.solidmodelmemories.net/Gallery/albums/userpics/thumb_Radial_Engine_015.JPG)(http://smm.solidmodelmemories.net/Gallery/albums/userpics/thumb_Radial_Engine_016.JPG) A slight trimming of the cylinder end makes for a snug fit in the cowling. Now all we need is the attachment of rods/sumps and the like to make the engines complete.
Lou
Lou,
Ingenious how you left the insulation on to made the larger diameter part of the cylinders!
Garet
Once every century I come up with a good idea. I guess that is it for the 21th Century.
Lou
Push rods have been added and will be trimmed once the glue dries. Addition of a sump and some wirirng will follow. The Bristol Hercules IV engine did not follow most engine designs in that the valves appear to be centrally located on the cylinder head rather than the outer portion of the cylinder heads on. Photos of the engine does not show any wiring in the front, so one must assume it is located behind the cylinders. This was not a great design as heat from the engine would continuously affect the electrical wiring.
More to come.
(http://smm.solidmodelmemories.net/Gallery/albums/userpics/thumb_Radial_017.JPG)
http://smm.solidmodelmemories.net/Gallery/displayimage.php?pos=-3501
The ignition harness is being fashioned from telephone wire.
(http://smm.solidmodelmemories.net/Gallery/albums/userpics/normal_DSCF8254.JPG)This project is moving very slooooowwwlllllyyyyyy.
Lou
The WACO has been finished for quite a while. I just realized I never posted a photo to this thread to show the completed installation.
Lou
Lou has reminded me to place the tiny Pobjoy Niagara engine here besides the Long Distance cook up page,so here we go,these little engines are models in their own right and great fun to search out suitable things to build them up from,everything on this is scrap,flexible electrical wire and odd bits of tube are ideal to make engines from,for the pushrods I strip the reed from a chinese fan and find that you can get fairly fine material from the reeds,the collector ring outlet pipes could have been fashioned from milliput but on this occasion I used thick solder bent with a pair of round pliers and the edges filed,then gel cyno makes the job easier as it grabs instantly.
Barry.
(http://smm.solidmodelmemories.net/Gallery/albums/userpics/10005/normal_POBJOY_9.JPG)
Very nice engine Barry. And I think you've hit the nail on the head in recognizing the infinite amount of "engineering" or just plain thought that distinguishes this hobby from the commercial counterpart.
Cliff.
Cliff in this age of pre-assembly and high detail products it is really good to know that within this group there are skilled craftsmen who still enjoy the benefits of scratch built items and keep the traditions of solid modelling really alive,we have no restraints on scale or types,the models can be as expensive or as cheap in materials as we so wish,to re-cycle scrap and make it into something beautiful is a real bonus.
The more solids that I build and see here the more I think this verges on an art form that has so many benefits,it rekindles history,it draws on what would otherwise be long lost drawings,its a social statement of times past of how we created these miniatures often under difficult wartime conditions.
Before I found this group I never believed that there were so many people still whittling away making solids ? but there are and it is because of this that my own interest had a real boost,gentlemen your models are such inspiration and a pleasure to see being built in small workshops and sheds,plus kitchen tables across the world.
As long as browsers will be tapping in 'Solid model' into their browsers then they will find us and help spread the ranks amongst us.
Barry.
I would be greatly interested in seeing how Kenji makes his radial engines. I have started on what I hope will look somewhat like a P&W R-1340.
The prototype cylinder is shown before winding is added to simulate the cooling fins. The rocker arm covers are round toothpicks and the cylinder are 1/4 and 1/8 inch dowels. Sorry for the picture quality. The black hose is the intake and the white one is the intale. Manifolds will be added later,
Lou
If my research is correct the JU-88 actually had inline water cooled engines . What most people think is a radial engine is actually the radiator .
greasecup
These radial engines are models in their own right and demand a certain care and attention during assembly,as Lou has shown it is surprising what can be pressed into service and they can be a real challenge as well.
So before you throw that electrical wire,flexible tubing or old decorative fan away think about what it can be used for ?
For some good ideas on engine building see the 'Aeromodeller' magazine articles and plans in our archives which show the breakdown of common and popular engines at that time.
The Jumo 211 was a 12 cylinder supercharged liquid cooled 60 degress inverted V piston engine,the cooling was effected with an annular radiator system mounted at the front of the engine giving that strange effect when mounted into the circular engine nacelles.
Barry.
Progress is being made on the P&W R-1340. All cylinders and a few extras have been constructed and the gearbox and intake manifolds have been mounted. I still need the oil sump, exhaust manifold and cylinder wire wrap to be done.
Lou
Lou,
Your engine has the reality. I like to make it only from the wood.
kenji.
Lou,
What scale is your R-1340 ? Looks great.
Mark
Thats a cracking engine there Lou,I see a Boeing P-26 Peashooter plan in the background.
Barry.
Kenji Thank You.
Mark 1/32 scale
Barry Yes
Lou
Lou, that's a very nice engine. On a test- stand too. Neat.
Cliff.
Test stand from 1/48 scale HAWK T-33A kit. It works but a bit to low to spin the prop.
Lou
Component breakdown:
1 pc Crankcase
1 pc Crankcase cover
1 pc Intake manifold
1 pc Ignition manifold
1 pc Spacer
1 pc Sump
1 pc Accessory case
1 pc Carburetor
1 pc Pump
1 pc Speed control
1 pc Magneto
1 pc Propeller shaft
9 pcs Cylinder upper
9 pcs Cylinder lower
9 pcs Cylinder core (secures upper and lower cylinder pieces to crankcase
9 pcs Intake pipe
9 pcs Ignition lead
18 pcs Rocker arm cover
18 pcs Rocker arm push rods
18 pcs Interconnector tube
18 pcs Wire wrap
Needed: Suitable airframe to mount the engine. It is heavier than it looks.
Lou
Nicely done, Lou. Congrats.
Ken Pugh
Thank you Ken. For now it be a stand alone model until I decide which airframe to build. I saw that the DHC-3 used this engine. ??
Lou
Lou,
The P-26A uses that engine as well.
Mark
It looks very effective Lou,once you paint it then everything pulls together and will look like metal,well done.
Barry.
Thank you Barry.
Lou
Per Lou's request here are photos of a 1:72 scale Napier Lion V engine for a Fairey IIID being completed as part of the Long Distance Flights cook-up.
Per Cliff Strachan's lead, I decided the best way to build such a tiny engine was at the end of a 1/4" square pine stick which formed the crankcase. 2mm dowel was used to make the twelve cylinders and these were topped off with basswood cylinder heads and intake manifolds. The cam drive shafts are pins at the rear of the cylinder banks. Valve covers are filed from aluminum finished with emery cloth and metal polish. Intake pipes are from solder. Exhaust stacks filed from 1mm paper clip wire. Thirty eight parts total of which eighteen are metal.
More views of the 1:72 Napier Lion V, my first 1:72 scratch-built engine.
The engine sitting on your finger really give the feel for the size and complexity of making such and engine. You must be congratulated on such an outstanding job.
Lou
Thanks Lou.
Mark
Mark I have to really support Lou's comments concerning the size of your engine. Sitting in your hand really gives one a perspective of its actual dimensions and the difficulty overcome in its construction. Great show again.
Cliff.
The membrane stick idea is certainly the easiest way to manage small objects during manufacture,you have something to hold onto while you cut,carve and shape.
Barry.
Fraser has completed a 1/48 Wasp Jr. for his DHC 2 Beaver. Check it out at http://smm.solidmodelmemories.net/SMF/index.php?topic=1797.0
(http://smm.solidmodelmemories.net/SMF/index.php?action=dlattach;topic=1797.0;attach=13826;image)
Lou