Discussion in 'Aircraft & Aviation' started by Gil, Sep 8, 2004.
This is very exciting to follow. - L.
Wow! It is looking amazing Gil!
After messing about for some 20 sketches the following is the final cylinder drawing. Approximating the real engine in paper turned out to be quite challenging but the final results were worth the effort. Several test builds were made to test ease of assembly before the resulting final version. More updates as they occur...,
Hanging on to every update. - L.
Looking good Gil. Also, any news on the C-47?
First thanks for your interest. Dustin, the C-47 will follow the Cyclone and modified cowl for the GPM -17G which will finish that project. The C-47 is next. Development of the R-1820 Cyclone will ease the design process for the Pratt & Whitney Twin Wasp R-1830.
Besides, I noticed you've got B-17Gs as your avatar..., could this be an indication?
Below is a 3D shot of progress so far..., pushrods, regulator, sump, ignition distribution and shaft need to be added. What isn't shown is the internal structure which facilitates building the engine without too much fidget. Most of the difficult parts are now complete (means that they've been through Pepakura successfully and test built). Getting the head cooling fins and valve assemblies to look real while making them easy to build devoured a disproportinate amount of time. Developing the Ignition Distribution design has led to a new method for constructing piping (no I'm not going to do an exhaust sytem) not to mention development of domed rocker covers...,
Need to pass the parts through Illustrator to add a detail, arrange on sheets, convert to .pdf and devlop the build instructions. One other point is the inclusion of the offset regulator for early versions used on SBD and I -16s.
More as it happens, Gil
Alpha Build Begins
Design of the Wright Cyclone is now at the Alpha Build milestone. Photos of the build will follow. The screen shot below is the build sheet.
Best regards, Gil
This is great. What a fine contribution this will be. - L.
This is exciting. It will be a wonderful sprucing up for all of the B-17 kits. This also means that you are one step closer to the C-47 that all of us are looking forward too
Yes Gil, my picture is an indication of what's ahead. I actually started working on the GPM B-17G, finished up the cockpit, and then needed the bubble piece of plastic that sits on top of the fuselage between the windscreen and the nose. I decided my best bet would be to wait a bit and buy either another canopy set, or buy or build a device for vacforming. I messed around a bit with boiling the plastic, but it was already too hard to pull the second it came out of the water. I will get something worked out eventually.
An alternative would be to find a ready made blister from the clear plastic that covers a host of articles that you can buy like candies kids toys cough drops and such. Vacuforming isn't that hard, when this flu epidemic peters out I'll resume the vacuform thread started last month. Anyways good luck.
Alpha Build Progress
A small bit of progress to report. An important note is that very expensive illustrator board has a tendency to delaminate and does not harden well. Common ordinary "Cheerio" cereal breakfast box material hardened easily becoming not unlike styrene sheet. The illustrator board was used anyway as it is more photogenic than cereal box board...,
The following photos show the crankcase former and alignment assembly in several stages of being built. The inner spider has to be cut very carefully. Center alignment of the three layers is accomplished with a pin through all layers. Thinned PVA (white glue) was thinly painted on all bonding surfaces and then clamped using miniature close pins. Center hole was cut using a sharpened brass tubing cutter.
The last photo shows a cylinder former dry fit to the crankcase assembly. The tab on the cylinder former has had the front and back sides sanded into a "wedge" shape which was then hardened with a drop of lacquer to facilate insertion and to resist layer separation.
Only nine more cylinder formers to go then....,
Hmmm, your cylinder assemblies look strangely similar to clothespins...
OOOOOHH, I get it now. Clever engineering. I like it already.
Gil, that is going to be awesome. As always, please show us more when you can.
VERY nice trick with the formers enabling a saddle shape! - L.
Thanks Leif. That's a very interesting site. I was particularly interested in this early R-1820. It was obviously designed for fixed pitch props, due to the lack of a prop governor. That allows for a much flater crankcase cover, and a shorter output shaft.
One of the "photo tours" on the site shows that there are a large number of engein exhibits at the Cavanaugh Flight Museum, which is not too far from me. I plan to visit there soon, whith camera in hand. Unfortunately, I'll have to wait for the weekend, since they're not open in the evenings.
Yes, R-1820 powered civilian "Gooney Birds" were known as DC-3s (or DSTs, etc.). Those that mounted the P&W R-1830 had an A suffix added to their designation. They were known as DC-3A, DST-A, etc. Many of these were "drafted" in the early days of the war, and recieved various "C" series MDS designations.
AFAIK, all C-47s and C-53s used the R-1830 (P&W "Twin Wasp"). Other users of the "Twin-Wasp" were the B-24, and many Wildcats (most F4F and all FM-1). The FM-2 changed over to the "Cyclone".
Built up a cylinder to test the fit..., kind of a sanity test to see if the 2D geometry is right. The illustrator board frame is covered with 24# copy paper thinned white glue used all around. To put the photo in perspective the total height of the cylinder to the top of the valve boxes is 13 mm.
Hey, that's great! The fins really seem to be there - what a nice pattern! - L.
Gear Case Test Build
Tried out a new technique to build reverse petal hemispheres. I'll let you be the judge..., The unexpected success of this experimental test build has resulted in a redesign of the gear case housing. The case is about a half inch (13 mm) in diameter.
Oh boy, this just calls for further instructions, as you of course realize, Gil! Learning how to shape a thing like this could set a new standard for the whole paper modeling community & industry. - Leif
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