paolo.severin's blog View Details
Posted by paolo.severin | Mar 21, 2010 @ 12:06 PM | 12,319 Views
See the new Fieseler Storch movie from "Dyed in the wool" by Toolto (8 min 50 sec)
Posted by paolo.severin | Mar 14, 2010 @ 09:25 AM | 12,303 Views
See a new wonderfull video of my models!
Extract from "Dyed in the wool" by Marco Gentili

Paolo Severin "Dyed in the wool" (8 min 12 sec)

Posted by paolo.severin | Jan 30, 2010 @ 10:37 AM | 14,549 Views
Fieseler Storch di Paolo Severin (4 min 15 sec)

Video of Fieseler 1/4 scale prototype.
See articles and drawings on my site
Posted by paolo.severin | Jan 28, 2010 @ 10:29 AM | 13,763 Views
The Baby Ace is ready!
Great flyer, easy to build, incredibly strongest.
Soon complete photo gallery on
Posted by paolo.severin | Jan 24, 2010 @ 10:34 AM | 12,981 Views
Video of my Bleriot at "Ali sul Tevere" field in Rome.
Engine Saito 180 Radial 3 cylinder 4 stroke.
You can download a complete article on my site

Bleriot by Paolo Severin (2 min 35 sec)

Posted by paolo.severin | Jan 10, 2010 @ 09:38 AM | 13,681 Views
You can download a pdf of an article on my site
Posted by paolo.severin | Jan 09, 2010 @ 01:57 AM | 15,649 Views
[/COLOR][/COLOR]Finally available the new Baby Ace kit, thanks to its simple construction is proposed at only 950 € (+ 20% VAT only for the EEC).
The Baby Ace kit is of the same quality of the other Paolo Severin kits, and includes welded stainless steel tube fuselage, tail planes, functional landing gear and struts. Balsa and CNC cut plywood wings, fiberglass cowl and instrument panel, and aeronautical quality aluminum plates CNC cut.
The coverage is in fabric (not included).

"Ready to weld kit"
for expert at only 500€
(+ 20% VAT only for the EEC).

Technical data:
Wing span: 2144 mm. (84,4”)
Lenght 1426 mm. (56,15”) without prop
Wing area: 79 dmq. (8,5 sq. ft.)
Weight: 5 kg. (11 lbs.) approx.
Power: 15/25 cc. (OS 160 boxer suggested for aerobatic performance)

In 1954, Mechanics Illustrated published plans for the Baby Ace, a Pitenpol look-alike, but a more up-to-date parasol, along with instruction for mounting a 65 hp Continental, a modern (for those years) engine. The engine and the cowl and gas tank were designed to be installed in a way similar to that of the Piper Cub. The fuselage of the Baby Ace had a welded steel frame. Wood formers were attached to the frame to give the fuselage his its turtledeck an off-the-frame sides and bottom. The Baby Ace's simple Cub-style landing gear had the same kind of bungee shock absorbers as that of the Cub and the plane had steereable tailwheel.
I like to think there's a club of early homebuilders, who have long since gone to that great big flyng field up in the sky. I bet they're real happy there's a whole new generation of modelers who also love to build and fly parasol-type aircraft like this Baby Ace.
(From Scale RC Modeler May 1988)
Posted by paolo.severin | Jan 03, 2010 @ 03:00 AM | 13,410 Views

Bücker Jungmaister 1/3 scale
Fieseler Storch 1/4 scale
Piper J3 Cub 1/4 scale
Baby Ace 1/4 scale
Posted by paolo.severin | Jan 02, 2010 @ 02:44 AM | 14,797 Views
Welded tube frames
I have been building for the last few years almost all the scale reproductions airplanes with a fuselage structure made with welded tubes (see photo 1).
The first airplane I built using such technique was the Fieseler Storch.
Not only I like them very much, but these structures are incredibly light and strong, (see the article about the Piper Cub on my site into download section). Also they are very quick to build.

The materials
The material I normally use is a stainless steel tube in various diameter sizes, ranging from 3 to 9 mm (0,118” to 0,354”), having a thickness of 0,25mm (0,01”) or 0,5mm (0,02”) for the most stressed out parts (see photo 2).

I use 30% silver alloy bars for welding. It’s sufficient to use a GPL or Butan gas welding pipe (see photo 3), you can find also some pipes that work with the cigarette lighter type of gas, in this case they don’t last long.
Even an oxygen type of pipe is ok, however I recommend to keep the flame very low and at a certain distance because it’s very powerful and , if the stainless steel overheats and turns black can not be welded.
Anyway a slight blackening of the tube is normal.

The welding technique.
The gas pipe, which has a wide flame, is good to weld the tubes together, the oxygen pipe is better for the welding of massive parts and the heat can be concentrated in precise spots
I suggest the beginners to buy only the gas pipe.

The tubes must be prepared so to fit...Continue Reading
Posted by paolo.severin | Jan 01, 2010 @ 03:16 AM | 15,916 Views
Baby Ace plans is ready!
You can download on my site
Posted by paolo.severin | Dec 29, 2009 @ 11:23 AM | 13,467 Views
The strength index of the welded tubes structures for a model has not been calculated but, based on an estimate done consulting a recent article of Eng. Gale’, “ The scale effect and the the flying models”, it’s easy to gather that the resistance to breaking in this kind of construction is many times higher than the one of a model with conventional construction.
Just thinking that while the full scale dimensions have been reduced , the point of breaking of the materials, especially of the stainless steel, is the same. This concept was made clear by Eng. Gale’ with a simple example “ … a big steel cube, weighing 60,000 Lb. hangs, like a still pendulum (Fig 1), attached to a square steel bar having one side that measures 1”.
Let’s assume, for practical reasons, that the breaking point of the bar is one pound over 60.000 square pound/inch: in other words this bar is one pound away from breaking. In theory, even putting a slice of pizza on the cube will cause the bar to break and the subsequent fall of the cube. Let’s look now the 1:10 scale model of such system; the square supporting bar has a side equal to 1/10” x 1/10”= 1/100 of, which means 100 times smaller, while the breaking point is still 60.000 lb/
Therefore the breaking point is 1/100 of 60.000, meaning 600 lb.
However the small cube in 1/10 scale weighs only 60 lb. (1/10x1/10x1/10x60.000): the small bar in a 1/10 scale bears 10 times the weight of the small cube. The scaled down bar has therefore a 10:1 increment of resistance . Conclusion: the resistance of every material in any scaled down model increases according to the scale factor.
We can conclude that a Piper ¼ scale, is 4 times more resistant than the full scale Piper.
Posted by paolo.severin | Dec 28, 2009 @ 12:36 PM | 13,504 Views
I milled a mold reproducing the rib structure with a CNC pantograph, from a 10 mm thick nylon sheet. I then drilled a 10mm hole at each intersection of the structure. I made then a sort of extractor screwing on a piece of chipboard some 6mm screws, having hexagonal head, so to match the holes on the nylon templates.

To build the rib I inserted lists (3x3 or 4x4 mm in accordance to scale) the cut outs, top and bottom are linden or spruce wood, obeche or hard balsa for the cross braces, and for the front of the rib I used poplar plywood cut on the pantograph.
The whole thing is pushed all the way down precisely into the template, then I dripped some drops of CA on each intersection of the structure, using also the 10mm holes so to add some CA drop from the bottom

After few minutes I layed the template on the extractor and by hammering the nylon slightly the rib came out of the template perfectly glued.

The addition of 0,6mm birch plywood plates has even overstrengthened the whole part.
The weight of each rib is almost the same of the rib made in lightened poplar plywood but with a far superior strength.
Posted by paolo.severin | Dec 28, 2009 @ 02:54 AM | 13,525 Views
Trailer of a new wonderfull documentary:

"Dyed in the wool" - promo anteprima (13 min 36 sec)
Posted by paolo.severin | Dec 27, 2009 @ 02:15 AM | 14,197 Views
Paolo Severin, an italian aeromodeller, has founded a new company to produce his own kits.
The Fieseler Fi 156 Storch and the Piper J3 Cub are already available. They are “museum scale” RC replicas, the plans were drawn from original factory drawings and the mainframe is made in welded stainless steel tube structure like the real planes.
This construction system gives exceptional lightness and strenght: Just for example, a balsa built Fieseler of the same size, weighs approximatively 17 kgs, while Severin kit weighs only 11,5 kg and it is much stronger. Servicing and repairs are quite easy, and finally this kind of kit will have a very long life, like a real plane.
The kits can be seen and purchased from a very exhaustive website, full of informations, downloads and suggestions.
Posted by paolo.severin | Dec 26, 2009 @ 02:02 AM | 14,419 Views
Thi is my 1/4 scale Fieseler Storch, the fuselage frame is all welded steel tube as the real plane, an is weight is 11,5 kg. Less than a classic balsa construction, but more, more strongest.

See details at:
Posted by paolo.severin | Dec 25, 2009 @ 09:17 AM | 13,450 Views
Many great classical airplanes had the fuselage in stainless steel welded tubes, wooden wing and were covered with fabric. Many still fly today, proving the effectiviness of such building technique that I have been using for the last few years successfully in model aviation, carrying out scaled down models incredibly light and strong. I want to make my experience and resources available to every modeller that wants to get the feeling of building and flying a real airplane. Just a little smaller.
Paolo Severin