• Welcome to Solid Model Memories.net.
 

Tutorial Advanced - Orta Saint - Hubert G - 1

Started by Gearup, June 12, 2022, 09:32:46 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

Gearup

Cylinder final assembly
Here is the set up I used to handle and assemble the cylinder and push rods. The cylinder is held in the fixture and the push rods are held by tweezers on a base. This allows me to get everything positioned close and then slide the tweezers over to final position. The blue apron is a necessity to catch flying parts....

Once in place a drop of CA is applied. IMG1166 IMG1188 IMG1189 IMG1191

After each cylinder is done, it is cut free from the dowel. Again the fixture holds it for a square cut. IMG1162 IMG1180

The cylinders will be glued into the model later for ease of handling.

lastvautour


Gearup

Propeller Carving

The propeller is always a fun thing to carve. It is three dimensional, symmetrical, mirrored shape with a twist and taper. You may have to make a few to get the shape and size right. 

I started with a maple blank about 4 inches long x 1/8 thick, x 1/4 wide. While maple is harder to carve, it will hold the detail nicely. Also give the small size it is strong and the cuts are small.
I drew the dark areas to remove for roughing it out. Looking at the picture of the airplane, it has a scimitar leading edge, ie it is curved like a sword where the training edge is straight. IMG1870

Lou has a tutorial on making a propeller blade. Give it a look at "detailing> propeller blades"

My best advice is to mark the front face and back face with arrows for direction of rotation. The dark areas marked on the front face are the taper of the trailing edge and the leading edge is left thick. The opposite face of the blade is somewhat parallel to the front face therefore the taper is at the leading edge, thinning out the leading edge. Also keep in mind the blades taper from the root to the tip....and twist.  No wonder the Wright brothers took a lot of time and testing to make a propeller! IMG1865

Make a center 1/16" hole at the center for reference and to allow the shaft to be fit. Carving is done with a sharp knife, chisel and sand paper. IMG 1866 IMG1878 IMG1881

Sand the blades smooth always looking for symmetry and thickness. I finished it with a coat of clear nail polish ( basically airplane dope) then painted it mahogany.

Gearup

Propeller shaft and metal hub

I really wanted the propeller to spin freely. Pictures do show a nice metal hub on the prop so I thought it could be interesting to make that as well. I did not want it to look like the prop was pinned to the model, so a proper shaft is required.

It is not necessary to make a rotating prop, so using a small round toothpick as a prop shaft would work just as well.

So heres my take on making a free rotating prop. I need a shaft, a bushing and a metal hub at the front. Also it should not fall off.

First I used a short piece of .032" brass and dipped the end into a melted blob of solder. IMG2238

I am fortunate to have a small wood lathe to spin the part with. A drill and sanding stick would also work. The lead free solder turns very well and I used a small wood turning tool I made from an 1/8" Allen key. This is shown by the wisp of shaving that was removed. IMG2239 IMG2240 IMG2242

The propeller hole was 1/16" and fit the 1/16" brass tubing perfectly. It is cut a bit longer, approx 1/32", than the thickness of the prop hub. Once CA glued onto the prop hub, clean the brass bushing hole out with a 1/32" drill. Cut another piece of 1/16" brass tube about 1/4" long. Insert the shaft into the prop bushing and slide the 1/4" long bushing over the shaft and leaveing a small gap from the prop bushing. Using pliers, crimp the busing onto the end of the shaft then trim the end off. Holding the end of the shaft and lightly blowing on the prop should set it spinning.IMG 2245 IMG2246

Now the prop is retained with the solder "hub" and is held securely to the model when the shaft end is glued into the nose.

Gearup

Wheels and tail skid

Again I used the lathe to turn the wheels. I use maple turned to 9/16". The wheel hubs are shaped like two plates joined face to face like a shallow cone. The tire is just a shallow groove on both sides.They were primed and painted white with black tires. IMG1883

Buttons if the right size from the dollar store will work nicely. Just fill in the button center with glazing putty or similar hard filler to get rid of holes or unwanted design.IMG2059

A tail skid was formed from a thin brass strip .025"x1" long x.125" wide folded double 5/32" at one end. The end was soldered to give a thickness to the mounting point of the skid. A .020" hole was drilled at the thick end and the solder reheated to secure a .020" brass pin to mount the skid. The sides were filed to taper and the thin part was bent to give it a spring shape. It was the trimmed to a length of 3/8" Paint it black and install after the model is painted. IMG2058 IMG2237 IMG2257

It was at this point that I noticed I had forgot the stabilizer struts under the tail. I fashioned these from brass tube as described in making and installing the wing struts. ImG 2060

Gearup

#80
Windshield

The airplane has two small wind shields. They appear to be tinted, so simply making one from card is good and then painted black. I just estimated the size of the windshield width and cut a crescent shape fit. It is about the same size a a large nail clipping...no I did not use one.....

Place them just forward of the cockpit and sloped aft with CA. Do this before installing the wing, its a lot easier.IMG2249

Gearup

Masking, Painting, Decals
Now is a good time to paint the final color of the model. I chose Model Air Aged White as the overall color with black markings. One of the members on the site, Gordon AKA 'Boomerang" helped me to find a color typical of the era for nonmiltary aircraft.
Clean up the model to get rid of finger oil etc. Touch up the primer as needed. 

I use an airbrush for my modelling. A few thin even coats are applied and then I let it dry at least overnight before masking. This model does not need a lot of masking as the only large second color is the black lettering.

I prefer to cut vinyl stencils to apply trim colors and lettering. I use a Silhouette vinyl cutter to make these masks. The free program associated with the cutter is Silhouette Studio. It has an easy to use interface and I really enjoy making up masks for all ,manor of projects.IMG2079

After creating the markings based on the pictures of the aircraft, I cut them on the machine using stencil vinyl that leaves no residue, leaves sharp edges and (generally) does not pull the paint away. I say generally because a poor paint job may suffer bad patches. Cleaning the model before paint is critical.

The masks are applied to the model using a transfer tape that holds the masking together while you transfer the design. It is essentially low tack soft masking tape. IMG2218 IMG2219 IMG2220 IMG2221 IMG2222

Once the mask is down and pressed with your fingernail, the transfer tape is removed revealing the mask. Additional masking tape is used to protect the rest of the model from overspray. I use cutouts in computer paper to surround the mask when possible.

Paint the markings with a few light coats of black paint.

The wing and fuselage are painted separately. On the fuselage the "-" is on the side strips. I did have a small patch of paint lift removing the mask, but a touchup with a brush worked pretty well.

Decals for the ARPIC logo were made on the same Silhouette Studio program, but they were printed on decal paper and applied as regular water slide decals due to the small size.

The rudder was sprayed with gloss clear and the decals applied IMG2232 IMG2233 IMG2255

After the model is assembled it is given a matt coat of clear that really evens out the look of the paint.

Gearup

decal application and cockpit panels

Brown paint was added to the instrument panel. the sparse set of dials was represented by a medium tip silver Sharpie marker dot.

Gearup

Mounting Engine Cylinders

An easy job is to mount the engine cylinders to the model. Set the cylinder in the mounting hole with the pushrods facing forward. The cylinder barrel should press in place and only require a touch of CA to hold them. Make sure to get the center line of the cylinder pointing to the center of the engine inside the cowl (the prop shaft). Make sure they are not tilted fore or aft.IMG2262

Gearup

Mount the wing

Set the model upside down on the wing with the forward pins in the holes. Put the aft struts in place located with their pins. Check for alignment and level of the wing. This should work out as the forward structure is pretty stiff and the aft struts will hold the angle of the wing.

When it all looks good, apply some CA to the 6 points and allow to harden IMG 2250

Gearup

Install wheels

I installed short brass 1/16" bushings in the wheel hubs. This was because the wheel hole was too big for the wire axels.

The wheels slide onto the axels and are secured with a drop of CA. Trim the axel flush if it is too long.IMG2234

Gearup

Install propeller

Make sure the hole for the prop shaft is drilled to 1/16". Insert the prop assembly into the nose. If needed add a small drop of CA on the end to secure it before you put it on. IMG2252
Give it a spin!

Gearup

FINISHED

That's it! The model is done. Like many of the models built by this group, it is a one of a kind. It is a tribute to my grandson's great-grand father on who was truly an air pioneer in 1930's Belgium!

It has proved to be a bit of a challenge to build not only for the complicated structure but also the sparse information on the airplane with many subtle variations in design. I learned a lot researching, building and writing about the construction process. The nice thing bout this hobby (dare I say craft) is the endless variety of subjects and the great support frommembers of this forum.

Thank you.

Now...whats next?

Fraser

lastvautour

Magnificent results Fraser. Your best model so far. What next?

Lou

Gearup

Thanks Lou. I'm thinking something with no struts....
Fraser