Avia BH-10, first production run - WIP

The Avia BH.10 was developed as a single-seat variant of the two-seat Avia BH.9 and the later Avia BH.11.
Unfortunately, the Avia BH.10 kit in 1/48 scale does not exist (or at least I do not know of its existence). So I decided to create Avia BH.10 using some parts from Avia BH.9 kit. 

I won't need the instructions from the kit when rebuilding. 

But some of these decals will be used. 

KP kit contains two trees with parts for Avia BH.11 from SMĚR. This is one of them.
I will have to modify most of the plastic parts and some parts I won't use at all. 

KP kit contains two trees with parts for Avia BH.11 by SMĚR. This is the second one.
I will have to modify most of the plastic parts and some parts I won't use at all. 

This is a new tree with parts for building the Avia BH.9.
I will have to modify most of the plastic parts and some parts I won't use at all. 

The transparent parts are too thick, I prefer to make new ones from thin transparent foil. 

The engine from the kit is too crude, I'll replace it with a more detailed 3D printed engine. 

The Avia BH.10 was produced in two production series, which differed slightly from each other. For the second production run, changes were made to the shape to simplify production.

In addition to these differences between the production series, some machines were specially modified for speed racing and endurance flights. An aerodynamic engine cowling was added, the protective pylon behind the cockpit was removed, and the landing gear was aerodynamically improved. In addition to these visible changes, the fuel and oil tanks of some machines were enlarged and the instrumentation changed. When building these machines, specific modifications must be made according to photographs of the particular machine. 

My model will be a production machine from the first production run. I will adapt the modifications of the kit parts to this.

In order to get the correct fuselage shape and size for the Avia BH.10, I will have to shorten and lower the fuselage from the kit. In the photo of the fuselage, I have marked the cut points with red lines so that I can adjust the size of the fuselage. (dimensions are in mm). At the same time I need to remove the pylon behind the rear cockpit and plug the entry holes to both cockpits. 

The only place I'm going to enlarge the fuselage is the extension of the front of the fuselage. The width of the kit fuselage is 1/50 scale. To get the correct 1/48 scale fuselage width, the front of the fuselage needs to be widened by 1mm. To get the correct fuselage shape after shortening the rear section, the rear section (as viewed from above) needs to be narrowed. In the photo the places where material will be removed are marked in red, the places where material will be added are marked in blue. 

Other parts that need to be reduced are the wings. The wing is longer and has more depth (width). In order to narrow the wing while maintaining the correct profile, I will cut the strip marked in red from the top of the wing and shorten it at the outer end by 6 mm. 

I will modify the lower part of the wing in the same way. But I will shorten the lower wing section by 6 mm on the side closer to the fuselage. 

According to the above drawing (Figures 9 and 10) I shortened the fuselage. I marked in red on the fuselage the part that still needs to be cut off. 

I removed the inner structure from the inside of the fuselage using a model micro grinder. It will be replaced with a new one later. 

On both halves of the fuselage, I sanded the rear fuselage so that it tapered smoothly towards the end of the fuselage. To widen the front of the fuselage, I glued a 1 mm thick plastic plate between the fuselage halves. 

To widen the front of the fuselage, I glued a 1 mm thick plastic plate between the fuselage halves. 

After extending and gluing the front part of the fuselage I glued the rear part of the fuselage. Then I blinded the entry holes to both cockpits. 

Finally I cut the lower part of the fuselage from the glued fuselage and sanded the rear part of the fuselage to the correct height. 

I cut out a section of the upper fuselage with access holes to the cockpit. I'm replacing it with a new dorsal section with one opening. 

I glued bulkheads to the rear of the fuselage to reinforce and maintain the correct fuselage shape. I used a thin plastic plate to make the bulkheads. 

I filled the nose of the fuselage with two-component sealant. The sealant provided the necessary material for future shaping of the bow to the correct shape. 

After the sealant cured, I glued a thin plastic plate to the fuselage bow and sanded it together with the bow to the correct shape. 

After adjusting the fuselage size, I also adjusted the wing size. First I cut a 4,5 mm wide strip lengthwise from all four parts of the wing.  

I glued the cut parts together. I reinforced the glued joints with a strip of thin plastic plate glued to the inside. 

I glued the tapered wing halves together. After the glue dries, you need to trim the wing on the side closer to the fuselage. 

I glued the tapered wing halves together. After the glue dries, you need to trim the wing on the side closer to the fuselage. 

The assembled wings have blinded holes on the upper side. New edges of the correct shape are glued to the trailing edges of the wings. 

I cut the cockpit entrance hole from a 0.5 mm thick plastic plate and the ribs from a 1 mm thick plastic plate.  

When viewed from the front, the special shape of the wings, typical of the single-planes Avie BH, stands out. 

I bent the plate with the opening and glued the ribs to it from the inside. 

After the glue dried, I adjusted the dimensions of the new fuselage part with the hole to match the cutout in the modified fuselage. 

First test of the new fuselage part, no glue yet. The new part was a success. Minor corrections are still needed to get the final shape.  

I cut new tail surfaces from a 1 mm thick plastic plate. I'll still be refining them into their final form. 

According to the photos and the drawing I finished grinding the engine bulkhead to the correct shape. 

I made new parts of the cockpit from plastic plates and plastic profiles. For the floor, rear bulkhead and vertical ribs I used 1 mm thick plastic sheets. For the side walls I used 0,15 mm thick paste film and for the horizontal rails I used 0,5x 0,5 mm thick plastic profile.
I used the seat from the kit. I thinned the too-thick walls of the backrest to match the thickness of the plywood it was made from. 

I painted the glued parts of the future cockpit with light beige paint and let it dry.
To represent the wooden surface, I applied dark brown oil paint to the painted parts. I have to wait for the oil paint to dry before I can continue to modify the cockpit. 

I made the dashboard out of plastic. I used the instrument decals from the kit and now I am making the frames from thin wire (the frames are just laid on the instruments for now, I will glue them tomorrow). The seat is still missing the seat belts.
I am gradually adding controls and instruments to the right and left side of the cockpit.  

I finished the right side of the cockpit. I added the control stick and pedals to the cockpit floor and glued the control wires to them. I glued the seat and leather padding over the seat to the partially assembled cockpit. Finally, I added the seat belts for the pilot. I made the controls and instruments from pieces of plastic plates and wires of various diameters. I made the seat belts from dyed tissue paper that I cut into narrow strips. I cut the buckles for attaching the belts out of plastic sheeting and painted them black. I didn't glue the right side of the cockpit yet to make the assembled cockpit easier to photograph. 

I tried making a new propeller out of colored cardboard. I glued strips of yellow and brown cardboard with CA glue and "varnished" the glued block with thin CA glue. After the CA glue dried, I sanded a new propeller out of the cardboard block and re-painted it with thin CA glue. I still need to sand the propeller lightly and do a wood drawing with brown oil paint. 

... and one more look, this time at the other side of the propeller. 

I glued the starboard side to the assembled cockpit and then glued the fully assembled cockpit to the fuselage. I glued the instrument panel to the top. I then placed (without gluing) the fuselage section with the inlet. Finally, I took some photos because ... 

...then I glued the part with the entry hole to the fuselage. But before I glued it on, I taped the inside of the entry hole with masking tape. Because now it would be time to putty and sand the fuselage, and without the tape, I would have dusted the cockpit. So the cockpit won't be visible for a while now. 

I closed the fuselage with a bottom cut out of a 0,5 mm thick plastic plate, I sealed the worst places locally with putty and then I painted the whole fuselage with a thin layer of thin putty. 

I closed the fuselage with a bottom cut out of a 0,5 mm thick plastic plate, I sealed the worst places locally with putty and then I painted the whole fuselage with a thin layer of thin putty. 

I also painted the wings and tail surfaces with thin putty. 

I also painted the wings and tail surfaces with thin putty. 

I glued a prism from plastic plates and sanded a new pylon from it. After sanding the fuselage, I'll glue it in place. 

The main parts of the model are ready for adding small details. 

The main parts of the model are ready for adding small details. 

The main parts of the model are ready for adding small details. 

The main parts of the model are ready for adding small details. 

When the parts are hastily assembled, it starts to look like an airplane. The main design features of the Avia BH are no longer denied. I don't think anyone will recognize the original parts from the Avia BH.9 now. 

When the parts are hastily assembled, it starts to look like an airplane. The main design features of the Avia BH are no longer denied. I don't think anyone will recognize the original parts from the Avia BH.9 now. 

I started carving the panel lines on the forward hull. I'll clean them up later. 

I started carving the panel lines on the forward hull. I'll clean them up later. 

I also engraved the outlines of the lower hull covers. I still need to engraved some small deails on the sides of the fuselage. When I have them all done, I'll clean up the lines. 

Rib bands are sprayed on the tail surfaces. 

I used a round-bladed scalpel on the wing surfaces, which were covered only with canvas and scraped to indicate the sagging of the canvas between the ribs. 

I put masking tape on the wings so I could spray the rib bands. After the masking tape was applied, I sprayed two coats of surfacer on the wings. 

When the surfacer was dry, I removed the masking tape from the wings. 

On the left side of the fuselage I added a trim around the footboards and cut a round cap above the horizontal tail surfaces. 

I finished the last details on the fuselage, drilled holes for the wire pins on the wings and for the struts. I glued solid wire pins into the wings and drilled holes for the struts, and added levers to the rudder to connect the control lines. 

I designed and drew a paint scheme for a machine I'm building. In drawing the scheme, I followed period photographs and the conventions used for this three-color camouflage scheme.
Since the photos are black and white and not all of them are of optimal quality, it's not 100%. However, I have tried to make the placement and shape of each color field as close to the photographs as possible. 

I started spraying camouflage paint. I sprayed the lightest shade on the top and sides first. For now, the look is not very convincing, but as I add more color fields, the look will gradually improve. Next up will be green, but that's for next time. 

After spraying the ochre paint, I applied masking tape to the fuselage, wings and tail surfaces for the green field shapes and then sprayed green paint. Finally, I repeated the whole process for the brown paint. 

After the paint dried, I removed all the masking tapes. I still have to spray the lower surfaces of the plane with silver paint. 

On the fuselage I corrected the shape and width of the green field behind the cockpit and then sprayed the lower surfaces with silver paint. 

After the paint dried, I applied the decals. I used the decals from the kit (BH.9), only the flags on the wings were reduced to the appropriate size.
After applying the decals I started painting the engine. 

From the kit I will use only the wheels and the platform with the wheel axle. I have modified both, though. I drilled a hole in the wheel rims to access the tire valve, and the wheels also got a new brass center tube.
I sanded the original axle off the wheel axle plate at the top and cut the axle off on both sides. I then cut a groove on the top of the plate for the new axle. Since I have either too narrow or too wide a saw, I used the wide one to cut the groove and then narrowed the groove by gluing in a plastic plate. I glued the new axle from the needle into the narrowed groove. Finally, I glued a cover cut from thin plastic sheeting to the center of the plate.
I made new chassis legs from a 0,5 mm thick plastic plate. I glued hard wire to the bottom end and strips of thin sheet metal to the top ends. The chassis legs are still semi-finished, I will work on them.
I made the landing gear struts out of thicker wire that I flattened at one end. I will adjust the exact length of the struts when I assemble the landing gear to the fuselage. 

I shortened the wing struts slightly, cut a groove at the end of all struts and glued a thin wire into it. I filled the grooves on both sides with CA glue and sanded the ends of the struts after drying. 

I sprayed the main parts of the chassis with paint. I will do the landing gear mounting to the fuselage later. The landing gear is not finished yet. And most importantly (like the rudder) I might damage it when adding details to the fuselage. 

I cut out thin plastic foil (0,1 mm) to make the wheels for the centre of the propeller. When drilling the holes around the perimeter, the thin plastic film was tearing, so I changed the procedure. I simply drilled a hole in the middle for the propeller centerline and glued the wheel to the propeller. And I drilled the holes around the circumference of the wheel after it was glued to the propeller. That way the holes could be drilled without any problems. 

View of the engine with propeller. It's just assembled without gluing. The engine and propeller still need finishing work. 

At the end of today I printed the serial numbers on transparent decal paper (the bottom two rows are for the Avii BH.11, which until today had no serial numbers). After spraying with clearcoat, the decals will be ready for application on both models. 

I made a "leather" trim around the cockpit entry hole from thin plastic wire insulation. The light green one on the fuselage glows nicely, but it will improve when painted the color of the skin. 

I painted the glued leather trim of the cockpit opening with dark brown paint.
I sprayed the wing struts and after the paint dried, I applied decals with serial numbers to the wing struts and fuselage. 

I glued the horizontal tail surfaces and wing struts to the fuselage.
There is still a lot missing on the model, but the Avia is starting to look similar. 

I made grommets with ropes to control the rudder. I used thin brass tubes, plastic foil and fishing line 0,14 mm diameter. The foil to which the grommets are glued will be trimmed later so that only a small rectangular pad just a little larger than the size of the grommets remains. 

I assembled a tank with a lid from a 1 mm diameter brass tube and a wheel cut from a 1 mm thick plastic plate. For the top of the lid, I made a strip of 0.1 mm thick plastic sheeting, which I glued edge to edge to the lid and sanded the wings to make the lid easier to open and close. Unfortunately the part is so small that I couldn't get a good photo of it. The wings are hard to see in the photo. 

I prepared a 1 mm narrow strip of brass sheet and assembled and glued the leaf spring of the spur with the foot. I made its screw anchorage to the hull from thin wire and its insulation. After the spur is painted, the wires at each end will be cut to the appropriate size. 

I made a new cockpit windshield out of clear acetate film. The original faceplate from the kit is too thick and modifying it would be more difficult than making a new one. The new faceplate is just trimmed to shape, but it is double the size for now and awaiting completion. 

The first cover has already appeared in front of the cockpit, which consists of a wheel made of thin plastic film and a conical cover cut from a piece of the frame. A little further forward of the cockpit (more to the right in the photo) a hole has been drilled for the tank cap sleeve. 

I glued the rudder and grommets with ropes for its control to the aft fuselage. I "closed" the treads with flaps and painted everything. I added a tank cap sleeve to the bow and glued a small plastic wheel to the engine bulkhead to help glue the engine in place. I spent most of the time assembling the main chassis. I had to look at the geometry and measure the correct length of the struts from the chassis leg to the center of the chassis centerline plate. 

I test fitted the landing gear wheels and engine (without gluing) to the model. When I did this and looked at the model, I was quite pleased.
I still have some work to do to finish the model, but it already looks like a BH-10. 

I test fitted the landing gear wheels and engine (without gluing) to the model. When I did this and looked at the model, I was quite pleased.
I still have some work to do to finish the model, but it already looks like a BH-10. 

I test fitted the landing gear wheels and engine (without gluing) to the model. When I did this and looked at the model, I was quite pleased.
I still have some work to do to finish the model, but it already looks like a BH-10. 

I glued the propeller to the engine, glued the engine and propeller to the engine bulkhead, added the wheels and wind shield and spur. Then I "smoked" the fuselage a bit from the exhausts and dirtied the lower surfaces from mud flying off the wheels ... and it looks like I'm done. 

And one more picture of the finished model.