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.