The mini indoor potez 58, cutting and construction 2

Hello everyone, I continued to build the mini Potez 58 ultra light for indoor flight, see at home if possible. I remind you for those who would like more details than in the « tutorials » part, you can find detailed videos of all phases of construction. Videos will be added as you go.

I remind you for those who would like to build it, that I make available the construction plan which you can download here, right there

So I started by assembling the half wings on the fuselage. The fuselage must be kept vertical by resting on wedges at right angles. Personally, I use a metal worktop with magnets to secure it.

You must be careful to respect the dihedral by leaning on supports and 0.8 mm carbon rods which are placed at the front and rear of the half wings.

To continue, I prepared the movable flaps of the stabilizer and the fin. I use a strip of sandpaper. I put myself at the edge of the work plan and sand at 45 ° each side.

The assembly is completed after checking for perfect squareness. The set is now ready to receive electronics and it weighs 8.3 g. It perfectly matches my objectives which was less than 10 g for the structure of the aircraft without the electronic equipment.

Tutorial for the construction of an ultra light potez 58 (part 2). Cutting and construction 1

You will find below the video describing the first stages of construction step by step of a Potez 58 of 46 cm wingspan with the ambition not to exceed 20-25 g (0.71-0.88 Oz) in total.

As a reminder, the plan can be downloaded here

And here is the video of the construction and assembly that you can find on my channel you tube

The ultra Light mini indoor potez 58, cutting and construction (1)

Hello everyone, I continued to build the mini Potez 58 ultra light for indoor flight, and why not in my living room. I remind you for those who would like more details than in the « tutorials » part, you can find detailed videos of all phases of construction. Videos will be added step by step.

I remind you for those who would like to build it, that I make available the construction plan which you can download here, right there below

So I glued all the pieces with tape on the 3 mm depron (0.119 Inch)

Then I cut using a new blade to avoid dulling the depron.

I then taped and stretched a 3 µm mylar sheet on my work surface. The openwork parts will be covered with mylar and not to put too much weight, I used spray glue from a brand of well-known cultural items

The weather is nice, so I put the glue spray in the garden (mine as it is forbidden to go outside our aown property), in a super thin layer. Attention, all the milligrams gained are important with this kind of construction.

Once the spray adhesive has been deposited, quickly go back to the workshop to glue the pieces with the mylar and to cut off the excess.

I then weighed all of the component parts of the aircraft before final assembly. My goal was to be below 10g (0.35 Oz) and at the moment the mass is 7.5g (0.25). So, it’s all right.

A mini indoor Potez 58. Specifications.

Too frustrating to be confined to the house with this damn COVID19. Do not give up, stay at home and above all continue to build.

I am embarking on a new challenge. Make a mini Potez 58 to fly indoors and why not in my living room …. For this second objective, not so confident, but let’s try.

First objective, define the size and mass and therefore calculate the wing loading. If we take in comparison a click from RC factory, we have a wing of 80 cm (31 In) for an average rope of 24 cm (9.4 In), which makes a wing load of 6.25g / dm² (1.5 oz/In²)for an aircraft weight of 120 g (4.23 Ounces) (battery included ) and 7.3g / dm² (1.7 oz/in²) if the mass is 140 g (4.94 ounces). Indoor it can fly really slowly. See the example below of the flight of my click 21. It’s good for a gymnasium, but far too big and fast for a smaller space

My osiris weighs a little less than 100 g (3.5 Ounces) and a wing load of 5.2 g / dm² (1.18 oz/In². See below the video of the flight and the speed difference due to a decrease of few wing loading points. The flight becomes slower. Much slower.

Vol de l’Osiris

So if you want to fly in a small space, you have to gain both weight and size, but by reducing the wing load. Which means, lighten everything and the heaviest, the on-board electronics.

So I took the plans of the initial Potez 58 and I increased the wing chord by 75%.

It is printed in 3 sizes, eg. 35, 41 and 50 cm (13.8, 16.14 and 19.7 In) wingspan. It is the 40 cm (16.14 In) one that I will make first. 27-30 g (0.95 to 1.5 once) is the maximum mass to be obtained so as not to exceed 5 to 5.5 g / dm² (1.14 to 1.25oz/In²)

Ignition, the magneto

And yes, the magneto which allows ignition when starting the engine on large aircraft is not yet reproduced on the dashboard. It is located on the far left; the number 1 on the photo below and you can see that it is missing on my reproduction.

below is an enlarged photo of the instrument of the 30’s period

It should be 6 mm in diameter. To start, I cut a 6 mm thick aluminum tube which I filled with balsa glued in the tube and a 7 mm washer to make the base.

The whole is sanded and presented on the scale board. Likewise, the magneto contact is printed on the right scale.

It remains to stick the washer, the tube filled with balsa and the image of the ignition.

The handle of the contactor is made in a piece of ABS of 5 mm long which is painted in silver color before being glued.The rivets are made with white glue and I used a carbon rod dipped in paint to paint them as precisely as possible

How I reproduced the rivets on the dashboard

The dashboard is not yet finished. It lacks a lot of details and in particular the rivets fixing instrument and those allowing to fix the board on the chassis in the cockpit.

So I started laying the rivets with a drop of white glue diluted slightly in water. Here is the result below as soon as the glue is applied and once dry

It is now a matter of painting them in metallic color to look like the real ones. To do this, I took metallic spray paint which I put in a glass container. Another is filled with white spirit to correct errors and clean up; The rivets are painted with a fine 0.8 mm carbon rod just dipped in paint and deposited on the rivets without shaking. In case of error or bad deposit, I used a fine forceps at the end of a cloth dipped in white spirit and I was able to clean.

Below is the dashboard next to the image of full scale cockpit image . There are of course instruments to be made, the magneto on the left and the one on the right that I do not know. If you know what it is, tell me, it will be super useful for me. Thanks.

Dashboard instruments

I used the rare photos of the full-size aircraft from 1935 to model the locations of the instruments in the dashboard.

Subsequently, my friend Alban Dury from the Angers GPPA helped me a lot by identifying the instruments. Here is his verdict.

1: Magneto contact graduated in 0, 1, 2 1 + 2 meaning Off, contact on magneto 1, contact on magneto 2, contact on both magnets

2 : engine tachometer.

3 : Low speed anemometer (graduated in km / h and called landing anemometer). Presumably from the Badin or Aéra brand.

4 :High speed anemometer (graduated in km / h and called cruise anemometer). Presumably from the Badin or Aéra brand.

5: Altimeter (graduated in hectometers)

.6: oil temperature.

7 : Oil pressure gauge

In addition, Alban had some of these instruments at the museum so he made me pictures that I could use to insert them into the dashboard.

A bit of work in Photoshop and some of the instruments are positioned on the board.

Do not hesitate to tell me if I made a mistake or if the instrument is not ad hoc …