The continuation of the realization of the cockpit

After having finished (for the moment) with the seats, I go on with the details of the cockpit and in particular a series of push buttons present on a lower dashboard (see red circle)

La photo originale de l’avion de 1936. The original photo on the 1936 plane

You can see that it is equipped with an instrument indicating the oil pressure and 4 push buttons, 3 on the part just below the dashboard and one on the lowest part below the dashboard.

The push buttons are made from 1 mm aluminium tube and round cut from 1.5 mm balsa wood.

The formwork of the lower part is also made of balsa wood and plywood for the facade part supporting the oil pressure gauge. Cellulose dope is applied to all the wooden elements.

Enduit cellulosique sur les parties en bois. Cellulose dope layed on wood parts

A coat of primer to coat the pores well before painting the different elements.

Dépôt d’une couche d’enduit garnissant. Deposition of a layer of primer.

The wooden block is painted black. I cut out a metal washer to make the outline of the instrument and the front part is glued on the wooden block. This part is drilled to receive the push buttons.

The metal tubes are inserted into the rounded balsa representing the button. The button itself has been painted with silver paint.

The buttons are glued to the facade and the wooden part. The 4th button is added on the lower sloping part.

The board with the instruments as well as the part made above are glued in place in the aircraft .

Note that the photos are taken in close-up and show all the defects that are less visible to normal eyes.

Front and rear seat adjustment system

I finished the seats by reproducing the slide systems that allow the seat to be adjusted forward and backward according to the size of the pilot.

I used 2 mm brass U-profile ordered in a model railroad shop.
One of the profile is glued with epoxy glue on the underside of the seat and another one on the trunk. The adjustment has to be done with care.

In the photos below, the seats are positioned forward and backward. The fixing in position is done with a scratch glued in place in the middle of the support box and the underside of the seat.

The front seats

I continued to reproduce the seats to scale to dress my cabin.
Reproducing the front seats, seems more complex than the back seat. Fortunately in the documentary resources provided by the GPPA, I have below the photos and diagram of the seats of the full-size aircraft.

original seat documents of the Potez 58

I have reproduced to scale all the seats, backrests and frames.

Drawing of the seats to scale

To make the frame for the backrest seat, I used 3 mm aluminium tube. It’s easy to bend and shape. However, on a hollow tube, bending leaves marks and dents in the tube. Some people recommend using fine sand to fill the tube and then bend it. Personally, I filled the tubes with water after sealing them with plastic film. Then I placed them in the freezer. After 2 hours, I was able to bend them with flat pliers. You have to go fast because it thaws quickly and leave the following ones in the freezer.

Afterwards, I cut a frame out of 15/10 plywood which will be glued to the frame and the seat of the seat.

The lower seat cushions are made like the back seat. Foam is cut to the right size. I then prepared cutting patterns and cut the fabric. The coupons are sewn on the reverse side and then flipped over like the real cushions.

Afterwards, I glued the seats in place on the plywood frame.

Then I made the backrests the same way I made the seats. The foam is less thick and should not fill the whole cover. Indeed, it will be necessary to connect the cover to the seat frames. This was done by ropes on the size plane. To reproduce this rope, I used sewing thread folded in 4 strands that I came to sew on the frame.

The seat had a front-to-rear adjuster and rested on a trunk. I reproduced this trunk in plywood 10/10. So I cut out the top and sides of the trunk.

Part of the box on which the seat will be placed

The assembly is done upside down with the top placed on a metal plate and held in place with magnetic brackets.

I added the side parts by using metal brackets to wedge them at 90°. The gluing is done with Cyanoacrylate glue. Afterwards, I cut pieces of 5 x 5 balsa wood to reinforce the angles.

The seat support boxes have been painted in dark grey to imitate a metal frame and the seats are placed on top of them. I still have to make the adjustment system with small profiles and seat belts.

Potez 58: The seats

After a long period of shutdown due to COVID-19 and the confinement period, I worked again on the details of the cockpit of my Potez 58. I am fortunate to have the original documents of the seats . Thanks to Air passion (GPPA) from Angers and its vice president Alban Dury.

The cabin is equipped with 3 seats. Two seats at the front and one passenger seat at the rear. I started with the seat cushions and the choice of foam came up very quickly. I tested the soft, hard foam and even styrodur expanded polystyrene.

For the seat covers, I first tried with skaï.

The result is really not great, firstly because the skaï is too thick for the scale and secondly because me and the sewing makes 2 … Anyway, I glue and I try to fold … But it’s not great. Luckily, Madame comes by and examines my work and gives me some notions of sewing. Then she finds me a piece of thin, smooth velvet and tells me how to make the patterns. In short, I have to reproduce the sewing techniques as they could have been done at the time on the cushions.

As you can see on the pictures above, there were many patterns and followed long evenings of sewing on the wrong side to turn the piece inside out and reproduce the seam on the top as on the real one.

Never has a plane part caused me so much pain. Below are the seat cushions. They’re not as good as I would have liked, but I don’t see how I can do better.

Then I started a trunk that will fit under the rear passenger seat. It’s made with a 15/10 PTC and I used a metal worktop and magnets as a square.

Then I put the pedestal, seat, armrest and backrest on the plane. Everything is put down without gluing and adjusting to see how it looks.

I still have a lot of work to do on the front seats, which are much more complicated with the sliding and replicating system for folding the backrest.

Construction of a hand-launched glider, Lucas Lepretre’s construction plan

Lucas, a friend on Facebook posted a video a few days ago of one of his constructions and the flight of a hand-launched « LLD » glider / DLG depron DIY « glider.

This glider is 80 cm wide and the plan is available on the Lucas’ you tube page. After some exchanges of messages to have some technical details, it is decided, I initiating the construction. I am all the more motivated that when resuming club activities, a member came to fly to the field with another launched hand and I loved it.

First step, printing and assembly of the plan and cutting of the parts on 3 and 6 mm (0.12 and 0.24 In) depron styrofoam.

The wing is made in 6 mm (0.24 In) depron and is sanded to give a profile to the wing. To do this, I have lean on the right edge of a table and I delimited the transition zone between the leading edge and the trailing edge.

The warhead is also sanded to give it a rounded shape. I added to the original plan of Lucas, an upper part to the warhead to form a cover above the electronics, which will be installed in the warhead.

A little decoration of the wings, with green paint for children, passed with a brush.

I then added 3 x 1 mm (0.12 x 0.04 In) carbon plates in the wings, the stabilizer and the fin to strengthen. The wing is glued with an 8 ° dihedral and the fin set in place on the fuselage beam. The latter is a 5 x 5 mm (0.2 x 0.2 In) hardwood rod.

I still have to cover the depron with a lamination film to protect it, to finish the assembly and to install the radio

Preparation of the setup, receiver, servo controls and motorization, suitable for the ultra light Potez 58 aircraft

All of the elements that make up the control and motorization system are miniaturized elements purchased on internet. In the photos below, you can see the motor, which is a brushed motor « NANO GEARBOX BRUSHED » with reduction gear. It measures 26 mm long and works with lipos 1s for planes of about 20 g.

Two nano servos DYS type. They are 22 mm long and, of course, they are analog
servos operating with voltages between 3.7 and 5 Volts. The 2 identical servos weigh a little less than 4 g and will have to be connected to the receiver.

The receiver is of the Deltang brand. It is a 0.65g model with a DSM2 type frequency modulation for spektrum transmitter

The set weighs 12g before wiring and soldering the elements.

You can see on the diagram below, the various connections that will have to be done. It was not so simple, because the wires are tiny.

It’s really small. You shouldn’t tremble. Nor should you have had too much alcohol the night before, I guarantee it. These photos were taken to show you how I did it with a third hand, to solder these wires on the receiver.

Additionally, I had to prepare an additional small connector to join the battery to the receiver.

Bellow are additional pictures from the various elements and the connections to adaptors to save weight.

I weighed the whole and mass is of 12.42 g and adding the propeller the mass is just under 14 g. If we add the 9 g of the plane, we get a total of 23 g, a little higher than expected, but remaining within good limits