In the photo above I determine the cutting angle that will apply to the two side beams. I use the 3,4,5 method known in the building trades, to know an angle from a right angle.

Then, below, I cut the beams to their length, according to the angle determined beforehand because the back of the VroumVroum! is wider than the front.

In the following images, I show the use of the fittings. The original ones are designed for 40mm wood, but mine are 36mm.

As the beams have a section of 40mm x 145mm x 3500mm, and my crosspieces are 36mm, the fittings are cut in two.

They are then embedded in the crosspieces and will then be bolted and screwed into the beams.

Here for the high crosspiece

Here for the low crossbar

A fine-tuning of the tenon before assembly.

Mortises on the beams (it's very noisy!), then installation of the first post.

The mortises are 54-56mm deep for slightly shorter tenons.

Since we don't have a garage, we work outside most of the time and are forced to protect the VroumVroum! until it is completely finished.

This tarpaulin and untarpaulin operation is quite tedious but unavoidable as it is.

In the video below, I temporarily set up the fittings that will receive the beam. I explain that once we have done all our checks, measurements, etc., the assembly will be coated with tung oil and permanently fixed with thread lock to prevent the nuts from loosening.

Then we take the beam with its post out of the greenhouse to prepare to put the whole thing in place on the VroumVroum!.

At this stage, there is no definitive fixing and the whole thing remains completely dismountable.

This time it's the moment of truth. We're going to put the beam in place and see if our calculations were correct or not!

The first operation consists of fixing the post to the lower crosspiece with a single screw that will serve as a pivot.

Then, the installation of the second post is done rather easily, and it too is fixed to its crosspiece with a single screw.

Finally, while Marie monitors the stability of the beam, I climb and fix the beam to its upper crosspiece.

There you go, we are satisfied. This temporary installation of the beam was essential for our checks and to determine at what height the floor of our bed will be above the cabin.

It is not obvious that there is a 20cm difference in the width of the vehicle between the front and the back of the beam. Yet they are there!

Ah! small detail; the beams are not made of chestnut but of Douglas fir. I regret it but my logs do not exceed 3.20m, that is 30cm too short. Too bad, we will make do!

Even in this view, the 1.60m width between the ends of the beams that will be available above the cabin is not obvious.

We have set ourselves the goal of not exceeding 2.30m in height all inclusive. For the moment, with our 2.22m above the beam, we are on target!

In the next episode, we will have dismantled the beam to pass it through tung oil as well as all the other parts. The second beam will be cut and shaped identically to the first and the whole will be permanently placed on the structure.
First, we will have moved the pick-up between two oaks and will lift the VroumVroum! using a sliding block on a zip line.
So see you soon ;-)