Temps requisComplexitéOutils & Matériaux

6 heures

Modérée

Communs pour le travail du cuir

I started thinking about this project after someone pointed out on the Leathercraft subreddit that a contest was being held on Instructable. I had been in a bit of a creative impasse for a few days so I welcomed the challenge as an opportunity to wake up my foggy brain.

I discovered the concept of backflow incense cones and burners recently after I had been commissioned to make a cone incense burner – which led to this white lotus flower project made with leather. I really love the concept of those incense burners which design is made to play around with the flow of smoke. Once again, it is a reddit post about a ceramic rocket that led me on the way to the design that we will be making in this tutorial.

After some initial research, I decided to try to replicate the rocket from the animated movie Wallace & Gromit: A grand day out as it reminded me of my childhood. Furthermore, the roundish and design of the rocket with its big door on the side was quite ideal for what I had in mind.


Making-of the pattern


I thought that I would be a good idea to write a few words about the design process as I think that it could be useful for other leather workers out there. Indeed, my initial problem was the following: how was I going to design a functional leather pattern starting from a reference image of the animated movie’s rocket?

After some more research and trial and error, this is what worked for me. I hope that some of you will find this process useful for their own project.

Designing the rocket on Blender

The first step was to create a 3D model of the rocket, using an image of reference as a guide. After trying different programs (Sketchup & autoCAD), I found that the workflow and the tools offered by Blender were by far the easiest for me to assimilate and work with.

I designed two different versions: one as close as possible to the original rocket which was built around 12 faces, and another one for which I halved the faces. I anticipated that the 12 faces version would be a nightmare to stitch, as well as be problematic regarding the size of the door (indeed, one of the requirement was that the door should be big enough to insert the incense cone through it).

Have a look at the notes de bas de pages to find some of the Youtube videos that taught me everything I needed to know to complete that step.


Printing and assembling paper models

Next I wanted to try out the models “IRL” to get a sense of the dimensions and of what would be the assembly process, all this without using precious leather as of yet.

In order to do this, I used the life saving “Export paper model” add-on in Blender.

On the model, I defined which edges should be separated and ended up two clicks later with a PDF representing resulting the paper model ready to be printed.

Following the numerical help automatically generated on the paper model, I then assembled the two versions of the paper rocket.

The result was thus: if the rocket made up of 12 sides was indeed more visually pleasing, it would not be practical from an assembly standpoint. So I decided to go with the 6 sides version.


Designing the pattern

At that point, going from paper model to proper pattern was very easy. I exported the paper model in SVG and imported it in Inkscape.

There I removed all the unnecessary parts that were used to assemble the paper models and used the offset tool to create the stitching lines.

A few manual adjustments later and the job was done!

Pré-requis


Techniques

Outils

  • Mallet or hammer
  • Stitching awl
  • Wooden edge slicker (optional)
  • Couteau de précision
  • Brush to apply the glue and the tokonole
  • 3.5mm hole punch
  • 2 aiguilles
  • Applicator for the dye (I used a piece of cotton rag)

Nomenclature

  • 4 oz veg tanned leather
  • A piece of metal screen
  • Water based dyes (white and red)
  • Ciment de contact pour cuir
  • Leather conditioning product
  • Tokonole (optional)
  • Beeswax
  • Thread (866 linen thread in that case)

Patron

Le patron gratuit peut être téléchargé ici.

Étapes de conception


Imprimer et découper le patron

Le PDF pour le patron est disponible ici.

Print it on A4 paper and cut-out the pieces of the project.

Prenez soin de vérifier que les dimensions du patron n'ont pas été altérées durant l'impression. Pour ce faire vous pouvez vérifier les mesures du carré d’étalonnage qui doit mesurer 5cm de coté.

Imprimer sur un papier épais rendra l'étape du traçage sur le cuir plus aisée. Un papier de 200g/cm2 ou plus est idéal, tant que votre imprimante peut le tolérer.


Tracing the pattern pieces onto the leather

Use the awl to trace the outline of the different pieces of the pattern on the leather and mark the location of the stitching holes.

Some pattern elements have to be duplicated. Here is the detail of how many pieces you should trace for each element:

  • A x3
  • B (without marking to position the window) x4
  • B (with marking to position the window) x1
  • C x1
  • D x1
  • E x1
  • F x1
  • G x1
  • H x6
  • I x1
  • J x1
  • K x1

The solid lines indicate cutting. The dashed lines are indications to help with positioning the pieces that will be glued on top.


Cutting-out the pieces that will form the rocket

Use an X-acto knife to cut-out all the pieces of the rocket.

Make sure to keep the inside piece of elements C (which will be the window) and E (which will be the door).

We are going to double-side some pieces to make them thicker.

The pieces in question are the 3 fins (elements A), the knob of the door (element G) and the door itself (inside cut-out of element E).

In order to do so, roughly trace the outline of your pieces on the backside of your piece of leather. This will help us know where to apply the leather cement.

Then, apply leather cement to the backside of the cutout pieces as well as to the areas that you have marked on the backside of the leather.

Glue the pieces on the opposite piece of leather. You can use some kind of roller (I used a coffee cup) to apply pressure and insure a strong bond between the two layers of leather.

Finally use your X-acto knife to cutout the pieces, using the edge of the first layer as a guide.

Cut a circle with a diameter=10cm in your metal screen. This piece will be the surface onto which the incense cone will be placed (thus the use of metal so that it doesn’t burn).


Teinter le cuir

Only the window (inside cut-out of element C) has to be dyed white. All the other pieces will be dyed red.

Apply several coats until you obtain the desired color. Don’t forget to dye the edges. I usually use a Q-tip in order to do so.

It is not really necessary to dye the backside as it will not be visible when the door of the rocket is closed.


Brunir les tranches

Use the method of your choice to burnish the edges.

You can start by using sandpaper to smooth out any irregularities. Since I am using second-grade leather, in my case it is unnecessary to do so as it would only fray the edges even more.

The method that I am using consists in applying a coat of Tokonole to the edge with my brush, and then rub the edge slicker swiftly against the edge in order to create friction and stick the fibers together. I start with the narrowest grove and make my way to the widest one.

Another method would be to apply water instead of Tokonole and to use a little cotton rag to create the necessary friction.


Assembling the window, the door and the fins

To install the window, start by scratching-out the area where it is destined to be glued on element B (this is to ensure that the cement can penetrate the top grain and provide a good bound).

Then, insert the white cut-out of the window back into its circling frame (elements C).

Apply contact cement to the backside of the window, as well as to the receiving area on element B. Position the window carefully and apply pressure to glue it in place.

Use you awl to perforate the stitching holes, using the marks left earlier as a guide.

Stitch the window to the panel using a regular saddle stitch.

If you are using polyester thread, finish your stitch by melting the two thread endings on the backside. I am using linen thread here so instead I made a knot and apply a little bit of glue to secure it.

As a rule of thumb when saddle stitching, I measure a length of thread equal to the distance that I have to stitch + a very fair margin and multiply it by 3.

Use the same procedure to attach the knob (element G) to the door (inside cutout of element E).

Stitch it as you would a button on a shirt.

To stitch the fins, first perforate the stitching holes with your awl. Then start stitching using a regular saddle stitch.

Only two of the sides have to be stitched for now, as the third one will be used to attach the fins to the panels of the rocket.


Preparing the stitching holes

Perforate all the remaining holes marked earlier with your awl.

Do the same on the bottom piece K and punch the exhaust holes with the 3.5mm hole punch.


Stitching it all together

Start by stitching all the top panels (the 6 elements B & D) to the central band using a saddle stitch.

Feel free to arrange the window and the door differently. I thought that it would look better having the spaces consistently (2 empty panels in between) but can absolutely choose to do it differently.

When the top panels are stitched, move on to the bottom ones (the 6 elements H) and repeat the same operation.

Now to join the panels together, start your stitching line at the top to start joining two adjacent panels. With a “reverse” cross stitch, make your way down all the way to the bottom of the H panels.

For a cross stitch like this, I measure a length of thread equal to the distance that I have to stitch + a very fair margin and multiply it by 5.

Every other panels pair, you will have to stitch a fin in between the two panels. In order to do that, use the same stitching technique except that you will pass the thread in the hole of the fin before reaching the other panel. You should start threading in the fin thusly 10 holes away from the last one at the bottom of the H panel.

At the end of this step, you will be left with only one edge open. Don’t stitch it closed it just yet.

Now we need to add the exhaust piece. Stitch it all around using the same stitching method as for the edges.

Then start stitching up the edge and stop your stitch line halfway up the rocket side. This way we can hide the knot under the central band and leave an opening to insert the metal screen because closing the rocket.

Insert the screen through the remaining open edge and put it into place. I stuck a bbq skewer through an exhaust hole to help positioning it.

You then want to stitch the top of the rocket just like we stitched the exhaust and continue down stitching down the edge to finish closing down the rocket.

Finally you can hide the knot under the central band and apply a bit of glue if the end-bits of the band are fraying a little.


Final touches

Finish your rocket by applying leather conditioner on the entire piece.

Congratulations, you’re done!


Résultat final

I hope you enjoyed following along this tutorial.

As always, please feel free to share any feedback about this tutorial or any project idea you’d like to see posted here.

Notes de bas de page


Le contenu en ligne suivant m'a apporté assistance technique ou inspiration durant la réalisation de ce projet:

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