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Case Study - Wanted Poster

In this article we look at how an unusual gift I received at the User Group was created and the technique that was used to create text VCarved into a textured background.

Over a number of years now I have been working with Tim Merrill (Vectric forum guru) to produce samples for the User Group meetings. Along with a few other very helpful customers Tim has brought to life many of the designs that have been created for presentation at the meetings. The most ambitious of these was probably the Mantelpiece (shown below) which Tim made and transported to the 2010 meeting in Memphis and which now resides in the Vectric office.

Drawing of design

This year I find out that Tim had been collaborating with some other people before the User Group and was surprised and very pleased to receive a personalized western style, wooden "Wanted" poster as a gift (right).

The idea for this was cooked up between Tim and his Canadian buddy, Rodger "T.R." MacMunn. Rodger asked Donna Larocque, an extremely talented artist who he collaborates with in his sign business to create a sketch showing me as a desperado (which must have been hard to imagine…) T.R. then took that and laid out the rest of the design for the poster including the text. Opinion was divided on whether $5 was an over or under evaluation of my worth.

 

Sketch of James as a desperadoSketch of full designAspire 3D Preview

Tim then enlisted the help of Aspire modeling maestro Michel Tyler (who creates Vectric's Monthly Projects). He created a 3D model of the sketch and sent that to Tim who then started to put the project together and create the toolpaths to produce the different parts.

Tim used some interesting techniques in the production of this so I asked him to document the steps and show how the finished part came together. Below you can see this step-by-step guide.

"One technique to achieve crisp painted text when using pocket and v-carve toolpaths in wood is to machine the text, seal the text and surrounding material with dewaxed shellac or similar clear finish, paint the text and finally sand the material surface to remove any paint.

However, as in this project, the material surface may not be smooth or flat, making this approach impractical.

As this was a completely 3D project, an alternate solution is available and here are the steps that were followed:"

Step 1: Toolpaths and Preparations

A 3D Roughing toolpath was calculated with the Machining Allowance set to 0.04". This means that the minimum amount of material left for the 3D Finish pass to remove is 0.04". To ensure a close finish to the surface I used a 3D Raster strategy not Z-Level Roughing.

All the text was selected and a v-carve toolpath calculated using a 90 degree v-bit with the box checked to "Project toolpath onto 3D model." This step is very important as it calculates the v-carve toolpath to follow the exact shape of the 3D surface.

Step 2: 3D Roughing Toolpath

With the material secured to the machine bed the 3D Roughing toolpath was completed, followed by the v-carve toolpath for the text.

Note: At this point the text is not going to look correct. This is because the v-carve toolpath is calculated for the underlying 3D surface and the 3D Roughing pass has left approximately 0.04" of extra material above this surface.

Step 3: Seal Text

Some woods allow paint bleed more than others, but it is always a good idea to seal any wood before applying paint.

The sealer used here was commercially available dewaxed shellac, thinned approximately 50-50 with denatured alcohol. It penetrates fast and dries in minutes.

About 4 to 6 coats were applied in less than an hour. After the last coat, it was allowed to completely dry for a few hours.

Step 4: Paint Text

After the sealer has dried completely, paint the text completely using color(s) of choice. As this was going to be an interior project, simple artist acrylic paint was used which is available from many department and hobby stores.

It dries fast so best technique is to apply 2-3 thin coats.

Notice you don't need to be fussy with the surface in this case as the wood will physically be removed during the 3D Finish toolpath.

Step 5: 3D Finish Toolpath

After the text paint has dried completely, run the 3D Finish toolpath.

This picture shows the 3D Finish toolpath, running in a raster strategy, approximately half done and the quality of the resulting text is apparent.

Step 6: Results

Here the 3D Finish toolpath has been completed, the sign cutout and prepared with a couple of coats of shellac.

Only remaining step is to apply glaze to bring the detail out in the 3D carving and simulate an aged look to the entire project.

The "poster" is now occupying pride of place in my house and as you would imagine creates a lot of questions from those who see it. Worryingly my kids both identified me as the man on the poster when I asked them who it was!

I would like to take the opportunity to publically thank T.R., Donna, Michael and Tim for taking the time to create and make this unique, one-of-a-kind gift.

James Booth

 

 

 


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