When I lent my services to a collegue who was working on a film about 12 years ago, I was introduced to the world of cnc. I remember watching this huge machining centre milling out a slab of mdf and turning it into a fantastic set of gears. I knew that it would have taken me hours to achieve the same thing with traditional power tools. I decided then that I would invest in a cnc router for my own business Oxenham Design. At that time I could turn on a computer, but even to check email seemed like a crazy set of operations. I persevered and learned every piece of relevant software I could get my hands on. I am now fortunate enough to be using Vectric's ASPIRE software, and Techno cnc routers, which has helped us to create some amazing projects, both in part, or in full. I thought that this blog would be a great place to share "behind the scenes" adventures with the software, materials and equipment we use, as well as the projects we build.

Tuesday, 4 October 2011

On with the post!

I drew our simple post vectors in Aspire. The top cap is just an oval rotated slightly.

I then used the node tool to 'CUT' the outermost vectors on each side of the cap. This, as you may have guessed, will be our 2 sweep rails.
If you look closely, you can see the dotted cross section I drew for the cap. I also rounded the corner edge of it to allow for an easier time blending it with the post body. A smooth, curved join will be less noticeable than a sharp one.
After selecting the top and bottom rails from our cap, then the cross section, voila. A nicely shaped cap with a smooth rounded edge. Make sure to set this component to 'MERGE'. This will let us blend it nicely later, with predictable results.
 The next step is to click the 'View along Y axis' button in the top right most corner in the 3d view window, Then select the 'Save shaded view' option from the VIEW menu bar. Give this image a name and location for saving. When done, import this image right back into Aspire. This is the 'perspective free' profile of our cap.
Now we need to trace this outline with the line tool. The easiest way is to draw a straight line from the left side of our component to the right, select the node editing tool, and convert the line to a bezier curve. Then just adjust the curve with the bezier node handles until you are satisfied with the shape. When your happy, you can delete the image as we don't need it anymore.
As our imported image's component size will vary, based upon how close or far we were zoomed in when we saved the image, we need a definitive size. This newly created vector is going to be our cross-section for the post body, so it stands to reason we need a measurement from the post. Using the measuring tool, let's measure the straight span at the top of the post body. Mine measured 4.185".
Now I just select my post cross section and set the size to 4.185" making sure the 'LINK XY' check-box is on. This will keep our profile intact both in length and width.
Select the post outline, and copy and paste it to a new layer. We may or may-not need this copy, but it's a small insurance policy later!!!  Now we need to go to each of the four post corners, and with the node editing tool 'CUT VECTOR' This will make the left and right sides of the post our rails for the up-coming 2 rail sweep we will be doing.
Select the right side node at the bottom of the post where we just finished cutting the vector, and pull it down just passed the curve of the bottom of the post. This will ensure the sweep incorporates the whole post outline. Use the copied vector that we moved to the new layer as a guide to keep the shape. Pulling the bottom node down will definitely change the shape, but just keep tweaking the node handles until it lines back up with the duplicated post shape. Now do the same to the left side.
Now we need to select the left, then right sides of the post, then the cross section we traced from the image, and apply the 2 rail sweep. If the relief comes out totally wacked, you may need to hit one of the "Revese rail direction" checkboxes. That will fix things for sure! Also be sure to make sure the component is set to 'MERGE' Now you might need to play with the tilt and height options in the component manager to tweak the shape to line up neatly with the post cap.
Feel free to stretch the cap so it works nicely with the post.
 Now we can import our Photoshop 'Toon Grain' bitmap we made, and convert it to a component. Line the new woodgrain component up over the post.
With the woodgrain component selected, we are going to tweak it with the "distort objects' setting. under the settings, select the bounding box option. Now we can control the shape of the bitmap like a vector. Convert the sides of the bitmap to a bezier and bend the shape to fit closely to the underlying post vectors. Do make sure that it is slightly oversized, this will give us something to trim off in the next few steps.
Select the post outline copy that we moved to the new layer a while back, and select the woodgrain as well. Now we just 'Clear component outside vector'.
Next we will bake the woodgrain and underlying post shape into one component.

The next post will cover making the post cap.......as soon as I can finish it!


  1. John Christensen5 October 2011 at 07:24

    Thanks! Awesome tutorial. Is there a particular reason you have a straight line inside your oval? Does it do anything?

  2. The straight line was due to the 'post' being created with a closed rectangle, thats all hawkeye!