The importance of radii
We’ve written about using ‘nodes’ with 3D objects made from wood before, but suggested it may not work for acrylic because it is more brittle and less forgiving.
There are, however, some tricks to it.
Saving yourself making time and cost
As many of you will know, you can save making time and cost by placing the pieces you want to cut directly side-by-side. This way the two pieces can share a cutting line between them – effectively cutting two sides in one stroke.
The trick to making this work, however, is the removal of the unneeded extra line. When you first place the objects directly side by side, you should be able to see the shared line as being a darker blue to the others – at this point it’s a double line – one blue line directly on top of the other.
Removing this extra line in Illustrator is straightforward, but in Inkscape it’s a bit more complex:
Before you begin: Select All and use the Path > Object to Path command.
Step 1: Select the Edit Paths by Nodes tool.
and with stunning results!Every day I see a a lot of good content go through my feeds and occasionally they are some real gems which lower the barrier for people to create great designs.
I saw two SketchUp plugins a while ago and have only just had a chance to test them out. I am amazed how easy it makes creating sliceform laser cut models and I’m wondering how I ever did this before. I wish I’d known about these when doing this project with my students back in 2009.
Upload with the assurance you’ve got it right.
I’ve put together this video tutorial of a process you can use to self-check your design files before uploading them using Illustrator – as well as covering all the common mistakes to look out for.
This is ideal if your design file won’t upload to Ponoko, or you want to be sure you’ve formatted everything correctly before getting us to make it…
My first Ponoko mess-up and how I could have avoided it…
LEFT: result of my original design. | RIGHT: what it was meant to look like.
Yes that’s right – I managed to make a TINY unreadable business card (about the size of a Mahjong tile) as a result of using the wrong Units when I was designing it. Suffice to say, Pixels do not equal Millimeters.
I console myself that this age of rapid prototyping and digital manufacturing allowed me to discover my mistake quickly and with minimal expense. Not like the $327.6 million which went down the drain due to improper Unit conversion with the Mars Climate Orbiter.
However, I could have easily spotted the mistake before even uploading my design. I now know that I could have prototyped my design at (virtually) zero cost to myself, using equipment available in my own home.
I could have printed out my design on paper.
So next time you’re uncertain whether your design is too detailed, if you’ve left enough room to fit chain through a hole, or if you want to see how large your Ponoko business cards will turn out…
Print it out at 100% Scale and make your first prototype FREE.
This year I was asked to redesign and teach a course at Victoria University of Wellington’s School of Design. The course was called Digital Creation and introduced first year students to computers and digital technologies. The aim was to teach them how to design for these tools to get the most expressive objects.
I’d like to show you a few of these projects and consider the principles behind them that could help inspire and refine your own exciting ideas.
This is just a quick note to follow up on some comments left on this blog post, How to improve your engraving results. The original post looked in detail at raster engraving and what you can do to improve your engraving results.
Andrés Santiago Pérez-Bergquist asked if we could post some images that showed vector engraving only so here they are.
During raster engraving the laser beam moves back and forth over an area to remove material and the intensity of the pulses controls how much material is removed. With vector engraving the laser traces along the line and the power of the beam is varied to control the depth of the engraving. This can be very detailed and accurate. The heaviest vector engraving is about 0.5mm deep and the light vector engraving is just enough to leave a mark on the surface of the material. The width of the engraved line is about 0.3mm depending on the material.
Click on the photos to see the engraving results on a selection of materials:
In the making guide we mention ‘nodes’ as a good idea if you want to create more complex 3D designs. But what is a node and how do you create a good one?
A node is typically used if your design has multiple parts that need to join together either by slotting or with a tab and hole joint.
Nodes are little bumps located in the slots or on tabs in your product that are there to help compensate for material thickness variations and the laser kerf. This idea is they compress when a product is assembled providing friction at points rather than along the whole surface of the slot. This means the slot can be fractionally wider at the opening allowing the pieces to be slotted together easily but still create a snug joint.
Finding the right balance between easy to put together but tight when assembled is no mean feat and is probably quite subjective. What I find easy to put together, some people don’t. It’s best to get a few people to have a go putting your design together if you intend to sell it as a flat pack item.
So what is the key for a successful node?
In 2008 I sought to try and quantify the kerf of our laser cutter, or how much material the laser cutter burns away when cutting specific materials.
The idea behind providing this information is so you can make a more educated guess of what sizes to draw your shapes if you are needing a tolerance fit. This information is particularly relevant if you are creating inlays and slotting joints*.
Please note that these are old figures, which we are hoping to update soon – we cannot guarantee super-precise kerf widths at this time.
Prototyping for yourself is the best way to guarantee the perfect result but hopefully this info will give you an idea of what to expect.
So anyway here are the results…