We have just switched suppliers for our bamboo timber. The new supplier provides a better quality material and has more scope for other thickness options and variations. We hope to add more bamboo options soon.

The new bamboo is the same in regards to thickness and appearance.

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?

Symmetry – It’s best to have nodes on both sides of a slot mirroring each other. This will minimize any potential twisting that might occur if nodes are offset.

Shape – A gentle curve works well. Something that leads on easily but provides good friction when it’s on.

Multiple sets – If the length of the slot allows, you can have two or more sets of nodes. Again will minimize any twisting that might want to happen. Have one pair near the start of the slot and one about halfway between the middle and the end of the slot.

Length of the node – The longer the node the gentler the curve which seems to make the pieces easier to slide on and off. The minimum length of the node should be approximately 0.2in or 5mm.

Width of the node – This will depend on the material you are using. If the material is dense, like MDF, and has little compression then the nodes should be shallow about 0.01in or 0.2mm each. So taking into account of nodes on both sides of the slot, that allows for 0.02in or 0.4mm in variation. If the material is less dense, like Eurolite Poplar, and therefore can compress more then you can use a bigger node, 0.02in or 0.5mm. It might pay to test a few different sizes in some mock ups (like the examples below) before committing to your full design to test exactly what will work with the material you wish to use.

This information will work best with the plywood and timbers offered on Ponoko. The timbers tend to be a lot more forgiving when creating interlocking designs whereas Acrylic can be brittle and a bit trickier to work with. I’ll go into more detail about plastic joints in a later post.

Below are diagrams of the experiment I did to illustrate the differences in node types with a video showing the physical results.

Now this information is to be used as a guide to help you reduce the number of prototypes needed when creating products with Ponoko. It should be used in conjunction with the information on the laser kerf in a previous post to help make a best guess at how to design your joints. Feel free to be creative with nodes and let us know any successes or failures so we can learn from them.

Being mostly a self taught vector software user I have often wondered about how to best control curves for any drawings I am creating. All to often I can look at my drawing and think something just isn’t right. Thankfully I came across some great posts by Juan over at Typies blog with some great tips on how the create the perfect curve.

Juan talks about vectors in relation to type but the principles are the same for drawings for a new necklace design or a personalized set of coasters. They are also applicable to all the vector drawing software we suggest, whether it is Illustrator, Corel, or the freebie Inkscape.

The first post is about the basics of vector drawing where he outlines the definitions of the terminology used in vector software packages and how to construct your shapes.

In the second he goes through 8 common vector drawing mistakes, showing examples of where to put your points, how many to have, and how to balance the handles.

Thanks for the tips Juan and I’ll be keeping an eye on your blog for any future advice.

via swissmiss

Most people wouldn’t think it was possible to create an amazing design from a sketch that takes 5 seconds to draw. Karl-Oskar proves this can be done with his 5 Second Plate. The form was created from a series of 5 second sketches that literally became the shape of the plate. The sketches were translated into digital files and cut from glass on a water-jet cutter.

I find this process very interesting especially in relation to Photomake and using digital technologies to express unqiue quality in a product made by a machine. When we first started talking about an online tool that would take sketches and turn them into laser cutting files, my first thought was how this might be utilized to create the perfect series of indiviualized products. I imagined drawing something over and over again, each one being slightly different because of the subtle variation in hand movements and then being able to sell them as unique pieces. This is the value of digital production over mass production that is becoming more popular. They allow us to create unique products at close to the same price as mass production but there is a ton of value in the uniqueness.

Karl’s 5 Second Plate captures this potential really well. Who knows, maybe one day all of the 5 second sketches could become a product. In the mean time it is great inspiration for how you might approach designing something to make on Photomake.

This week 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*. These figures are averages and the usual caveats apply. Prototyping for yourself is the best way to guarantee the perfect result but hopefully this info can mean one less prototype.

So anyway here are the results. For those using imperial

And for those on the metric system.

So what does that mean?

If you are wanting to combine/inlay materials, say a white square within a red one, or something like ColinFrancis’ jewelry, then you can use this data to help determine what dimensions to create the shapes in your eps files at.

If you were to draw some parts to be cut from 3mm acrylic as dimensioned below,

the white square on the right would end up at 39.80mm and the hole in the middle of the red square would be 40.20mm.

However if they are dimensioned to allow for the laser burning material away, both the hole and the white square will come out at 40mm and they should fit snugly together.

This video shows what I am talking about. The square labeled ‘40’ shows what happens in the first diagram, or when the dimensions for the hole and the bit to go into the hole are the same. The square labeled ‘40.20’ shows a square drawn to allow for the laser kerf. The parts fit snugly together with a nice click.

Anyway, I hope that can be some inspiration for you. Happy making.

* slotting joints also rely on the thickness of the material being consistent to be successful. All our materials have a thickness tolerance of +/- 10% of the material thickness. I will create a post in the future which will address slotting joints in more detail but for now you can refer to here for notes about nodes or ask a question in the forums.

So this is the first in a series of new making content that I will be bringing you through the blog. This test shows how the laser cutter handles raster engraving of different font sizes and how you can improve the quality of your engraving.

Our current set up uses 3 colors for 3 different intensities of raster engraving, light grey for light raster engraving, medium grey for medium raster engraving and black for heavy raster engraving. The way the laser cutter works is like an old dot matrix printer except instead of dots of ink it uses pulses of the laser beam. For the black the density of the pulses is the highest and you get good resolution. For the lighter engraving there is less density of pulses and this produces a lower resolution especially if the text or shape being engraved is small. This is most noticeable around the edges of the shapes and on curves or diagonal lines.

You can see what I am talking about below. With the smallest text pieces the resolution isn’t so great and some of the text is even missing whereas the heavy raster engraving has smooth lines and looks crisp.

One thing you can do to improve the quality of the engraving is put a vector engraving line around your text or shapes to make the edges more crisp. There are pros and cons for using this technique and it largely depends on which material you are using. Personally I like a heavy raster engraving on any of the plastics but a medium raster engraving with a medium vector outline on the timbers.

See below for more some detail shots of the different variations and make up your own mind from there.

In black acrylic –

In the technoply beech -

In eurolite poplar –

So this is a small selection of the materials but should give a fair indication of what to expect when raster engraving. Engraving on the timbers will produce a fairly similar result as the 2 shown and engraving on the other acrylic colors will have the same affect as on the black.

PETG or styrene are nearly impossible to photograph to show the differences in the engraving details and deserve a more specific post in the future. For now you can refer to this post in the forum which has a few tips in it.

Last week the 3rd year Industrial Design students at Victoria University presented the prototypes of the 3D printers they had designed. The challenge was to design and make a “green” 3D printer in 4 weeks with a limited budget. The students innovative thinking looked at ways to make use of waste material and repurpose it into new objects.

‘Stack’ used the waste paper from generated by a bank and a ’steampunk’ sewing machine to create layered forms based on an interpretation of the banks statistical data.

‘Nexus’ created forms by building up layers of bubbled gelatin. The results had some pretty amazing visual qualities.

And ‘Equinox’ focused the power of the sun to selectively dry layers of recycled paint to build up fluid forms.

This is the second year that 3D printers have been create by the VUW students, with the last years post here. It will be interesting to see what ideas they come up with next year.

Posted in Dan Emery, Design, Digital Manufacturing, Fabbers by danemery | 4 comments