Connecting With Your Other Half

2014-12-04 TieI’ve just been experimenting with some designs that are made up of connectable pieces, and this is the outcome of a test print to see if the pieces will connect and hold together. This is one of the great things about 3D printing – within an hour being able to test a concept and have the confidence to move forward with the design. I’m also pretty pleased that the ‘Up! Plus 2‘ I’m using is doing a good job at producing these 1.5mm diameter pieces, with only a bit of messy detail at the round connection points. Moving this into an SLS process should solve this for the final outcome.

– Posted by James Novak

Tutorial – Abstract Wireframe Lattice in Solidworks

Abstract Wireframe AllWhile working on part of a new design for 3D printing I thought I’d capture a few of the key stages and put together a brief tutorial about how to create a complex-looking wireframe (or lattice) design. Who said Solidworks couldn’t do complex organic models?? (this article has been updated slightly on 2/12/2014 since I modified my process – that’s Solidworks for you, there’s always a million ways to achieve the same outcome. Some are just a little cleaner than others).

Step 1 is to setup some planes with sketches defining the rough shape of the object you want. This is important to get the overall size right and control the shape. By putting some planes at angles, this will increase the visual complexity rather than all planes parallel.

Step 2 is to create a 3D Sketch – then imagine you’re a spider and draw lines between vertices! Setting up the planes in step 1 means your 3D sketch will be easy to control (if you’ve tried 3D sketching without any guides you know how quickly it can get out of control).

Step 3 can be done in a number of ways depending how accurate you want to be, and how patient you are. The first part is the same no matter which option you go for – create a plane perpendicular at the end point of 1 of the lines (by clicking the line as the first reference, and the endpoint of that line as the second). Draw a circle on the plane with the line through the center. Give it a dimension, then right click on the dimension and ‘Link Values.’ Create a new name, which will allow you to draw upon the parametric capabilities of Solidworks as you move forward and link all dimensions together, meaning you can update 1 and the entire model will rebuild with this new diameter. Now you can either exit the sketch and use the ‘Sweep‘ function, linking up as many lines as you like, which will look OK but will result in sharp junctions at each vertex which even a fillet won’t perfect. Or if you are a bit OCD like me go 1 line at a time either as a ‘Sweep’ feature, or ‘Extrude‘ using the ‘up to vertex’ option to the endpoint of the line.

Step 4 is to repeat, repeat, repeat! This is also where the ‘Link Value’ becomes useful – when you sketch each new circle and add a dimension, just right-click on the dimension and go to the ‘Link Value’ option. There will be a drop-down menu where you can select the name of the dimension you created in the first sketch. This will link all the diameters together using a single dimension. You can keep the ‘Merge’ option checked, or un-check to leave each extrude as a separate body to combine at the end. Up to you, I usually merge everything as I go if possible (saves any surprises at the end).

Step 5 Once the framework is complete, the last step is to fill all those little joints between the cylinders. Simplest method if you are working in part mode is to sketch on one of the flat surfaces, convert one of the circles, then turn this into a semi-circle. This will allow you to do a 360 degree ‘Revolve‘ feature, filling any gaps in the joint. If you prefer you can complete this step after creating each cylinder so you don’t lose track. If you’ve modeled as separate bodies, you can now use the ‘Combine‘ feature to join all those individual pieces together as a single solid.

Hope that’s useful, I know it’s more time-consuming than some other CAD software out there, but it’s also extremely accurate. This model took about 2 hours to complete. Leave a comment if you have any questions, or share it around.

– Posted by James Novak

MeshLab Saves the Day

141129 Meshlab ReductionI’m on a roll against huge STL file sizes! You can look back at some of the past story here, but in summary I have a complex section of a design that started off being a collection of separate truncated octahedron parts. When saved as an STL, the file size was 259MB, which for something only the size of an Up! Plus 2 print plate, was pretty ridiculous.

It took me a lot of mucking around but eventually I reduced the STL file size by merging all those separate parts to form a single solid within Solidworks. That’s the 104MB pictured above.

Now I have just discovered the freely available MeshLab software, which in a matter of seconds has simplified the mesh to half the file size, without compromising quality. Now if you’re a 3D printing nerd like me, that’s cool! I’m sure with tweaking this could be further reduced, which is important since the part I’ve been testing is only a portion of a larger product, and I need it to be less than 100MB for uploading to i.Materialise in the future.

Looks like MeshLab does a whole range of other things like repairing meshes and cleaning up textures, so if you’re slow like I obviously am, download MeshLab now!

– Posted by James Novak

Merging Saves MB’s

Test SectionIf you’re keeping score you may know that I’ve been losing against the might of HUGE file sizes and failed 3D prints (check out the last attempt here). Looks like my luck is turning!

This is the truncated octahedron segment that was meant to print the other day, with an STL file size of 259MB. My hunch about turning the assembly into a part file and combining all the solid bodies (which takes at least half an hour!) has finally come good, with an STL file now less than half the size at 104MB. Happy Days 🙂

The issue has been one of overlapping geometry, which Solidworks seems to hate – rather than each truncated octahedron perfectly lining up, they are actually about 0.02mm away from perfection; a detail that has taken weeks of on and off experimentation to get right! So if you want my hot tip, stop trying to model so damn perfectly!

– Posted by James Novak

Failure and 3D Printing go Hand-in-Hand

2014-11-19 FailureWell the picture says it all – fail! As mentioned in an earlier post, I’m playing around with a truncated octahedron structure. I put this 3D print on at uni (Up! Plus 2 printer) late yesterday afternoon with a 13.5 hour print time, expecting to find it all nicely completed this morning. For those using 3D printers regularly like me, failure quickly becomes part of the norm (I feel like somewhere around 1 in 5 have some sort of error – what do you think?).

Looks like there were 2 failures; firstly the small pieces meant to be around the rectangle section in the middle haven’t stuck to the plate properly, causing some ‘fairy-flossing’. Secondly, after running the print again, looks like the extruder is clogged or dead. No material coming out, which is why this print (which was meant to fill the plate) doesn’t have piles of plastic everywhere. Time for some maintenance!

I also wonder if the file itself is causing any problems – still having file-size issues with the complex linear patterns used. This particular STL file is 259MB, and only accounts for about a fifth of the total final product…. Hmmm back to watching Solidworks crash trying to combine all the parts into a single solid, reducing the number of surfaces and therefore file size. Well that’s the theory anyway!

– Posted by James Novak

Hack it up

2014-11-13 ClampsThere is nothing better than getting away from the computer screen and into the workshop to test the fundamentals of an idea. It can be rough, dirty, ugly, but oh so useful!

Case in point; a few clamps sliced and diced together to form an adjustable rig. Really quick to build and demonstrates what can’t be tested in sketches, and would take too long in CAD. Thank you Glenn Smith for teaching me the value of model-making and hacking! There was recently a story on Jonathan Ive discussing exactly this need for designers to learn “how to make stuff,” not just pretty digital images of a 3-dimensional object.

Sorry I can’t share any more details about what this is for! Another one of those hush hush projects 😉

– Posted by James Novak

Cheating is Winning

Band TemplatesI have to admit I’m not one of those designers who can spend endless hours with markers and pens putting my imagination onto paper. I’m a little jealous of people with that skill/patience. However there are times where it’s the best way to generate a lot of ideas, really quickly. But I still like to cheat!

To kick off a new project I’ve quickly drawn up a few different views of a wrist-band shape, which will allow me to trace the linework for my concepts – a really simple way to have a consistent look across all ideas.

And since I’m such a nice guy I’m letting you download the PDF for FREE! If you’re working on any wrist/arm/leg product it may just come in handy. Just click the link below.

Download ‘Band Template’

– Posted by James Novak

Truncated Octahedron

Solidworks to 3D PrintI came across the truncated octahedron during my Honours studies, researching shapes that would fill 3D spaces without leaving any gaps. Now that I have the time to get back to some of these ideas, I’m quickly blowing the Solidworks file size into the hundreds of MB’s! But the great thing about this shape is that it can print on the ‘Up! Plus 2’ 3D printer without any support structure, and is strong enough to stand on. In this photo you can see the CAD file and one of my 3D prints of a segment.

I’m currently looking at combining all the parts into a solid body as it seems to save a substantial amount of MB’s when converted to an STL file if everything is joined – I guess because there are less individual surfaces all intersecting. Just a pain to do!

– Posted by James Novak