Calibration: Tightening the belts

Here is our first test print of the main body of the Mars Rover Curiosity. Fill was set quite low which accounts for some aspects of the low-quality appearance, but there are other things we can address. The fine details on the left hand side for example, should have resolved to a higher level of detail. 

First step: tighten the belts! If the belts are loose (and they were) the print head responds sluggishly and with less accuracy. The smaller belts from the motors were easy to adjust simply using a screwdriver, but there was no simple way to tighten the larger axis belts on the Ultimaker without getting really fiddly.

I ended up printing the solution using a pre-made design from Thingiverse. They are tiny clips that fit on the edges of the existing belt support blocks. Incredibly simple, yet effective! 

Here is a thumbnail of the STl file for the clips and a link to the Thingiverse page.

I chose this belt-tightening system because of its simplicity, but there are lots of alternatives, such as the curved clip below. I was concerned about it hitting the side pulleys for wider print jobs though and the potential noise from dragging against the plywood frame – but I still like it’s elegant design.

The good news is that tightening the belts showed immediate improvement in the print jobs. The bad news is that in the middle of printing the next job I ran into what I predict may become a major hurdle for reliable printing with PLA on the Ultimaker: print head blockage (cue dramatic music).

//josh

Replacement PCB board arrives

A few weeks later and we have finally received our replacement PCB board from Ultimaking Ltd.

Swapping the boards out was a bit fiddly, but all went to plan. Below you can see the wires re-attached ready for installation.

Here is our Ultimaker in ‘Service mode’ with the new board installed underneath. This is also a good shot of the fan module which I want to mod later to dampen some of its noisy vibrations. Wood on metal isn’t very conducive to a quiet 3D printing operation!

The great news is the new board has fixed our problems, the extruder now functions normally. The bad news is that I still don’t know exactly what was wrong with the last board – but signs point either to a faulty component or a bad solder joint. I had to send the faulty board back to Ultimaking, so this may remain an (unimportant) mystery.

Here is a picture of the first test print in progress, the Mars Rover Curiosity! This job was set to quite a low infill so you can see the individual print tracks. The finished result was very crude, but was expected for an uncalibrated machine.

//josh

The Ultimaker Arrives

Thanks to the speedy construction of our new Ultimaker by Miles and son, we have been able to get started with the first round of testing in the utilisation of low-cost 3D printing at UNSW.

As a technology, 3D printing has an incredibly bright future, with a potential to revolutionise industry around the world. For now, most high-end applications of the technology are prohibitively expensive. The introduction of low-cost 3D printing means that anyone can become familiar with the technology, limited only by the range of materials available and build quality (for now). 

Despite these limitations, low cost 3D printers have the ability to be incredibly useful rapid prototyping tools. Specifically as an Industrial Design student at UNSW, I’m interested in how 3D printing can help the design process by giving students the means to quickly mock up physical models from CAD drawings. 

Why did we choose the Ultimaker? In our initial research into low-cost 3D printing, we considered many different models. Other strong contenders for the research program were the MakerBot Replicator, The Bits from Bytes 3D Touch, the PP3D Up! and the 3D Systems Cube.

Initially we favoured the Replicator and 3D Touch for having dual extruders. Apart from the ability to print in two colours, we thought that dual extrusion was potentially most useful for printing secondary support structures. The beauty of a water soluble PVA system for example, would be the ability to print functional enclosed mechanisms such as gearboxes by simply dissolving the internal supports away with water. Imagine the ability to print a functional clock, with internal mechanisms that you never have to assemble!

Because of a few limitations with dual extrusion (complexity, reliability and cost), we came to the conclusion that it wasn’t a practical requirement for the average student. Instead we focused on the three main attributes we judged as important for common use:

Print quality.

Print speed.

Print cost.

The Ultimaker surprisingly came first in all of these key attributes by quite a large margin. It was therefore was an easy choice as our test machine. More on these attributes as we begin testing.

Now that it has arrived, what are our first impressions? Apart from the build process which I hear from Miles was surprisingly straightforward, we have run into a few problems. After running tests we have discovered a fault with the extrusion mechanism on our unit responsible for feeding the plastic filament to the print head. It’s a small but significant malfunction; we can’t print without it!

Thankfully, Ultimaking support have been very helpful and already have replacement parts for us in the mail. We reserve our judgement of the Ultimaker’s printing abilities until we can get the new parts installed and running. 

Fingers crossed we get it working soon!

//josh