Category Archives: Featured

3D printer has arrived!

After nearly a month long wait my Bee Prusa 3D printer has arrived.

I don’t blame The 3D Shop – who I purchased it from, as their stock was held up by customs.  Just the usual trials of international freight!  They did however keep me appraised of the situation, which was good.

I bought two rolls of filament to go with the printer (since it has two heads) – PLA and PVA.  PLA is mostly good for prototyping, or projects where structural strength of the plastic isn’t important.  PVA filament (yes, it’s the same as the glue!) is great for printing scaffolding.  If your design required support as it is laid down, then PVA is very convenient, once the print process is complete, then the object can be placed in warm water, and the PVA scaffolding simply dissolves away.  It’s very clever and one of the principal reasons that I opted for a twin head printer.

So, the next step is I need to complete my second generation photographic stage (complete with inbuilt LED lighting, mount for camera, power supply for 240V AC, 12V and 5V DC and more.  It’s going to be great and it will let me make a good clear film of the assembly process for the machine.

Invisible IR spotlight

Another old project that I recently dug up and want to complete is this REALLY powerful invisible infrared spotlight.

I chose 940 nanometer infrared LEDs for the job as they are completely invisible to the naked eye.  I should insert a WARNING here:

If you are thinking of replicating this project, you need to be aware that it is uncertain if very powerful IR light like this can damage the retina in the eyes of humans and animals.  Therefore, the best thing to do is to be cautious.  DON’T look into the IR beam directly.

DON’T point the beam at people or animals that are close.  No-one wants eye damage.  Safety first, last, always.

2016-08-07 17.02.59Building the spotlight was an interesting project.  It uses 304 infrared LEDs that emit infrared light in the 940 nanometer range.  The LEDs have a beam angle of 15 degrees, so the light is reasonably focused without needing a lens on the front of the unit.

It has a light sensor in it, so that it automatically turns on in low light conditions where a wildlife cam, or CCTV camera might need extra illumination.

I also added a fan to the enclosure as the density of the LEDs lead to a fair amount of heat being generated!

The power supply to the unit is 24 volts to keep the current draw down, so there is a 24 to 12 volt transformer in the housing as well to run the cooling fan.

Testing of the prototype went well, the LEDs are seriously bright and made for very effective illumination in total darkness.

ir-spotlight-casingI came across an old sketch that I made of the housing, so I thought I would add it in.  I have another set of  LEDs mounted and soldered in to another board to make a second unit one day, so it’s good to have the original housing drawing.  Note that the cooling fan ended up on the back of the unit rather than the top as suggested here.

I will post more about this project in due course.

3D printer has been ordered!

Update: the supplier expects to have stock in on Monday 15th.  So I should have a printer by the end of the week!

I came to the realisation that many of the projects that I am planning would benefit greatly from being able to 3D print parts (like cases for electronics).

To that end I have just ordered a Bee Prusa 3D printer from The 3D Printer in Melbourne (https://www.the3dprinter.com.au/) at a cost of AUD$958.  Note: the price of the same unit direct from the manufacturer is about AUD$200 less, however, the shipping cost from Europe was $250 approximately, so it made more sense to buy locally.

Why this machine?  A few reasons:

Cost – the Bee Prusa is very cheap for its capabilities (more on that later).  It’s equivalent to $3000 in functionality.

Self assemble – to sell so cheap, Bee leave out the assembly, which is fine by me.  I love to tinker and build and it will make for some interesting content to post here.

Functionality – the Bee Prusa has dual extruder heads, maximum head temperature of 300 degrees celcius, a heated platform, support for a very wide range of filaments, a large printing volume for it’s class (approx. 200mm cubed) and best of all a minimum print thickness for 20 microns (!).  Unless you are prepared to spend a LOT more money, you aren’t going to do better – at least on specs.

It also seems to have a good reputation for reliability and usability.  Time will tell on that front I guess, but I am optimistic.

Downsides are, no direct computer connection.  You have to put the file to be printed on an SD card and transfer the card to the machine (not a big problem really).  The bigger issue for the Bee Prusa is that it isn’t enclosed.

There are two problems with this.  The first is that hot plastic off gasses nasty smells which may be harmful – and should be ventilated!  The other problem is that without an enclosure the work piece can cool too quickly.  This can be a problem with some of the more exotic printing filaments as rapid cooling can lead to warping and inaccuracy (and even print failure I expect).

Some quick googling reveals that there is no inherent problem with fabricating a simple enclosure around the entire unit.  I will likely make something in clear acrylic and ideally add a small extractor fan to it to vent nasty gasses.

There’s a lot more to be said about the Bee Prusa, but I will save it for another post.