Yes, the 3D printer is working, and has actually managed to print its first object. But more on that in a bit. First, a bit more of a look at the printer itself.
The printer is a RigidBot, and was purchased through a Kickstarter project. It took a lot longer to arrive than was originally anticipated, and there was certainly some angst on the way. However, it finally arrived, and wasn’t too hard to assemble (despite the instruction manual). There is a Google+ community which are very supportive, and a great source of advise on the machine, and printing in general.
The printer has a 10″x10″x10″ build area, so can make some pretty significant objects. It could be scaled up if I ever wanted to (not that I am likely to). It has a dual extruder which allows it to print two colours simultaneously (or two different materials) It is primarily designed to print PLA and ABS plastics with the extruders that it came with. These may get upgraded at some stage, depending on how well it behaves!
Bit of a view of the printer head, otherwise (and more commonly known as) the extruder. It consists of a stepper motor that draws the plastic in and down into a PTFE tube that leads to the nozzle. The nozzle is heated to around 200C (depending on the specific material – 195C-210C or so for PLA, and around 230C for ABS). That is heated by an element – these are at the end of the red leads in the image above. There is also a thermocouple attached to the same block, to accurately control the temp.
This the X and Z axis motors – the Z axis has the threaded rod. The X axis is controlled with a belt attached to the print head. On the right hand rod, you can see one of the limit switches, which is used by the control software to zero the location of the head.
The Z axis has two motors working in tandem – this has its good points and its bad points (when one jambs!). I have taken to using a dry machine lubricant (with PTFE) on the shafts and threads, which has made a lot of difference.
The extruder head only moves along the X axis (and the rails it is on are raised and lowered by the Z axis). To get the Y axis, the platform that the print is made on also moves (this view is from underneath).
The green board is the heater element, allowing the base to be heated to 40-110C or so to aid adherence, and prevent warpage (especially of ABS).
View underneath the extruder, showing the two 0.4mm nozzles.
Another view of one of the nozzles, the heating element (with red wires), and the thermocouple (wires passing into the hex connector).
The first print run went well for a time – a little robot figure, but it didn’t have a head! Took a while to work out why (and with advice from a forum member). Turned out the default temperature setting in Cura (a slicing/printing program) was too high, so the filament melted before it should have, causing a blockage.
The next attempt worked well, printing at 60mm/s, 195C with 0.2mm per layer.
I haven’t been able to repeat the result, as the next few prints detached from the bed partway through the print. The recommended blue tape is not working in this case, even when I tried another suggestion which involved hair spray, so I’ve ordered something more appropriate for the task – some polyamide tape, and some vinyl bed tape – either should make a lot of difference.
A few initial teething problems, but we’ll get through those. I’m sure there will never be a time when the system is perfectly reliable – it will always need some tweaks and mods. At least it is an interesting learning curve!
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