Printing
From Wiki
Copied from Tony's blogpost at http://rapmanv3.blogspot.com/2009/05/printing_08.html and edited a little bit. Tony's words: I don't suggest that the following notes are the definitive guide but they should give you decent results on the V3 machine. Try the techniques and please give feedback as there is no actual substitute for the experience gained from use of the machine.
The RapMan has been used with reasonable success on several materials, each has its own little quirks needed to get the best out of them. Tested so far: PCL, PLA, PP, HDPE & ABS (several types).
These notes describe printing with ABS, this is one of the easier materials to work with and probably the most popular choice for RP parts. Please follow the Setting up the Cartesian Robot & Setting up the Extruder tutorial before attempting to print anything. This will ensure you have a nice square, free running machine with a fully functioning extruder. So now we can run off perfect prints, right?
Well, the answer is yes and no. You may be lucky and produce some very sharp prints from the off but the chances are that the results will be variable.
Contents |
Your first print object
Tradition states you print off a mimimug. This is not a bad one to try first, its small therefore prints quite quickly, it has a flat base with thin(ish) walls so you get to see how the machine behaves.
Prepare for printing
Print bed used for ABS is usually made out of acrylic. First thing you might want to do is break the surface of the acrylic, the high gloss finish of fresh acrylic enables the ABS to stick so well you may have trouble removing your finished object from the print bed. Try using the edge of a Stanley knife blade. Drag it over the print area sideways, all you are trying to do is frost the printing surface a little.
Test your machine
Most prints start with a raft. The purpose of printing a raft is to create an accurate bed on which to build your object. The acrylic table may have debris stuck to it from previous printing, it may be slightly warped or even as you get a few hours on the machine form thermal cracks in the surface. The raft removes any chance of these faults spoiling the print. It also serves another purpose, it holds your print firm during the build, this is especially important as any warping mid build would render the object dimensionally inaccurate or void the whole print. On several occasions prints have been lost through warping sometimes hours into the build, this is no joke!
So the raft needs to be flat and stuck down well to the table.
Start the test object, observe the machine home then move over to the rest position while the extruder warms up. When it is up to temperature, the motor starts and the extruder moves over to the print site. As the raft pattern begins notice how the filament is deposited on the table. A round filament will hardly adhere to the table at all, in fact it will probably lift off before you get to the end of the raft. On the other hand if the nozzle is skating across the surface of the acrylic and only the faintest smear of plastic is laid down. This will cause unnecessary strain on the extruder and you will probably find the filament skips. What you are looking for is something halfway between, a nice fat track maybe double the filament thickness. This will adhere to the table well and serve as a good bed for subsequent layers.
Once you have printed a few objects you will soon find what sticks and what does not.
Observe the RapMan print the rest of your object
Watch RapMan build your object layer by layer.
Removal of the object
The easiest way to remove object from the print bed is to slide a flat blade under the raft and work all the way round, chances are the object will pop off before you are finished. Alternatively if the object remains stubbornly fixed to the table. Push the blade as far as you can under one edge, then get a flat bladed screwdriver and use it to push the back of the blade. If you do this please take care with the blade! Tip: mark the X axis orientation on the print with a felt tip pen.
You now have your first minimug off the printer. If your print was successful, congratulations and have a toast! If your print came out less then perfect check the common print faults page
