How to choose, buy and assemble a 3D printer?

blog_3d_assembled

‘Hell yeah, let’s get a 3D printer kit!’ – Wait a minute, not so fast… what kinds are there? Which ones are the best? Which ones are available as kit? This post is the story of my introduction into 3d-land!

The Kit

blog_3d_kit
After looking around I decided i wanted a simple 3 axis Prusa I3 printer, but not a single sheet frame (which is not as good as the ones with extra support), and build with quality parts. Finally my eye fell on the Makerfarm Prusa I3 kit. They came in 6″ and 8″. Bigger is not always better, but the same calibration fault on a bigger distance is a smaller calibration fault per distance unit… so in fact bigger is better in this case 😉 It had a plywood lasered frame, which is light, easy to drill and strong enough. The only disadvantage was that it needed to be shipped from the USA to Europe, which results in extra taxes when it passes the customs. Since i did not find a complete identical kit over here and there were video manual available to assemble the kit I decided to throw my money at Makerfarm, which I do not regret at all!

Extras

blog_3d_extra

The kit was complete except from a power supply and glass plate to put on the heath bed. And well… without any filament there’s no fun at all. I also bought a role of wide kapton tape to put on the glass plate because that helps keeping ABS parts to stick to the surface better.

Assembly

Laser cut plywood fits perfectly, everything needed was in the kit. Guided by excellent video tutorials it was assembled in about 2,5 hour. It reminded me at the Lego Technic I played with a lot when I was younger…

First tests

blog_first

The first thing you want to do is making sure your end stops work. Manually move the printer head and press the endstop it could hit in that direction. The head should stop! Repeat for all axes. Then let the extruder run idle for a while to make sure the cogs work nicely together. Tighten the gap between after it has run for a while. Do the same for the belt-driven parts. Tighten it up a bit, run it a couple of times over the full range, then tighten more if needed. Then the big moment comes, printing your first object! Mine was a very small companion cube (from the game Portal) taken from Thingiverse.
Unexpected remarkable good prints with default settings!

Best practices

Use all anti-warp tricks you can use for printing ABS!
Temperature vs layer time is important. When the area varies a lot and gets small the part may overheat and warp on those layers. Printing multiple parts at once solves this problem, but I advise to do that only with designs that you have successfully printed before.
Layer height defines how fine and smooth the outer shell of your parts will be. Lower layers give better results but take longer to print and overhang will be more difficult. I print between 0.15 and 0.3mm layer height with my 0,4mm nozzle.

Improvements

Since the frame will be ripped apart when driven beyond limits, an extra Z end stop is certainly not a bad idea! My firmware had it enabled (altough it should not) out of the box so I only had to add a switch and plug in the wires to the board.
I used a teflon hose (used to build bowden extruders) from my filament spool holder to my extruder. This makes sure the filament doesn’t get stuck somewhere and I can move around the spool holder as much as I want without disturbing the print.
Bed leveling and z-axis end stop definitely need updates afterwards…

Maintenance

The Z-axis end stop needs recalibration from time to time. Keep in mind that it comes closer to the heath bed when it is hot, so cold-calibrate it with a sheet of paper in between, not against the glass plate.
As any mechanical device, it needs to be oiled. Use oil with a thickness of the oil you put in your car. Do not use thick grease or very thin oil. Grease will not work for the tiny axial bearings and thin oil wil drip right off! Move all axes while oiling to spread it even and get some oil in the bearings and on all threads of the Z-axis stepper rod. Preferably you put a towel or plastic sac over it when you are not using it to prevent dust. I put a sheet of paper on the heathbed when it’s cold to prevent dust and non-sticky prints and that seems to work great! Bed leveling should also be checked often since it can change easily when touching the heathbed or guiding mechanism. Always check if the first layer is evenly spread, else stop the print and level your bed! (and recalibrate Z end stop afterwards!)

Final toughts

3D printer kits are nice if you know how to handle tools, you have what our german friends call ‘Fingerspitzengefuhl’ and you like to experiment and have patience. If you want to print with something that just comes out of the box an plug into your computer like a regular inktjet- or laserprinter then you better double your budget and search for a smaller, fully assembled and calibrated printer.

Leave a Reply

Your email address will not be published. Required fields are marked *