Printing collapsible lightsabers and swords
Each sword/lightsaber typically has three types of designs
- Print-in-place; Prints once, all as one part.
- Removable Blade; The hilt prints in multiple parts so the blade print separately and inserted at assembly. This allows a broken blade segment to be replaced.
- Dual Extrusion; This model has been separated into two parts for a multiple color printer.
Additional supports are not used on any of my original lightsaber or sword designs. There are a couple models that have built in supports but they are very small and you don’t need to turn on supports in your slicer. Infill or perimeters is not important because the walls are so thin, I set it at 2 walls 15% infill. I print all my hilts with a .4mm nozzle at .2mm layer heights. Higher layer heights and larger nozzles may work at your own discretion as I have not tired it yet.
The blades can be printed concentrically as an assembly or individually in vase mode. Personally I prefer printing the blades in vase mode. Its more work in the slicer but the result is much nicer and easier to achieve. You wont have a layer seam and it may even be a bit stronger. Vase mode makes it easier to troubleshoot and fine tune since you are printing the blades individually with no seam.
If printing in vase mode, there is a stl for each blade. The vase mode files are solid, this is so your slicer knows not to print an internal perimeter. If printing at 100% scale, set the line width to .90mm. Print the hilt and the last two blade segments first. This will allow you to test the last blade in the hilt and the two blades together. If the blades don't catch, bump your line width up .2mm or so. If they catch too soon, reduce the line width. The blade should overlap about 50mm.
Top and Bottom Layers
Turn the top and bottom layers off for every blade segment except the first, you want top layers on the tip of the blade.
I normally print blades with a .4mm nozzle and .25mm layer height but a bigger nozzle and higher layer heights can be used. Just note to run slow because the blade diameters are small so you will need lots of cooling.
When scaling also scale the line width by the same amount. So If I want to print at 50% scale, instead of a line width of .9mm, I would set a line with of .45mm. Depending on the scaling, you may have to switch to a larger or smaller nozzle.
If you plan to print concentrically, a single stl contains all the blades. When printing the blades concentrically use a .4mm nozzle and set the line width to .43 so the blades are two shell thick. This print is sensitive to the layer seam, first layer, and extruder calibration. It’s a good idea to make sure your setting are tuned so the blades don’t fuse if using this method.
Before printing the blade assembly perform the test print first. If you can print it with NOTHING attaching the rings together, then you should be able to successfully print the full sword. The test print is a total of 24mm high so I change settings every 8mm(3x) then compare the changes until I achieve the best result. The settings that will have the most impact are; flowrate, retraction distance/speed, coast, wipe, and extra restart distance. You may also try; seam location, speed, temperature, and z-hop.
Each printer is going to be different but in the case of my rep-rap printers I use a negative “extra restart” distance to reduce the size of the layer seam. For my MK3, tuning coast and wipe settings helped a lot.
Note: if your test print sticks only at the first layer that is a because your first layer is to low causing “elephants foot”.Scaling
You can scale up in concentric mode but you cant scale down unless you switch your nozzle so it is at least half the thickness of the wall(.85mm). For example, if you want a 75% scale blade, use a .3mm nozzle.
Question and Answers
Q. Why did my print Fuse?
A1. Only on the first layer- Check your first layer height.
A2. Only on the layer seams- Tune the test print, look at retraction settings.
A3. All around- Calibrate Extruder. Tune test print, look at flow rate or “horizontal size compensation”
Q Why don’t my blades interlock correctly when printing in vase mode.
A1. Too loose- Increase your “intrusion width.
A2. Too tight- Decrease you “line width”, or check for elephants foot.
Q. Why are the vase mode files not hollow?
A. So the slicer knows not to make a inner perimeter.
Q. Why is my pommel breaking?
A. Add more top and bottom layers.
Q. Do I need to change my nozzle to print in vase mode?
A. Nope, a .4mm nozzle can print a .85mm line width fine in vase mode.
Q. What material is best?
A. PLA or PETG might be marginally more durable.