This is a modular rod that I plan to make the basis of several designs. It prints in vase mode, and the shape on both ends is essentially a screw with a very high pitch, with one end being slightly wider—about the width of your nozzle, or your line width—to allow the smaller end to screw and nest into the wider end. This design allows the rod to be visually continuous.
A solid mod rod is now available! You can print that one in PLA with a regular size nozzle.
This is meant to be used for props and decorations, and not for anything structural or weight-bearing. It is designed and tested to be printed in PETG with a larger nozzle. Various nozzle sizes and materials may work, but I've only tested this to be strong enough for my purposes with PETG and a 0.8mm nozzle (sliced to print at a 0.9mm line width.) (0.4mm with regular PLA definitely will be too fragile, but some PLA with a wider nozzle may be strong enough—if you test any sizes and materials, let me know!)
Why vase mode? Because 1) it's faster and uses less material, and 2) the continuous spiraling path means there are not clear planes of cleavage at every layer. And 3) it's hollow, so you have the option of, say, running a string of lights through it.
FYI: A standard nozzle is 0.4mm. This is designed to be printed with a larger nozzle, e.g. 0.8mm. It is possible some materials may be strong enough to work printed with a standard nozzle, but I haven't tested this at all.
How to Print:
- Spiral Vase Mode (with 0 bottom layers)
- PETG
- You're going to want the best layer adhesion and strength you can get, so aim higher in the filament's temperature range and use as little fan as possible, ideally 0%. If you need to adjust something for cooling, opt to slow the print speed down before adding fan.
- 0.8mm nozzle at 0.9mm line width
- Prusa Slicer, at least, usually slices vase mode prints to a bit wider than your nozzle size
- Because there are a range of nozzle sizes, I wanted to include versions of the rod for a range of offsets, although be aware that I have only test printed the 0.9mm version! In additional files, you can find a .zip file with versions of the model with offsets: 0.4mm-1.4mm and 2mm.
- For a 0.8mm nozzle, I've used an offset of 0.9mm as the difference in size between the smaller end and the larger end. There may be some range on the fit—0.8mm or 1mm might work slightly better, for example. So you can also try the different offsets if you have trouble with fit.
- 0 bottom layers
- UNLESS you are printing the rod that goes on the bottom, and don't plan to use any sort of decorative finial
- If you want a bit more strength or have trouble with bed adhesion, you can also choose to print with bottom layers; I recommend doing this with a more opaque filament. Be sure you aren't planning to run lights or other decorative elements through the rod first. Also look out for elephant's foot on the first layer, which may get in the way of fit.
- 18cm tall
- The .stl file is already oriented correctly. It prints with the smaller end at the bottom, because that's the end you may choose to have some bottom layers on, as well as the end you can get away with accidentally printing bottom layers on. :P
- Do not: manually adjust size without writing down exactly what you did; mirror anything unless you are going to mirror everything. These sorts of adjustments will make the rod incompatible with the baseline rod, and with unaltered attachments.
- If you're uncertain what offset size you need, I have also included a .zip file of 2.5cm tall offset sizing testers, plus a 2.5cm tall example of the small end. The small end is always the same size.
Assembly
- Carefully screw the smaller end of one rod into the larger end of another. Make sure the shape is aligned and it should go without too much trouble, but don't force it.
- The larger/outside end of the rod faces up; if you're printing a topper, it will fit into the larger end.
- The overlap of the rods can vary depending on fit, but you'll get about 15-16cm of length per rod, added onto the original 18cm.
Also in the files I've uploaded:
- a range of offsets for a 16cm version if you need something a bit shorter
- A big-to-big converter, either 18cm or 7cm, wherein the entire rod is the size of the bigger end. This will allow you to attach a bottom finial, or a topper design at both ends.
New to vase mode or still learning?
- Spiral vase mode takes the outside wall of a solid, continuous model and calculates a continuous single spiraling path to print to the top.
- In Prusa slicer, this is the “Spiral vase” option you can check off in Print Settings > Layers and Perimeters. It will automatically change several of your settings to be compatible with the mode.
- In Cura slicer: Special Modes > Spiralize Outer Contour
- To get a good vase mode print, you'll want to refine a couple more settings. IMO you should test settings for each filament, as well as for different layer heights, to determine a temperature, extrusion %, and speed (if the speed hasn't been slowed down automatically) to get a nice, clean vase mode print with that filament. Too much extrusion will get you tiny bumps around your print; too little can make it too fragile and prone to cracking between layers. With PETG, I've had the best results printing at a higher temperature for strength, and turning the fan off or keeping it as low as possible.
- If you're still getting bumps: especially if you're on a more basic machine like an Ender 3, it may be a matter of computing and RAM, and your printer having tiny moments where it pauses. Fixes include using a faster microSD, being hardwired to the printer if you usually use OctoPrint, or upgrading your firmware (this is what worked for me) with options including arc calculation (marlin 2.0 and on), disallowing the printer from writing to the SD card, and turning off the power failure recovery mode. (The latter is very useful but may cause those little pauses with a big file.)
lytta
