Wobble help for tall, thin vase mode prints
I'm trying to print this telescoping sword for a Halloween costume, but I'm having trouble with wobble. The sword blade segments are tall, thin, PETG, and vase mode, so the wobble factor is high. I had to scale it down to 80% size to fit in the MK3's print volume and my kids' hands, but that also exacerbated the thinness. This seems to be a worst-case scenario for wobble, so I'm looking for any advice on how to get these printed straight and true.
Things I've done:
- As recommended by the print instructions, I setting the extrusion width to 0.8mm (w/ 0.4mm nozzle) for thicker, more stable walls.
- Added a wide brim (inner and outer) for extra adhesion and hopefully stability.
- Slowed down the print speed from default 45mm/s to:
- 35mm/s - helped a small amount
- 10mm/s - helped a medium amount
- 3mm/s - currently running, agonizingly slow, and I can already see some wobble starting around 70mm height.
- Surface stability: the printer is on a very heavy cabinet with no wobble.
Things I haven't done:
- Have not gradually decreased print speed with Z height. I tried, but I couldn't find a way to make the print speed slow down linearly with Z height in PrusaSlicer. I could only add one height range modifier, not multiple (is there a way?). I also tried multiple Slabs with speed settings but it was very tedious.
- Have not added supports, because vase mode.
- Have not tried more rigid filament like PLA, because it needs to be durable for dueling.
- Have not done any printer maintenance/calibration like checking belt tension, etc, because I'm not sure where to start.
That's the situation, and here are some pictures. The print is oriented like this:
This was the first print, at 45mm/s.
Close-up.
The slower print speeds diminished the problem somewhat, but it's still very noticeable.
Many thanks for any help!
RE: Wobble help for tall, thin vase mode prints
Update, I started going through the regular maintenance guide and found a scratch on the top X axis rod. I'm trying the print again in a part of the print bed that won't overlap with the scratch.
RE: Wobble help for tall, thin vase mode prints
I haven't tried that file but I did print an earlier model after giving in to pester power ... it lasted about three minutes so
it needs to be durable for dueling.
don't be too optimistic.
Sometimes a print wobble in a tall, thin part is exacerbated by resonance, a small change in speed, faster or slower, might be enough to de-tune the problem.
regular maintenance guide and found a scratch on the top X axis rod.
You may be able to rotate the rod by a few degrees, enough to move the rough spot away from the bearing point until you can do serious repairs. There is a possibility your linear bearing(s) is/are damaged as well as the rod but both are available as spares.
Cheerio,
RE: Wobble help for tall, thin vase mode prints
Thanks for your message, @diem. I have tried many different speeds, see the OP, and the difference was noticeable but minimal. The one thing I didn't try was going faster. After moving away from the scratched area, the print was much better. There's still a bit of wobble, but far less. I also discovered several similar scratches in other parts of the rod. Maybe dry or damaged bearings. 🙁
I'll replace the rod and clean or replace the bearings, add some new lubricant, and hopefully it'll be good as new. Thanks again @diem.