PETG takes too long…
Hello everyone!
I find that the start of a print is too long with PETG. I measured it, and the printer takes exactly 16 minutes before starting the print. Do you have any suggestions to improve the startup time?
Thanks for your replies! 🙂
RE: PETG takes too long…
Hello.
It depends on how familiar you are with your printer and how well you understand what the G-code does at the beginning and why.
For example, I made some adjustments and removed the nozzle cleaning. Instead, I installed a brush.
The G-code in the slicer was also adjusted.
https://www.printables.com/model/1565570-prusa-core-one-nozzle-wiper-remix-with-steel-brush
Mods for Core One: Core One HT 450 degrees, Comfortable display , Very fast print start and Reducing noises
Mods for Prusa XL: Very fast print start
RE: PETG takes too long…
My nozzle is always clean—I always make sure it is—but the printer stays in ‘standby’ and I’m not really sure why. Yes, it heats up, but I think it does the bed first and then the nozzle… anyway! It takes 15 minutes before starting, and I feel like there’s room for improvement… way too long!
RE:
Yes, you may need to edit the G-code startup sequence. See links above ("very fast print start"). Some experimentation may pay off (high risk high reward - failure is part of the game but you may e.g. need to unclog a nozzle, clean up an extruder or fight Spaghetti monsters).
Looking back on my Core One experience (learning-by-doing, test prints typically as small as possible to save time), the excessive startup time stands high on my list of "lessons learned / things to avoid next time".
It's one of the things I appreciate on my Klipper printer - it responds immediately (with nozzle and bed at temperature): Hit the button, upload complete, head starts moving, purge and here we go. In some cases e.g. Z layer test chips there is basically no perceptible delay.
The price is, no more hand-holding - managing bed meshing is my responsibility now. Swap the sheet for a thicker one without telling the printer, and it'll venture into "subtractive" CNC machining ... for entertainment value, I should maybe post a picture of that "formerly" smooth PEI plate 🙂
RE: PETG takes too long…
I don’t have this issue with PLA, and my MK3S+ is much faster to start a print… much faster, actually!
RE:
MK3S has an inductive probe for bed meshing, correct? Core one uses nozzle touch but that requires parts to be at temperature, or thermal expansion causes offsets.
I'm not familiar with MK3S but Core one first heating up to print temperature for loading filament, then cooling down for probing (to not melt holes into the sheet) then heating up again for the print takes time. As said, it's largely under your control if you run your own startup G-code and understand its implications.
RE: PETG takes too long…
You don't need to do a heat soak for smaller parts. In the start g-code section look for G29 G and replace it with this which will skip the heat soak based on the print area.
; ── Bed Heat Soak ───────────────────────────────────────────────
; Allow bed to thermally stabilize before MBL so the mesh reflects
; the bed's true expanded state.
;
; Tuning variables:
; heat_soak_area — area threshold in mm² (default 100×100mm = 10,000mm²)
; small_print_dwell — dwell time in seconds for small prints
;
{local print_w = first_layer_print_max[0] - first_layer_print_min[0]}
{local print_h = first_layer_print_max[1] - first_layer_print_min[1]}
{local heat_soak_area = 10000} ; threshold: 100×100mm
{local small_print_dwell = 10} ; short dwell in seconds for small prints
{if print_w * print_h < heat_soak_area}
G4 S{small_print_dwell} ; small print — short dwell sufficient
{else}
G29 G ; large print — full bed stabilization wait
{endif}
RE: PETG takes too long…
Hello everyone!
I find that the start of a print is too long with PETG. I measured it, and the printer takes exactly 16 minutes before starting the print. Do you have any suggestions to improve the startup time?
Thanks for your replies! 🙂
I don’t have this issue with PLA, and my MK3S+ is much faster to start a print… much faster, actually!
With modern CoreXY printers like the Core One, the heat soak matters for larger prints and for warp-prone engineering materials. As the bed and chamber come up to temperature, the bed plate expands in XY and the Z components grow vertically. Letting that stabilize before probing keeps the mesh accurate. Skip it and the first layer can be off enough to cause warping or parts lifting off the plate.
Generally though for PETG and PLA that have strong bed adhesion, you can usually skip this step.
RE: PETG takes too long…
For small prints my MK3S was definitely faster, though its quite convenient to start printing without having to go out to the garage. But if Im there and just printing something small i skip the soaking period, it doesnt seem to affect small prints noticeably. Would have been nice if it could be skipped remotely aswell.