Carbon fiber is the filler; the binder itself is usually what’s sensitive to the solvent, and that can be a wide variety of epoxies. So really depends on the manufacturer and application.
I tested a few things out with belt tensioning and squareness and while they do affect the VFA test a bit (sometimes the velocity at which VFA disappears goes up or down, sometimes it does not), none make it completely go away in the 100mm/s or lower regime. If you want to show your particular VFA problem, you must use SoftFever and run a VFA test. Prints are misleading as the slicer will dynamically change velocities throughout the print based on cooling, etc. My guess for the Facebook post is that the print happened to have outer velocities in the 100-150mm/s range, and slight changes in belt tension will in fact affect when VFA starts and stops, but not significantly.
Anyone here look into CoreXY printers other than the Bambu? I was planning on building my own before I got Bambus (definitely the better choice), and when I’ve looked into other CoreXY debugging forums, apparently it’s just a very common issue with this type of high speed printer. It kind of seems like there are going to be speeds that the motion system are better suited for, and the Bambu’s simply better at high speeds than it is at low speeds:
I also just got a brand new Bambu and it had exactly the same behavior. This might be either very common or just a characteristic of the Bambu / CoreXY printers. There are forbidden speed ranges for the compensated motion control system.
VFA general notes:
If you want to test / report VFA, use SoftFever and run the VFA test. Your surface speeds can vary wildly from part to part depending on slicer settings so a single print isn’t very useful
At high speeds (100-200+mm/s) the artifacts disappear. Print your outer perimeters faster if possible.
Prusa recently released Mk4 uses 0.9 degree steppers and marketed as to help remove VFA’s as seen on their Mk3 printers which use 1.8 degree steppers. Maybe this is something to consider. The belts on a core XY are rather long, maybe there’s some electric effect due to that and steppers will impart their vibrations through the belts?
I tried many different positions. Also the extreme ones far to the left and right. It doesn’t make any difference in my case.
Maybe input shaping is faulty. Is there any way to turn it off? Some undocumented gcode or MQTT request?
EDIT: Ok, I tried “M975 S0”. But again no difference.
Carbon bikes do not have bare carbon exposed to the outside. Most likely it’s about preserving prints and lacquer. Carbon fibers and epoxy they are made from shouldn’t be affected by IPA.
Right, but look at my picture. At that low speed, the VFA is awful. The suggestion to boost speed to avoid VFA is incompatible with printing shiny silk.
Have you already tried to simply place the printer on the ground for a testprint? Sometimes these kind of artifacts simply appear from a wobbly surface or resonance compensation feet.
I would test it right on the floor without any extra dampening and see if that helps.
I have really no clue of what are causing you this artifact, especially with PLA wich often works great.
Anyways I reallize that this thread have turned to talk only on VFA, that’s why you should open your own topic, and give as much information as you can in your first post.
About VFA, Prusa have resolved this problem (visible on MK3) ont their new MK4 by using 0.9° stepper motors, so maybe this is only related to stepper motors used in Bambu printer
Could it be that the better stepper motors are more expensive? I myself work in a company that manufactures frequency converters. Here, even with the smallest fan, every cent is turned over 3 times. The main thing is that the components are cheap and the margin increases. Surely it’s no different here in our case - the majority of customers are satisfied with the printer, so why should the manufacturer change anything?
Of course, I don’t know if that’s the case, but it seems reasonable to assume that it is.
