Print Speed and Travel Speed

[changedsoul 2]

Its my understanding Travel Speed is the speed at which the printer moves from one point to the other while not print. I would only assume then, the Travel Acceleration would be tied to the Travel Speed, and the Print Acceleration would be tied to Print Speed.

I deliberately turned down my Print acceleration to control ringing and ghosting. I still want it to rapid quite fast when not printing though.

When seems to be happening though is Cura ignores the Travel Acceleration value and uses the Print Acceleration for both Print and acceleration.

Can someone verify this is so? Possibly a code error that can be fixed in the next release?

[DaHai8 72]

Could also be the jerk settings causing ringing

[changedsoul 2]

Could also be the jerk settings causing ringing

 

I appreciate the comment, but this is not what I was asking. I wanted to know why the Travel Acceleration seems to have no effect.

[neotko 1,413]

Why would travel acceleration have any effect on ringing? As soon it stops at jerk speed and resumes printing, the time from recovering the extrusion (since in theory when moving form a to b it should have retract) then the vibrations from the travel-non-print move shouldn't affect the print. Disable retractions completely and then this changes ofc.

Print speed Print acceleration and jerk are the ones responsible for the ringing. Ofc the real responsable is the thin shafts, the heavy printhead, the bowden shaking, the motors noise, the rigidity of the frame, the viscosity of the material, how fast/slow colds... But that's not what you asked.

Short answer. Travel speed for non print moves, doesn't affect ringing unless you don't use retractions.

If you want to learn about ringing and tests you can check this very old, post

https://ultimaker.com/en/community/3532-prevent-ringing-wobbly-surface-after-sharp-corners

Also if you remove ringing, lowering jerk to a very low speed you will have side effects. Like you can read here

https://printedsolid.com/blogs/news/a-solid-foundation-for-high-quality-corners

[DaHai8 72]

 

Could also be the jerk settings causing ringing

 

I appreciate the comment, but this is not what I was asking. I wanted to know why the Travel Acceleration seems to have no effect.

 

...uh, because it may be that Travel Acceleration is not causing the ringing, Jerk is...

[changedsoul 2]

..uh, because it may be that Travel Acceleration is not causing the ringing, Jerk is...

Why would travel acceleration have any effect on ringing?

...UH, ok well it seems you guys have completely missed my original question.

Ignoring why I was adjusting the Print and Travel Acceleration completely, I just like to play with settings(this will by my new reason ok?).

Adjusting Travel Acceleration has no effect while printing. When rapiding to a location, Cura still uses the Print Acceleration Setting.

[neotko 1,413]

Again. Acceleration is a firmware/marlin/gcode setting./command

What could be happening is that they ain't sending the correct gcode to change print/travel setting and they just adjust print. You could see that by opening the gcode and reading how they do the M205 etcetc to see if it does what you want to do.

Doing some google seems the issue is marked for 2.7

https://github.com/Ultimaker/Cura/issues/2032

[changedsoul 2]

OK, I see the M204 commands in the code. Maybe they are being applied in the wrong locations? I see M204 for both values of Print and Travel acceleration.

Seems Marlin has indeed changed their use of M204. I will wait for later releases of Cura to see if these updates are applied.

Thanks for the help.