Help with..... "ghosting"???? Maybe...

[peirof]

Hi,

Not DUET related....

Since a few prints, I am having trouble with the surface finish of the prints.

In general the finish of the pieces is good but you can see what they call "ghosting" ....

This print its do it with: PLA (193/65), Speed 50 mm/s, layer height 0.1 mm

I attach the photos:

The issue is that from what I have read in google, it is a mechanical problem, in a Delta printer, possibly produced by the tension of the belts. At this point I have to say that my printer is modified, it is a Delta with movement by "linear guides" and steel reinforced belts, the white ones.

The issue is that I have checked the tension of the belts, by hand, and it gives me the feeling that they are tight, so the main question would be:

• Is there a way to give the belts the correct tension? and what would it be?

Another question that maybe was before:

The problem of the impressions, can have other causes that are not the tension of the belts? (I have also read something that if the printing speed is very high, it can also appear, but I print at 50 mm / s, which does not seem fast ...)

[Phaedrux]

@peirof said in Help with..... "ghosting"???? Maybe...:

steel reinforced belts, the white ones.

That may be part of your problem. I would suggest switching to a glass fiber reinforced belt instead. The white steel belts aren't great for printers. The pulleys we use are too tight a radius and the steel core strands can snap quickly and the belts stretch and act as springs.

[peirof]

But.... i dont know what happens....

Test i have do.... without touch the printer... i have printed a piece with this:

• PLA
• temp 195/65
  -Layer Height: 0.2 mmm (nozzle 0.4)
• Print Speed: 50 mm/s (but....)

With Duet Web Control.... start at 25% of speed, and i was raising, think remember that steps were these (25% / 50% / 75% /100% /125% / 150%)...
And the results are good, i can't see ghosting.... maybe its for the piece, the ghosting apears when they have to change of panel...

![cameringo_20200502_051854.jpg]

Only in this image i can see something similar in the foreground corner

In the top layer there is quality issues, think i was printing at 150% if speed..

Please.... what can be... the issue in the first piece?

[dc42]

Ghosting occurs when there is a sharp change in movement direction, for example a 90 degree corner. It's affected by jerk and acceleration settings.

RRF provides a mechanism to reduce ghosting at a single frequency. See https://duet3d.dozuki.com/Wiki/Gcode#Section_M593_Configure_Dynamic_Acceleration_Adjustment.

[peirof]

Its a pro parameter....

But.... How can know the frecuency?

[dc42]

@peirof said in Help with..... "ghosting"???? Maybe...:

Its a pro parameter....

But.... How can know the frecuency?

It's described in the M593 description.