Welcome to the SeeMeCNC Community

Hey folks.

First I was wondering if there is an area for uploaded settings for the Rostock Max that work great?
It's like everyone is trying to reinvent the wheel in a way and it's very time consuming testing print after print.

Some models that are solid I can print fairly well, but anything FLAT comes out very bad and ratty as in my pic of the 2 right items.

The first layers print very smooth when solid, but why would an item sliced print the final layers so badly?
Here is a pic.
Is there a way to force the final few layers to be printed as fine as possible to get a good surface?

As usual it's probably something I'm doing or not doing.
many thanks in advance

truenorthtrader, firstly, you would need to list the software chain you are using - firmware, host, slicer. Each is different and has different parameters.

However, in looking at your photo I can make a few observations:

1) the item on the left is different than the 2 on the right in that you are looking at the perimeter of the print whereas the other 2 you are looking down into the filling. I bet the perimeters on those 2 look decent too.
2) the infill on the 2 on the right is not complete, it doesn't touch the inside and outside perimeters, etc. This looks more like a calibration issue (filament diameter measured? and set in your slicer? temperatures? material type? extruder calibrated? all the usual suspects.

How do the first 2-3 layers look as they are printing and afterwards?

It is hard to tell for sure but it looks like maybe a little backlash - I am looking at the gaps between fill and perimeter on the right most part. It seems the gap is larger at the left than at the right - in particular the bottom "point". Check your carriages for backlash. You can also measure it with a dial or test indicator if you have one.

Good luck and report back!

Largely agree with mhackney.
My other observations would be that the top down prints seem to have a couple of locations where the solid infill has broken when trying to bridge over the sparse infill.
This is usually a combination of two things, too little plastic, causing it to stretch excessively and break, or insufficient cooling in which case the head starts to drag the in fill backwards and forwards before the top layer is printed.

It should be noted that backlash on a delta printer sould be measured towards/away from the towers, not in X/Y like a conventional printer.

Simple calibration objects are also much easier to diagnose IMO.

Thank you guys !

I checked my cheapskates last night seemed ok but I retightened everything to make sure everything is seated without movement.
Recalibrated again from the beginning to PID Autotune printed again, same results

I then increased the Infil to 50% instead of the 20% it was a tad better

The beginning looks great, first few layers going down well but always ends up ratty.

The middle item has a sunken line around the edge and around the middle circle but the far right object should be perfectly flat and smooth.

Using Repetier-Host Mac 0.53
Here is the G Code to see my settings. I've messed with a few things each print but get the same results.
Note i'm using the fine Nozzle .368 size

I'm including the .stl file of this a free file if anyone can see anything in it that needs specific settings. I scaled it to 50 as it's really small
I used this one as less plastic is needed.

; generated by Slic3r 0.9.8 on 2013-02-11 at 13:14:10

; layer_height = 0.2
; perimeters = 3
; top_solid_layers = 3
; bottom_solid_layers = 3
; fill_density = 0.5
; perimeter_speed = 30
; infill_speed = 30
; travel_speed = 200
; scale = 1
; nozzle_diameter = .368
; filament_diameter = 1.9
; extrusion_multiplier = 0.9
; perimeters extrusion width = 0.57mm
; infill extrusion width = 0.57mm
; support material extrusion width = 0.57mm
; first layer extrusion width = 0.39mm

M107
M190 S65 ; wait for bed temperature to be reached
M104 S210 ; set temperature
G28
G1 Z300 F7500
M109 S210 ; wait for temperature to be reached
G90 ; use absolute coordinates
G21 ; set units to millimeters
G92 E0
M82 ; use absolute distances for extrusion
G1 F3300.000 E-2.00000
G92 E0

The only two odd things I see is the filament diameter but it could be that large (mine has always been 1.75 or a little smaller) and the temperature. I noted on my build thread a big difference in temp measured at the nozzle and at the barrel. This is different than the earlier hot end designs (or at least seems to be different).

I have finally got my printer printing and my first print - a calibration cube - is showing some of the same symptoms as you are seeing. I am using a .05mm nozzle.

Don't gorget to check/tighten the pulley set screws too! Mine were slipping slightly on acceleration, leading to all sorts of inexplicable problems!

mhackney wrote:Don't gorget to check/tighten the pulley set screws too! Mine were slipping slightly on acceleration, leading to all sorts of inexplicable problems!

Yep I had this issue when I started out and didn't track it down until one of the set screws fell out of the pulley.
I would strongly recommend the use of loctite or other thread locker on them.

Loctite applied. I use it on everything!