which rules? config.g vs slicer?

[Phaedrux]

Messing with it can be the best way to learn. That's why I like to live tune things while a print is happening. That way I can quickly switch between two values and watch it for a few layers to see how it affects things.

Same thing with the speed and extrusion factor adjustments to live tune speed and extrusion multiplier. Adjust the multiplier until things are looking right, then just multiply your sliced speed or extrusion multiplier by the tuned multiplier and you get a new value to put into the slicer that should give you what you want.

You can kind of think of jerk as a minimum speed value. The system will try and maintain that speed through direction changes and will accelerate and decelerate before and after those speeds. It can get very technical beyond that basic description. Junction deviate and curve profiles, etc. That's getting into the weeds a bit for our purposes.

[Phaedrux]

0_1536790117534_50mm rounded.stl

You can use this STL to further tune your extrusion multiplier in Slic3r, or flow multiplier as Cura calls it. Print it in vase mode with no top, no bottom, and 1 perimeter. It'll take a couple minutes. If you have a 0.4 nozzle slice it at 0.2 layer height and 0.4 extrusion width. It should print a single walled square cylinder. Measure the thickness of the walls with calipers.

Old extrusion multiplier * (Expected thickness/Measured thickness) = New extrusion multiplier

Beyond that, you can make finer adjustments with the extrusion multiplier in the DWC or Panel Due until your perimeters have no gaps between them, and your solid infill layers are nice and smooth with no gaps, and don't pile up into ridges.

[SupraGuy]

@opentoideas said in which rules? config.g vs slicer?:

The problem is that the tool carriage just is not solid enough and corners are not sharp.

Just jumping in here, but this doesn't loik like a problem with the tool carriage, this looks to me like "ringing" where the belts are allowing the print head to continue moving on intertia for a moment after the motors have told it to print a corner. Shortly after the change in direction, the nozzle gets dragged back to its center position, but the result is a ridge off of the edge of the corner. As you print higher, these appear as waves on flat surfaces immediately after a corner, typically on the left side of the flat surface.

Tightening belts can help with this, as well as making sure that there's little compliance in the belt holders where it moves the carriage or printer bed. Also, reducing moving mass will help reduce the inertial pulling the print nozzle past its target. If these things are not under control, no amount of reducing acceleration values will make it stop.

[Phaedrux]

@supraguy I think he actually has a damaged print carriage mount due to a previous head crash.

But totally agree about belts.

From the photo it's hard to see what vertical print surfaces look like. Also the high number of perimeters could be causing some over extrusion. Caused by the way that plastic gets dragged around corners and get pulled inward.

Start with 2 perimeters and increase from there. Usually no more than 5 for when you want a really durable mechanical part. Plus it's usually faster to just add more top or bottom solid layers, since the print speed can be consistently higher, due to not having to make constant direction changes like perimeters do.

[opentoideas]

@supraguy

I have been all through the mechanics of this machine while I am waiting for bits to improve things and belts are tight and everything is as solid as can be expected with the exception of the bed which as its only held badly in the center and has a flimsy mounting plate that has compliance that gets worse the further from the centre you move. the X carriage was also never designed to handle the additional weight of the direct drive extruder and the bottom wheel mount not only flexes but bends out of shape over time.

to be fair the standard head with bowden is so light that this would not have been an issue so I don't blame the machine but until I get the parts to try and correct this its what I have to work with.

whilst I can tighten things up by the end of a print (or sooner) the weight has deformed the tang that the wheel bolts to and I have to disassemble it straighten it out and start again. this is obviously less than ideal and wont work for long as the tang will fatigue but hopefully long enough to print the parts I will need for the alterations.

yes there is clear ringing on the X and Y faces, on the bottom gaps from under extrusion and other artifacts on all sides. I think Phaedrux is on the right track and I messed up the speeds.

@Phaedrux

since I am gaining quite a collection here are all of the faces

I think the bottom face cube its the last one I printed with more normal settings and I will give your numbers a try next. now you mention it I think I upped the perimeters to 4 to see if that would help which it didn't so I will set that back to 2

I am looking forward to playing with the settings more once I have the mechanical problems sorted out but while the machine is so loose I am conscious that it will be difficult to know which settings are making real differences and what is just the result of poor mechanics.(especially for a novice like me)

My plan is to go for "good enough" and design / find the parts I need and print them. once I complete the repairs and get the machine a bit more dialled in I can then reprint the parts if I am not happy with them.