tiny holes postprocessing plug in

[JCD 28]

Here is a sample piece for this problem, a plate with a cylinder hole which diameter is small (2 -3 mm)

 

 

if you look at the preview slicing for the first layer below is the picture

 

there is a problem if the speed of the red circle outer wall is too high. The picture below give an idea of what would happen, the blue line .

The plastic , which in this place, is alone and not glued to the brim as the red square, will be dragged by the movement of the nozzle.

So the hole is very badly initiated,

 

 

One solution is to drastically lower down ( to 10mm/s for instance) the printing speed for the outer wall and inner wall during this kind of movement.

You have to do that only on the first layer, on the other layers, the printed filament sticks a lot better the plastic on the level below, than on the hot bed

 

This is what this plugIn does; reducing the printing speed on outer and inner walls on the first layer if the nozzle changes direction over very short distances (such as those made to make a circle)

 

The plugIn is realised with 2 files, to achieve 2 main goals

 

1) allow a debbugging process using stand alone Python with IDLE interpreter (I shall show it in a seperate post later)

2) create a script superclass to get all the mechanic to have the scripts follow the same process in the GCode file

 

For this you have 2 files, myScripts for the super script class and the script file here BottomTinyHolesSpeed1.py

 

Below a picture of the begining of the GCode file after post process

You can see that 2 scripts were executed (BLHWS1 which is this one and RPT1 which is a new version of the plug in I gave in another post)

I tried to launch twice the 2 plug ins and as they are designed to be launched only once the super script class manage it and write it in the GCode

 

 

Also, in the LAYER 0, which is the one on the hot bed, the script modify the printing speed in the walls of the tiny hole

 inside the red line the lower speed and in the blue line the older one

 

 

 

 

scripts.zip

Edited April 25, 2019 by JCD

[gr5 2,210]

So I have the opposite problem.  The bottom layer prints perfectly but the hole gets smaller as you move to higher layers.

 

You need to "squish" more.  You need the bed closer to the nozzle.  What kind of printer is this?  What kind of "leveling" procedure do you use?

 

More on getting the bottom layer to stick well:

 

[gr5 2,210]

As you can see in this picture - I printed a single layer only and the "P" in "Paul" for example came out exactly as desired.

[gr5 2,210]

Here is someone else who printed with the nozzle too far from the bed.  It barely stuck at all.  You are probably somewhere in between - not sticking well but not as bad as the below photo shows.  You can verify this by pushing the bed closer to the nozzle (if you have a cantilevered bed).

[alexjx 8]

I think this is a good idea. Though I agree that the root cause is the leveling. But for beginners to do a good leveling is difficult. Because it is not really a measurable thing. It requires quite a lot experience. So why not make the tool do more that we could get started. Instead of being frustrated and leave. 

[JCD 28]

I have an Anet A8, and I use the 'sheet of paper' method to level the bed, maybe once on ten times, but the dragged problem occurs even after calibrating (i do'nt print under 30mm/s for the 1st layer)

With the script everything's fine

 

If I remember, this capability to lower down the speed for tiny holes exist in some other slicing sofware