Using Slic3r with the Retractable Purge Mechanism

@vintagepc64

That's awesome! Thank you! I'm going to reference the link on the Thingiverse page too.

Why are the Codes for tool change in Thingiverse and here so different?

Posted by: @bigbrain3d

@vintagepc64

That's awesome! Thank you! I'm going to reference the link on the Thingiverse page too.

Awesome - I'd figured I'd already done the heavy lifting and math, so I might as well share. 

I also hope to re-enable wipe-to-infill and wipe-to-object support in the future, as well as port some other features I'd dabbled with - things that are easily doable when you don't have to respect the constraints of a purge tower, like a tool randomizer that inserted tool changes at random (but boundable) layer numbers, and filament dithering, where you get a pseudo-colour by alternating two colours on a series of adjacent layers.

@vintagepc64

Can you post a step by step manual with sample values and some pictures? 

This would be very nice.

Certainly once things are more stable, but not at this time; I would prefer to spend my available time getting the code up to snuff instead of writing copy that is likely to change as the code itself changes.

(sorry)

There isn't much to it currently, and the key steps are outlined in the readme on the github. Is there something specific that's unclear and I can address in short order?

@vintagepc64

Those are very interesting ideas. This will really help the community. Obviously, our hope is that this will replace the purge block completely someday and these features will help 🙂

@tobias-stegmiller

Probably just because this is a live thread and work in progress. With Thingiverse we need release updates but first they need to be demonstrated by the community to be the better way. It's great to have the feedback from dedicated users. We've been adding notes on Thingiverse to projects, such as these, so that users can find the information they need.

I have found a code that works for me. 

I didn’t changed the code so much. 

My problem is that the X Motor becomes very hot. I use only 2 of the springs. 

can I fix the issue with the heatness?

I played a litte bit with the M907 X.
Why do you take 800-850 and 650 for default?
I can't find 650 for default in the internet, but i found 540 for loud and 270 for silent mode?

I used 600 for the Blob and 540 for default yesterday. Now it takes much longer until the X Motor becomes hot. But its always to hot compared with the normal Purge Block.

The next thing is, that after the blob it makes a G1 E-0.8 F2100 retraction. 
Did you take this value because of the standard retraction settings of the PrusaSlicer?

@tobias-stegmiller

Recently another user (@jens-giesser) did some experimenting with the current values and found that what worked best for the High value was 450ma and for the Low value was 300ma. Prusa support also confirmed that 300ma is the default in the i3 firmware.  Here is the post about that.

We've update all the online instructions to include these new values.

@bigbrain3d
that sound very good. I will test it immediately tomorrow.

Now, it works nearly perfectly.
My X motor stays cool.

My problem is the color change is at the first 3 layers.
In Prusa Slicer i have changed the retraction for PLA to 1.5 mm.
In the code i changed the last G1 E-0.8 F2100 to G1 E-2 F2100.
At the first 3 Layers it looks like that my MK3s doesn't do the 1.5mm retraction.
After the 3rd. layer everthing looks perfekt.

Hi @vintagepc64,

I'm trying to test your post processing script now; though I admit to complete ineptitude on the subject of python.

I'm sure that I'm missing something simple but I cannot get the script to run. Would  you mind correcting my process?

Here are the steps I took:

1. installed python for windows 10 v3.8.1
2. inserted the exact line "BUCKET_X <256.65>" into the start gcode section in PrusaSlicer
3. inserted "T[next_extruder]; RPM FROM [previous_extruder]" into the on tool change section in PrusaSlicer
4. turned off the purge tower
5. sliced model
6. exported the gcode file "frog.gcode" to the same directory as python
7. copied unmodified "tower2RPM.py" script to the same directory as python
8. ran python.exe which opened a command window
9. ran this exact command "python tower2RPM.py [frog.gcode] > [frog2.gcode]"
10. got the attached error 'invalid syntax'

Any help would be appreciated! Thanks!!

Sorry for the confusion. Some of the brackets are meant to indicate placeholders. For example, the start gcode should not have them, e.g. 

; BUCKET_X 246.25

Similarly, the python command should not either. For example my command looks as follows:

python ~/eclipse-workspace/tower2bucket/tower2RPM.py 3_4_test_cubes.gcode > 3_4_test_out.gcode       

Note you should invoke python from a command window, not the python prompt. IIRC if you bring up a python prompt it is an interactive python session and you're expected to type python syntax. Just use the Windows command prompt.

I'd also suggest re-downloading the script, I just merged some improvements that fix how the purge is chunked into pieces.

Hope that helps!

I updated the readme with helpful images.