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G Code question - Modify wipe?  

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lurc
 lurc
(@lurc)
Active Member
G Code question - Modify wipe?

Is it possible to modify the wipe that the printer does immediately before printing?

As my printer comes to temperature it tends to produce a blob of filament. As it moves straight down right before the wipe, that blob gets pushed up into the nozzle. Often that blob ends up hanging on long enough to make it to the print. I'd like to change the wipe so that as the head is moving down it has already started to move sideways. This way the blob might begin to grab the sheet and get spread out into that wipe, instead of hanging onto my nozzle.

I see this in the start G code but honestly not sure where to start as I don't speak g code:

; intro line

G1 X170 F1000G1

Z0.2 F720

G1 X110.0 E8.0 F900

G1 X40.0 E10.0 F700

G92 E0.0

 

Any help is most appreciated!

Posted : 02/02/2022 2:43 am
Bob
 Bob
(@bob-2)
Reputable Member
RE: G Code question - Modify wipe?

I keep a pair of tweezers next to my printer.  As it approaches temperature I pluck off the strand.  Since it's a wise idea to watch your first layer or two this suits me.

Cheers

-Bob

Prusa I3 Mk2 kit upgraded to Mk2.5s, Ender3 with many mods, Prusa Mini kit with Bondtech heat break, Prusa I3 Mk3s+ kit

Posted : 02/02/2022 2:57 am
lurc
 lurc
(@lurc)
Active Member
Topic starter answered:
RE:

I do cut off any remaining bits from the prior print.

I'm not fast enough to reach in with a pair of tweezers and cleanly grab a blob of filament in the couple of seconds that the temp causes the blob. It's also too low for me to see the back side.

 

Maybe if it were a little higher I could?

Is it possible to tweak to code to have it start off higher?

This post was modified 3 years ago by lurc
Posted : 02/02/2022 3:18 am
Diem
 Diem
(@diem)
Illustrious Member

For anything that is going to matter I wipe the nozzle with a fragment of filament as the extruder starts moving.  Just use a scrap from a previous unload, it sticks to the dangle, if present, really well.

Cheerio,

Posted : 02/02/2022 9:51 am
lurc
 lurc
(@lurc)
Active Member
Topic starter answered:
RE:

 

Posted by: @diem

For anything that is going to matter I wipe the nozzle with a fragment of filament as the extruder starts moving.  Just use a scrap from a previous unload, it sticks to the dangle, if present, really well.

Cheerio,

I tried that using a previous wipe line and it's difficult, but yes, it does work a little better (for me) than trying to grab with tweezers.

It would be "really easy" if I could have it do the warmup from a higher position. So I'd still like to know how to get it to come up to temp for the wipe line from say 10mm higher.

So if anyone can help me with that, I would appreciate it.

This post was modified 3 years ago by lurc
Posted : 02/02/2022 2:58 pm
lurc
 lurc
(@lurc)
Active Member
Topic starter answered:
RE:

I think I have answered my own question by learning a bit of G-code. But the movement is boxy and I would prefer for it to be a smooth arc of some sort. I will keep refining it until I have a solution, but for now, I modified the original G Code from this:

G90 ; use absolute coordinates
M83 ; extruder relative mode
M104 S170 ; set extruder temp for bed leveling
M140 S[first_layer_bed_temperature] ; set bed temp
M109 R170 ; wait for bed leveling temp
M190 S[first_layer_bed_temperature] ; wait for bed temp
G28 ; home all without mesh bed level
G29 ; mesh bed leveling 
M104 S[first_layer_temperature] ; set extruder temp
G92 E0.0
G1 Y-2.0 X179 F2400
G1 Z3 F720
M109 S[first_layer_temperature] ; wait for extruder temp

; intro line
G1 X170 F1000
G1 Z0.2 F720
G1 X110.0 E8.0 F900
G1 X40.0 E10.0 F700
G92 E0.0

M221 S95 ; set flow

 

To this:

G90 ; use absolute coordinates
M83 ; extruder relative mode
M104 S170 ; set extruder temp for bed leveling
M140 S[first_layer_bed_temperature] ; set bed temp
M109 R170 ; wait for bed leveling temp
M190 S[first_layer_bed_temperature] ; wait for bed temp
G28 ; home all without mesh bed level
G29 ; mesh bed leveling 
M104 S[first_layer_temperature] ; set extruder temp
G92 E0.0
G1 Y-2.0 X179 F2400
G1 Z15 F720
M109 S[first_layer_temperature] ; wait for extruder temp

; intro line
G1 X170 F1000
G1 Z8 F720
G1 X165.0 E8.0 F900
G1 Z8 F720
G1 X160.0 E8.0 F900
G1 Z4 F720
G1 X155.0 E8.0 F900
G1 Z2 F720
G1 X150.0 E8.0 F900
G1 Z0.2 F720
G1 X110.0 E8.0 F900
G1 X40.0 E10.0 F700
G92 E0.0

M221 S95 ; set flow

 

This post was modified 3 years ago by lurc
Posted : 02/02/2022 3:49 pm
lurc
 lurc
(@lurc)
Active Member
Topic starter answered:
RE: G Code question - Modify wipe?

oops. Slight change to the steps will make it a hair smoother:

G90 ; use absolute coordinates
M83 ; extruder relative mode
M104 S170 ; set extruder temp for bed leveling
M140 S[first_layer_bed_temperature] ; set bed temp
M109 R170 ; wait for bed leveling temp
M190 S[first_layer_bed_temperature] ; wait for bed temp
G28 ; home all without mesh bed level
G29 ; mesh bed leveling 
M104 S[first_layer_temperature] ; set extruder temp
G92 E0.0
G1 Y-2.0 X179 F2400
G1 Z15 F720
M109 S[first_layer_temperature] ; wait for extruder temp

; intro line
G1 X170 F1000
G1 Z8 F720
G1 X165.0 E8.0 F900
G1 Z6 F720
G1 X160.0 E8.0 F900
G1 Z4 F720
G1 X155.0 E8.0 F900
G1 Z2 F720
G1 X150.0 E8.0 F900
G1 Z0.2 F720
G1 X110.0 E8.0 F900
G1 X40.0 E10.0 F700
G92 E0.0

M221 S95 ; set flow

 

Posted : 02/02/2022 3:58 pm
Diem
 Diem
(@diem)
Illustrious Member

OR:  Press and hold the button until it switches to the Z height display then dial it up as far as you need.

Cheerio,

Posted : 02/02/2022 4:40 pm
lurc
 lurc
(@lurc)
Active Member
Topic starter answered:
RE: G Code question - Modify wipe?

OK. Success!

I'd love for it to be an exponential decaying arc but that is more math than I want to get into.

Here is the code. I ended up lowering the z before the intro line to 6. The 15 I had it set to was unnecessary but I had to start someplace.

G90 ; use absolute coordinates
M83 ; extruder relative mode
M104 S170 ; set extruder temp for bed leveling
M140 S[first_layer_bed_temperature] ; set bed temp
M109 R170 ; wait for bed leveling temp
M190 S[first_layer_bed_temperature] ; wait for bed temp
G28 ; home all without mesh bed level
G29 ; mesh bed leveling 
M104 S[first_layer_temperature] ; set extruder temp
G92 E0.0
G1 Y-2.0 X179 F2400
G1 Z6 F720
M109 S[first_layer_temperature] ; wait for extruder temp

; intro line
G1 X170 Z5 F1000
G1 X135.0 Z2.5 E8.0 F720
G1 X115.0 Z0.2 E8.0 F720
G1 X110.0 E8.0 F720
G1 X40.0 E10.0 F700
G92 E0.0

M221 S95 ; set flow

I will upload a video of how this works shortly.

Posted : 02/02/2022 4:51 pm
lurc
 lurc
(@lurc)
Active Member
Topic starter answered:
RE: G Code question - Modify wipe?

Video is uploading now:

Posted : 02/02/2022 5:17 pm
Chris Laudermilk
(@chris-laudermilk)
Estimable Member
RE: G Code question - Modify wipe?

Nice. Learning is part of the fun of this hobby.

Mini+ (kit) - Revo Micro | Antler Cooling | WiFi (4.4.0RC1)

Posted : 03/02/2022 3:59 pm
KineMechanic
(@kinemechanic)
New Member
RE: G Code question - Modify wipe?

Really cool solution!

This has annoyed me too and I always wait and grab the blob with pliers (or my fingers).

I might give this a try.

It would save me this minor nuisance.

Thanks for sharing!

Posted : 10/02/2022 10:22 pm
Ichschonwieder
(@ichschonwieder)
New Member
RE: G Code question - Modify wipe?

Thanks for sharing!

Added the configuration and it seems to work well.

Posted : 14/02/2022 9:58 am
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