nozzle wipe

deckingman

@arhi Neat - I really must find time to stat looking at conditional gcode.

Danal

This works reasonably well. Orange silicone strip is aircraft baffling material. Just tried it because I have a ton of it. It is stiff enough that when dropped into a three sided slot, it wipes plenty well. Tool mounting always makes three passes over this; no intelligence, just does it every time.

0:/sys/tpost0.g
; Runs after firmware thinks Tool0 is selected
; Note: tool offsets are applied at this point!
; Note that commands prefixed with G53 will NOT apply the tool offset.

G53 G0 X1        F5000				; Square move to avoid diagonals. 
G53 G0      Y350 F5000  ; Rapid to the approach position without any current tool.  This lets the human know the next command is waiting on this new tool. 
M116 H1                 ; Wait for set temperatures to be reached

M302 P0                  ; Prevent Cold Extrudes, just in case temp setpoints are at 0


G53 G1 Y373 F2500        ; Move to the pickup position with tool0.
M98 P"/macros/tool_lock.g" ; Lock the tool
G53 G1 Y355 F2500        ; Retract the entire tool and wipe Backwards.
G53 G1 Y370 F5000        ; Wipe Forwards.
G53 G1 Y355 F5000        ; Wipe Backwards.
G53 G1 Y370 F5000        ; Wipe Forwards.
G53 G1 Y275 F5000       ; Wipe Backwards and get clear of tool row, in case next move is large X move. 

G1 R2 Z0        ; Restore prior position now accounting for new tool offset

Sample resulting print, no cleanup at all, straight off the bed. NOT perfect (for one thing it needs more shells on the 'top' curved areas), but pretty good in terms of clean transitions. With a little bit of post process, it became really nice.

IMG_0421 (1).jpeg

A Former User

I have been using soft brass bristle brushes with an auto wipe system for a long time, the nozzle travels between two rows of the brush bristles.

Nozzles are holding up well, so much so I have never even noticed them needing to be changed .

I didn't make too much of it, it just works.

Maybe too much thought on a simple problem is being applied.

Danal

@CaLviNx said in nozzle wipe:

Maybe too much thought on a simple problem is being applied.

Nah, this group would NEVER do that!!! 27 steppers and five switches to align something that snaps into place anyway? GREAT!

jens55

If we liked things simple we would just buy a printer and ... imagine that .... print stuff.
There is no fun in that

A Former User

@jens55 said in nozzle wipe:

If we liked things simple we would just buy a printer and ... imagine that .... print stuff.
There is no fun in that

If you say so.

zapta

@Danal said in nozzle wipe:

This works reasonably well. Orange silicone strip is aircraft baffling material. Just tried it because I have a ton of it

The results look very good. Any idea where one can source that or a similar material?

Danal

@zapta said in nozzle wipe:

@Danal said in nozzle wipe:

This works reasonably well. Orange silicone strip is aircraft baffling material. Just tried it because I have a ton of it

The results look very good. Any idea where one can source that or a similar material?

You can buy a foot of it for $2.50. I'm not sure what their minimums are... shipping... etc. My orders are always big.

https://www.aircraftspruce.com/catalog/appages/siliconecowlseals.php?clickkey=4767

zapta

@Danal, thanks, will give it a try. My goal is to wipe PETG every few layers. Need to figure out where to install it since my nozzle doesn't go beyond the bed.

SpoonUnit

I use a silicone cooking brush - something along the lines of these:

https://smile.amazon.co.uk/Silicone-Basting-Pastry-Brushes-Barbecue/dp/B077TJHT9G/ref=sr_1_10?dchild=1&keywords=silicone+cooking+brush&qid=1588030483&sr=8-10

The only bit I'm interested is the brush, so the rest is cut off, and the tines are cut down to about 15mm, so they become reasonably stiff. The nice thing about passing the nozzle through the brush seems to be that a) the filament gets caught in the brush, and b) the brush cleans the underside of the hot end and nozzle if mounted at the right height. The hot end isn't in contact with it long enough to impart any significant heat, but even so, the silicone can handle pretty high temps.

Here's how it ends up looking, with one mounted either side of the bed:

I prime 30mm reasonably fast just infront of the brush to create a thickish string, pass back and forth through the brush along slightly different lines to avoid re-collection of the string, then move immediately to begin printing.

Here's a closer view of the wipe:

arhi

@SpoonUnit I was looking at that brush too but was afraid bristles are too soft to do anything

A Former User

@zapta said in nozzle wipe:

@Danal, thanks, will give it a try. My goal is to wipe PETG every few layers. Need to figure out where to install it since my nozzle doesn't go beyond the bed.

Why do you feel you need to wipe the nozzle every few layers?

dc42

@arhi said in nozzle wipe:

if sensors.analog[1].lastReading < 200
echo "Extruder too cold, no point wiping, aborting the wipe"
M99

On a multi-tool printer I suggest the following instead:

if state.currentTool < 0
  echo "No tool loaded, cancelling wipe"
  M99
if heat.heaters[tools[state.currentTool].heaters[0]].current < 200
  echo "Extruder too cold, no point wiping, aborting the wipe"
  M99

PaulHew

I have been wanting to wipe the nozzle for ages on my Railcore after seeing @deckingman wipe system
I am in the UK and found a company who sells Silicone sheet which can withstand 300 degrees.
Just ordered a 3 and a 4mm sheet from TYM Seals and Gaskets
They have an ebay page also.

Regards
Paul

deckingman

I can also add that you can stick silicone sheet/strip to aluminium with silicone sanitary adhesive/sealant. So if you can't mill a slot to hold the aluminium, then this method might work.

Caveat 1 - It worked for me but it might depend on the grade/type of silicone you buy.
Caveat 2 - I made sure the aluminium was clean and free of any oil by wiping it with Acetone. Also, the aluminium was newish so hadn't oxidised.
Caveat 3 - Not all silicone adhesives are equal - I used Dow Corning 785 (clear).
Caveat 4 - While it seems to have stuck like the proverbial excrement to bedding fabric, I have no idea how long it will stay stuck (nor any reason to think that it might become detached over time).

arhi

@dc42 said in nozzle wipe:

On a multi-tool printer I suggest the following instead:

Awesome. I gave up on multi tool on the ender5 since e3d ms-tc arrived but still, this is better as I assume a lot of scripts I will use on more printers (as I plan to replace most of my printer boards and unify them to RRF)

arhi

@deckingman now that you mention "silicone in tube", ages ago I created a heat shield around my old rapman nozzles with silicone for some car gaskets from car parts store that is supposed to be good up to 300C. 250-260C many years later it's still standing so I guess it's usable. I think I seen people use it to mold the heat block socks out of it. Might be interesting to design a mold to create silicone "brush" specifically designed to clean nozzle

deckingman

@arhi I don't see why not. For info, I once made a "sock" for one of my Diamond hot ends using this stuff which is supposedly good for 370 degC https://www.dwrplastics.com/high-temperature-resistant.html. I'd guess something like that would also work if one wanted to make a "brush" from scratch.

arhi

@deckingman lot of nice molding materials available, unfortunately, not accessible for all of us .. but this car stuff is available in local shops so ... I'll think about it. I know they have green, red and black. One is I think 300C, other 370C and one is IIRC 700C but I might be wrong will check the shops it's clearly marked on the tube
I think bigger issue is "what" to design, what a "perfect" brush for this would look like maybe a "cup", dunno, need to think about it, interesting anyhow

zapta

@CaLviNx said in nozzle wipe:

Why do you feel you need to wipe the nozzle every few layers?

Mostly for PETG. Over time the nozzle collect small pieces that later land on the part.

I also have a Micro Swiss nozzle on order. It supposed to be smooth and 'PETGphobic'. Will see how that one goes.