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jweaver

Anyone got any tips for printing when the first layer has lots of tiny part?

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Say your first layer had lots of really small parts. Does anyone have any tips on how to stop them getting "flicked" off the bed?

This is an example:

http://www.thingiverse.com/thing:51806

You have to use support, so the first layer is 60+ tiny little squares.. In the process of laying them, there is often a little blob of plastic.. And this catches on the head and flicks them off.

As such Its impossible to get the first layer down.. I generally lay my first layer at 205 degrees (PLA) but wonder if this is causing too much oozing.. So I have gone cooler and get less blobs, but still loose some of the supports.

Does anyone have any tips on how you cope with this? Transit slower? Faster? Printer slower? Move the head up??

Anyone have any ideas how I can do this.

I had the same problem with this but gave up:

http://www.thingiverse.com/thing:362357

SO I am now going back to see if its possible.

Jon

 

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I find blue tape with alcohol with a little bit of smooshing works better than heated buildplate for tiny parts. The tape has a tiny bit of give so even if it experiences some type of torque from the printhead it doesn't pop off as readily as glass.

 

Unfortunatpy. Already using blue tape hich i have sanded and cleaned with alcohol.. Generally i have no problems with adhesion, but ther is something sbout these single layered tiny parts which just ping off.

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Solution is simple but CURA developers dont want to implement it.

Problem with these kinds of prints (that i print allot) is that there are multiple perimeters.

Cura does not like to retract before goint from one perimeter to another, so when it does it ruins it.

I keep on bringing this issue but all i get is "retract while combing" or tweak retraction distance settings.

Problem is that if i do any of the two, problem gets solved but another problem emerges, it starts to retract too much to a point when filament is grinded and print is ruined.

It is impossible to tweak the settings so it would retract before perimeter change, because all those settings are distance based and not following the rule as to "where it needs to retract" but rather "how far before retract"

Who is to say "how far" from one perimeter to another ? No one knows so those settings are useless.

I dont think that cura will ever evolve to a point where it will start and finish each individual perimeter and retract before each one.

So in that regard i gave up on CURA.

There is free software that does work that way alowing complex objects like these to be printed without a hastle. Its called Craftware. Craftware prints each perimeter and retracts before switching to the next. It also has an option to prime, so you can give little extra prime after retraction to make it start even better.

Craftware does have a problem that i absolutely hate, but its not going to ruin your life, so give it a try.

 

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Solution is simple but CURA developers dont want to implement it.

Problem with these kinds of prints (that i print allot) is that there are multiple perimeters.

Cura does not like to retract before goint from one perimeter to another, so when it does it ruins it.

I keep on bringing this issue but all i get is "retract while combing" or tweak retraction distance settings.

Problem is that if i do any of the two, problem gets solved but another problem emerges, it starts to retract too much to a point when filament is grinded and print is ruined.

It is impossible to tweak the settings so it would retract before perimeter change, because all those settings are distance based and not following the rule as to "where it needs to retract" but rather "how far before retract"

Who is to say "how far" from one perimeter to another ? No one knows so those settings are useless.

I dont think that cura will ever evolve to a point where it will start and finish each individual perimeter and retract before each one.

So in that regard i gave up on CURA.

There is free software that does work that way alowing complex objects like these to be printed without a hastle. Its called Craftware. Craftware prints each perimeter and retracts before switching to the next. It also has an option to prime, so you can give little extra prime after retraction to make it start even better.

Craftware does have a problem that i absolutely hate, but its not going to ruin your life, so give it a try.

Cheers.> i was going to ask whether playing with retraction values or turning off combing might help.. As I think the problem is that after each little shape, little 'blobs' are left.. And this catches the head next time around.

Perhaps I could look at different software for this kind of print.. ANd will check out Craftware..

But what is this "problem that you absolutely hate"??

 

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Craftware uses raster method insted of vector to generate paths.

Imagine a cube filled with balls. Thats how it works. Vector is geenrating straight lines so its more accurate.

I dont like craftware because of those ballz that make things sort of inflated in all directions.

Their method is perfect for models that have problems, because it does not care about its structure, it treats its boudaries where as vector required model to be somewhat correctly made.

Other then that, program is awesome and am sure u gonna love it.

 

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I know you don't want to hear it tony but I'll mention RetractWhileCombing again :p Mostly because I just wanted to ask if you've tried enabling the head lift and if that made any difference? And you can of course set it to just do this maneuver on the first layer to try and keep the number of retractions down a bit.

 

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Its distance based no matter what you do with it.

It should be event based, such as retract for perimeters.

Should be very ewsy to implement. I will try to implement it into my gcode layer modifyer program. It will require me to reprocess each code but atleast it will work if code has comments for perimeters and fills etc as i suspect it does.

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Its distance based no matter what you do with it.

It should be event based, such as retract for perimeters.

Sure, I was just wondering if you had tried it and if it helped. When we don't have what we want we have to make do with what we have.

I have to be honest, I don't even understand what the 'retraction' settings do.. And what combing even means.

So I don't even know how retraction/combing might help me. Or why it would be used...

Retraction is when the printer sucks back a small amount of material before performing a travel move. This is to reduce the pressure in the print head so that it is less prone to drooling plastic during the move which would produce strings. The settings determine how long this travel move has to be before retraction kicks in.

Combing is another technique to try and avoid stringing. Instead of sucking the filament back and moving the shortest distance possible, it instead tries to perform travel moves only over printed areas. By doing this it prevents the head from travelling over outside perimeters. Say you're printing a "C", instead of jumping across that small gap to get to the other side it would instead make the head travel along the "C" shape, over the infill, to get across.

 

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Solution is simple but CURA developers dont want to implement it.

Problem with these kinds of prints (that i print allot) is that there are multiple perimeters.

Cura does not like to retract before goint from one perimeter to another, so when it does it ruins it.

I keep on bringing this issue but all i get is "retract while combing" or tweak retraction distance settings.

Problem is that if i do any of the two, problem gets solved but another problem emerges, it starts to retract too much to a point when filament is grinded and print is ruined.

It is impossible to tweak the settings so it would retract before perimeter change, because all those settings are distance based and not following the rule as to "where it needs to retract" but rather "how far before retract"

Who is to say "how far" from one perimeter to another ? No one knows so those settings are useless.

I dont think that cura will ever evolve to a point where it will start and finish each individual perimeter and retract before each one.

So in that regard i gave up on CURA.

There is free software that does work that way alowing complex objects like these to be printed without a hastle. Its called Craftware. Craftware prints each perimeter and retracts before switching to the next. It also has an option to prime, so you can give little extra prime after retraction to make it start even better.

Craftware does have a problem that i absolutely hate, but its not going to ruin your life, so give it a try.

So what is the solution then? And how do you know it's simple to implement? That already implies that you know software engineering, which also means there is little stopping you from implementing it :)

 

 

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Its eazy to add because slicer adds comments into the code that help to identify what part of the process print is in.

For example:

;TYPE:WALL-INNER (stands for perimeter)

RetractWhile combing insertre retraction before this line BUT ONLY IF distance is matched.

It is as simple as adding retract command right before each ;TYPE:WALL-INNER and ;TYPE:WALL-OUTER

;TYPE:FILL is where it starts to fill. Standard distance based retraction settings would be ok.

How ever i notice that retraction does not get reset, instead it continues to add value making it dificult.

Solution would be to reset the E right before each retraction, so that exact same retraction can be entered into the code instead of based on how much was extruded before.

Example the retraction from skirt to outer wall

G1 X1.844 Y15.955 E15.56963 ;normal extrusion

G1 F1800 E12.56963 ;retraction

G0 F9000 X6.044 Y20.155

;TYPE:WALL-INNER

G1 F1800 E15.56963 ;back to normal extrusion

Solution is to reset the extruder to 0 before each wall and then start extruding from 0 rather then from last known extrusion distance.

It actually makes more sence. doing it this way.

G1 X1.844 Y15.955 E15.56963 ;normal extrusion

G92 E0 ;reset extruder to 0

G1 F1800 E-1.00 ;

G0 F9000 X6.044 Y20.155

;TYPE:WALL-INNER

G1 F1800 E1.00 ;Resume extrusion from 0 instead of previously known 15.56963

 

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Solution is simple but CURA developers dont want to implement it.

Problem with these kinds of prints (that i print allot) is that there are multiple perimeters.

Cura does not like to retract before goint from one perimeter to another, so when it does it ruins it.

I keep on bringing this issue but all i get is "retract while combing" or tweak retraction distance settings.

Problem is that if i do any of the two, problem gets solved but another problem emerges, it starts to retract too much to a point when filament is grinded and print is ruined.

It is impossible to tweak the settings so it would retract before perimeter change, because all those settings are distance based and not following the rule as to "where it needs to retract" but rather "how far before retract"

Who is to say "how far" from one perimeter to another ? No one knows so those settings are useless.

I dont think that cura will ever evolve to a point where it will start and finish each individual perimeter and retract before each one.

So in that regard i gave up on CURA.

There is free software that does work that way alowing complex objects like these to be printed without a hastle. Its called Craftware. Craftware prints each perimeter and retracts before switching to the next. It also has an option to prime, so you can give little extra prime after retraction to make it start even better.

Craftware does have a problem that i absolutely hate, but its not going to ruin your life, so give it a try.

 

This has been driving me nuts for weeks. I print small parts for multirotors and other RC gear, many of them have small holes for zip ties or small bolts 1-3mm in diameter. I get alot of first layer issues because of this and never really understood why until I read your posts here, so thank you :) Ill give craftware a shot as well.

 

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Nuts ?

This has been driving be ballz and i cant stand it.

Because CURA does not reset extruder before each perimeter, i cannot manually enter retraction befor each perimeter using text eitor, it keeps on adding value to previous soevery layer its different value.

Craftware resets extrusion each time but they already do retract before perimters so i dont have to worry about that.

Please dont get me wrong, i am not here to say "CURA is garbage and Craftware is the KING"

I do the same thing on craftware forums. I thank them for way they handle retraction but mock them for using raster slicer that ruins prescision prints.

For CURA i love the simplicity and quality prints i get, but i absolutely hate the way it handles retraction.

I wish i could program plugin to make it retract where it should, but i cant.

If i could, CURA would be my one and only 3d printing software.

 

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OK i worked hard for some hrs and came up with this.

I would search the entire file each line for ;TYPE:WALL-OUTER and read next line

 


G1 F1800 X20.398 Y17.608 E112.27644

So i would get

 


;TYPE:WALL-OUTER
G1 F1800 X20.398 Y17.608 E112.27644

I would then isolate the 112.27644 and substract 3 resulting the 109.27644

Then i would write new line above with new value resulting the code below:

 


;TYPE:WALL-OUTER
G1 F1800 X20.398 Y17.608 E109.27644
G1 F1800 X20.398 Y17.608 E112.27644

I repeat same process for inner walls in hopes to get retraction before each perimeter.

When i print test object (rectangular box with round cutout) i get retraction in the middle of the wall without nozzle

I even tried doing this trick

 


G1 F1800 E109.27644
;TYPE:WALL-OUTER
G1 F1800 X20.398 Y17.608 E112.27644

but it was the same thing. Perimeters are simply not perimeters because they jump one to another without completeing one first.

Look at this part of the code;

 


G1 X10.999 Y13.919 E26.88579
G0 F9000 X5.747 Y8.207
G1 F1200 X44.596 Y8.207 E28.82398

There is a jump from one wall to another without any comment.

The only solution i see is to add retraction before each

 


G0 ;command

Problem with that is that there could be multiple lines with G0 so i cant do it. It will be overkill with retraction and too compicated to comeup with a string manipulation that would figure it out.

I am absolutely powerless to alter the code using what ever programming skills i have, change must take on the slicer level, not in my room.

Please do something.

 

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Actually, in my experience, retracting on the first layer is usually bad, as it increases the chances you rip off the print. (note, my experience is mostly on tape) due to the fact that it leaves a tiny blob and that blob can be snagged with the nozzle.

You could just disable combing and most likely get the result you are after.

 

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No i cant just disable combing because retraction will still be distance based.

There is no way aroudn it.

Am not sure why you have problem with retraction on 1st layer but my problem is NO retraction on 1st layer is what causing walls to rip and tare.

I dont know what to do. Cura gives prescision print but sucks at perimeters. Craftware does crap prescision but rocks at perimeters. I cant use either one.

Slic3er is the same, among its countless options it has no options for handling perimeters.

I gotta find something else.

 

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Actually, in my experience, retracting on the first layer is usually bad, as it increases the chances you rip off the print. (note, my experience is mostly on tape) due to the fact that it leaves a tiny blob and that blob can be snagged with the nozzle.

 

You could just disable combing and most likely get the result you are after.

 

This is exaclty what i am seeing. The little blobs get snagged and the first layer is destroyed. Are you suggesting i can turn retraction off for the first layer? Is there a feature or plugin to do that?

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Hmm I've never had this issue with Cura. It does first layers fantastically with or without combing or retraction. Are you guys/girls running heated beds? This sounds just like an adhesion issue, not a slicing issue. Painters tape works pretty well, but I've had the best luck with the purple coloured glue stick.

 

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Hmm I've never had this issue with Cura. It does first layers fantastically with or without combing or retraction. Are you guys/girls running heated beds? This sounds just like an adhesion issue, not a slicing issue. Painters tape works pretty well, but I've had the best luck with the purple coloured glue stick.

 

 

I am using PLA on an unheated bed, but am using blue tape.

I generally dont have a problem with adhesion.. But when i get a lot of TINY parts on the first layer, a lot of the shapes arnt full "closed" and the open end has a little blob which snags when the head passes.

I wondered if it was "oozing", but have lowered the temperature and it hasnt helped. So i think its got a lot to do with retraction and i am not even sure where to start.

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I do the same thing. BLue tape cold bed.

Its a perfect solution for eazy removal of PLA printed parts.

No adheasion problems no removal problems. One problem is that when there is no retraction before wall-to-wall travel, it peals off little bit.

Then it makes amove around that pealed off area and tares it.

I can avouid pealing off by using ABS juice or glue stick or what ever, but then i wouild have to fight with the removal which is not something i want to deal with.

 

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This is starting to do my head in now...

I was printing a large print yesterday and due to its design, had 6 co-incidental 'tiny' parts on the bottom layer.. And they just kept snagging.

Sometimes they wouldn't print at all. Other times, they would only part print, leaving a "blob" which caused the head to snag it on the next pass.

I don't even fully understand whats causing this. .Is it the 'retraction'? Would it make sense not to retract on the first layer, after all, any 'strings' which are created would be easy to remove?

If so, is there a plugin which will allow no retraction on the first layer?

Or am I completely confusing the use of retraction?

Jon

 

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Don't bother asking about plugin. All u gonna get is "retract while combing" replies.

They are all useless because they are triggering based on distance.

Retraction should trigger at the end before it moves to another perimeter. Those perimeters can be far or close so tweaking distance is useless.

For the time being I suggest u try crafteare unique. If u have MAC u are in luck, their latest version has vector slicing feature and it already does retract before each perimeter as it should. Not only that, it can also prime after retraction.

Its super cool program and free.

I use cura for mechanical prints because of vector slicer, but when it comes to retraction, it just drives me nuts.

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I have no doubt that I need to try different software, but I just don't want to learn another application all over again as I have my CURA settings how I want them.

And the problem in this case is that its a very simple model.. WHIhc i would want printed in CURA.. But the bottom has some openings which are triggering some small 'parts' in the first layer.

My question here is more about understanding the problem.. Is the fact that I am getting incomplete parts on the first layer down to "retraction"? If so, could I simply turn retraction off? And if so, this is why I asked whether there is a plugin to allow the ONLY first layer to be printed without retraction.

 

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