The care & nurture of a 3d printer...

Started by Wulf, 10 March 2019, 03:46:12 AM

Previous topic - Next topic

Wulf

Quote from: fred. on 11 March 2019, 09:46:55 PM
I assume that while a model is printing, you can just leave the printer to it? Or does it need monitoring while its printing?
I watch the print until I'm confident it's adhering and will print. I just started another print and aborted it twice because I wasn't happy that every part was stuck down. Better to stop it after 5 minutes rather than let it fail after 5 hours... This 3rd time, it looks fine. I watched the first 1mm or so print. It'll now take about 8 more hours to print... I'll be going to bed soon, it may well finish in time before I go to work tomorrow morning at 7am...  After the first few prints, I've been confident enough to leave it running overnight & while I'm at work, so long as I see it off to a good start.

There is always, however, the possibility of a disaster, a bit comes loose from the print bed, or some support proves inadequate & the print just becomes a mess. But if that happened while you were watching you couldn't stop it anyway...

fred.

That makes sense.

Do you think you are getting a higher success rate now you have more experience, or is it still quite hit and miss?
2011 Painting Competition - Winner!
2012 Painting Competition - 2 x Runner-Up
2016 Painting Competition - Runner-Up!
2017 Paint-Off - 3 x Winner!

My wife's creations: Jewellery and decorations with sparkle and shine at http://www.Etsy.com/uk/shop/ISCHIOCrafts

Wulf

Quote from: fred. on 11 March 2019, 10:32:03 PM
Do you think you are getting a higher success rate now you have more experience, or is it still quite hit and miss?
Definitely better, but now I'm experimenting more with even finer detail vs. speed - I don't want to take 6 hours to print one  10mm scale tank, but I do want the finest possible detail... - so I am getting failures caused by that. Right now I intend to test other Build Plate Adhesion methods, and increase the percentage of my support (10% is proving barely adequate). If I played it safe, or printed bigger things, I would be quite confident of success. I can, for instance, print buildings quite successfully so long as the walls aren't too thin, or scaled up 1:200 scale tanks (which look a bit chunky at 1:150).

Still having minor issues with stringing too, I'll have to dismantle my filament feed after this print & try and get it more precise.

Westmarcher

I got lost when the Palestine Liberation Army got involved.   :-/

But keep up the good work, anyway, Wulf.  :-bd
I may not have gone where I intended to go, but I think I have ended up where I needed to be.

barbarian

Played a bit with the printer (Creality) of a friend. The worst part is even the room temperature is a factor.
I think these entry level printers are no good to small scale like 10mm. Even 28 mm is rubbish on these.
I can see being used for scenery I guess.
Still need to test more and more.
2015 Painting Competition - Winner!
2018 Painting Competition - Runner-Up!

Wulf

Quote from: barbarian on 13 March 2019, 04:08:00 PM
I think these entry level printers are no good to small scale like 10mm. Even 28 mm is rubbish on these.
It depends what you want and what you expect. I'm happily creating 10mm scale tanks to rival the detail level of cheaper metal & resin minis, but at a fraction of the cost of even those cheap ones. Yes, you certainly get visible surface layering & artefacts, but from gaming table ranges & angles those are negligible.

Techno

Sounds like, you pays your money and you take your choice. :)

If you're happy with what you're producing, Wulf....and I would be !... that's the 'main thing'.

Cheers - Phil

Steve J

I agree with Phil. I tend to look at a lot of this stuff from my professional modelmaking point of view, where it simply doesn't cut the mustard for most of the time. From a home point of view they are more than adequate, which is what really counts.

Wulf

Quote from: GrumpyOldMan on 10 March 2019, 11:20:11 PM
If you really want to get into the 3d world you could have a look at getting some models from the 3D sketchup warehouse
Finally checked out Sketchup, and, while it's nice to have more options, as far as I can see these tanks don't come with separate turrets, which makes them considerably less useful to me. Very nice, but I'm hoping there are easier alternatives.

Wulf

01 April 2019, 08:43:05 PM #24 Last Edit: 01 April 2019, 10:21:02 PM by Wulf
Apologies for having left this thread hanging, and now seemingly resurrecting it. It was always my intention to continue, but I felt I couldn't discuss problems with stringing and support until I solved my own problems with stringing & support...

First, a couple of definitions in case any terminology is confusing issues. The files containing information that define a 3d shape are commonly called 'meshes'. To print them, you need a bit of software called a 'slicer', which converts them into code that can be understood by your specific printer. I use 'Cura', a popular and, importantly, free program. The printer I have is an Ender 3 Pro by Creality, which I have, since last posting, upgraded a bit. Normally the 1.75mm diameter plastic 'wire' that feeds the printer, properly called 'filament' is pushed into a nozzle hot enough to partially melt it so it extrudes through a 0.4mm hole - I upgraded to a 0.3mm nozzle allowing for finer detail. I have a 0.2mm one too, but decided to be moderate...

OK, so.. Stringing...
What is stringing? Well, this is, and a nasty dose of it too...

Any of you familiar with plastic modelling may have tried stretched sprue - take a bit of the sprue, the frame or runner that holds the plastic bits of a kit together, hold both ends while heating the middle with a candle or other heat source, and, when the middle goes soft, pull the ends apart while moving away from the heat. That fine plastic line that stretches out is great as a radio antenna, but a damn menace on the 3d print bed. You see, the hot nozzle, full of partially melted plastic, is in contact with the model being printed and, when the nozzle moves away to go to another part of the print job, it stretches out that string. Note this is only a problem when the nozzle has stopped printing and is moving to another bit that needs printing. Leaving plastic behind during printing is called... well... printing...

So, how do you stop stringing?
There are a few factors involved, but the most important is Retraction. This is a setting in every slicer, although frankly I can't imagine why you'd want to switch it off! Basically it pulls the filament back from the hot nozzle - it doesn't actually suck it back into the nozzle, but stops the pressure forcing it out. After that, the two important factors are temperature - if the filament is so hot it dribbles then it'll still string - and speed - print slowly so the filament isn't being pushed through too fast to retract properly, but set travel speed - the speed the nozzle moves away from the print - high so the potential string doesn't form. There are a few other factors, one important one in Cura is 'Limit Support Retraction' - Cura, apparently, doesn't retract when moving from Support to Support, to save time, since Support doesn't have to be tidy or pretty. OK on a single-part print but with a dozen bits on the build plate it's a mess, so turn this OFF. In that pic above virtually every string is from Support to Support already, so if I only knew about this setting... I'd not have learned as much about the whole process! And then there's 'Coasting'. Not entirely certain what this does ( I think it stops the pressure pushing the filament just BEFORE it stops printing), but it works... turn it on.

So, did I beat Stringing?
More or less, yes...

Still the odd tiny thin thread, but that'll probably always happen. I now print at 190 degrees nozzle temperature, with a print speed of 35mm/s (this is a general speed, the outer wall of a print prints at half this speed for accuracy) and a travel speed between printing of 200mm/s. Initially I read that travel speed should be 'high'. Well, I thought, I print at 35, so maybe 80 would be 'high'. Nah. 150-200 is recommended... With the other settings mentioned and a hell of a lot of tweaking, it's lovely.

Next up, Support...

Wulf

Can someone remind me of how to make those pics smaller on this page?

...assuming anyone is actually reading this...

fsn

01 April 2019, 09:02:20 PM #26 Last Edit: 01 April 2019, 09:03:57 PM by fsn
lol.

after the img  put width=300 or height=300

I've done it here. If you reply and insert this answer as a quote, you can see wot I dun.


Lord Oik of Runcorn (You may refer to me as Milord Oik)

Oik of the Year 2013, 2014; Prize for originality and 'having a go, bless him', 2015
3 votes in the 2016 Painting Competition!; 2017-2019 The Wilderness years
Oik of the Year 2020; 7 votes in the 2021 Painting Competition
11 votes in the 2022 Painting Competition (Double figures!)
2023 - the year of Gerald:
2024 Painting Competition - Runner-Up!

Wulf


fred.

Thanks Wulf, a very useful and detailed post.

The photos look fine to me in their original size.

There seems to be loads of spare material underneath everything - I assume this is support material. Is this hard to remove? And why do the turrets have so much underneath them?
2011 Painting Competition - Winner!
2012 Painting Competition - 2 x Runner-Up
2016 Painting Competition - Runner-Up!
2017 Paint-Off - 3 x Winner!

My wife's creations: Jewellery and decorations with sparkle and shine at http://www.Etsy.com/uk/shop/ISCHIOCrafts

Wulf

Quote from: fred. on 01 April 2019, 10:30:09 PM
Thanks Wulf, a very useful and detailed post.

The photos look fine to me in their original size.

There seems to be loads of spare material underneath everything - I assume this is support material. Is this hard to remove? And why do the turrets have so much underneath them?
That is indeed support, and that's the next topic. Good point about the turrets, basically that's support clearing the turret pin - I'll provide a 'before & after' pic to illustrate that.