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bob-hepple

Help with print quality before I lose the plot

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Hi,

 

I am new to 3d printing not a total idiot but after 2 weeks of messing about with the Ultimaker 2 I need some advise where I am going wrong if at all (limits of the printer).

 

My ultimaker 2 arrived and without me knowing it the limit switch on the z had been jammed shut

with a wire this caused a lot of aggravation then the fun started material bringing in the feeder ect., I was using ABS and could not get any decent finishes so I went to PLA and still can't get a decent finish even though it starts off fine. I calibrated the bed I print at speed 50 with layer time at about 20 not fast at all but with any overhang at all it is not good even the Robot comes out naff, I have hopefully uploaded this. also uploaded a pic of print of the design for the feeder mechanism from I Robert on the premise that it will cause me problems sooner or later so might swell try printing them. as you can see from the pic again this is messy while in other areas its fine. i purchased the ultimaker todo a specific job but doubt it will do it. I am using the latest firmware and the latest Cura which is being very unfriendly in the printing support areas i Roberts piece had supports turned on everywhere but did not do the 3mm lock nut area.. as you can see it Gold PLA which came with the machine. where I purchased the machine said it might be the colour thats causing me problems (I find that hard to believe YOUR THOUGHTS)

 

p.s print quality .10

 

Can anyone help.before I take a hit and sell the machine...

 

 

 

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hi

Sorry for that hear we go

Layer Ht .10

Shell Thickness 1.00

Retraction Enabled

Fill Density 60%

Bot Top Thickness 1.0

Print speed 50

Support Everywhere

Platform Type Brim

Nozzle size 0.4

init layer 0.3

Cut off obj Btm NO

Dual ext overlap 0.15 (this was in mabe I should set to 0 ?? )

Travel sod 50

btm layer spd 20

infill spd 20 inner shell spd 20 cool layer time 5 fans On

Bed temp was set to 75

Nozle temp 250 (as default for PLA)

hope this helps

Bob

 

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Dual ext overlap 0.15 (this was in mabe I should set to 0 ?? )

 

Ignore that - you don't have a second extruder.

 

Bed temp was set to 75

Nozle temp 250 (as default for PLA)

 

Wow! Much too hot for PLA. Dangerously hot - a little dangerous - leave PLA at that temp without printing for a half hour and you will have to take your nozzle out and burn all the PLA out.

Anyway - do bed at 50-60C for PLA (100C for ABS). 75C for PLA is a last resort after you can't get any of the other methods of getting the part to stick to the bed and you still get major warping (corners lifting) on large parts.

75C will give bad quality on the bottom 5mm or so where the air is too hot. It will pull inward kind of look like warping but it's just that the material is too soft on the corners when the next layer goes down. 75C won't affect more than 20mm off the bed.

I vaguely remember that gold needs lower temp - maybe even 190C. But start at 210C or 220C. If you get any underextrusion (holes in the wall, or skipping feeder) then slow it down to 35mm/sec but 50mm/sec should be fine regarding overhangs.

Also make sure your side fans are working. They need to be at 100% by the time you get to the first overhang. By default they come on at 5mm up. Make sure minimum and maximum fan speeds are both at 100.

Many printers fan connections disconnected during shipping so this is a likely problem. Test that the 3rd fan at the rear also comes on (the 3rd fan comes on as soon as power is on - even before the lights).

To test that side fans work do:

PRINT, select any print, then immediatly go to TUNE and set fans to 100%. Turn off machine when done testing so that it doesn't start printing (will not start printing while you stay in TUNE menu).

 

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what make of pla are you using in the robot

 

Diamond age. Very nice filament but no longer sold in USA. But there are better filaments in UK (I'm jealous). But this is mostly irrelevant as I can get this kind of result with every standard PLA I've tried including many from Ultimaker.

 

I like the picture of your Robot it would be good to know how you got that

 

That particular Robot was before I had a UM2 (last fall) so it was done on UM Original but I've printed robots on UM2 just as good.

Exact settings for the robot in the photo above are in post #19 here - also there are more photos zoomed in closer above that posting and other discussion about getting quality robots (other objects have other challenges so this is mostly UM robot related):

http://umforum.ultimaker.com/index.php?/topic/3038-can-your-ultimakerultimaker2-print-such-quality/?p=28588

 

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G5 I tried lowering the temp 195

speed 96

material flow100

 

same pal Gold Ultimakers

front was slight improvement but the back is dreadful.

 

 

this file I used was the default that came with the machine.

 

any help appreciated it has been suggested by the retailer I change PLA to a different colour I noted he didn't offer to exchange. but thats just more expense

 

 

 

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Unfortunately it looks like no one was around last night to push your posts through. We're only human I'm afraid. The good news is that your posts will show up immediately now.

As for your print. Slow it down, you say that you're printing at 96mm/s which is quite fast and will degrade quality. If you look at the settings gr5 linked to you will see that not only did he slow down to 20mm/s but he also printed two robots at once to increase cooling time. Printing two at once will improve the ears and antennas in particular.

Now you will think "20mm/s, really? That's super slow!" and yes, it is quite slow. But for delicate prints (the robot is actually a fairly tricky print) where quality is your first priority you sometimes have to be patient.

 

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also: Shell Thickness 1.00 <- Don't do this. Your nozzle is 0.4mm. Ideally your shell thickness should be multitudes of your nozzle size (0.4, 0.8 (standard), 1.2,etc).

Could you please slice something with *all* the basic settings as provides by Cura. Only when you get that right should you start experimenting (and blaming the machine for being 'faulty').

Also; The robot prints far better on tape then it does on heated bed. Small prints + heated bed is quite tricky.

 

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Thanks for the replies but I have to say to nallath I am NOT blaming the machine. If you take that view I Am sorry, BUT the machine was sent with a sample file and in a naive way I thought the machine should print it!, and then I find not only does it NOT print it you then have to adjust the default temp for PLA from 210 to anywhere from 190 upwards. I purchased the machine because I want to print experimental parts for a charity and while I know there is a learning curve it doesn't help when the machine is delivered with trapped limit switches and missing bed screws... Come on £2000.00 you expect better.

I Robert thank you for your feedback and I will certainly try your constructive and informative suggestions And I understand why gr5 printed two robots that's cool. Could I ask you two questions does the colour of the PLA play an important part in the quality if so could you suggest a stable colour to use. I am not a robot freak and personally don't want any more the point of doing this was to understand then adapt future prints. Your feeder mechanism was impressive but when I printed one of you parts see above the recess for the 3mm lock nut failed and this is what ultimately led me to print the dam robot file to get a stable print process.

The print for the body worked well and the result was nice and clean my problems are overhang . And I guess this is what I need to learn. It has sunk in temp/speed are paramount.

Thanks

Bob

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Adjusting temperature based on material, what type of object you're printing and depending on print settings is normal. That's just the nature of the beast. Even highly refined processes like injection moulding have to do experimentation before everything is dialed in perfectly for a part. I visited such a place a year or so back and the guy there told me about a handle where they had to adjust the tool so that the proper bend in the handle happened after the part was ejected and cooling down. Plastic can be a bit fickle :)

And yes, the perfect temperature can differ slightly between manufacturers and even between colours from the same manufacturer. All that said though I usually use a temperature of 235C which seems to work well for the type of prints I usually do. This "goldilocks" temperature may well be different for you and it's simply a matter of experimentation.

But looking back it's amazing how well these types of printers print out of the box these days. Go back just a few years and things looked very very different.

As for my part that you tried to print. Yeah, that area can be a bit tricky. I want to re-design it slightly but the thing is that there's so damn little space to work with. Ideally I'd like to make it about 2-3mm thicker but there's simply no room. At least not if I want to keep it symmetrical, I've toyed with the idea of having it protrude outwards a bit but.. eh, I dunno :)

 

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The additives to PLA that give it color affect the melting point. Gold PLA is fine as far as I know. I've printed with UM Gold and looked over my notes and I had printed 2 things that I still have at 220C and they came out beautiful - they were not as tricky as the robot (not much overhangs). But be warned every time you switch colors there is a chance that you will have to adjust temperature. It's not about quality - it's about melting point and viscosity and glass temperature.

Getting back to your robot - the main advice is what robert said - lower speed to 20 if you want the quality I got. And stay with 190C which is a good temperature for that slow slow speed. But if you print at 96mm/sec - you might need to increase temp a little to get that PLA to flow through that tiny nozzle hole. The pressures can be quite high in the nozzle and these reduce quality.

nalalth's advice about shell is also critial - 1mm is bad choice for shell - I hadn't noticed that. Use .8mm (two passes) or 1.2mm (3 passes). But never 1mm except for extremely specialized things which you will hopefully never have to print.

Actually I wish Cura would turn that yellow when you choose something not a multiple of the nozzle diameter.

I rarely print at 20mm/sec. In fact I think that was the most recent time (about 9 months ago). But this was kind of a contest to get the best possible quality. I usually print at 35mm/sec for show pieces and 75mm/sec for things that no one will see. I've learned to be patient and not rush a print and letting the printer run for 36 hours no longer scares me (although most of my prints are under 4 hours).

 

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Ok another attempt and the last.

I re sampled the Robot

Basic Settings Cura

layer ht .2

shell thickness 1.2

retract yes

botm top thickness 1.0

fill 60%

print speed 30

support none

platform adhesion brim

Advanced Settings

init layer 0.3

cut obj no

dual extrude 0

travel speed 30

botom layer spd 20

infix speed 20

outer shell 20

inner shell 20

cool layer time 5

fans on

 

 

Temp in Fine tune was 190.00

bed 60

(I listened)

these are what I set in cura and presume what is set in gcode?? question where does speed in fine tune come into play?? I set this to 50% and when got to belly still thought it was fast and reduced it down to 40 is this 40% of the time set in dura which was 30 ?? (help)

is there a way of setting the temp (190) into the programme so it runs 1 programme at one temp and another at ??

the pics show a little stringing but Im pleased enough to carry on with what I purchased the machine for and when I

spot overhang I'll know reduce speed and watch the temp..

Bob

 

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I set this to 50% and when got to belly still thought it was fast and reduced it down to 40 is this 40% of the time set in dura which was 30 ?? (help)

Yes. 50% feedrate in TUNE menu with 30mm/sec print speed results in 15mm/sec print speed. 40% would be 12mm/sec print speed. This is much slower than you need. 20mm/sec should be plenty slow.

is there a way of setting the temp (190) into the programme so it runs 1 programme at one temp and another at ??

The idea is the temperature has more to do with the color so you can set the temp on the printer. Then if you print another robot in blue you can raise the temperature without changing anything in Cura.

However you can look at "tweakAtZ" plugin which lets you set the temp exactly and can vary for different parts of the print.

The stringing was mostly on the antennas - it's very small and easily removed with fingers.

That robot looks great. You can improve the tops of the antennas by printing 2 robots but I think it's fine.

A few more things:

Travel speed should be as fast as possible - this will help *break* the strings. The default is 150mm/sec. You can probably go to 250mm/sec but 150 is a good start.

Infill speed and inner shell speed are typically *faster* than the outer shell speed. This is because you don't care about the quality inside so much. But I recommend you leave these at the same speed as the shell speed. Don't slow down - don't speed up. If you are in a rush this is a good thing to increase the speed on (infill speed) or just try 0 infill as the robot prints fine with zero infill.

Bottom layer speed should be nice and slow so you have that set good right now. 35mm/sec is plenty slow enough though for most thing. In fact I rarely go slower than 35mm/sec for anything.

You can print this much faster and still get good quality.

 

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