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gman

Help with my print. Need advice how to fix. new user

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Welcome to the forum! I'm sure that we'll get you printing soon. The first advice would be to stop 'changing settings like crazy' and take a methodical approach :-) Go for a medium speed print, fairly thick layers, and hot, easy to extrude plastic - say 50mm/s, 0.2mm layers, at 220ºC (assuming you are printing PLA). Let's get that working right, and then you can start to tweak settings, one at a time, so that you get a feel for what works well for what types of print. I highly recommend taking lots of photos, or keeping (and labeling) your test prints, and keep a notebook or spreadsheet where you track the settings that you are using.

More specifically, however, I can't help you as the photobucket link doesn't work. Can you add the pictures to your gallery on this site, and then link to that? (Click on your name in top right of the page... go to 'My Gallery' and upload pictures there. Then in your forum post, click on 'My Media' and then insert a link to either one particular album, or individual images.)

 

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Hi,

I just received an Ultimaker second hand from a friend. He rarely uses it.

The extruder keeps on getting the bits of PLA layed down stick back up. Then subsequently makes a blotchy mess because it gets deposited in clumps randomly

I know it isnt the gcode Z height because the raft seems to be ok. What is the cause of this? how to correct?

Kindly refer to OWL image in the album.

 

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Okay. Lol. Okay. Well the main problem is the filament diameter parameter in Cura. You have it set to 1.73mm yet I assume it is closer to 3mm. This means it is trying to put out (3/1.73)^2 or 3X more filament than normal. So it is just flowing out all over the place.

You should be able to print a lot faster 50mm or 75mm should be fine. And fill density of 20% should be plenty - don't need 55%. Retraction should be 4.5, not 7. travel speed can be 150mm no problem (not 30) Bottom layer at 10mm is a good setting. Cool should be set more to 7 seconds (not 20!) and get rid of minimum speed. That minimum speed (in expert/cool setting) will hurt you some day possibly.

But basically the only parameter that was really messing you up was that filament diameter.

 

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Well something is wrong.

Well for one it looks like it might be too hot. Maybe the hot end is hotter than the requested 220C. Can you measure it somehow? 220C or even 240C should be fine for this print but it just looks wrong.

Try lowering to 190C just to see if that changes the print much. Make sure the fan is working - the fan could possibly be the entire problem if it is broken. Or if it is spinning backwards and sucking instead of blowing.

Also I think your belts are loose - the loose belts will keep the infill from reaching the edge/sides. There's a good video explaining how to test the belts and how to tighten them:

www.youtube.com/watch?v=grHmmmSoOfc

If the belts are fine (long and short) I still think there might be some backlash from something else but the belts are the most likely so check those first.

Don't change too many settings at once. Those other settings suggestions shouldn't be causing the problems you are seeing. And get rid of the "minimum speed" of 5 in the cool settings. Set it to zero. That can also cause things to be too hot.

Also maybe disable retraction just to see if that helps - I don't know what retraction settings to use for 1.75mm as I'm not sure if it is "bunching up" in the clear bowden tube or if a smaller tube was installed. The UM really doesn't work well with 1.75mm unless you modify both the hot end and the bowden tube although some get away with modifying the bowden only. For 3mm you want 4.5mm retraction. You have 7mm but maybe that's the best setting - I don't know. So maybe just disable the feature for a test. If you don't retract you can get something called "stringing" but since you don't have gaps in your print it doesn't matter.

Maybe you can take a video of the second layer as it goes down? Or clearer pictures of a particularly bad layer?

 

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Ok, now owl become a little bit better thanks to your suggestions but still not good enough.

There are oozing PLA, I think my printer is struggling to print details (feathers). How come?

Im now printing at 200C, 14%infill, 30density, speed 50, infill speed 20, layer time 0, travel 65, minimum layer time 0. filament diameter 1.71, 100%flow

 

 

 

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Hi Gman

From the looks of this print and the pic of your previous settings maybe your fan if off.

I suggest you reset your profile to default in Cura and then change your filament setting back to 1.71mm if that's what it measures to.

You could then also turn off the raft and try another print.

 

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You should delete the infill speed setting, and let your infill print at the same speed as the perimeters. In some cases you might want to print it faster than the perimeter. There are pretty much no reasons to ever print it slower than the perimeter. Up your travel speed to 150. And set a minimum layer time of 7 seconds, to make sure the plastic has time to cool between passes. Judging from how smudged and glossy the print looks, it looks like you're printing really hot - do you have any way to double check the temperature sensor on your print head (e.g., with a separate thermometer?).

I didn't see mention of what layer height you are using? I'd definitely start with 0.2mm for now, so that your tests will print reasonably fast, and then you can go to finer layers once the basics are right.

This is kinda of a fiddly print, with a lot of detail, and overhangs. I'd recommend starting with a simple cube or cylinder, and see how that turns out. Take some photos of the first layer, so we can see how consistent the extrusion is, how regular the shape is, whether the infill touches the perimeters etc.

 

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Your owl is getting better but there is some serious serious cooling issue. Did you check the fan? What was the deal? Could it be off? Could it be backwards? Please reply about the fan. The fan. The fan. The one near the nozzle. It should be spinning. Need more info.

I'd like to suggest other things it could be but most likely it's the fan. It could be backwards. Seriously - check the fan. Let us know. If you are convinced the fan is working, I will tell you my second choice for the problem, but I suspect it's the fan. I mentioned the fan in an earlier post because - well that's what it looks like when the fan is off. There are other possibilities but I'm afraid you won't answer my question about the fan.

 

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I added more pictures. and that is the reason why i have to print infills slower..i think,

When it prints at same printspeed(50mm) it will miss some spots and then get worse over time as the height goes up(as you can see), Anyway to correct this? Im confused why infills should go faster than print speed.

Lol, so sorry gr5. i wasnt able to answer you. yes the fan is good. What other reason could it be?

Early layers are GOOD at least for me, arent they?

Oh was able to accurately(from calipers) measure filament diameter @ 1.67-1.7, i put the value at 1.68.

Btw, gr5 advised against minimum layer time, yet mr illuminart says otherwise. Can please explain why? i dont understand

 

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No, George said to get remove the minimum speed setting, and set minimum layer time to 7, the same as I did.

In theory, you can print infill faster than the outside because you don't care what the infill looks like, and it's always laying down on top of earlier infill. The outside you want to look good, and it has to handle overhangs and subtle details. So, you might decide to print the outside at a slower speed (30-50mm/s) and the infill much faster (100-150mm/s). There can be issues with that approach due to varying pressure in the head, but some of us do it.

But for right now, you're not close to that point. You should be able to print this with everything at the same speed at 50mm/s and get good results.

Change the minimum layer time, and try again. Also, print a circle as I suggested above.

 

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yes the fan is good. What other reason could it be?

 

Did you feel it? Are you really really sure?

The next most likely thing is you need to increase "minimum layer time". I found that 5 seconds is enough but whatever it is for you then you should double it.

These 2 things are by far the most likely - I've seen this many times and your basic problem has to do with cooling. Other causes: Are you printing in an environment that is very hot? Say over 90 or 100F? (Over 35C?)? There is some kind of problem with heat - just don't know what it is. Maybe the nozzle is hotter than you think. Even though the UM thinks the nozzle is at 200C it might in fact be at 260C. So lowering as low as you can go might help - for example lowring the nozzle temp to 180C might in fact bring it down to 240C which should be low enough. If you have some kind of method for measuring temperature accurately that would help.

Maybe you have a weird filament that is melting at lower temperatures. You could start with a cold nozzle and increase the temp slowly from 50C to 180C and keep some pressure on the extruder wheel with your hand. See at what temp the filament starts coming out. This is unlikely the problem but gives you an idea. There is definitely a heat issue here.

 

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Hello these are pics of column and box prints as you suggested. Also made tweaks to profile but still have some mess...now printing at 195 and minimum layer 7

Filament comes out at 150-160C is this weird?

Printed the box at 180C.

Now i noticed my model is 20x20x20. Have measure by calipers the actual model size is

20.8X20.8X11.24mm! How can this be?

 

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Sorry but I absolutely refuse to believe that an Ultimaker can print anything that looks like that.

The only prints I have seen like that came from really badly assembled medel etc REPRAPS.

If thats an Ultimaker making those shapes it must be in absolutely horrific condition, and on the verge

of total mechanical breakdown.

I think looking at the layer to layer alignement that you need to post some pics of the printer itself as

I would say the slicer settings are the least of your problems right now.

 

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Or your steps-per-z setting has gotten configured wrongly. Do you have an Ulticontroller? If so, you can check and set the setting in the 'Control -> Motion' menu. If not, you'll need to use gcode. If you're using a computer to connect to the printer for printing, does it report the steps per mm settings when you reset the printer?

The x,y dimensions are always going to be slightly off due to shrinkage etc, and I suspect they'll get better once you fix the z problem. It looks like your platform is only moving half the distance that it is supposed to each time, and so twice as much plastic is getting squashed into each layer as should be. That will certainly account for the messy print finish.

 

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Now i noticed my model is 20x20x20. Have measure by calipers the actual model size is

20.8X20.8X11.24mm! H

 

Aha! There's the whole problem! Your z axis is messed up and it's putting out almost twice as much filament as it should be.

Now you need to calibrate your z axis. Don't print anything. Use Cura or pronterface to move the z screw up and down 10mm and measure how far it actually goes. You need to fix the steps per mm in the z axis. You are probably off by a factor of exactly 2.

If you have an ulticontroller, make sure you save the settings to the prom or you will lose these when you power cycle the UM.

If you don't have an ulticontroller you definitely want to get pronterface. It's free and wonderful. It can make it easy for you to adjust and read back the current steps per mm. Also with pronterface you will need to save to eeprom.

In addition to pronterface refer often to this guide of gcodes:

http://reprap.org/wiki/G-code

Especially M92 and the M50X commands.

 

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No, the dimensions should all be spot on to within a small fraction of a mm. You won't get it exactly right, due to cooling shrinkage. But it should be pretty close. Particularly the z height (although it may be taller than the STL by the amount of the 'extra height on first layer', since that is literally an added thickness).

 

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The x,y,z axes of the UM should be accurate to at least .1mm but the printed model won't be. If you print a cube you should expect some shrinkage. With PLA 20x20x20 mm cube I would expect no more than .5mm X or Y error in the final product (except maybe the bottom few layers). But the height should be correct within .2mm.

So getting 12mm when expecting 15mm is pretty far off.

You can calibrate any axis without actually extruding plastic. For the Z axis you can tape some paper or a ruler near one of the back corners of the machine, put something flat like a pencil or ruler on the bed so that it points to the ruler or paper and then move the bed up and down with pronterface or cura.

But you shouldn't have to calibrate x,y, or z axes as the UM always should have the same values for those axes. The extruder is the only axes typically that could use some minor calibration:

#define DEFAULT_AXIS_STEPS_PER_UNIT {78.7402,78.7402,200*8/3,760*1.1} // default steps per unit for ultimaker

 

I got the above line from the Marlin code in configuration.h. These are the steps/mm for x,y,z,e (extruder) axes.

 

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