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Hello,

I'm working on trying to calibrate our machine and I thought that I would start to post some images of my work in progress. I'm hoping that people will spot some pitfalls and comment on how to fix these issues. So far I have been printing out TONS of calibration cubes.

...or really like a dozen.

I seemed to get those to look ok, but when I applied those settings to other parts they didn't work at all. Once the machine is calibrated shouldn't those settings for the most part apply to other models as well?

I'm not sure that I have a grasp of what the filament looks like when it's too cold, or too hot. I assume when it is too cold, it just gets choked in the head and doesn't come out or if it does it's not enough. When it's too hot I assume is gets so hot that after it comes out of the nozzle it doesn't cool quickly enough so it becomes a bit gummy and sticks to itself and the hot end. If the bed is too cold I assume that the extruded filament won't stick. So if you have a good surface and the part isn't sticking keep cranking up the temperature? When it's too hot? No idea. I assume that I run out of current before that time.

I have also been playing around with the Extruder Step Per MM value and cranking that down so that less material is being forced out of the hot end. This has definitely helped with material sticking to the heated bed better.

Why do my parts look so (excuse my language) boogery? No idea. I also don't understand why the thin walled test cubes are so irregular in their thickness.

Any comments are entirely appreciated!

[img]http://i.imgur.com/JJdwnBn.jpg[/img]

[img]http://i.imgur.com/rC4XQTw.jpg[/img]

[img]http://i.imgur.com/CuCNddJ.jpg[/img]

[img]http://i.imgur.com/ucdzz4U.jpg[/img]

[img]http://i.imgur.com/MrAY7Lu.jpg[/img]

[img]http://i.imgur.com/UZJVCqq.jpg[/img]

[img]http://i.imgur.com/9F6a4XX.jpg[/img]

[img]http://i.imgur.com/TYrlLH3.jpg[/img]

[img]http://i.imgur.com/a1RkIPm.jpg[/img]

Wow and congrats! You're printing!

In general, I'm not sure you're doing this - but stick with one print and get it right, then move on. I know it's easy to get bored with the same object. Every object will print differently but you need to stabilize first and then go with different prints. (I made this mistake too, lots of wasted time.)

From what I see, you're not extruding enough and then extruding too much filament. Steps per - are fairly set and there are lots of posts about it - I'm not sure of the authoritative one but use google search and do: site:forum.seemecnc.com and the search terms and you'll get more than a few posts to read.

If you're happy with the calibration cube or similar, then move on.

Also, before you start in again, there is this.

http://forum.seemecnc.com/viewtopic.php ... 35&start=0

Lastly, the big focus is to get the machine right - with a single print and then it's almost all software from there - which too is very important: If you're having problems printing something, always say which you are using: Kisslicer, Cura, Slic3r...

Good luck!

(Guys - we need a sticky or official doc on this one, it is like some of us are rotating on who handles this question - with minor differences in the answer.)

Part of what I see is the Delta Arm Blues.
See this part of the forum: http://forum.seemecnc.com/viewtopic.php?f=54&t=1434

This will explain what is happening and why and how you can fix it.

Hi Guys,

Thanks for you responses. I've been going pretty methodically combing through the forums and feel that I am making progress, but a lot of it feels like muddling through. I have been using Repetier Host on a Rambo 1.1 board and Slic3r as my slicer.

It's good to hear that once things are dialed in that there are less changes, I was afraid that I was going to have to go through this process with every object I print. I have used a commercial 3D printer for years and I never had to do any calibration to it, so I was hoping that was the case. I much prefer being able to service my own machine so I'm never going back, but that is a different story! I have seen both of those topics here on the forum and I will review them again and make sure that I have covered them all. With this post I was hoping to encourage other people to post "ugly prints" as well and solutions they find to the problems. I've done a ton of reading, but I would like to have some reference that says "this looks like this for this reason -- don't do that -- here is how you fix it". This would indeed be a great sticky. It would be hugely helpful.

Part of what has been challenging is that I could get a part like the calibration cube from the assembly guide looking good, then I would move on to the next object and it wouldn't print. I believe after the second object was a 20mm cube with just walls and then filled entirely. I had to use fairly radically different hot end and bed temps to get the second model to print. The filament settings for the Calibration Cube was in the 228c, 90c and the 20mm Cube would be 230c, 104c respectively. Once I had the 20mm Calibration Cube dialed in I thought "great, now I try something different". I did a bed calibration object off Thingiverse and it would only print on half of the bed. After looking at the Rostock Max Calibration Guide I eventually realized that I hadn't leveled all three axis only, origin, Z and Y. Once I figured that I discovered that my bed is convex and higher in the middle. I adjusted the PRINTER_RADIUS setting to compensate for that in the EEPROM. I then discovered the .5mm Walled Calibration Cube (http://www.thingiverse.com/thing:5573 ) off of the above mentioned posting and started using that. That is when I discovered how I was squirting WAY too much plastic and it wouldn't stick down to the base. I'll try and bring it up the Extruder Step Per MM value in the EEPROM. Just a heads up to folks that are using the new EZ Struder be sure and adjust that value WAY down to at least 92.667 and dial it in from there. It moves much faster than Steve's Extruder does.

After getting the .5mm Walled Calibration Cube's settings dialed in I thought great now I can print something I actually want! That's where the cable chain link above comes in. It was clearly starved for plastic at first and I kept dialing up the Extruder Step Per MM value to make it look better. Alas, I ran into the heated bed woes where the extruded filament would not stick to the bed.

As for the "boogers" I have not found a setting to get rid of those. I know that if I set random start points it is a lot better. I thought that it was just excess filament and when I dialed back Extruder Step Per MM they would go away. They didn't. I'm concerned about "The Delta Arm Blues" and figure that I may have either slop and/or tight hinges in the carriage. Probably need to upgrade to the carbon fiber arms, but I want this setup dialed in before I do that.

As an idea I wonder if we should be encouraging people to be putting the setup specs of their machines in their signatures to help people get an idea of what works for other people? Knowing what other people are using for Hot End & Bed Temps/Extruder Step Per MM/Slicing Software/etc. would be very interesting and helpful. I know that it change wildly based off of filament and what is on the bed but it is still a target.

Again thanks for your input and I will review those postings again and see what I missed.

Steve

92.6 is great for the EZ with 16 microstepping on the Rambo v1.1. You'll want half of that for the older boards. I have a hard time picturing how too much plastic is stopping your prints from adhering. With your steps/mm set right I would recommend measuring your filament in many spots and make sure your filament size is set correctly in Slic3r. I would also check and make sure you have the correct nozzle size entered there as well.

The boogers (it's ok to use, it's a technical term) are caused by ooze. Ooze is completely independent from flow. Although, backing flow down will help fix ooze; but in the process you will starve your print for plastic leading to what you see in the chain links, holes and boogers. Ooze is caused by pressure remaining in the nozzle on nozzle moves. You want to pull just enough plastic back from the nozzle to relieve that pressure, but not so much that you starve the print for plastic upon restarting the extrusion.

I'm wondering if you have a heat problem. If your hot end temperature were fluctuating, that could make the plastic come out in blobs.

I can think of three things to check.

• Is the hot end thermistor making contact with the metal and sealed from outside air?
• Did you run the PID tuning procedure?
• in the temperature graph (or on the front panel) does the temperature change much? Mine is always within a degree of the set point.

There may be other issues too. (Delta Arm Blues, extrusion rate, other?) These things are hardest to debug when more than one thing is wrong at a time.