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LePaul

Quick question...bed to nozzle...

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I'm still tweaking to get that first layer to look "smooshed" as you guys have kindly advised.

On each edge, as I calibrate and adjust the four screws on the bed, I'm using a piece of paper to guide me. If I can't pull it back and forth, I loosen it slightly.

But I'm not quite at that "smooshed" quality of first layer.

I know this calibration can take time to nail down, I am curious what worked well for you?

Again...I know I ask a lot of questions...but I appreciate your feedback. :geek:

 

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Yes, piece of paper is the way I do it. At each corner, tighten the screw until the paper slides freely under the nozzle, then unscrew it slowly, until you just begin to feel the nozzle catch on the paper as you move the paper around. Repeat that in all four corners, and then loosen all four screws another 1/8 turn, to compensate for the thickness of the paper.

Don't overthink it... sometimes you'll get better first layers than others... so long as the layer goes down and stays stuck, you'll be fine.

 

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This is a good question as it still frustrates me - even yesterday. It wasn't priming the nozzle as much as normal and it took me 3 tries to get a print started but at first I thought it was levelling. Or maybe it *was* levelling. I'll never know as I messed with both things.

Anyway, to answer you... it all depends - if your first layer is .3mm thick it shouldn't be smooshed much because your bead is .3mm high and .4mm wide and that is almost square (.4 by .4) but squished by 25%. But if your first layer in Cura is .2 or .1mm then it *should* be smooshed. So I guess I should ask - what is your first layer in Cura? I'm going to guess you use the "quickprint" settings. It's time to use the "full settings" mode.

If your print is sticking very well to the tape and when you are done printing you are having a hell of a time getting it off without ripping the blue tape then you are fine.

If your print popped right off then you need to squish it in a little more (either that or it's because you didn't remove the waxy surface from the tape using isopropyl (aka rubbing) alcohol).

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I agree, like most of the settings you chose for your Ultimaker, rarely one of them stands alone.

Most of the values are effected by another setting. Like speed-print temperature, etc.

Just as the calibration of your Nozzle-bed level.

It depends on what your first layer is.

 

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I no longer adjust my bed using the paper method. I have found it to be unnecessarily tedious and the process too distanced from the result it is trying to achieve. It is much easier to simply send a job which has a large and long skirt and adjust the screws while the skirt prints, until you have a uniform, well-adhered first layer.

This process eliminates all of the guesswork and conflated variables associated with the paper method, because you directly influence the end result in real time.

 

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I have found that it is easier to find the proper distance between hot nozzle and bed by using this device instead of using the leveling screws: http://www.thingiverse.com/thing:62819

Granted this only works assuming you have already leveled your bed. I just use a flashlight and use the jog function in Cura to move the nozzle to various points and then initiate the z axis home function. From there I just determine the correct distance by eye. If I need to make any adjustments, I simply turn the one screw at the top of the aforementioned device the required distance and repeat the process. Only takes me a minute or two after changing the tape on the bed.

I also agree with gr5 on the fact that there is not one "sweet spot" for all prints. You should change you distance depending on your first and perhaps succeeding layers.

 

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I've been doing as Nick suggests for a long time. It just takes a bit of a trained eye to notice what the proper line width should be as it's printing, but it is easy enough to pick up. Basically, unless my first layer is really having trouble sticking, I am just checking to make sure the fill looks like this - - - - - , not -^-^-^-^- (bed being too close and pushing excess PLA into the line next to it then upward) or -v-v-v- (bed being too far away, causing a line that is too tall and not pushing the PLA out to the width expected for the volume). Of course, that requires that your steps per E is pretty dang close to the value it needs to be. If you think it is, just give yourself a couple of one/two layer prints with some fill in them and a skirt to start picking up on what the proper line width should be. Also, a darker color is easier to pick up on the tape/platform as it can look more opaque if the layer is too thin...

 

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I commend your ASCII, that's an excellent guideline!

I did three test prints tonight.

The first was the Ultimaker Robot and that came out really well.

I then thought I would try a smaller scale version of the gothic chapel but it seemed like I was dragging stringers all over the place.

I cleaned the surface...replaced with new (wider) painter's tape and printer this gear out, which has a tic-tac-toe pattern in the middle of it. I printing it using the Fine setting and .2 layer height. Overall it looks really good but, as you can see in the picture below, there's probably a little room for improvement. (Temp was 220c)

gallery_536_202_105963.jpg

 

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Thanks :) Looking at the inconsistency of the skirt line, I would say you have some slight bed level issues. Bottom right looks too low (looks like the extrusion slid across the tape) while the top left looks too high (extrusion color change indicating the layer is slightly thinner there). Obviously the part printed and stuck to the bed so you are very close on that and any issues after the first two layers are going to be something you are going to want to adjust in the slicer, with either speed or jumping into the advanced settings.

 

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But if you look at the size of the tape compared to the size of the print, i think the deviation in height in the skirt is not due to an offset of the build platform. The print is rather small, so the offset would be less noticeable.

Also, if the tape is going in X, the skirt indicates the bed is too high and front AND back, and not in the middle (Left/Right), which is odd.

Now that i look at it again.. i think we are being fooled by the sharp shadow and the skirt is the same all around ;)

 

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Like I said, you really are very close, I was just nitpicking! If I was to suggest something more substantial I would say try to limit the stringing (that stuff inside the holes) by turning your speed up a notch and seeing how that affects things. There are a couple more things that you can try with regards to retraction, but on such a small spread, speed would be my first move.

 

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I simply look at the skirt, that's why I was critical of those two areas in the skirt. Making the skirt further from the part and multiple lines give you a bit more time and distance to eyeball it. As the skirt is printing I adjust the screws as needed. This tends to work very well as I'm usually within a half turn on at most two screws from part to part. Plus, going all crazy with a dial or feeler gauge is faaaaar too time consuming in my opinion for what I'm doing because the only way it would be relevant would be to do it before EVERY part as every time you take one off the build platform, the platform is going to change. Slightly, yes, but it will change a bit. Most times you can print again without an adjustment, but if doesn't immediately pop off, you would want to re-calibrate. I have found that just adjusting it as the skirt is printing gives me more than adequate results, and quick enough to understand that I can teach a student within two or three prints how to get it close enough to print that I don't have to babysit them the entire time. There's no way I'm having them mess with a dial gauge or feeler gauge and having it be as easily understood as quickly as it is. Like I said, just look for a consistent line on the skirt and you are golden, with the top right of the photo being the part that I would strive to achieve all the way around (if it is indeed different). If the photo slightly misrepresents what the skirt looks like, then you are good to go. If you do want to go after the dial/feeler gauge, Amazon is your best friend.

 

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Yes.

Actually I took the advice someone mentioned and adjusted while the nozzle was hot. I used the Ulticontroller to move the X and Y axis around each corner and adjust each bed screw a bit...I stuck with the 'paper fit thru' as a guide for this print...it came out pretty good. Feedback welcome...I think I'll stop messing with it and finally move on to some larger prints (the Eiffel Tower one I see on Thingiverse is calling me)

 

 

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.I think I'll stop messing with it and finally move on to some larger prints

 

If you mean "stop messing with levelling" then good luck with that. Everytime you pop a piece off the bed it changes. Or just over time the bed droops (gets lower and lower every day a tiny bit).

Don't use the UC to move the head. Just push it around with your hand. On the UC under "prepare" you can do "home all axes" and then conveniently above that is "disable servos" which then allows you to push the head around. Extruder also.

 

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Don't use the UC to move the head. Just push it around with your hand. On the UC under "prepare" you can do "home all axes" and then conveniently above that is "disable servos" which then allows you to push the head around. Extruder also.

 

Ah, disable servos...that's a great tip

I've been searching for some other fun things to try printing. The owl came out fantastic (scaled down to 2 inches tall) I wanted to try some of the statue ones I have seen posted on the Ultimaker site but haven't found the STL of them

Thanks again for all of your assistance.

 

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