1 Topic by DarrellS

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Topic: Please review my test print

Last night I downloaded and printed thing number 109114 from Thingiverse to test out my printer.

I have attached two images of the item and I was wondering if you can tell me what I should do to get a better print.

The leg laying horizontally in the first image is supposed to be a simple smooth finish, but as you can see there are three "waves" that appear to travel down it. They break up at about 3/4 of the way down and the wave pattern changes for a small stretch and then returns to the original pattern. When printed that portion is sticking up. After doing the first test print I installed one of the Z backlash solutions I found on Thingiverse and I printed it again and received the exact same patterning right down to the changed wave pattern at 3/4 of the way down.

In the second image I am questioning the waviness of the edges. This may be the state of the art and if it is that is fine, but I just thought I would ask to see if there is something further I can do to improve the prints.

Thank You

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2 Reply by AZERATE

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Re: Please review my test print

My vote is for over extrusion. Make sure you have calibrated your extruder and perform a PID tuning on the "E" stepper on your board.

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3 Reply by mdrVB6

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Re: Please review my test print

Your second image looks like mine when I had the nozzle too close to the bed and the layers are squishing more than you want them too, causing it to blob out to the side.  It obviously was not bad enough to prevent it coming out at all, but as small as a quarter turn deeper on your z-screw might make it just right.

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4 Reply by DarrellS

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Re: Please review my test print

Well, I don't know what is going on now. I went through the extruder calibration and changed the steps, but the default multiplier in slicer was set to 0.6, so I changed that to one. I leveled the bed again and set the distance between the bed and the extruder nozzle everywhere from .1mm to .4mm and my prints are worse than they have ever been. Most of them I am just having to stop after a couple of layers because the machine is about to shake itself apart from the extruder nozzle hitting what it has already put down.

I have done the paper method to level the bed several times. The piece I am currently trying to print is one of the dial indicator holders, but I can't get it printed because the Solidoodle starts shaking after about three layers.

Does anyone have any ideas to why I am having this shaking problem now? This is starting to become a lot more frustration than it is worth.

I have included a photo of the few layers that printed from the last piece before the shaking got to be too much.

Thanks for any help.

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5 Reply by lueman

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Re: Please review my test print

once calibrated you need to check the Z-offset in printer settings, I set mine to no more than 50% of the z-stop height. so for example if I set z-stop to .305 (my feeler gauge won't go to .30) then my z-offset is -.15. again these are just my settings but they work for me. Also I noticed you get  blobbing, check see if either your extrusion is set too high or if you are stopping in the middle of a print, the latter is caused by mis-matched port settings.

SD4 with E3D V6.

Those who don't know ask, those who don't care comment,  those who comment without answers  hide ignorance for fear of asking. Be fearless!

6 Reply by DarrellS

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Re: Please review my test print

Thanks for the information lueman. I will check my Z-offset tonight.

The one print in my last post was stopped in the middle of printing. If by port settings you are referring to the baud and parity settings, I am pretty sure those are okay because running things in manual works without any problem. The computer portion of things I actually do understand.

I calibrated my extruder by marking the filament with a start band and a stop band that were 100mm apart. I fed the filament in a millimeter at a time until the start band was just at the extruder. I then extruded 100mm and put a mark on the filament at the extruder. I retracted the filament and measured from the stop line to the last mark I made and it was 30mm if I remember correctly. I adjusted the number of steps based on that over extrusion and marked the filament again for another 100mm and followed the same process and the stop mark ended up right at the extruder like it should have. So I believe I have that done.

I just don't understand what setting has changed to get the nozzle to start hitting the previous layer now on a regular basis.

I am printing with ABS if that is of any importance.

7 Reply by mdrVB6

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Re: Please review my test print

Keep in mind that you don't have to do anything with your Z offset, that is only one way to do it.  If you get your nozzle distance from the bed just right manually, you don't have to think about Z offset. 

Additionally, it sounds like you have calibrated your extrusion length but did you also calibrate flow rate?  Here is a good walk thru: http://solidoodletips.wordpress.com/201 … flow-rate/

If your flow rate multiplier is set to 1.0, I would almost guarantee you are over extruding.  Mine is set to 0.70 +/- 0.02 depending on filament brand. 

It would help in diagnosing your problems if we could see how your first layer looks.  If you are over extruding and/ or printing too close to the bed, it should be obvious from the start.  Print an object with a large, flat bottom and stop it before the second layer and post a pic.  Here is an example of a good first layer with a well calibrated extrusion multiplier and proper distance from the bed.
http://i.imgur.com/8tucyId.jpg

SD4 w/ RUMBA, E3D Volcano, all bearings, glass bed

8 Reply by grob (edited by grob 2014-08-04 06:49:34)

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Re: Please review my test print

mdrVB6 wrote:

If your flow rate multiplier is set to 1.0, I would almost guarantee you are over extruding.  Mine is set to 0.70 +/- 0.02 depending on filament brand.

+1

Although I'm usually around the 0.80 mark - it will be different for everyone; it will vary between hot ends and filaments. My understanding is that it's less than 1 because it's the only place die swell is taken into account. EDIT: this is not correct; only applies to free-air extrusion, garbage-in = garbage-out still. smile

I'd recommend putting yours back down to 0.8, then doing the wall-thickness calibration (Ian Johnson's Guide) to find the ideal value. Note that the wall thickness you target should be 120% your nozzle diameter or thereabouts, which for newer SD's is 0.40x1.2 = c. 0.48mm (I use 0.50mm for the sake of round numbers, works fine...).

Post your results here, even if they're good! smile

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9 Reply by adrian

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Re: Please review my test print

umm - just remember... if you have properly calibrated your extruders steps-per-mm, AND have the right filament diameter, your multiplier can (and should) end up a lot closer to 1.0 ... The multiplier is a fudge factor to compensate for bad values in either of the other two data sets... the 'stock' SD stepper has grossly incorrect steps-per-mm, but its compensated for in the smaller multiplier.

You should never adjust *just* the multiplier either. Make sure the following are correct; in order (as they each build on each other):

Extruder Steps-per-mm
Filament Diamater - make it as accurate as possible to 2 decimal places... measure at least 10 times over 10 meters+ of filament and average that value after discarding highest and lowest readings.
Set multiplier to 1.0, and now do the print wall calibration and set the appropriate Multiplier.

Now, you will note, as it is a complimentary calculation between the three - any change to any value will change the equation. So different filament diameters, different extruder arm tension (which can influence steps-per-mm due to the change in 'effective diameter' of the drive-cog (tighter arm digs more into filament, reducing diameter compared to a looser tension arm)) will required different multipliers.

On a 'stock' solidoodle, with uncalibrated steps-per-mm on the extruder, and a ballpark filament diameter, then 0.8-0.9 is a good starting place; but don't hold your breathe on having constant wall widths smile

10 Reply by DarrellS

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Re: Please review my test print

Thanks for the information on calibrating the flow rate. That definitely fixed the dragging over the previous layer. Though my number for the multiplier is .61 which is a long way from one. I retested my extruder calibration and the steps are still matching over 100mm.

11 Reply by exineport

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Re: Please review my test print

Just remember there's an order to things too - No use chasing your tail when step number one was completed last.

Solidoodle 2 Pro - 3mm Glass Bed