1 Topic by jspisak

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Topic: Help with twisting and lifting

First of all I want to thank everyone for the help yesterday I am getting much better print quality! But it seems I have two (maybe one more) little issues. It seems on the longer (bigger) prints the object is lifting from the bed after a while at the edges. Almost like it is curling up... Also, after a while (I think around the time it starts lifting) the print starts twisting and getting out of line. I assume because of the lift but haven't put the two and two together. See attached you can see the top layers got skewed....

2 Reply by jspisak

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Re: Help with twisting and lifting

Sorry attached here...

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3 Reply by ronsii

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Re: Help with twisting and lifting

Looks like you are losing steps from overextrusion... if you extrude too much the added plastic buildup will interfere with the printhead and cause too much drag to the point that the steppers can lose steps and give the skewed effect.

4 Reply by grob

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Re: Help with twisting and lifting

Hello again jspisak! Looking at the wiggly edges and the nozzle marks in the top surface it does look like you're still overextruding quite a lot, and as Ronsii says this could be causing your trouble.

Curling up at the corners is something that happens quite easily. It's mostly because the middle of the print is cooling down and (as all materials do) shrinking, which makes the whole thing bend and the corners pop up. There are plenty of threads on this forum and elsewhere about curling and various ways to make the print stay stuck, but step one will be to get your flow rate right.

How did you go with the extruder calibration yesterday? What is your EEPROM extruder steps-per-mm set to, and what is your filament diameter and extrusion multiplier in the slic3r filament settings? Every printer is a bit different, but we might be able to tell you if anything looks a bit out-of-range.

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5 Reply by jspisak

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Re: Help with twisting and lifting

Hello all! thank you again for all of your comments, I am now running a second print test of the batarang after doing the extrusion calibration. When I did the calibration it looked like I was over extruding about 30 MM so doing the math I set the Steps per mm to 106 from 138... I ran one test at 106 and it was much improved, however it looked like I was then under extruding (had some lines and areas that the filament was not touching, soooooooo this test i bumped it up a little to 115 (just taking a guess here) and it looks to be a little better, but might need to bump it up more.  I also messed with the z stop just a bit after calibrating the bed again because It does not seem to be getting a "squished" line on the first pass. I am afraid to push the print head even closer to the bed as it seems like i am already there based on the solidoodle bed calibration video. I am using a business card to test the height and they were using a metro card it looked like, but I cant imagine it would be much thicker.  when i press it between it has some resistance just like the guy said... Maybe I need to raise it even further. BUT, MUCH THANKS to all the suggestions as it is getting better and better!

6 Reply by wardjr

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Re: Help with twisting and lifting

You want to squish as much as you can get by with.  You should stick with the extrusion calibration math.  Then adjust your Z height as tight as your extruder will allow if it's too tight it will start to strip the filament.  You want it close to that point though.  Then check and see if you have z-offset set to zero.  All that adjustment means nothing if your slicer then moves the bed to a different height.  When you have it right and print a single line (skirt works great) it should be close to 2 times the width of your nozzle diameter (.8mm-1mm) wide.  Remember that in the SD video they are using a metro card on a machine that is set to over-extrude to compensate for uneven bed surfaces.  If your on glass you don't need the over extrusion.  In fact I set my first layer to roughly half extrusion width on that first layer.  This puts down a first layer that is smooth, almost transparent  and impossible to remove until the bed cools.

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7 Reply by jspisak

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Re: Help with twisting and lifting

Again I want to say thank you to all your help! Every single suggestion has tightened up my prints considerably! Looks like I have one more little tweak but can't figure out what may be causing it. If you look at this snowflake you can see there are some gaps but only in the same diagonal direction. The other direction is fine.

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8 Reply by wardjr

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Re: Help with twisting and lifting

jspisak wrote:

Again I want to say thank you to all your help! Every single suggestion has tightened up my prints considerably! Looks like I have one more little tweak but can't figure out what may be causing it. If you look at this snowflake you can see there are some gaps but only in the same diagonal direction. The other direction is fine.

Glad things are improving,
Pillow block with ball bearings on the rear Y-axis drive rod should solve the issue your seeing.
http://www.soliforum.com/topic/4824/how … -for-ever/

Printit Industries Model 8.10 fully enclosed CoreXY, Chamber heat
3-SD3's & a Workbench all fully enclosed, RH-Slic3r Win7pro, E3D V6, Volcano & Cyclops Hot End
SSR/500W AC Heated Glass Bed, Linear bearings on SS rods. Direct Drive Y-axis, BulldogXL
Thanks to all for your contributions

wardjr's Website

9 Reply by grob

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Re: Help with twisting and lifting

+1 on ward's suggestion, gotta lose a little bit of y-backlash to fill those gaps. Still on the to-do list for my machine too!
Looks like your extrusion is good now though, the detail (text for example) is looking pretty slick, nice work. smile

SD3. Mk2b + glass, heated enclosure, GT2 belts, direct drive y shaft, linear bearings, bowden-feed E3D v5 w/ 0.9° stepper
Smoothieboard via Octoprint on RPi