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CostumeBiz

Arrrrrgghhhh it almost printed it !!! HELP!!!

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Oh masters of the Ultimaker universe I am printing a cross gaurd on my UM2E and it printed perfectly until the last 11 minutes then it slipped somehow and the filament isn't cooling fast enough and I am getting gobbly goop. I am using simplify3D and have changed the fan setting to 100% for layers less than 3 seconds. What else can be done?

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You have a few choices.  One choice is to add a tower that is slightly taller than the part - that way your part will have a little time to cool while printing the tower.

 

Another choice is to rotate this print 90 degrees so it is flatter to the bed.  This might make one side ugly and that might be a problem for you.  But it would give all areas of the print plenty of time to cool down.

 

The problem is probably also related to the extreme overhang so printing it "flat" could really help a lot. 

 

 

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Those shifts might come from the edges curling up, and the nozzle brutally banging into these edges, and missing a few steps. Just a guess, but not unlikely. I have occasionally had models being knocked off the build plate, if the edges curled up 1 or 2mm, at a layer height of only 0.1mm. This causes brutal crashing of the nozzle into the edge.

 

For small models I use a dummy tower to print such small things where extra cooling time is needed. But for a large model like this, it would waste quite a lot of material. Unless you really hollow-out the dummy tower at places where no extra cooling is needed.

 

Depending on the purpose, an option might be to cut the model in half using a vertical cutter plane, print both halves flat on the glass, and glue them together and sand the seams. Then you need no support at all, and there will be no overhangs (except for the little hole in the center).

 

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Well I decided to check the tightness of the X Y pulleys and discovered that I am missing one of the 5mm spacers allowing one of the Y rods to move when the machine is covering a large area. Gonna go to the hardware store to see if I can find something to put there. As far as printing points goes...small projectiles and tubular items  less than 1/4"  diameter just do not print correctly.

 

I am going to change over to a Olson block in a few days what fan mods has anyone played with?

 

Can anyone show me pictures of successful pointy prints they have done on their UM's? and how they achieved them?

 

Decided to print the part on my CR10 S5 she can handle these types of prints see image from the CR10 of the same model with the same supports.

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38 minutes ago, yellowshark said:

Comparing the two images then in your original image the right hand pointy bit looks screwed too; assuming the version of the model is the same.

There was a very small build up on one arm just knocked it down with sand paper but seeing as I do not have to include additional objects in the print to get this quality I am good... the infill was 100%.

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OK now the culprit has been made clear. It appears that there was no loose pulley afterall and that the problem was the slicing software First image with layer shifting was sliced by Simpllify3D image 2nd image by Cura. So why???  Why is Simplify3D sketchin out well past the midway of the print? I checked the print volume and the numbers where correct. I am at a loss... Hate using Cura but will be forced to if Simplify3D issues cannot be overcome.

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Edited by CostumeBiz

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Marlin is very complicated (the firmware in your printer).  I could explain why different slicers are going to have different results but it would take an hour.  If you really want to know spend at least 10 hours going over the motion planner and slowly all will become clear why changing the angles on two consecutive moves, moving Z axis while moving X, changing speeds slightly, can make all the difference on how much actual acceleration is happening.

 

The short answer is slight changes in gcode can make large changes in acceleration and the higher the acceleration the more likely you will have a pulley slip.

 

The solution is to tighten the hell out of your pulleys.  All 6 on the slipping axis.  I think that looks like your Y axis.  Make sure you have a 2mm hex driver (the same driver as for all the other screws on the printer) and tighten those set screws VERY tight.  So tight you are scared something will break.  Usually it's one of the two on the short belt and really it's usually the one on the stepper motor.  If you use a L shaped allen wrench your fingers should hurt after.  

 

If you don't believe me then mark the shaft and pulley on the stepper motor with a sharpie and next time it fails look at the markings and you'll see they slipped.

 

There's also a tiny possibility (5%) that the problem is your stepper driver is overheating.  If you are printing in a hot room (e.g. 30C) then I'd lower the X/Y current to 1000ma (it's a setting in the menu system if you have tinker marlin installed - probably not an option with the standard UM firmware).  You can verify this is the problem by removing the bottom cover, printing with a book under one side of the printer (tilted - yes you can even print upside down - it doesn't matter) and having a table fan blow air under there.  But 95% chance you have to tighten a set screw.

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Thank you I will check the short belts on the stepper motor and test mark the belts.

Simplify3D said to reduce the printing speed to 50% but at what layer height should I change the speed?

 

In regards to the stepper motor I do have the unit enclosed as I am working with ABS but its not all that hot in there.

 

Tinker Marlin? How can I install it and where can I get it.

I have changed the jerk and acceleration settings on my CR10 for better prints can I do the same with Tinker Marlin?

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It's not a simplify3d proglem.  It's a pulley-slipping-on-shaft problem.  It takes 5-10 minutes to fix depending on if you have to take the cover of (2 screws) and the motor out (4 screws) versus just do it from above (you can push the head around by hand to get the set screw to line up).

 

 

Regarding the stepper driver - they are under the printer.  The steppers don't have any electrical components other than 2 coils of wire.  I mean if you live someplace warm like India.  Or Egypt.  And don't have air conditioning.  Then I would suspect the air temp first and lower the stepper driver current.  It's adjustable for this exact reason as they get very hot.  Hot enough to boil water.  The steppers also get pretty hot but not as hot as the drivers I think.  80C is a common temp for the steppers and they can handle that easily.

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Hmmmmm that just does not make sense why would the print go perfectly using Cura.. and wonky half thru using Simplify3D?  Are you thinking the lack of speed control on S3D is causing slippage? Well I tightened all the screws I could reach... the one on the actual Y motor proved to hard to get the tool into.

 

 

Bryn

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4 hours ago, CostumeBiz said:

I have changed the jerk and acceleration settings on my CR10 for better prints can I do the same with Tinker Marlin?

 

Yes, but you don't need it for this purpose. You can adjust the motions settings with the standard firmware too. On an UM2 you find it in the menu:

Maintenance -> Advanced -> Motion settings

 

28 minutes ago, CostumeBiz said:

why would the print go perfectly using Cura.. and wonky half thru using Simplify3D?

 

To rule out some things: can you show us the starting script from the S3D settings?

 

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M907 E1400 ; increase extruder current

G28 ; home all axes

G1 X20 Y10 F3000 ; bring extruder to front

G92 E0 ; zero the extruded length

G1 Z10 ; lower

G1 E19 F200 ; purge nozzle quickly

G1 E26 F60 ; purge nozzle slowly

G92 E0 ; zero the extruded length again

G1 E-5.5 F400 ; retract

G1 X190 Z0 F9000 ; pull away filament

G1 X210 F9000 ; wipe

G1 Y20 F9000 ; wipe

G1 E0 ; feed filament back

 

Here's the starting script from Simplify3D

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6 hours ago, CostumeBiz said:

Well I tightened all the screws I could reach... the one on the actual Y motor proved to hard to get the tool into.

Yes.  Well there are 2 screws holding the cover over the Y stepper.  And then 4 screws holding the stepper in place.

 

Although if you really try you might be able to tighten it without taking anything apart and save yourself 5 minutes.

 

You really have to tighten that one pulley.  It doesn't take too long to get to it.  Maybe 5 minutes.  Much faster than doing a 1 hour print only to have it get ruined again.  Also - when you *do* tighten it, mark the shaft and pulley with a sharpie so you can see if I was wrong.  But 95% of the time it's one of the two pulleys on the short belt.

 

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