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thomas-roager

Layers not bonding

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Hello folks.

I have been having this problem from the beginning of my time with ABS.

Heres my setup:

Custom Ultimaker with ramps 1.4

Airtripper Bowden

1.75 Blue ABS from RRW

Using cura. (Slic3r gives wierd results for me)

Hotend: E3D v5 , 245c first layer, 240 rest.

Heated bed: Mk2a, 100c first layer, 94 rest.

The picture should tell everything.

But my observation is that the layers Wont Bond correctly , i Can peel the layers of the print. (I Got No fans blowing)

Please help me out, i have building a prusa and Then this UM and havent Got 1 print out of it yet.

gr5 edit - added link to pictures:

https://docs.google.com/folderview?id=0B44jifdi0ZbBSlVPbDlVSjI1X0U&usp=docslist_api

 

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Does you extrusion look good? Ignoring the first layer, do the lines touch nicely? Or is there a gap between every line as seen from above?

If extrusion is good then you need more heat. I only ever print 245C with ABS. That's only 5C hotter than you. I suspect your temperature is off a bit - maybe the probe is too far from the nozzle tip? Maybe the probe is off by 15C? Try raising the temp another 10C or so to about 250C - that's what I would try. But if you get it too hot you can get a clog.

When layers separate you usually need more heat.

 

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Now that I see your photo I changed my mind!

The *walls* aren't bonding.

I think you have backlash (also known as "play"). This can be caused by friction too high or belts too loose. Probably belts too loose. Try sliding both X and Y stepper down a bit to tighten the belts. You might have to tighten you long belts also.

Paradoxically, if the long belts are too tight then friction will be too high and you can also get the same symptoms.

Also if friction is high check that if you loosen some of the 8 endcaps maybe friction will lower drastically.

 

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gr5:

Thanks for your fast answar. Ill try with higher temp tomorrow and ill check my belts. But last i checked , they were quite tight. I could maybe get some friction because of the endcaps. I Got the fine tuning endcaps from thingiverse and i really dont like em.

But when i watch the layers be printed it looks like it touches each other, or maybe it doesnt look like that?

I tried lowering the size og the filament and Then the print looked wierd ..

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You should be able to move the head with one finger on each block on the sides. Easily. So that is one finger each hand - each finger pushing on one side block. Try this with the X axis also.

If you pluck the long belts like strings they should make a low pitched note.

The short belts (to the steppers) should be much tighter - quite tight. Maybe 3Kg force pushing down on the stepper while tightening?

In one of the photos from overhead one of the curved edges was almost not touching the second shell layer inside. I think that's the main problem. Higher temperature may also help but I think this is mainly "backlash".

 

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i just tried at a higher temp. i have to get to 265-270 before i get good layer bonding. everything below gives bad bonding. but now i have little trouble with skipping steps of the x axis. now I'm trying to mount a better fan onto of my ramps to see if it was overheating.

 

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You should be able to move the head with one finger on each block on the sides. Easily. So that is one finger each hand - each finger pushing on one side block. Try this with the X axis also.

If you pluck the long belts like strings they should make a low pitched note.

The short belts (to the steppers) should be much tighter - quite tight. Maybe 3Kg force pushing down on the stepper while tightening?

In one of the photos from overhead one of the curved edges was almost not touching the second shell layer inside. I think that's the main problem. Higher temperature may also help but I think this is mainly "backlash".

Please gr5 se this video.

https://docs.google.com/file/d/0B44jifdi0ZbBckpISG5RYW4tMTg/edit?usp=docslist_api

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Your Y axis friction looks fine.

Your X axis has issus - that ticking is the belt riding up on the pulley I think.

You need to check your alignment - the X belts should be directly below the X rods. Directly. As you slide the X to the left then you can check the left end of both X rods and see if the belts are lined up perfectly. At least one of them isn't I think. Loosen that pulley and slide it along the shaft until it's perfectly under the rod then retighten. And tighten the pulley set screw a lot! The hex tool should twist some.

If you make another video, pluck the belts with the head in a corner. All 8 top/bottom halves of the 4 long belts and also the 2 short belts (either side).

I'm not 100% certain you have backlash. It sure looked like it but maybe it's fine other than the clicking (minor issue).

You said you checked the endcaps right? And if you loosen them then the head doesn't move any easier?

You can also put a few drops of light oil on all 6 rods (4 thick rods, 2 thin rods) although they shouldn't need it. Any light oil is fine but better to use oil with as few additives as possible (WD40 has additives that you are better off without). But any light oil should be fine.

 

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Your Y axis friction looks fine.

Your X axis has issus - that ticking is the belt riding up on the pulley I think.

You need to check your alignment - the X belts should be directly below the X rods. Directly. As you slide the X to the left then you can check the left end of both X rods and see if the belts are lined up perfectly. At least one of them isn't I think. Loosen that pulley and slide it along the shaft until it's perfectly under the rod then retighten. And tighten the pulley set screw a lot! The hex tool should twist some.

If you make another video, pluck the belts with the head in a corner. All 8 top/bottom halves of the 4 long belts and also the 2 short belts (either side).

I'm not 100% certain you have backlash. It sure looked like it but maybe it's fine other than the clicking (minor issue).

You said you checked the endcaps right? And if you loosen them then the head doesn't move any easier?

You can also put a few drops of light oil on all 6 rods (4 thick rods, 2 thin rods) although they shouldn't need it. Any light oil is fine but better to use oil with as few additives as possible (WD40 has additives that you are better off without). But any light oil should be fine.

 

i think its my bearing for the x axis thats bad ..

yes it was a really bad bearing. can make a rattle sound when i shake it :O damn some work to find that error !!

 

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the pressure fit bearings. i replaced it and now it doesn't have a clicking noise.

i have changed my bearings for the x&y axis (11x8x30) to some peak material and it runs a lot smoother. now i can move it with 1 finger from all sides.

but I'm still left out with the problem, the layers are cracking even at 265 degrees. and also my prints got some kind of ringing or maybe the infill is creating the ringing of my parts I'm not sure.

and i found out i was under extruding. i changed that. but that still doesn't solve my problem :( I'm afraid i have to change back to PLA even though I'm not a fan of PLA.

 

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