Prusa i3 + ABS

Hello.

i got this printing problem.
[drive.google.com]
[drive.google.com]

i got a Prusa i3 with a 0.5 nozzle All metal J Head.
Im using Cura as my slicer because of the simplicity. (and Slic3r are even worse.)

Layer Thickness: 0.25
Shell Thickness: 1
Hot End Temp: 220
Bed Temp: 110
Print Speed 45mm/s
Using Raft as Adhersion

Retraction Distance: 4.2
Retraction Speed: 40mm/s

first of all my prints got layers showing alot and i got delamination. How to help those problems ?
i tried calibrating my extruder and i think i got it right.
What to do ?

Thanks in Advance.

No one ?

Looks like inconsistent extrution, are you sure that the extruder can do 40mm/s retracts, and that it is not skipping when printing?

Also check for gunk in the hobbed bolt.

220 degree is a bit low for ABS, I would try at least 235 degrees, this should advoid delamination, if you are not underextruding too much.

Quote
Ralf
Looks like inconsistent extrution, are you sure that the extruder can do 40mm/s retracts, and that it is not skipping when printing?

Also check for gunk in the hobbed bolt.

220 degree is a bit low for ABS, I would try at least 235 degrees, this should advoid delamination, if you are not underextruding too much.

Im not sure it can do the 40mm/s for retraction.. but i get no blobs in the print with the 4.2mm and 40mm/s in retraction in Cura.
no bunks or filament grinding in the hobbed bolt...

I'm having a hard time getting over 220 degrees because of my 30x30mm fan cooling the hot end.

I just got the E3D Bowden hot end , and I'm planning to use it with airtrippers bowden extruder. and just got some laser cut parts for my frame (i have been building my own frame).
maybe this would help ? I'm not sure.

but when I'm calibrating my hot end to retract 100mm I'm getting around 96 and sometimes 104... i can't get it closer and when I'm near the 100mm I'm getting a lot of over extrusion..

You could try to lower the retraction speed to 20mm/s just to see if it changes anything, if for some reason the extruder is skipping, when it is un-retracting, you will have under extrusion after every retracts. It looks like that is happening around the hole on the first picture.

Ideally you shouldn't use a fan when printing ABS, I use it sometimes, but only at about 20-30% speed, just to create a bit of circulation around the print. If I crank it any higher, I have issues with warping, and the print coming off the bed.

Also a source of the layering, could be the heated bed moving up and down from heat expansion, this can happen when PID isn't enabled, or properly tuned for the heated bed. I've been there.. [forums.reprap.org]

Quote
Ralf
You could try to lower the retraction speed to 20mm/s just to see if it changes anything, if for some reason the extruder is skipping, when it is un-retracting, you will have under extrusion after every retracts. It looks like that is happening around the hole on the first picture.

Ideally you shouldn't use a fan when printing ABS, I use it sometimes, but only at about 20-30% speed, just to create a bit of circulation around the print. If I crank it any higher, I have issues with warping, and the print coming off the bed.

Also a source of the layering, could be the heated bed moving up and down from heat expansion, this can happen when PID isn't enabled, or properly tuned for the heated bed. I've been there.. [forums.reprap.org]

Ill try with the retraction speed settings, maybe it is running too fast.

I'm using a fan to cool my hot end, same way the E3D is cooled at the fins. no cooling on the object at all.
maybe i should at a fan like you say 20-30% speed just to make better overhangs and such. i got no issues with warping on the bed(only if its big objects!)
i use an aluminum bed and my bed temperature is around 108 degrees celsius.
My setup for my heated bed is 6mm alu plate underneath then a little space, then the PCB MK2A and then again 3mm alu plate, onto where I'm printing there is kapton tape to make it stick. Maybe i should do something else ?

Seems pretty stable to me..

I use glass with Kapton on top of the PCB heater, but I have considered switching to Aluminium, to get a more even heat distribution, when using the fan.

i have been looking for Ninja Printer Plate or the carbon printer plate to replace the kapton tape. but haven't seen any good reviews of it yet, and quite expensive.
so i really don't think the heated bed is my problem for the delimitation, and i think a heated chamber is a lot of work and can't find any good chambers for the Prusa i3.

I'm waiting for some new filament to print some new parts for my printer to adapt my E3D and new frame but hope that solve my extrusion problems.
But I'm wondering if i should use a direct drive or bowden i can't decide what type i should use yet. Any recommendation ??

If you want to print fast, a bowden setup is the way to go, as it keeps the weight down on the moving parts. But unless you have a H-Bot or a Delta printer you will still be limited by the weight of the moving bed.

Well my problem isn't the speed its more likely the quality of the print, I'm seeing a lot of layers now, id like to reduce the over/under extrusion I'm getting.

The defects seen on the pictures you posted, wont disapear by switching to a bowden setup, it might be even more dificult to get rid of them, as you have a few more variables to take into account with a bowden setup.

My limited experience with a bowden setup is that it requires more tuning to get nice results, compared to a classic setup with the extruder mounted directly above the hotend. Also swapping filament is a bit more tedious, on a bowden setup. So if I were you, I would wait until I had everything under control, before I moved to a bowden setup.

Quote
Ralf
The defects seen on the pictures you posted, wont disapear by switching to a bowden setup, it might be even more dificult to get rid of them, as you have a few more variables to take into account with a bowden setup.

My limited experience with a bowden setup is that it requires more tuning to get nice results, compared to a classic setup with the extruder mounted directly above the hotend. Also swapping filament is a bit more tedious, on a bowden setup. So if I were you, I would wait until I had everything under control, before I moved to a bowden setup.

Okay thanks for the input.

But what to do about the delamination ?

You should try to get the pemperature up a bit, wraping the heater block on the hotend in some kind of isolation, will help, but depending on hotend design, this is easier said than done, I use "power wrap" normally used to isolate exhaust manifolds. An alternative is Kapton applied loose, e.g. with a lot of folds and air boubbles, the uglier the better..

Also take a close look at the hobbed bolt, if the hobbing isn't even all the way around, the diameter is probably also not even, and this affects extrusion rate which will vary with the revolution of the hobbed bolt, printing tall single wall object might reveal this as a pattern.

Quote
Ralf
You should try to get the pemperature up a bit, wraping the heater block on the hotend in some kind of isolation, will help, but depending on hotend design, this is easier said than done, I use "power wrap" normally used to isolate exhaust manifolds. An alternative is Kapton applied loose, e.g. with a lot of folds and air boubbles, the uglier the better..

Also take a close look at the hobbed bolt, if the hobbing isn't even all the way around, the diameter is probably also not even, and this affects extrusion rate which will vary with the revolution of the hobbed bolt, printing tall single wall object might reveal this as a pattern.

Well i just Got the e3d and waiting for some parts to Mount it on my printer, so the heat Will soon not have the heat problem.
And i Got the hobbed bolt from reprapworld og works quite Well. No problems there.

But Will those factors solve my delamination?

There is no guarantees, but printing ABS too cold, typically leads to delamination.

Your hobbed bolt is probably ok if it's from RepRapWorld.

Quote
Ralf
There is no guarantees, but printing ABS too cold, typically leads to delamination.

Your hobbed bolt is probably ok if it's from RepRapWorld.

the delimitation isn't caused by room temperature ?

It ts perfectly doable to print ABS at room temperature without the parts delaminating, of course boxing the printer in a heated chamber is better.

Quote
Ralf
It ts perfectly doable to print ABS at room temperature without the parts delaminating, of course boxing the printer in a heated chamber is better.

What do you recommend for printing in room temp? More heat on extruder and What about heatbed ?
I Can only get it to stick at 108 or more on the bed.

More heat on the hotend, 108 is fine for the bed, but if you get problems with overhangs and pointy details curling up, for the bottom 1-5 mm of the print, you might have to lower the bed temperature after the first layer.

Quote
Ralf
More heat on the hotend, 108 is fine for the bed, but if you get problems with overhangs and pointy details curling up, for the bottom 1-5 mm of the print, you might have to lower the bed temperature after the first layer.

So 240 on the hotend ?

Yep should be fine, you can even go higher, some print at 250 degrees, I normally print ABS at 245, and that works ok.

Maybe i should try it out Then. But What speed settings?

You will have to experiment with the parameters, to find out what works best on your printer, there is simply too many variables that can be tuned, and something which works on one printer might not work on another printer.

There is a reason why comercial printers is locked down in every way, requiring filament from the vendor, and has a limited selection of hotends etc. as this is the only way the manufacture can guarentee that the printer will work, and produce predictable and reproducible prints, no matter where it is set up, or by who.

Start out with some relative conservative settings, and use as many defaults as possible, and the tune from there.
30mm/s printing speed, and 0.25mm layer height, 2mm retraction @20mm/s, 110 degrees on the print bed, 240 degrees hotend for ABS, should get you started.
As for firmware accleration 1000mm/s2 for XY and 2500mm/s2 should work on most printers, XY and E jerk settings around 20, Z jerk 0.4

Quote
Ralf
You will have to experiment with the parameters, to find out what works best on your printer, there is simply too many variables that can be tuned, and something which works on one printer might not work on another printer.

There is a reason why comercial printers is locked down in every way, requiring filament from the vendor, and has a limited selection of hotends etc. as this is the only way the manufacture can guarentee that the printer will work, and produce predictable and reproducible prints, no matter where it is set up, or by who.

Start out with some relative conservative settings, and use as many defaults as possible, and the tune from there.
30mm/s printing speed, and 0.25mm layer height, 2mm retraction @20mm/s, 110 degrees on the print bed, 240 degrees hotend for ABS, should get you started.
As for firmware accleration 1000mm/s2 for XY and 2500mm/s2 should work on most printers, XY and E jerk settings around 20, Z jerk 0.4

Thats a good start, ill try this next week, to see if i can go with all the standard settings.

If you are still getting de-lamination issues check for random air movement around the room, or even the fan on your hot-end. Even the slightest amount of air movement can suck the heat right out of your hot-bed. If you are still having issues with large ABS parts try covering your printer with a turkey/oven bag. The idea here is to help prevent outside air movement from affecting your print, but also retain some heat keeping the part warm.

Quote
ikilledkenny
If you are still getting de-lamination issues check for random air movement around the room, or even the fan on your hot-end. Even the slightest amount of air movement can suck the heat right out of your hot-bed. If you are still having issues with large ABS parts try covering your printer with a turkey/oven bag. The idea here is to help prevent outside air movement from affecting your print, but also retain some heat keeping the part warm.

So your recommendation is basically a heated chamber ?