Prusa i3 + ABS April 05, 2014 12:04PM |
Registered: 10 years ago Posts: 100 |
Re: Prusa i3 + ABS April 07, 2014 01:18AM |
Registered: 10 years ago Posts: 100 |
Re: Prusa i3 + ABS April 07, 2014 09:02AM |
Registered: 11 years ago Posts: 198 |
Re: Prusa i3 + ABS April 07, 2014 09:11AM |
Registered: 10 years ago Posts: 100 |
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.
Re: Prusa i3 + ABS April 08, 2014 04:24PM |
Registered: 11 years ago Posts: 198 |
Re: Prusa i3 + ABS April 09, 2014 01:44AM |
Registered: 10 years ago Posts: 100 |
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]
Re: Prusa i3 + ABS April 09, 2014 03:39AM |
Registered: 11 years ago Posts: 198 |
Re: Prusa i3 + ABS April 09, 2014 04:04AM |
Registered: 10 years ago Posts: 100 |
Re: Prusa i3 + ABS April 09, 2014 04:26AM |
Registered: 11 years ago Posts: 198 |
Re: Prusa i3 + ABS April 09, 2014 04:31AM |
Registered: 10 years ago Posts: 100 |
Re: Prusa i3 + ABS April 09, 2014 05:05AM |
Registered: 11 years ago Posts: 198 |
Re: Prusa i3 + ABS April 09, 2014 07:36AM |
Registered: 10 years ago Posts: 100 |
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.
Re: Prusa i3 + ABS April 09, 2014 12:35PM |
Registered: 11 years ago Posts: 198 |
Re: Prusa i3 + ABS April 09, 2014 04:17PM |
Registered: 10 years ago Posts: 100 |
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.
Re: Prusa i3 + ABS April 09, 2014 05:07PM |
Registered: 11 years ago Posts: 198 |
Re: Prusa i3 + ABS April 10, 2014 03:01AM |
Registered: 10 years ago Posts: 100 |
Re: Prusa i3 + ABS April 10, 2014 03:02PM |
Registered: 11 years ago Posts: 198 |
Re: Prusa i3 + ABS April 10, 2014 03:04PM |
Registered: 10 years ago Posts: 100 |
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.
Re: Prusa i3 + ABS April 10, 2014 03:14PM |
Registered: 11 years ago Posts: 198 |
Re: Prusa i3 + ABS April 10, 2014 03:18PM |
Registered: 10 years ago Posts: 100 |
Re: Prusa i3 + ABS April 10, 2014 03:32PM |
Registered: 11 years ago Posts: 198 |
Re: Prusa i3 + ABS April 10, 2014 03:40PM |
Registered: 10 years ago Posts: 100 |
Re: Prusa i3 + ABS April 11, 2014 02:45AM |
Registered: 11 years ago Posts: 198 |
Re: Prusa i3 + ABS April 11, 2014 03:26AM |
Registered: 10 years ago Posts: 100 |
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
Re: Prusa i3 + ABS April 11, 2014 07:29AM |
Registered: 12 years ago Posts: 99 |
Re: Prusa i3 + ABS April 11, 2014 07:31AM |
Registered: 10 years ago Posts: 100 |
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.