http://www.devogeninteractive.com/pi...1_5333EDB9&jpg
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I love these little tips. We are all plagued by intermittent anomalies and these kinds of things can help ease the frustration. Who know if it's really a 100% perfect solution but it sounds reasonable.
Who knows, we are all new at this I guess :) I think of this more of a habit than a solution, I use filament from all different sources, I found the really bright colourful ones tended to do this, as well as the clear ABS, and since I started practicing this a few months ago, never had a block since.Quote:
Originally Posted by RobH2
i took the habit of cutting the filament just above the plastic plate that hold the strepstruders and always feeding it down, then runing about 1m of the new fillament. I have been doing this for 4 month and never had a problem changing filament.
This is probably more referring to dormant filament that has been left in the extruder for a while. If you are regularly changing filament then it shouldn't happen anyway.Quote:
Originally Posted by chomiliert
Thanks so much for the tip Geoff! I've been wondering about best practice for changing filament. :)
Are there any other concerns a first timer should have about changing filament?
I'm not sure of 100% perfect, but it for sure has caused me to not have any jam's since I have had my machine.
On a side note....as said, I have not had any jam's. But I have been getting a lot of hours into the machine. Should I take apart the extruders and clean them anyway, or just leave it alone since I have not had a problem?
I have a new technique that I use to clean my hot ends. It's worked perfectly for 6-months now and I've had no jams or residual filament issues.
This works best with nylon filament (because it has some lubricity) but it's still useful with any type. When I say "works best with nylon" what I mean is if you are printing with ABS, PLA or anything else and you want to clean the head, do it with a short piece of nylon filament.
Steps:
1. Extrude 10mm and then pull your ABS or whatever out at working temp (say it's 230C).
2. Insert a piece of nylon to in and extrude manually until you see it start to come out.
3. Cut the hotend temp to 130C and let it settle. Once there let it sit for a couple of minutes at that temp.
4. Very, very slowly, back the nylon out. I mean like 1mm/second or slower. If you go too fast you'll separate it inside and not get the whole tip. Once you do it a few times you'll get the feel. Once you've moved it about 10mm you are good to pull it out faster.
What comes out is a nylon plug with the shape of the inside of the hot end and a little tip where it was sticking out of the orifice. Stuck to the outside of the filament is whatever else was in there. Do the steps two or three times if necessary to get it perfectly clean inside. No dismantling or chemicals are needed. It's great for clearing jams too.
Here's a shot of one of my cleaning sessions. The left-hand one was first. The right hand one is now clean and perfect:
http://3dprintboard.com/attachment.p...tid=4538&stc=1
I can say this "When Geoff speaks......" Listen carefully and save yourself hours and hours of aggravation! He give the most thoughtful advice and is speaking from hours and hours of experience. I have been reading many of his post on this forum and I seek them out for the "cut to the chase" no BS approach that he take in his responses to others!
Thanks for the headsup!
Good info, thanks.
i have found the best way to change filament is to just cut the old stock flush with the bit it enters the stepper part, then feed new ontop, let it feed till the new colour is coming out the nozzle, no blockages, no problems so far. as for the 2nd extruder when thats not being used i empty it fully (well till nothing comes out the nozzle)
I used to do that too and even went as far as to take an exacto and drill a conical hole in the end of the part already in the extruder and then sharpen the end of the new filament. Then they would stay in alignment on the way in.Quote:
Originally Posted by Ghosty
Once the filament in the extruder is past the hobbled bolt it doesn't get any "push" anymore. I was printing something that had a lot of retractions. It was pushing my new filament back up and leaving the lower filament without any "push" and causing problems.
Now what I do is turn the hot end down to 120C when I'm ready to change filaments. I let it sit for a few minutes and then I manually back the filament out slowly, mm by mm. After I've pulled about 30mm out I remove it at a normal speed by spinning the large gear. When it comes out it's usually the shape of the inside of the hot end.
What that does in one step is purge the hot end of most of the residual plastic and it also is a bit of a cleaning as it pulls any debris, dust or dirt out that might be in there. I keep filament cleaners on my filaments but I'm sure some debris slips by now and then. I talk about the process here ( http://3dprintboard.com/showthread.p...n+hotend+nylon) in post #8, as a solution to jams.
I think this is especially important if say I've been using ABS and switch to PLA. I print the ABS at 230C and the PLA at 195C. If there is any ABS left in the hotend when I put the PLA through at a lower temp, the ABS is not fully melted and jams can occur. The other scenario is also an issue. If I have printed PLA and now want to print Nylon I have to heat the hotend to 245C. PLA melts at 195C and by the time the residual PLA gets to 245C it can burn and become a hard knot. That can promote a clog.
Using this method has worked well and I like it better than the old way I did it, and, I used to like that old way. I feel this is better on a number of levels.
i see what your saying, but i only ever use pla (i cant stand the smell of abs melting).