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Copperfil etc.

Posted: Fri Jan 09, 2015 11:04 pm
by dunginhawk
So here is the problem im facing with copperfil... As the print gets higher. this one is about 4-5 inches at the top here... you can see as it starts to get higher, it gets worse and worse... thats extrusion problems, and blobbing a bit.
I think its caused by friction in my bowden tube as its getting higher, and there is more resistance in the tube. Is there anywhere I can move the feeder, or re position it to remove this issue? Ive tried to print this item 7 times now and i just cant get it done...

thanks in advance folks.
[img]http://i1132.photobucket.com/albums/m562/dunginhawk/5782D714-3EB4-444B-8988-31B2C99ED4BC_zpsmyzhcjtf.jpg[/img]

Re: Copperfil etc.

Posted: Sat Jan 10, 2015 9:52 am
by mhackney
duginhawk, I don't know what your setup is now so hard to recommend anything. I switched my Bowden types to PTFE and have great success - they are much slipperier. I also have a RM v1 with the sidearm extruder mount (although I have 2 top mounts also). The Bowden path to the side arm mount is a nice cruciform top to bottom and not the helical tight curve you get with the top mount. Here's a photo - sorry my machine sits in front of a window andit is bright white outside with the snow! But you can see the more graceful open arc of the sediment vs the top mount. This is extreme case of course with the hotness homed but you get the point.
FullSizeRender.jpg

Re: Copperfil etc.

Posted: Sat Jan 10, 2015 11:41 am
by dunginhawk
strange, you actually have more angle in your bottom extruder than i have in mine... im going to be stuck printing pla and abs forever lol

Re: Copperfil etc.

Posted: Sat Jan 10, 2015 12:04 pm
by mhackney
The photo may be deceptive, it is a very open smooth arc. I print everything with no problem so it does work!

Re: Copperfil etc.

Posted: Sat Jan 10, 2015 12:18 pm
by DavidF
Im kind of thinking that it may be you are trying to print it too cold and too fast. What temp are you printing at and what speed, also what nozzle diameter?

Re: Copperfil etc.

Posted: Sat Jan 10, 2015 12:31 pm
by dunginhawk
.5 nozzle, stock.. 195 degrees, and 10-15mm/s

Re: Copperfil etc.

Posted: Sat Jan 10, 2015 7:20 pm
by dunginhawk
so yeah, i just printed with natural PLA from microcenter (i like that stuff) (just got it). it printed all the way to the top with no issues at all. perfectly good..
so its something with the friction in the tube as the print goes higher.

Re: Copperfil etc.

Posted: Sat Jan 10, 2015 8:11 pm
by DavidF
I think you should try bumping the temp a bit, somewhere between 205 and 210 but keep your speeds the same, the .5mm nozzle should be fine but I suspect as you move higher off the bed there is a decrease in temp of the pla in the nozzle (even though it still shows the proper temp reading from the thermistor)
This recommendation may seem a bit off the wall, but please try it.

Re: Copperfil etc.

Posted: Sun Jan 11, 2015 9:28 am
by dunginhawk
i will do so... hard to keep wasting so much in copper each time :) stuff is PRICEY haha

Re: Copperfil etc.

Posted: Sun Jan 11, 2015 1:45 pm
by dunginhawk
so i ran a tower test print using under 2m of filament i had laying around as to not waste more... ran it at 5mm/s and 210 degrees...
the result is??????






[img]http://i1132.photobucket.com/albums/m562/dunginhawk/326463AE-A2E7-4EB2-8DB7-CE879B441035_zps9pq9wx5o.jpg[/img]






keep in mind the mess up at the end, was due to no more filament to feed... so disregard that :)

would you care to elaborate on why the nozzle may be cooler higher up?

Re: Copperfil etc.

Posted: Sun Jan 11, 2015 7:22 pm
by DavidF
I'm terrible at explaining things but if you take temp readings of the part as it gets higher off the heated bed you'll see it.

Re: Copperfil etc.

Posted: Sun Jan 11, 2015 9:14 pm
by mhackney
What I observe in your photos and description is filament starving. Given the regularity that this happens at a larger Z and then when you start a new print all is fine, I believe you have some form of binding in the filament feed path. Here's a test...

bring the system up to temperature
lower down to Z=10 or so
manually feed (push) the filament through (depress the red lever on EZStruder and push!), feel the resistance
now raise to Z = where ever the top of your part is when that problem happens ( pick the height of the part in the last photo)
manually feed again

Did you feel anything different, more pressure?

If so, then isolate and fix, if not do the same test but now use your host software to extrude 50mm at 50mm/s at Z=10 and then again at Z="the height". What happens now?

Re: Copperfil etc.

Posted: Sun Jan 11, 2015 11:19 pm
by DavidF
well I feel a bit dumb now. I can not see pictures when im on my phone and was thinking it printed ok that time around. :oops:
Thing is I had experienced the same issues a couple of times and bumping the temp 10c fixed it just fine.

Re: Copperfil etc.

Posted: Mon Jan 12, 2015 1:23 am
by dunginhawk
David, it absolutely printed fine that time... the top of the print looks starved because it was... the filament ran out ... i had about 2 meters laying around to do my test tower and it worked like a charm... went above the overall height of my main project with no issues at all.. so i do think there is something to this temperature thing.. if i run another print at the same temp and speed, and it fails, then ill have to look elsewhere, but the test print worked man. thanks

Re: Copperfil etc.

Posted: Mon Jan 12, 2015 7:59 am
by mhackney
It wasn't clear to me that this print worked either. Running out of filament is abrupt and would not result in that sort of open layering (filament starving) - especially that band about 20% down from the top.

Temperature and extrusion speed are directly proportional. Once you determine the optima temp for a filament at a particular speed, as you raise e the print speed you have to raise the temperatures since the filament is not in the hot zone long enough to melt. Every filament is different. This bronze and copper filled PLA requires a bit more heat than pure PLA and from my experiments seems to be a little more sensitive to needing more heat at faster extrusion rates.

Re: Copperfil etc.

Posted: Mon Jan 12, 2015 9:35 am
by DavidF
mhackney is right, thats still starving for filament, the print is better yes, but not quite there yet.

Re: Copperfil etc.

Posted: Mon Jan 12, 2015 9:48 am
by DavidF
Im thinking pull the nozzle and inspect between the brass and ptfe liner to see if there is some ooze/creep between where the two meet.

Re: Copperfil etc.

Posted: Mon Jan 12, 2015 4:32 pm
by dunginhawk
yikes.. never done that.. not sure id know exactly what im looking at :)

Re: Copperfil etc.

Posted: Tue Jan 13, 2015 12:32 am
by DavidF
somewhere on here there is a thread with detailed pictures showing the tear down of the hot end, been awhile though. Try mhackenys suggestion first and see if you notice anything.

Re: Copperfil etc.

Posted: Tue Jan 13, 2015 9:17 am
by mhackney
Here is a photo showing my polishing results (first attempt). The top two rings (Bronze and copper) are my prints, right off the printer and polished. The bottom bronze ring was sent to me by a friend in Maryland. It was a little rougher off his machine (a cartesian printer of some make).

I used fine green pyramids with water trickle. My rings were polished for 12 hours and took on a lovely metallic sheen. His was polished for 36 hours and the sheen was about the same after 12 hours. I was hoping that the abrasive media would remove the extrusion lines so I wouldn't have to sand the parts before polishing. That seems not to have happened even after 36 hours.
FullSizeRender.jpg

Re: Copperfil etc.

Posted: Tue Jan 13, 2015 10:10 am
by dunginhawk
wow... those polished up amazingly well... thats one of my problems.. ive gotten some good prints, but i can never get that polish like you have.. fantastic work