Hot end nozzle jam (I think)

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hvdd
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Re: Hot end nozzle jam (I think)

Post by hvdd »

top slider is speed set to 125 here
bottom slider is flow set to 110

twicx
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Post by twicx »

I FINALLY got to run a test print or two. Firstly, I'm having to run the hot end much hotter than before. It now needs to be 210 just to feed. But anyway, it wasn't feeding right at all, even if i tightened the hell out of the screw/washer/spring bit of the extruder. So I added an extra curved washer/flat washer to the array, and it helped a little. It helped enough that in repeteir host if i feed normally, it'll feed.

When I ran the test print, first problem was the head was too far from the bed. Fixed that, try again. It would print a few layers, then not feed. Tightened the spring even more. Same again. Le sigh...

On another note, because I'm getting closer, it's settings here that I'm wondering about:
Image

These aren't the settings I normally use, but I'm just wondering what people use for Feedrate, Flowrate, and Speed [mm/min]?

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gfeliksdal
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Post by gfeliksdal »

To lower the speed of prnting on the fly you should lower the feedrate. Either with the slider or by typing it on the right of the slider. As discussed in the mail the first thing I would try is to print a new extruder arm. If it is deformed too much it might not be able to put enough pressure on the filament. To print the arm and reduce slipping, I would try to print at a feedrate of 50%. And at max 200 degC. A too high temperature could also raise problems because when the top part gets closer to 60 degC the filament in the top part of the hot-end expands and could get stuck at the top part cause inconsistent filament feeding. To get more margin in that respect, you could try to put the fan at 12V blowing cool air on top. I hope you'll manage to print it :)

superhornet59
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Post by superhornet59 »

Yeah, the extruder is a little iffy.

In Repetier Host, feedrate adjusts x-y-z speed. 200% multiplies the speed of each by.. well.. 200%. Flowrate, in theory anyway, adjusts how fast the filament is fed. Now whether the % change controls the feed rate in mm/s of filament, or mm^3/s of plastic, I don't know, obviously there is a big difference though. I've played around with from one extreme to another and generally haven't seen any particularly noticeable changes, but maybe that's just me.

twicx
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Post by twicx »

Image

so the fan that cools the hot end is now running on 12V. Tried temperature of 180, 185, 190 and 200. Tried it with a feedrate of 40,50,60,70,80 and 100, and flow rate I kept at 100. The screw to tighten the extruder is pretty damn tight. It'll feed no problem through repeteir host, but not consistently through a print job. It seems to be an issue with a lack of tension on the extruder, but I cant print a replacement arm. :/ Would it make a difference if I changed the trimpot for the extruder motor? (I'm just throwing out ideas at this stage.)

twicx
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Post by twicx »

Well shit.

So today I noticed a bit of a crack in part of the extruder. I'm not sure what part you'd call it, but it's the bit that the hot end sits into, the part in this post: http://www.felixprinters.com/forum/view ... t=10#p2593

The crack is on one of the supports of it. It's on the side nearest to the steel frame. I undid the screw that holds it to the extruder main base part, and a piece of it came away. I tried to superglue it back, it's just drying now.

So it looks like both that part and the extruder arm need urgent replacing. Makes it very very difficult to do if i cant print them though.

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gfeliksdal
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Post by gfeliksdal »

Hi twicx, I guess that needs full replacement of the extruder parts. The glueing usually holds long enough to print new parts, but the extruder arm is a different story, since there is so much presure on it constantly. You could try to put it in hot water to deform it back. Then after placing it back onto the extruder assembly you could print the new parts. Otherwise If you mail me we could arrange something to get you up and running again.

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