I am running into a weird problem with 1.75mm filament and the new extruder design. The best I can describe it is that when the filament is going from the rollers (feeders) to the extruder (top/opening), sometimes the filament will bend and start to push through the gap between the top of the extruder and the rollers. This happens about 1 out of 3 prints. I can't figure out why this is happening and its wasting a bunch of filament because I have had this happen 50% of the way through a print .
The older extruder design didn't have this problem because the PTFE sleeving would rise up a bit and sit just below the rollers and there would be almost no gap between them, atleast nothing for the filament to bend/force its way past. I also assume that 3mm filament won't have this problem, its much more thicker and won't bend so easily.
Has anyone else noticed this problem? If so, have you found a solution?
I'm not running the new design, so I'm not sure if this will help you or not, but I had this problem when I first got my machine built. What I found was the tube was not centered directly below the grooves in the rollers. The filament was hitting on the bevel of the tube, and sometimes went sideways and came out the small gap between the rollers and the tube. I took it apart and played around with everything enough until I got it centered, and the problem went away. If I remember correctly (never a sure thing!) I put a washer under one side to tip the tube sideways just enough to get it lined up.
Maybe your's is doing the same thing?
Home made Cnc, 2 CarveWright wood carving machines, Laser cutter/engraver, large format vinyl cutter, large format printer, and now a 3D Printer! Oh, and a shop full of equipment to take large expensive pieces of wood and turn them into scrap and sawdust.
dougmsbbs wrote:I'm not running the new design, so I'm not sure if this will help you or not, but I had this problem when I first got my machine built. What I found was the tube was not centered directly below the grooves in the rollers. The filament was hitting on the bevel of the tube, and sometimes went sideways and came out the small gap between the rollers and the tube. I took it apart and played around with everything enough until I got it centered, and the problem went away. If I remember correctly (never a sure thing!) I put a washer under one side to tip the tube sideways just enough to get it lined up.
Maybe your's is doing the same thing?
Yeah, I noticed that with the new black extruder parts I can't get the rollers and extruder lined up to allow the filament to travel straight from one to the other. I might have to modify the base plate to allow the extruder to sit right below the rollers and allow for more up and down adjustment control.
Did you solve the problem? I am quite curious as I am seriously considering the move to the new Black Nylon Extruder and redesigned hot end but, if there is still a problem with filament squeeze out I will have to reconsider my options.
I was having the same problem with the old hot end on my machine. I solved it by beveling the top of the peek tube and unscrewing it a bit so that it nested up in the V formed by the rollers. I also noticed that the tube was not always centered under the opening and that it would shift off to the side a bit midway through a print most likely due to softening of the plastics from the hot end. I do not yet have a fan mounted to cool the peek tube yet. It's on my to-do list for sure.
I haven't modified the plastic parts (yet), I took the approach of carefully aligning the rollers with the opening of the extruder. So far (crossing fingers) I haven't had a problem with the filament squeezing between the extruder and rollers.
I will keep you posted if I run into any other problems. Overall the extruder design on the H-1 is solid, it has a tremendous amount of torque when pushing the filament into the extruder and is easily disassembled when servicing is needed. I also have a printrbot with a Ubis hotend and a 'wade style' driver, the upside to that design is the simplicity of the driver and hotend, few parts and the hobbed bolt really grabs ahold of the filament.
Both design have their up and downs, but I wouldn't hesitate to purchase the H-1 extruder/feeder.
I have 2 issues with the older H1 hotend (not that I would say don't buy it), the roller on the cold end tends to slip long before the hobbed bolt on a wades style extruder will chew up filament, this somewhat reduces the value of the higher ratio gear train itself since it limits the maximum reliable feedrate, and as a result printing speed.
I actually like the gear train design and using nylon gears is certainly a win, but without the roller providing a better grip it's somewhat wasted.
On the hotend, it tends to dribble plastic on moves (resulting in stringing) more than the other hotends I have here. The Budaschnozle hot end I have on my Mendel Max has very little dribbling even with very short retracts.
Now I have an original hot end with the updated nozzle, I haven't tried the new one and it's not really a fair comparison anyway since the Budaschnozle costs more than the Hot and Cold ends on the H1 combined.
I am having the same problem with new style hot end. The 1.75 filament buckles and wads up inside the extruder over half the time. Long prints have to be slowed down to 70% of my normal feed rates to stop buckling.
The feed tube inlet needs to be closer to rollers, even tapered to go up between rollers a bit.
My original style hot end NEVER did this.
Maybe a taller cone shaped threaded cap that replaces the knurled ring.
May need two sizes 1.75 and 3mm
The hole hole in this cone nut should closely fit the diameter of filament.
The entry hole on new head is larger, 3.6mm vs. 2mm on my old one. I think this contributes to the buckling problem.
~*Brian V.
RostockMAX v2 (Stock)
MAX METAL "ShortyMAX"
MAX METAL Rostock MAX Printer Frame
NEMESIS Air Delta v1 & v2 -Aluminum delta printers
Rostock MAX "KITT" - Tri-Force Frame
GRABER i3 "Slim"
This is what I am thinking, a cone shaped cap.
Thoughts?
~*Brian V.
RostockMAX v2 (Stock)
MAX METAL "ShortyMAX"
MAX METAL Rostock MAX Printer Frame
NEMESIS Air Delta v1 & v2 -Aluminum delta printers
Rostock MAX "KITT" - Tri-Force Frame
GRABER i3 "Slim"
bvandiepenbos wrote:This is what I am thinking, a cone shaped cap.
Thoughts?
H-11 hot end cone nut.jpg
The more I think about it, the cap would have to replace the threaded thumb nut (as you said in your previous posts) that comes with the extruder. There is just not enough space to put something over the entire thing and it would have to be made out of metal not printed :-/.
I think you are onto something Brian. Currently my extruder is not usable for long prints even if I slow it down. I think something like this would definitely be able to solve this problem. I don't think there will be a need for 3mm filament, it's thick enough to withstand the feeders forcing it into the extruder.
Excellent solution!
That is exactly what I did to my original hot end, only it was on the peek part and I only beveled 2 sides but, since then I haven't had any problems with filament squeeze out, even on long prints.
Your solution of a cone shaped cap is beautiful, even if it has to be machined from metal I no longer have any reservations about getting one of the new hot ends.
Perhaps the guys at SeeMeCNC would consider this design change, even if they use a 3+mm hole I'm sure it would still work.
I'm on it. As Brian is the closest to our shop (literally like 2 miles!) and he sent a mole in to work for us for a few weeks on another printer design (his son!), he'll prob be the guinnea pig on the new cap style.
Hey John, your awesome!
just let me know when and I will stop and pick it up to test.
Thanks.
~*Brian V.
RostockMAX v2 (Stock)
MAX METAL "ShortyMAX"
MAX METAL Rostock MAX Printer Frame
NEMESIS Air Delta v1 & v2 -Aluminum delta printers
Rostock MAX "KITT" - Tri-Force Frame
GRABER i3 "Slim"
I'm working on a "ferrul" insert to go in from the inside that has the smaller dia. ID for 1.75mm filament. I honestly havn't had a problem with it doing that, steve's did up in detroit, but i found that his extruder wasn't fully clipped into the stubs on the base plate, so it was offset from the hole a bit.
I noticed that the new black extruder plate is causing the my extruder to not sit level (tilts to one side), I think this maybe part of the problem.
At this point I can't correct this issue without modifying the base plate/other parts. Every time I print I run into this issue.
I had to remove the black extruder base and go back to the clear one, I couldn't get it to line up correctly no matter what I tried. Bad news/good news but still was a bit of a nuisance. At least we're printing again.
Just a quick update. I finally got the new extruder design working with 1.75mm filament without any issue. Been using it for a few days now.
I had modify the extruder and the black plastic mounting plate a little bit.
I basically took this idea from Brian, I ground down the threaded aluminum housing of the extruder to a point (see pics below).
Then I ground down the black plastic mounting plate and used some extra hardware (screws/washers), this allow the extruder top to fit close in between the rollers.
The filament is supported most of the time from entering the rollers to exiting into the top of the extruder.
hey all, sorry I have been away from the forum for a few weeks, we have been blessed witha ton of jobs at work so I have not had a chance to do anything with printer problem.
I or John still will make up a modified cap with infeed guide.
Mike, looks like you came up with a good solution also. nice work.
What I am thinking is spacing hot end the down with a washer to gain some more meat for the cone shaped cap.
John suggested to me that maybe my feed roller tension is to tight causing filamament to bow then not aligning as well? I have not had a chance to test that, my printer is currently apart... redoing my wiring and electrnics mounting to clean things up and make it easier to transport.
The Dell tower PC that runs printer has enough room to put the driver board, power supply, and temp controller inside the PC case.
Probably lay PC on it's side with a board on top for printer to mount and a sliding keyboard drawer under the PC.
May even mount the monitor on a arm obove printer ...then I only have one thing to transport. Also could put wheels and handle on the whole thing, from a old rolling suitcase.
~*Brian V.
RostockMAX v2 (Stock)
MAX METAL "ShortyMAX"
MAX METAL Rostock MAX Printer Frame
NEMESIS Air Delta v1 & v2 -Aluminum delta printers
Rostock MAX "KITT" - Tri-Force Frame
GRABER i3 "Slim"
Interesting! I'd never seen this with my H1 but now my son is completing the H1.1 (it's his senior research project in high school) and when we fired it up we had this happen several times. However, we were using the new black extruder with my H1 hot end (we are waiting for a part for the new hot end). I also swapped out the entire extruder with my extruder and had it happen again - this time, everything was right off my H1 except the black base plate that the extruder base clamps too. We'll take it apart and check alignment and maybe implement this idea.
cheers,
Michael
Sublime Layers - my blog on Musings and Experiments in 3D Printing Technology and Art
Yes the new black parts have a little more 'wiggle' room in the tabs on the back of them, which makes it a bit harder to just click in and go with 1.75mm filament. 3mm isn't so much a problem though.
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