PTFE Bulging
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Damon
Jul 29, 2010, 5:20:09 PM7/29/10
to MakerBot Operators
Hi,
I just finished building my MakerBot this week and did a few prints.
Very cool!
However, now I think I may have gotten myself into a bit of trouble.
While doing some prints this evening, I was experimenting with
temperature settings in Skeinforge because I had issues with the
filament getting jammed. I read that when this happens, it can be that
the temperature is too low making the filament offer too much
resistance. I experimented a bit, and got good flow at 240 using the
control panel. So, I upped the temperature settings under raft to 240
and tried again. At that point, the prints got a lot worse (the
extruded plastic didn't seem to stick to itself as well as before).
Then I noticed that my PTFE was bulging and that plastic was seeping
out the bottom of it.
That looks pretty bad to me. Do I have to get a new PTFE and rebuild
my extruder? Can I continue printing with it as is? Can I fix it?
Thanks,
Damon
I just finished building my MakerBot this week and did a few prints.
Very cool!
However, now I think I may have gotten myself into a bit of trouble.
While doing some prints this evening, I was experimenting with
temperature settings in Skeinforge because I had issues with the
filament getting jammed. I read that when this happens, it can be that
the temperature is too low making the filament offer too much
resistance. I experimented a bit, and got good flow at 240 using the
control panel. So, I upped the temperature settings under raft to 240
and tried again. At that point, the prints got a lot worse (the
extruded plastic didn't seem to stick to itself as well as before).
Then I noticed that my PTFE was bulging and that plastic was seeping
out the bottom of it.
That looks pretty bad to me. Do I have to get a new PTFE and rebuild
my extruder? Can I continue printing with it as is? Can I fix it?
Thanks,
Damon
JohnA.
Jul 29, 2010, 5:56:07 PM7/29/10
to MakerBot Operators
First -- this happens to a lot of people, don't fret.
Second -- you can absolutely keep printing. The blob might get
bigger, but it'll survive.
There are ways to prevent this sort of thing, including but not
limited to:
- get a peek insulator (instead of PTFE)
- 'armor' a new PTFE insulator with copper pipe joint
- put a hose clamp around a PTFE insulator instead
- don't print so hot
- make sure that your M6 nut is ABOVE the big washer !
- a dozen other things I can't think of.
Pics:
Peek and an armored PTFE: http://www.flickr.com/photos/jabella/4612502523/in/set-72157623829152993/
Armored PTFE: http://www.flickr.com/photos/jabella/4612505571/in/set-72157623829152993/
Hose-clamped PEEK (probably overkill):
http://www.flickr.com/photos/jabella/4589939234/in/set-72157623829152993/
JohnA.
Second -- you can absolutely keep printing. The blob might get
bigger, but it'll survive.
There are ways to prevent this sort of thing, including but not
limited to:
- get a peek insulator (instead of PTFE)
- 'armor' a new PTFE insulator with copper pipe joint
- put a hose clamp around a PTFE insulator instead
- don't print so hot
- make sure that your M6 nut is ABOVE the big washer !
- a dozen other things I can't think of.
Pics:
Peek and an armored PTFE: http://www.flickr.com/photos/jabella/4612502523/in/set-72157623829152993/
Armored PTFE: http://www.flickr.com/photos/jabella/4612505571/in/set-72157623829152993/
Hose-clamped PEEK (probably overkill):
http://www.flickr.com/photos/jabella/4589939234/in/set-72157623829152993/
JohnA.
Damon
Jul 29, 2010, 6:15:45 PM7/29/10
to make...@googlegroups.com
Awesome. Thanks! I happen to have a hose clamp, so I'll start there.
Also, I'll try to keep the temp down a bit. I don't have a
thermocouple to calibrate the temperature correctly, so I'm going with
trial and error here.
Also, I'll try to keep the temp down a bit. I don't have a
thermocouple to calibrate the temperature correctly, so I'm going with
trial and error here.
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mctrivia
Jul 30, 2010, 12:31:12 AM7/30/10
to MakerBot Operators
i would order a hybrid insulator to use after this fails. I had this
problem and it worked for a while but it did not forever.
On Jul 29, 5:15 pm, Damon <damonkoh...@gmail.com> wrote:
> Awesome. Thanks! I happen to have a hose clamp, so I'll start there.
> Also, I'll try to keep the temp down a bit. I don't have a
> thermocouple to calibrate the temperature correctly, so I'm going with
> trial and error here.
>
>
>
> On Thu, Jul 29, 2010 at 11:56 PM, JohnA. <john.abe...@gmail.com> wrote:
> > First -- this happens to a lot of people, don't fret.
>
> > Second -- you can absolutely keep printing. The blob might get
> > bigger, but it'll survive.
>
> > There are ways to prevent this sort of thing, including but not
> > limited to:
>
> > - get a peek insulator (instead of PTFE)
> > - 'armor' a new PTFE insulator with copper pipe joint
> > - put a hose clamp around a PTFE insulator instead
> > - don't print so hot
> > - make sure that your M6 nut is ABOVE the big washer !
> > - a dozen other things I can't think of.
>
> > Pics:
>
> > Peek and an armored PTFE: http://www.flickr.com/photos/jabella/4612502523/in/set-72157623829152...
> > Armored PTFE: http://www.flickr.com/photos/jabella/4612505571/in/set-72157623829152...
> > Hose-clamped PEEK (probably overkill):
> >http://www.flickr.com/photos/jabella/4589939234/in/set-72157623829152...
problem and it worked for a while but it did not forever.
On Jul 29, 5:15 pm, Damon <damonkoh...@gmail.com> wrote:
> Awesome. Thanks! I happen to have a hose clamp, so I'll start there.
> Also, I'll try to keep the temp down a bit. I don't have a
> thermocouple to calibrate the temperature correctly, so I'm going with
> trial and error here.
>
>
>
> On Thu, Jul 29, 2010 at 11:56 PM, JohnA. <john.abe...@gmail.com> wrote:
> > First -- this happens to a lot of people, don't fret.
>
> > Second -- you can absolutely keep printing. The blob might get
> > bigger, but it'll survive.
>
> > There are ways to prevent this sort of thing, including but not
> > limited to:
>
> > - get a peek insulator (instead of PTFE)
> > - 'armor' a new PTFE insulator with copper pipe joint
> > - put a hose clamp around a PTFE insulator instead
> > - don't print so hot
> > - make sure that your M6 nut is ABOVE the big washer !
> > - a dozen other things I can't think of.
>
> > Pics:
>
> > Armored PTFE: http://www.flickr.com/photos/jabella/4612505571/in/set-72157623829152...
> > Hose-clamped PEEK (probably overkill):
> >http://www.flickr.com/photos/jabella/4589939234/in/set-72157623829152...
JohnA.
Jul 30, 2010, 7:46:38 AM7/30/10
to MakerBot Operators
If he's only printing in abs there would be no need for a hybrid; peek
would be fine.
JohnA.
On Jul 30, 12:31 am, mctrivia <squarerootofnegative...@gmail.com>
wrote:
MakerBot Space2
Jul 30, 2010, 10:06:42 AM7/30/10
to MakerBot Operators
Congrats on getting your Bot up! as for the bulge, mine bulged at
235c while upping the temp. I ordered two PTFE replacements and used
a copper sleeve. That is a 1/2 cooper pluming joint with no rib in it.
It cost me about 50cents. You can still print with a bulge and it
will at times erupt again. The problem is you never know what is going
to happen in that situation. You could have 5 good prints and then a
leak or a leak in the middle of a print. I decided I wanted to
replace the PTFE on mine. I now print at 242c with mine and have had
no problems since replacing it. I tried a clamp before that to try to
control the leak, it didn't work. Besides the cooper sleeve my
extruder is standard.
http://www.flickr.com/photos/51037280@N08/4837971482/
http://www.flickr.com/photos/51037280@N08/4839377094/
http://www.flickr.com/photos/51037280@N08/4837997508/
You could also check out makergear.com and get a Peek barrier or even
better the entire heat side of the extruder. They are very good ! I
got one for the second Bot I'm building.
Good luck
Brandon
235c while upping the temp. I ordered two PTFE replacements and used
a copper sleeve. That is a 1/2 cooper pluming joint with no rib in it.
It cost me about 50cents. You can still print with a bulge and it
will at times erupt again. The problem is you never know what is going
to happen in that situation. You could have 5 good prints and then a
leak or a leak in the middle of a print. I decided I wanted to
replace the PTFE on mine. I now print at 242c with mine and have had
no problems since replacing it. I tried a clamp before that to try to
control the leak, it didn't work. Besides the cooper sleeve my
extruder is standard.
http://www.flickr.com/photos/51037280@N08/4837971482/
http://www.flickr.com/photos/51037280@N08/4839377094/
http://www.flickr.com/photos/51037280@N08/4837997508/
You could also check out makergear.com and get a Peek barrier or even
better the entire heat side of the extruder. They are very good ! I
got one for the second Bot I'm building.
Good luck
Brandon
Damon
Jul 30, 2010, 10:48:32 AM7/30/10
to make...@googlegroups.com
Thanks everybody!
I took the plastruder apart, added a hose clamp, and readjusted the
idler wheel which seemed to have gotten out of alignment (too tight
judging by the 2mm steel rod). After that, I slowly upped the temp
until I found 227 works quite well.
Damon
Damon
Jul 31, 2010, 5:05:18 AM7/31/10
to make...@googlegroups.com
I thought I had everything working again (I did manage one very nice
z-axis knob print) but now I'm stumped.
z-axis knob print) but now I'm stumped.
My plastruder stops extruding after between 30-90 seconds depending on
how hot I set it (hotter extrudes longer). But, in the end the
filament always gets stripped. Watching it go through the pinch wheel,
I can see the teeth marks get closer and closer together until
eventually it strips the filament and I have to quickly reverse things
to get the filament back out.
The teeth marks look good at about 0.35 mm deep. I don't have problems
until it gets lower into the heated barrel. I think I'm probably
having problems where the barrel and PTFE barrier meet (just a guess
though). I hesitate to unscrew my PTFE now that it has bulged. I'm not
sure I'll be able to screw it back in properly.
Any advice on what to try next?
Damon
ddurant
Jul 31, 2010, 9:09:02 AM7/31/10
to MakerBot Operators
> The teeth marks look good at about 0.35 mm deep.
Max width of the filament is more important than the depth of the
teeth marks, though getting a good grip is also important.
The size of the hole at the top of the PTFE is about 3.25mm, or was on
mine anyway. If the pinch wheel is gripping so much that the filament
gets squished to more than that width, you'll get stalls and stripping
because the extruder motor doesn't have enough push to get the
filament through.
On Jul 31, 5:05 am, Damon <damonkoh...@gmail.com> wrote:
> I thought I had everything working again (I did manage one very nice
> z-axis knob print) but now I'm stumped.
>
> My plastruder stops extruding after between 30-90 seconds depending on
> how hot I set it (hotter extrudes longer). But, in the end the
> filament always gets stripped. Watching it go through the pinch wheel,
> I can see the teeth marks get closer and closer together until
> eventually it strips the filament and I have to quickly reverse things
> to get the filament back out.
>
> The teeth marks look good at about 0.35 mm deep. I don't have problems
> until it gets lower into the heated barrel. I think I'm probably
> having problems where the barrel and PTFE barrier meet (just a guess
> though). I hesitate to unscrew my PTFE now that it has bulged. I'm not
> sure I'll be able to screw it back in properly.
>
> Any advice on what to try next?
>
> Damon
>
>
>
>
>
> On Fri, Jul 30, 2010 at 4:48 PM, Damon <damonkoh...@gmail.com> wrote:
> > Thanks everybody!
>
> > I took the plastruder apart, added a hose clamp, and readjusted the
> > idler wheel which seemed to have gotten out of alignment (too tight
> > judging by the 2mm steel rod). After that, I slowly upped the temp
> > until I found 227 works quite well.
>
> > Damon
>
>
> - Show quoted text -
Damon
Jul 31, 2010, 10:17:58 AM7/31/10
to MakerBot Operators
Thanks, but that doesn't seem to be the problem. I measured the entry
of the PTFE and it's 3.45 mm. The max width of my pinched filament is
3.12 mm.
However, I did find manage to improve things a bit by loosening the
idler wheel. The 2mm rod now slides in and out quite easily. It slides
past the teeth without turning the motor. I still seem to have good
grip on the filament (0.33 mm deep teeth now) and I can sometimes
extrude for a quite a while using the control panel. When I pause to
start a print though, it starts printing and then eventually (after a
minute or two) it stops and strips the filament again.
I've tried ramping up the temperature again, but that doesn't seem to
solve anything. The best print I made last night was at 225. Today I
ramped up all the way to 240 again trying to stop the stripping. In
the midst of all the problems though, I suppose I may need to floss
the teeth again since I see flakes of plastic in the idler wheel
housing. It's hard to get everything adjusted just so without having
to take it apart and start all over again! :/
When I back out the filament, I often have a very thin, tubular sheet
of plastic stuck to it. I guess that's just what stuck to the inside
of the barrel?
On another note, I can't seem to find a setting to change what
skeinforge uses for the extrusion test temperature. After tweaking
settings and regenerating the gcode, I always have to manually modify
the first instruction to use the correct temperature.
Damon
> > --http://www.damonkohler.com/-Hide quoted text -
of the PTFE and it's 3.45 mm. The max width of my pinched filament is
3.12 mm.
However, I did find manage to improve things a bit by loosening the
idler wheel. The 2mm rod now slides in and out quite easily. It slides
past the teeth without turning the motor. I still seem to have good
grip on the filament (0.33 mm deep teeth now) and I can sometimes
extrude for a quite a while using the control panel. When I pause to
start a print though, it starts printing and then eventually (after a
minute or two) it stops and strips the filament again.
I've tried ramping up the temperature again, but that doesn't seem to
solve anything. The best print I made last night was at 225. Today I
ramped up all the way to 240 again trying to stop the stripping. In
the midst of all the problems though, I suppose I may need to floss
the teeth again since I see flakes of plastic in the idler wheel
housing. It's hard to get everything adjusted just so without having
to take it apart and start all over again! :/
When I back out the filament, I often have a very thin, tubular sheet
of plastic stuck to it. I guess that's just what stuck to the inside
of the barrel?
On another note, I can't seem to find a setting to change what
skeinforge uses for the extrusion test temperature. After tweaking
settings and regenerating the gcode, I always have to manually modify
the first instruction to use the correct temperature.
Damon
ddurant
Jul 31, 2010, 10:35:40 AM7/31/10
to MakerBot Operators
The test extrusion comes from your start.gcode (or possible start.txt)
file - it's not generated.
Do you have, in ReplicatorG, temperature monitoring during builds
enabled in File->Preferences? I usually leave that off but you might
want to enable it. That would at least show you what the temperature
is doing before the stalls. If it's staying close to where you set it
(and if you've updated the thermistor settings & PID settings) you can
probably forget about temperature issues and go back to 220.
> > > --http://www.damonkohler.com/-Hidequoted text -
>
> > > - Show quoted text -- Hide quoted text -
file - it's not generated.
Do you have, in ReplicatorG, temperature monitoring during builds
enabled in File->Preferences? I usually leave that off but you might
want to enable it. That would at least show you what the temperature
is doing before the stalls. If it's staying close to where you set it
(and if you've updated the thermistor settings & PID settings) you can
probably forget about temperature issues and go back to 220.
>
> > > - Show quoted text -- Hide quoted text -
Damon
Jul 31, 2010, 10:50:44 AM7/31/10
to make...@googlegroups.com
My temperature readings are quite stable. I do, however, notice a
difference in how hard the motor is working as I decrease the
temperature. I think the sweet spot temperature-wise is 225 for me.
difference in how hard the motor is working as I decrease the
temperature. I think the sweet spot temperature-wise is 225 for me.
What else should I look for? Just finished flossing again,
reassembling for another round with the looser idler wheel.
ddurant
Jul 31, 2010, 11:06:05 AM7/31/10
to MakerBot Operators
> My temperature readings are quite stable
Do you mean in the control panel or when it's trying to build? Two
different animals there. Changing what's in the control panel has zero
effect on what it's going to do as it builds.
Any chance you're getting too close to the build platform or previous
layer of the build? I've heard that if you don't get the plastic
somewhere to go, it will strip.
I think stripping can be caused by:
- wrong temperture
- wrong idler adjustment (either way - loose or tight - or wobbly)
- something physically in the way (clogged nozzle, stuff at the PTFE/
barrel join)
- flakey motor
The first 2 seem to be, by far, the most common.
Can you extruder for more than, say, 5 minutes via the control panel?
>
> >> > > - Show quoted text -- Hide quoted text -
>
> >> - Show quoted text -
>
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> >> - Show quoted text -
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Damon
Jul 31, 2010, 11:34:26 AM7/31/10
to make...@googlegroups.com
On Sat, Jul 31, 2010 at 5:06 PM, ddurant <ddur...@gmail.com> wrote:
>> My temperature readings are quite stable
>
> Do you mean in the control panel or when it's trying to build? Two
> different animals there. Changing what's in the control panel has zero
> effect on what it's going to do as it builds.
>> My temperature readings are quite stable
>
> Do you mean in the control panel or when it's trying to build? Two
> different animals there. Changing what's in the control panel has zero
> effect on what it's going to do as it builds.
If I get to the point where I'm trying to do another print, I'll watch
it and see. In the control panel, my temperature is very stable.
> Any chance you're getting too close to the build platform or previous
> layer of the build? I've heard that if you don't get the plastic
> somewhere to go, it will strip.
I read that too. I don't think that's the problem. I can reproduce
this while just extruding 10 mm above the platform.
> I think stripping can be caused by:
> - wrong temperture
> - wrong idler adjustment (either way - loose or tight - or wobbly)
I'll keep experimenting with this. The 2 mm rod is nice, but figuring
out exactly how tight against it the wheel should be and trying to
keep it in place while tightening it is quite challenging.
> - something physically in the way (clogged nozzle, stuff at the PTFE/
> barrel join)
Since I can get plastic to extrude, and it looks clean, I don't think
there's a clog. Though, I guess it could be getting hung up between
the barrel and PTFE.
> - flakey motor
My motor does ooze out grease around the drive shaft. Is this normal?
I had a peek inside and it looks like there's plenty of grease in the
gearbox.
>
> The first 2 seem to be, by far, the most common.
>
> Can you extruder for more than, say, 5 minutes via the control panel?
Currently, no. I'm tweaking the idler wheel, trying to find a good setting.
Damon
Jul 31, 2010, 1:13:09 PM7/31/10
to make...@googlegroups.com
ddurant
Jul 31, 2010, 6:07:29 PM7/31/10
to MakerBot Operators
> My motor does ooze out grease around the drive shaft. Is this normal?
> I had a peek inside and it looks like there's plenty of grease in the
> gearbox.
I have no idea if that's ok or not. I'm pretty sure mine doesn't do
> I had a peek inside and it looks like there's plenty of grease in the
> gearbox.
that. There was somebody in the forums a week or 3 ago having all
sorts of extruder problems that finally got sorted with a new motor
but that doesn't mean yours is toast.
Maybe somebody else knows how to test if the motor is losing it..
On Jul 31, 11:34 am, Damon <damonkoh...@gmail.com> wrote:
>
> read more »- Hide quoted text -
Ross Mosshart
Jul 31, 2010, 6:45:04 PM7/31/10
to make...@googlegroups.com
Mine does, it's just the nature of the beast...so Long as it isn't, you know, _GUSHING_ or anything.
Damon
Aug 1, 2010, 2:14:57 PM8/1/10
to make...@googlegroups.com
After 3 days of troubleshooting and trial and error, I've given up. I
think the bulging in my PTFE exposed the edges of the heater barrel
and that is causing the filament to hang up. No amount of flossing,
tweaking the idler wheel, and temperature experimentation has gotten
me results.
think the bulging in my PTFE exposed the edges of the heater barrel
and that is causing the filament to hang up. No amount of flossing,
tweaking the idler wheel, and temperature experimentation has gotten
me results.
So, I've ordered some upgrades. I'm getting an aluminum idler wheel
and brass Mk5 drive gear off Ebay. I'm also getting a PEEK plastruder
from MakerGear.
It's disappointing to have to replace parts already. I think I've
printed 4 small things successfully. Not sure what went wrong :/
Hopefully the new stuff will be more robust.
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