Date: Wed, 9 May 2012 20:03:32 -0700 (PDT) From: TSDF-3D To: makerbot@googlegroups.com Message-ID: <15786667.2661.1336619012916.JavaMail.geo-discussion-forums@ynff16> In-Reply-To: <28579988.308.1336101746510.JavaMail.geo-discussion-forums@vbmi19> References: <28579988.308.1336101746510.JavaMail.geo-discussion-forums@vbmi19> Subject: Re: Extruder Jam on Replicator..help. MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="----=_Part_2659_23902611.1336619012915" ------=_Part_2659_23902611.1336619012915 Content-Type: multipart/alternative; boundary="----=_Part_2660_17527824.1336619012915" ------=_Part_2660_17527824.1336619012915 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit I'm working through a similar if not same issue: pasted below are my notes on an open support ticket In mid print the right side extruder stopped feeding. I aborted the job. There was no teltale clicking from the drive wheel slipping on the filament. Using Rep G control panel to trouble shoot, I heated up the nozzle and jogged the stepstruder at various speeds. At any speed above 4-5 rpm, it would either feed intermittently or stall altogether unless I assisted by pushing in filament from then top. For comparison, the left extruder will run @10rpm with no problem. I initially assumed that the Drive wheel set screw might be loose, but disassembly and check confirmed it is tight, and wheel and motor shaft are moving together. I have done the following in this order: - cleaned the drive wheel teeth. Some buildup, but not looking too clogged. - bent slightly one of the brass washers in the plunger stack to add more force to plunger>filament>drive wheel - removed bent washer, replaced with two new washers- so total of three brass and two thick plastic spacers in plunger stack. This filament was hard to start it was so tight, but problem stayed constant. Intermittent feed above 4-5 rpm. And sometimes no feed at 3. - switched filament to other stepstruder- works fine, it's not the material or spool resistance or snag in the feed tube, etc. - with the fan and heat sink off, looking at the wheel as it tries to feed, the stepper appears to be stalling, without the drive wheel slipping on the filament. It advances a portion of a degree and shifts back unless I apply assist force to the filament indeed. So.... I'm wondering if the stepper is getting full power? Could a driver MOSFET be failing? Should I try swapping plugs between the two steppers to test this? NEXT DAY: Here's an update of additional things Ive tried: - running filament through at a range of speeds, pushing from the top as needed. - backing out filament at cooler temps - swapping motor drives (no change) its not electronics must be mechanical on that extruder. - changing plunger spacing - changing filament - shifting drive wheel fore /aft on stepper shaft, relative to the filament path - different clamping screw tightnesses. then i started changing temps. I found that at higher temps i can get filament to feed faster without stalling or losing steps, or slipping: 220 deg @ 3 rpm 240 deg @ 5 rpm 260 deg @ 7 rpm after that, at 8 rpm or faster, stalling get progressively worse. NOTE: the left side 'struder will put out @ 10 rpm @ 220 with no problems. the output diameter is fat though, at .62 mm, whereas the problem 'struder is making threads @ .36 - .42 mm. So, this leads me to think that perhaps I have a Thermistor calibration problem. Also, observed the following: the drive wheel teeth do not look very crisp or sharp- appear to be somewhat burnished, and that the threads emerging from the bad side tend to curl and loop rather than drop straight out. this side has gotten about 10 x more use than the other side. perhaps 50 hrs total by now. Is there a way to calibrate the nozzle thermistor? Tomorrow I will try to measure temps with an IR temp sensor. Should I try replacing the nozzle and drive wheel? > > ------=_Part_2660_17527824.1336619012915 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable I'm working through a similar if not same issue: pasted below are my notes = on an open support ticket


In mid print the right = side extruder stopped feeding. I aborted the job. There was no teltale clic= king from the drive wheel slipping on the filament.

Using Rep G control pa= nel to trouble shoot, I heated up the nozzle and jogged the stepstruder at = various speeds. At any speed above 4-5 rpm, it would either feed intermitte= ntly or stall altogether unless I assisted by pushing in filament from then= top. For comparison, the left extruder will run @10rpm with no problem.

I= initially assumed that the Drive wheel set screw might be loose, but disas= sembly and check confirmed it is tight, and wheel and motor shaft are movin= g together.
I have done the following in this order:
- cleaned the dr= ive wheel teeth. Some buildup, but not looking too clogged.
- bent sligh= tly one of the brass washers in the plunger stack to add more force to plun= ger>filament>drive wheel
- removed bent washer, replaced with two = new washers- so total of three brass and two thick plastic spacers in plung= er stack. This filament was hard to start it was so tight, but problem stay= ed constant. Intermittent feed above 4-5 rpm. And sometimes no feed at 3.- switched filament to other stepstruder- works fine, it's not the materi= al or spool resistance or snag in the feed tube, etc.
- with the fan and= heat sink off, looking at the wheel as it tries to feed, the stepper appea= rs to be stalling, without the drive wheel slipping on the filament. It adv= ances a portion of a degree and shifts back unless I apply assist force to = the filament indeed.

So.... I'm wondering if the stepper is getting full p= ower? Could a driver MOSFET be failing?

Should I try swapping plugs betwee= n the two steppers to test this?

NEXT DAY:

=
Here's an update of additional things Ive tried:
- running filame= nt through at a range of speeds, pushing from the top as needed.
- bac= king out filament at cooler temps
- swapping motor drives (no change) = its not electronics must be mechanical on that extruder.
- changing pl= unger spacing
- changing filament
- shifting drive wheel fore /af= t on stepper shaft, relative to the filament path
- different clamping= screw tightnesses.

then i started changing temps. I found t= hat at higher temps i can get filament to feed faster without stalling or l= osing steps, or slipping: 
220 deg @ 3 rpm
240 deg @ 5 rpm
260 deg @ 7 rpm
after that, at 8 rpm or faster, stalling get progr= essively worse.
NOTE: the left side 'struder will put out @ 10 rpm @ 2= 20 with no problems. the output diameter is fat though, at .62 mm, whereas = the problem 'struder is making threads @ .36 - .42 mm.

So, t= his leads me to think that perhaps I have a Thermistor calibration problem.=

Also, observed the following: the drive wheel teeth do not = look very crisp or sharp- appear to be somewhat burnished, and that the thr= eads emerging from the bad side tend to curl and loop rather than drop stra= ight out. this side has gotten about 10 x more use than the other side. per= haps  50 hrs total by now.

Is there a way to calibrate = the nozzle thermistor? Tomorrow I will try to measure temps with an IR temp= sensor. Should I try replacing the nozzle and drive wheel?

------=_Part_2660_17527824.1336619012915-- ------=_Part_2659_23902611.1336619012915--