E3D v5 All Metal w/Direct Pinch skipping/clicking problem

Discussion in 'E3D-v6 and Lite6' started by AlexC, Mar 25, 2014.

  1. AlexC

    AlexC Well-Known Member

    Joined:
    Mar 25, 2014
    Messages:
    46
    Likes Received:
    0
    Re: E3D v5 All Metal w/Direct Pinch skipping/clicking proble

    So I got my replacement heat break from e3D (thank you) and of course the first thing I did was poke at it with the microscope. Unfortunately the second one did not look much better than the first in regards to rough patches and ledges. They claimed to have inspected it, But these rough patches are easily visible by the naked eye, so I am a bit perplexed by that.

    Decide for yourself,.

    Heatbreak #1http://www.alexcphoto.com/Stuff/CleanBarrel.mp4
    Heatbreak #2http://www.alexcphoto.com/Stuff/e3D_Round2.mp4

    Then as a sort of sanity check I decided to disassemble a few other hot ends and inspect them with the microscope,.

    Brass J-head MK5: http://www.alexcphoto.com/Stuff/GoodJHead.mp4
    Prusa: http://www.alexcphoto.com/Stuff/PrusaNozzleMKII.mp4
    A random ebay heat break: http://www.alexcphoto.com/Stuff/China1.mp4

    Ultimately only the prusa was mirror smooth on the inside surface (due to its construction it was hard to get light down its barrel, so the video is hard to tell, but you can just barely see that it is mirror smooth for the most part), (BTW, the prusa never jams with PLA). The others all showed varying types of rough surfaces(but still less than the e3D to my eye). But only the prusa is in the same price point as the e3D and only the persa is stainless like the e3D,. so it’s the only direct comparison I have here at the moment.

    So after venting a bit at e3D on friday in an e-mail for sending me another rough barrel (sorry e3D. it’s been a stressful week),. I decided to spend the weekend doing everything possible to get one of the barrels to work. I choose the second one they sent, mostly because the second while having about the equivalent amount of surface roughness it did have one or two fewer hard ledges.

    I tried the hot end stock,. Jam, jam, jam,. Right from the very first print, so no buildup over time as some have been suggesting.

    Then disassembled, & cleaned,.

    And I then repeated the seasoning process as I had with barrel #1. Same results as with barrel #1, things improved, 100% lockups stopped happening, but the amount of skipping and voids where still enough to ruin most prints, and from teh very first print again so again no build up over time.

    So I disassembled, & cleaned,. (I wanted to find a process that worked from as close to factory clean as I could realistically manage)

    Now I tried something new,. One user suggested to do additional polishing,. Stainless polish + cotton pipe cleaner in a power drill,. So I polished the barrel for a few min with the drill turning in one direction (half speed), while also moving the barrel slowly up and down the pipe cleaner. Then I reversed the drill to turn the other direction for a few min and polished some more in the same manner.

    And then a thorough cleaning first with wd-40 then with MEEK to dissolve and remove any residue from the polish. Finally a look down the barrel showed a bit of improvement.

    For the next step I did the seasoning as part of the 290c nozzle tightening process when I re-assembled (so I seasoned at a much more aggressive temp than previously suggested), in that I coated the inner barrel with canola oil (no plastic), ran it up to 280-290c & tightened the nozzle down (this did have the oil smoking, and spattering) then I dropped temps down to 210c and let the oil bake for 20min,. Then I cycled the heat up and down 5 min 210, cool down, then 5 min cold, then 5 min 210,. Cool down, Then 5 min cold,. Then 5 min 210,. (as instructed by a professional chef friend of mine) (Still no plastic in barrel) Then I ran filament through till all signs of the oil where gone.

    After that, now everything seems to be working at moderate speeds (Tested up into the 60mm/s so far), and a retract setting of 0.5mm (1/2 default in Repetier, this also seems to be an important variable.)

    I do not know which solved the problem, the extra baking in at higher temps & cycling the temp with oil present,. Or the polishing,. I suspect both factored in, But I will say this with 98% certainty, regardless of which one did the job, both point back to the roughness of the inner barrels as the culprit,.

    Unfortunately every time I suggest that e3D needs to polish a bit more, or that the roughness is part of the problem they suggest a different culprit,. I can’t say for sure who is right,. I don’t know their exact machining process, and as an unknown outsider they are dubious to trust my assessment over their own, and I don’t blame them, I don’t make hot ends for a living. But hopefully they poke at this problem on their own and come to the realization that a little more polishing can’t hurt, and trying it for a time to see the results might just pay out in fewer support tickets & complaints, only time will tell.

    I also suspect that the random placement of the rough patches have a lot to do with who has problems and who does not,. Aka some barrels can be that rough and be ok,. Others, if the rough patch is right near the glass transition zone,… jam (both barrels I received had the rough patches in the ½ of the barrel closest to the heat break in the glass transition zone, although #2 was a bit more spread out.)

    ----

    Side note, since some have asked, Inc e3D, my extruder’s (All three of them identical) work perfectly with a j-head MK5, buddhashnoozle, Ubis, and a Prusa hotend @ speeds in the 80-100mm/s range (I have been swapping hotends out frequently over the last few weeks to test differences in print quality & maintanance so I can say this with certainty) I cannot logically consider my extruders as the issue if they can work with all of those well, but not with the stock e3D all metal, which should in theory be easier to push due to it having the smallest glass transition zone,.

    I have also experimented with three different hobbed pulleys for filament feeding and even one small diameter one that claims 33% more torque, and two different motor strengths (one that’s even powerful enough to direct pinch 3mm if I need it to), and I have a third even more powerful motor on order now to hopefully remove any chance of the problem returning.

    ----

    Please note that all of my finding are for PLA only, simply because I’m stubborn and purchased this hot end for my PLA machine. ABS is a whole other ball park and from what I hear the e3D is absolutely great at that, so eventually I may just cave and put it on my ABS machine if the problem ever returns (if the seasoning ever wears off, etc.).

    The only thing I can say for 100% certainty,. Despite my personal experience with it,. When this hot end works, it produces absolutely beautiful results,.
     
  2. Eaglezsoar

    Eaglezsoar Administrator

    Joined:
    Mar 7, 2014
    Messages:
    267
    Likes Received:
    0
    Re: E3D v5 All Metal w/Direct Pinch skipping/clicking proble

    From all of the other forums I read I just want to say that you are on the right track with the polishing that you are doing.
     
  3. mhackney

    mhackney Well-Known Member

    Joined:
    Mar 4, 2014
    Messages:
    53
    Likes Received:
    11
    Re: E3D v5 All Metal w/Direct Pinch skipping/clicking proble

    Very good write-up AlexC. This re-enforces my observations and experiments too with both the E3D v5 and the Kraken - which share a similar heat break design and probably machining setup and tooling.

    I also found that PLA roughened from the hobbed gear exasperated the problem. Partly, this was due to "snagging" where the filament enters the reduced diameter part of the heat break. In the E3D design, the PTFE Bowden tube goes right through the PTC and ends in the heat break - a nice design IMO. However, there was a shape edge right at that entry point on a few of my breaks that could snag the filament passing through. I chamfered that with a drill bit and polished along with the bore. I also experimented with beveling the end of the PFE so it would mate into the bore better (it is a conical bottom, not flat, from drilling most likely).

    I did not do the Canola treatment on mine, the deburr and polish did the trick.

    One comment about extruders. I use ezStruders from SeeMeCNC on my Rostock Max and Kraken. They can actually generate enough torque that when a jam occurs, they will take a divot out of the PLA itself. When this happens, there is nothing for the hobbed gear to grip so the only remedy is to pull the filament out and start over, or manually push it through. This tells me the jam is pretty severe and that the extruder is more than capable of pushing the filament. One other thing is, as mentioned above, the hobbed gears on this extruder are VERY aggressive. You can see the sharp cuts they leave in PLA. This is much less of a problem on ABS as it is softer and deforms and reforms whereas PLA is actually cut. I detuned by hobbed gears to make them less aggressive and that went a long way to minimize jams.

    Cheers,
    Michael
     
  4. Josh

    Josh Administrator
    Staff Member

    Joined:
    Feb 26, 2014
    Messages:
    183
    Likes Received:
    38
    Re: E3D v5 All Metal w/Direct Pinch skipping/clicking proble

    Again Alex, we appreciate your comments which are helping us debug this issue.

    I would contend that we did not acknowledge the surface finish to be important, it is just that we have literally thousands of customers out there printing PLA through our HotEnds and there are often other factors that are the culprit. In this case we absolutely agree that surface finish does seem to be the problem.

    We are working out these issues with our machinist and are working to refine our finishing techniques with the aim to improve the consistency of the surface.

    I am glad that you have got the HotEnd up and running. Please do keep me posted with your progress, good and bad!
     
  5. mhackney

    mhackney Well-Known Member

    Joined:
    Mar 4, 2014
    Messages:
    53
    Likes Received:
    11
    Re: E3D v5 All Metal w/Direct Pinch skipping/clicking proble

    Hey guys, the Kraken has the same basic mechanical setup as the E3D (I have both) but with water cooling. I find it is less prone to PLA jamming but just when I have it dialed in, printing reliably and very nicely, odd filament starving issues pop up once again. I've slowed down, sped up, increased temps, decreased temps, polished, deburred, scrutinized, dissected, injected, rejected, ... you get the point (with a tip of the hat to Arlo Guthrie). I've not had a single jam with ABS with these hot ends.

    I've also experienced the filament chewing phenomenon and worked on the extruder end of things - cooling fan on the driver, tuning the current setting, debarring the sharp knobbed gear, etc. Each time I do something things seem really good for a while. And when I say good, I mean the best PLA parts I've ever printed.

    Just yesterday, after reliably printing dozens of parts, things started going astray again (filament starving). I thought I had addressed and at least thought about all of the problem possibilities and even combined, this is still occurring. Once I get into this state, I disassemble the hot end, clean, ream and reassemble and am good to go - for awhile. It is nearly impossible to determine where the issue is occurring and I've tried to look at the bore with a scope, the filament itself when I remove it, etc.

    I am starting to suspect and think about the heat break geometry or nozzle itself. I do not think the brass-SS joint is at fault in my situation. I've polished both ends (the brass nozzle and SS heat break), assembled at 300°C and when I disassemble and look later this joint is mirror like with no evidence of leaking.

    ...

    While I was writing this I was able to pull a complete filament out of a "jammed" hot end (Kraken) by chilling it down. This is a deburred and polished heat break and had been printing well for over a week (LOTS of parts). I used my little USB microscope to scrutinize things and do some more experiments. Here's what I captured:

    http://forum.seemecnc.com/download/file ... &mode=view

    Note that you can even see the .4mm tip that was in the nozzle. The dirt and stuff on the filament are my fault, they came from the brass threads (oxidation). A couple of points:

    The .40mm tip section is pretty long, something like 2mm
    You can also see a ridge where the plastic filled the chambers between the heat break and nozzle. You can see that much clearer here:

    http://forum.seemecnc.com/download/file ... &mode=view

    The other thing I was able to capture was where the cold break occurred.

    http://forum.seemecnc.com/download/file ... &mode=view


    You can clearly see the enlarged diameter of the PLA right up to thee top of the narrow heat break and where the water cooling would take effect. (Note also that I bent my heat break :( ) I have 3 others with the Kraken so I have more to play until a replacement arrives.

    The other think interesting about this photo is that the melted PLA is clearly well below where the PTFE tube inserts into the top of the break. I had theorized that this is where the jamming might occur. I've since been able to dissect a second plug today and it shows the same thing.

    And that led me to some experiments.

    I removed the hot end assembly from the water jacket and heated it up to temperature. I inserted a 2" section of PTFE in the top of the heat break and then pushed some PLA down the bore. This was the heartbreak and nozzle shown above after pulling the plug out. As soon as I pushed, PLA flowed very easily for about 1cm and then more and more pressure was required. I tried this 4 or 5 times to verify. The temp was 195°C. I then started ramping the temp up in 5° increments. Long story short, at 220°C I was able to carefully push many cm of filament without the apparent plugging. At the lower temps, the extrusion would often come out curlycued, like there was some obstruction in the tip. I did a lot of permutations and even removed the heat break and used PTFE down to the nozzle. It really seemed like the jam was occurring down in the nozzle itself.

    I then did some experiments with positioning the tip further away from the heated block - attached by only a couple of threads. Now, it was nearly impossible to push any filament until I got to 115°C. This might not be unexpected since there is much less metal-to-metal contact for the brass nozzle to heat transfer properly. That leads me to wonder if perhaps the nozzle is fluctuating in temp and when it cools, the PLA freezes and backs up and plugs. Almost anything can make the nozzle cool - the movement as it prints, air from a part cooling fan (or cold end fan), rapid transfer of filament (at high extrude speeds), retract, etc.

    I'm not sure what to make of this yet. Options like insulating the tip with Kapton tape or a ceramic paste come to mind. Meanwhile, I just successfully printed a part at 220°C (for PLA!) that I was completely unable to print yesterday in 6 attempts using exactly the same hot end with no additional cleaning or polishing. I am going to attempt a print at 210, 200, ... and see what happens. This is very perplexing as I've printed this exact spool of PLA with this exact same hot end at 185°C on much more complex parts (lots of short hops and retracts) with no problems multiple times. Just odd!
     
  6. Eaglezsoar

    Eaglezsoar Administrator

    Joined:
    Mar 7, 2014
    Messages:
    267
    Likes Received:
    0
    Re: E3D v5 All Metal w/Direct Pinch skipping/clicking proble

    Michael, none of your jpg files got posted. It just shows the file name which you can't open.
    Just thought you would like to know.
     
  7. mhackney

    mhackney Well-Known Member

    Joined:
    Mar 4, 2014
    Messages:
    53
    Likes Received:
    11
    Re: E3D v5 All Metal w/Direct Pinch skipping/clicking proble

    Yes, I see that there is a limit of 700 pixels and these are bigger. I just changed them to active links. It's too big a pain to reduce and rehost these. Sorry folks, you can see the images at the links now.
     
  8. AlexC

    AlexC Well-Known Member

    Joined:
    Mar 25, 2014
    Messages:
    46
    Likes Received:
    0
    Re: E3D v5 All Metal w/Direct Pinch skipping/clicking proble

    Its only been a week or two, but so far the v5 hot end is now treating me very well after polishing/seasoning.
    http://forum.e3d-online.com/viewtopic.php?f=11&t=114&p=734#p734

    I only had filament chewing issues as a side effect of the jamming issue,. now that the jamming is gone, the chewing is gone to, so id say, stay focused on resolving the jamming with polishing/seasoning. Once you fix that issue the chewing will likely go away on its own. At this point I am pushing the filament with a tiny "2600g.cm" stepper on a direct pinch @ ~ 60mm/s without issue. You just have to resolve the jamming, then it flows like butter left out in the sun.

    Iv hit no issue on the seal between heat break and nozzle, the machining there seems to be spot on. On one of my rebuilds in between resolving this issue i even forgot to high temp tighten, and it didn't leak a drop (i don't recommend forgetting that step though). just remember to set the heartbreak depth so that the nozzle still has a little gap between the nozzle and the heat block when fully tightened down and you should be fine.
     
  9. mhackney

    mhackney Well-Known Member

    Joined:
    Mar 4, 2014
    Messages:
    53
    Likes Received:
    11
    Re: E3D v5 All Metal w/Direct Pinch skipping/clicking proble

    I have an update and discovery on the nozzles. Firstly, let me say that I've been down all of the same paths -

    deburing the opening to the nozzle in the heat break seems to "work" for several weeks. I was printing PLA quite well and then all of a sudden the jamming problem returned. So I...

    meticulously polished the inside of the heat break to a mirror like surface. Again, I was printing for several weeks at high speeds. But I did notice that I had to print at higher temps (200-205°C) than I would normally print this PLA (185°C) on my other hot ends. "No worries" I thought. Then jamming started again. So I...

    discovered that the cobbed gear in the ezStruder was very sharp and physically damaging the PLA. This was not so much a problem with softer ABS. "Ah ha" I thought, this rough surface was the culprit, it could get hung up at various places and lead to jamming. Problem solved. I was printing perfectly for a few more weeks when... jamming started occurring again sporadically.

    So then I noticed that my RAMBo stepper driver was getting really hot so I installed a fan to cool it. Again, the problems went away for well over a month and literally 100s of beautifully printed parts. Then last week I started getting jamming again.

    This time, I rolled up my sleeves and dug in to find "THE" culprit. I found something interesting and describe it in detail on the SeeMeCNC forum here: http://forum.seemecnc.com/viewtopic.php ... 590#p36280

    Basically, the bore of all 5 of my .4mm nozzles is about 2mm long. Compare that with .5mm for a J-Head and every other brand of nozzle I had and measured was well below 1mm bore length. So I modified the bore on one of my nozzles to .5mm (I describe how to do it in the post).

    I've emailed Josh and Sanjay about this discovery and my results but haven't heard back yet. Meanwhile, I have now printed well over 100 parts - more than 90 of them were parts that I struggled to print without some form of PLA jamming at some time - with absolutely NO PLA JAMMING. The short .5mm nozzle bore is critical I believe. Not only did these parts print perfectly, I was able to print them at lower and reasonable PLA temperatures of 185-190°C and at speeds up to and above 60mm/s. This is the fastest speed and lowest temps I've ever been able to sustain printing with the Kraken. The same "fix" applies to the E3D hot end as they share the same nozzle and basic geometry. I'd like to know what the actual bore length spec is for the .4mm nozzles and if there is any/much variability between our bores. You can read about how to measure it at my link if you;d like to measure yours for the common good!

    I am now more confident that the long 2mm bore on the .4mm E3D nozzles has been the root of most, if not all, PLA jamming issues. Of course, this needs more people to have success with this change. But, I have been down every avenue making steady progress.

    regards,
    Michael
     
  10. Eaglezsoar

    Eaglezsoar Administrator

    Joined:
    Mar 7, 2014
    Messages:
    267
    Likes Received:
    0
    Re: E3D v5 All Metal w/Direct Pinch skipping/clicking proble

    You have spent a lot of time troubleshooting and analyzing your results and the results have been positive.
    Hopefully Sanjay and or Josh will take a look at the processes you have used and the data you have generated and get back to you.
     
  11. AlexC

    AlexC Well-Known Member

    Joined:
    Mar 25, 2014
    Messages:
    46
    Likes Received:
    0
    Re: E3D v5 All Metal w/Direct Pinch skipping/clicking proble

    hmm,. interesting, i hadn't noticed the long nozzle path,. i kind of wonder if that's actually a good thing on the ejection end,. for smoothness,. when you have a fluid pinch point with back pressure such as a nozzle, if the ejection end is to close to the entrance of the bottle neck you get added turbulence in the fluid being ejected, a longer path may let the fluid stabilize and shoot out in a more uniformed manner, (Of course fluid viscosity & speed factors in as well, and we are going fairly slow,.). but, it may be the answer to one of the mysteries iv been trying to figure out about this hot end actually.

    is it the nozzle,... Might be an easy one to test,. polish a heat break,. then season the heat break with one nozzle,. clear the oil and print a few parts to confirm that the polishing/seasoning has things working again,. print a few more just to make sure all or most of the loose oil is out of the system,. then,. change the nozzle to one that's never been seasoned,. if it immediately starts jamming again, or within a few prints. (with a freshly seasoned heatbreak, but an unseasoned nozzle) then it might just be some factor of the nozzle, (the thought there would be that when your seasoning the heatbreak, what your really doing is seasoning the nozzle that's also present, and at some point that wears off). if it does not start immediately jamming with a un-seasoned nozzle, then its likely still in the heat break since the issue did not return.

    or flip that the other way,. season a tip, and not the heat break,.. that way the heat break is not contaminating the unseasoned nozzle with traces of oil. (little trickier but do-able)

    If changing either to unseasoned also caused jamming then it might be a factor of both needing the seasoning,.

    Only problem with those tests is you'd have to have a larger test group than 2-3 to get real results due to slight variances in the machining,.. but if you had a dozen of these, that's how you'd get the answer between nozzle, heat break, or both.

    For now I am not touching my setup, its finally working and i have a back log of prints to get through, If it fails again at some point ill jump back into testing down this road,. till then fingers crossed,.

    Since you shortened the nozzle path have you noticed any loss in smoothness, corner consistency, ejection curling, bridge quality, drool,. etc,. ?
     
  12. BadDevices

    BadDevices Member

    Joined:
    Mar 28, 2014
    Messages:
    8
    Likes Received:
    0
    Re: E3D v5 All Metal w/Direct Pinch skipping/clicking proble

    Hi all, we are following the evolution of this thread with a lot of interest because also us are struggling a bit with this problem and we are trying to exclude all the possible uncertainties from our machine in order to concentrate only on the hotend.
    Don't want to go OT, but first of all, in order to maintain compact the carriage of the BadPrinter2 we does not use the original fan shroud, but put the fan on the cold end very close to the heatsink and seems that probably some turbolence or something similar affects the way in which the cold end was cooled (the first part was quite hot), so we install the original one and try to maintain as much as original the hotend and now the cold end remain fresh, so we can start to concentrate only on the hotend. But this lesson learned is that cooling the heatsink is very important.
    The problem of jamming still remains, especially printing at low speed and 0.1 mm layer so when the flow rate is probably quite low for us.
    Sanjay alreayd write us that it will send us replacement heatbreak, but in the meanwhile we want to contribute making testing on the modification all of you discovered. So we will go with playtesting and post results in order to increase the samples tested :)

    1.) Seasoning: we seasoned two hot end with olive oil (don't know is there are contraindication to this respect canola oil) but it seems not resolve the problem

    2.) Polishing: we polish the internal of the heatbreak with "sidol" http://www.henkel.it/detergenza/accessibile/scheda.asp?pageid=c&ID=114 that is a metal polish and pipe cleaning and drill, but this polish is very liquid so probably "clean" very well the internal of the heatbreak, but does not remove the burrs or machining scratches, so we intend to try with more agressive polish (sidol+baking soda or dremel polish). At the moment of two polished (with our method) heatbreak, none resolve the problem

    3.) Nozzle length reduction: we intend to measure or modify directly the nozzle to test if the the mhackney modification works also for us, in order to give also our experience. We have also to check if we have some "old" nozzle and see the difference. I say old nozzle, because when we buy the first our 2 E3D hotend (probably v4 in the second quarter of last year): one has a nozzle with one shape and the other is sligthly different (probably here Josh can confirm that there was a changing on nozzle supplier or it's only my wrong perception of the difference) and we are sure that one of the "old" E3D that had printed since august of last year without a single problem of PLA jamming.

    So, we hope in the week-end to make some good experiment and update on the progress and to have some feedback from Josh and Sanjay about the evolution on this problem
     
  13. mhackney

    mhackney Well-Known Member

    Joined:
    Mar 4, 2014
    Messages:
    53
    Likes Received:
    11
    Re: E3D v5 All Metal w/Direct Pinch skipping/clicking proble

    One other comment - I suspect the long nozzle bore AND the reduced heat conductive path into the nozzle with the E3D design (see below) work hand-in-hand to create some if not all of these problems. This may be one reason why some people experience the problem and others don't - that and the way and quantity we each print. I am pretty much on the ragged edge of producing production parts on my printer at breakneck speed so I am really stressing things.

    Comment on the nozzle conductivity. If you look at the heat flow path from the aluminum heater block into the brass nozzle there is significantly less contact area than other hot ends. For one, the nozzle is supposed to stand proud of the heat block, so there is no contact there. Then, the back end of the nozzle is in contact with lower conductivity SS, finally, the threaded section is quite small (5 threads or so) and that is really the primary way heat gets transferred into the nozzle/tip. Combine that with a long bore and the chances for "freezing" go up. I personally observed this on this latest debugging path by removing the heat brake and Bowden from the equation and getting the nozzle to jam - and it was in the tip/bore. Pretty conclusive to me but I've been very conservative and not claiming victory until I've really pounded on the printer - and I have now and everything is perfect.

    AlexC - absolutely NO issues with a .5mm bore in terms of surface quality, curling, dimensionality, etc. In fact, I believe my surface finish is better now than it ever has been and I'm experiencing less stringing on parts that were problematic in the past. The J-Head has a .5mm bore - that was after earlier versions had a longer bore. Other than it can not handle high temp materials as easily, the J-Head is a great hot end for PLA and ABS. Now that I've seemed to debugged my E3D and Kraken, they are even better - I can print at much higher speeds at lower PLA temperatures and get really nice finishes.

    Cheers,
    Michael
     
  14. AlexC

    AlexC Well-Known Member

    Joined:
    Mar 25, 2014
    Messages:
    46
    Likes Received:
    0
    Re: E3D v5 All Metal w/Direct Pinch skipping/clicking proble

    Thanks,. and interesting to know about the history of the J-head starting with a longer path and then shortening over the various revisions,.

    I have also been noticing that the stock #5 thermistor is no where near as accurate as the more commonly used #6 thermistor,. with a #6 i get a proper, constant, PWM power signal that keeps the temps accurate to ~ 0.5 deg C, but with the #5 on the hot end i get a much sloppier ~ 5 deg c fluctuation that shows in the surface finish of the part (yes, i updated my firmware inbetween screen caps),... and the PWM power signal is spiking like a hot bed rather than leveling out like it should on a PWM hotend. This fluctuation might also be adding to the issue as 5 deg swings are plenty to futz with filament flow, especially if you like to print as cool as possible... (or maybe i only see this due to random factor XYZ, I am still troubleshooting this one, just putting it out there to see if anyone else has noticed similar)
     

    Attached Files:

  15. Eaglezsoar

    Eaglezsoar Administrator

    Joined:
    Mar 7, 2014
    Messages:
    267
    Likes Received:
    0
    Re: E3D v5 All Metal w/Direct Pinch skipping/clicking proble

    How do you tell if you get a #5 or a #6 Thermistor?
     
  16. AlexC

    AlexC Well-Known Member

    Joined:
    Mar 25, 2014
    Messages:
    46
    Likes Received:
    0
    Re: E3D v5 All Metal w/Direct Pinch skipping/clicking proble

    My understanding is that all e3D v5 thermistors are #5's, because a # 5 can handle a bit higher max temps, but i could be wrong.

    The default thermistor for a J-head-MK5(according to the specs on the reprap wiki) and Ubis hotends are #6's
    Though with J-heads many deviate so you have to ask the individual supplier.
    And most other hot ends iv tested are also #6's

    The part I really don't know is, are these 10%, 5%, 3%, 2% or 1% thermistors (component accuracy variance),. i am starting to think this #5 i have is a 10%,. and i usually only use 1 - 3% ers on hotends for the best accuracy,.. a hot bed is fine with a 10% er,. but not a hotend.

    Though admittedly this is the first time iv used a #5 so,. still looking for something i might be doing wrong on this end, though i have it printing,. but there are these bands of color shift through the print that directly corresponds to the timing of the 5 deg flux,.

    This is the 5 Deg banding i am seeing with the #5 but not with the #6,.

    Originally i thought i was having Z height consistency issues, or Z wobble from somewhat springy Z couplers I am testing out,.. but i measured the various layer heights across this print with the digital microscope and its consistent,. I then thought it it was potentially inconsistent diameter filament producing a slight flux in the filament pressure, because i also see ever so slight side wall bulging with the color shift. but i did a print watching the filament diameter at consistent intervals, and the diameter shifted much more randomly than the color shift pattern which seams to be almost perfectly even timing,. then i noticed the saw tooth pattern to the hotends PWM signal with the #5,.. and it matched perfectly. so now i am likely to switch back to the #6 after i test one or two more work around theories,.
     

    Attached Files:

  17. BadDevices

    BadDevices Member

    Joined:
    Mar 28, 2014
    Messages:
    8
    Likes Received:
    0
    Re: E3D v5 All Metal w/Direct Pinch skipping/clicking proble

    Ok, yesterday evening we try the mhackney mod: we made it on two of the four nozzle that we had.
    We use a brand new 2mm drill bit and a battery driven drill (we doesn't have the pin vise) paying very attention to don't exceed.
    We measure the deep of the 2mm bore with the drill in place and then the drill alone to have the difference that represent, more or less the .4 bore part (with some uncertainty for the tapered transition from 2 to .4).
    We go down leaving about 0.6 mm length orifice, then we reassembly everithing as per E3D instruction (so tighting the nozzle on the heatbreak and not the thermal block, leaving the small gap possible).
    Pushing the filament by hand seems to be more easy now, so we try a print: it's late so we can't start a long print, but we try with one of a problematic filament we have (a brown RepRap.me filament that is almost 1.85 mm, so normally with big friction also in the bowden) and after a couple of centimeter of very good print the starving and jamming occurs again.
    The print was 0.1 mm layer and very slow, about 220°C.

    So, reading the mhackney post, we are quite sure that he identify the problem and that this is the correct solution, so one failed print means nothing (considering this filament) so today we will try with other type, more close to the 1.75 diameter and keep update on the result :)

    A question: I see that the use of thermal paste or grease is already discussed somewhere in the forum, to be used on the thermistor (we put thermal paste, but we thing to avoid this in future and use only kapton) or as Alex suggests, a little bit on the heat-block on the heatsink side; but do you think can be a good idea, in order to increase the termal conductivity toward the nozzle, to use a "silver or ceramic" thermal paste on the nozzle thread and between the flat side of the nozzle against the thermal block?
    The paste is soft, so we can tighten the nozzle against the heat-break as required by E3D, but filling the small gap with a conductive path; anyone had tried this?
     
  18. mhackney

    mhackney Well-Known Member

    Joined:
    Mar 4, 2014
    Messages:
    53
    Likes Received:
    11
    Re: E3D v5 All Metal w/Direct Pinch skipping/clicking proble

    Here's a video printing my tenkara line holders on my SeeMeCNC Rostock Max v1 in PLA at 80 mm/s on PEI at 50°C. This is the Kraken hot end, PLA at 190°C with my "shortened nozzle bore" mod to the Kraken nozzle.

    [youtube]http://www.youtube.com/watch?v=ZnuU1EQGx60[/youtube]

    I can print all day at these speeds with the Kraken now. I'm also starting to bump up the speeds to see how high I can go. Unbelievably (at least based on my earlier experience) I have not had to bump the temp for PLA up much at all - this is 190°C and I have actually printed at this speed at 185°C but why push it!

    All of the rattling you hear are my binder clips vibrating during the sinuous infill. I was never able to print PLA this fast on my E3D or Kraken before the mod, let alone at this low temperature.

    The thermal paste idea is interesting. None of my pastes have high enough temp ratings. Do you know of any pastes that are spec'd for up to 250°C or higher?
     
  19. AlexC

    AlexC Well-Known Member

    Joined:
    Mar 25, 2014
    Messages:
    46
    Likes Received:
    0
    Re: E3D v5 All Metal w/Direct Pinch skipping/clicking proble

    Just to clarify the only place i have put thermal "grease" is on the heatsink side of the heatbreak, and not on the heat block side of the heat break. and only a small dab on the lower 1/3 of that side of the heat break.



    I would not recommend using thermal "paste" anywhere on the hot end,. some thermal pastes get hard and brittle over time and will lock up your threads,. only use thermal "grease" in this manner.

    I would also not recommend using anything on the thermistor unless your absolutely 110% sure it is non conductive. just wedge it in there and it should be fine as long as its not overly loose..

    Unsure if a little thermal grease on the nozzle threads would cause any troubles or be beneficial,. would be worth a test maybe,. i would start with a very small dab.
     

    Attached Files:

  20. Eaglezsoar

    Eaglezsoar Administrator

    Joined:
    Mar 7, 2014
    Messages:
    267
    Likes Received:
    0
    Re: E3D v5 All Metal w/Direct Pinch skipping/clicking proble

    That small amount of thermal grease shouldn't hurt a thing.
     

Share This Page