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Posts posted by hcpl

  1. Calinb yours needed many modifications in order to work!

    I checked all these details on my machine now and I have the same issue with the driving bolt. It needs to machined also in order to get the good part completely aligned in the driving slot of the extruder. Good to know. I'll keep that in mind if the new hot end is still not working.

    The delrin part pushing the filament against the driving bolt is not an issue with mine (other than user error in the beginning) since I have the V2 version of that. You should really print that now you can. I have both and the difference is significant!

    Nice color on yours! Happy printing.

    edit: I just noticed another difference. You have a white clip in the grey part where the filament enters the bowden tube. Mine is the same grey color as the bigger part. It also has a rubber ringer underneath the clip. I think that is to protect the bowden tube when you let the filament enter by a driving extruder.

  2. Okay good and bad news. The good news is that there was indeed material on the PEEK again so I cleaned that off. Measured the parts and it should be possible for the 2 to meet. So I tightened the PEEK on the brass pipe and noticed the brass got passed the part where the PLA was before... only to realize I forgot the alu plate in between. Unscrewed and started remounting with everything in place. While mounting I started to heat up also anticipating perfect extrusion.

    A little distraction from my kid asking about the wifi on her tablet. Went away a few minutes to check. Got back and started to finish tightening the PEEK on the brass, not realizing it was all heated up already and I was deforming the PEEK until the brass cracked!

    I'm out for a few days until the replacement is received. The good thing is that I'll know what to check for when mounting.

  3. Lol I missed this crucial post! Let me reply to that also.


    Thanks! I am printing now and my filament barely has any drive marks in it. Your filament is obviously being deformed, ground, and chewed-up to force it though the hot end. I''ve made three changes to parts in my kit (one with my lathe and two with my mill). I'll describe more about them later, but you have the Bertho drive, so only one of my mods might apply to you.

    Great to hear your set now! That picture of filament was before I understood that my extruder drive was indeed abusing the filament. Today it's much better on that side, leaving only small toothmarks. I'll make a picture of that improvement this evening.


    Edit2: could less heat make an improvment?
    I think it might. I think temperature can change how and where plastic jams in the hot end.

    Also to report back this evening after some new heat tests now that I have the extruder drive fixed.


    If the issue is filament blocking between the parts stacked on top of each other, then why are there so many parts in between? Why isn't the tube mounted on top of the top brass?

    The link you provided explains the official reasons.

    http://daid.eu/blag/2012/08/31/ult ... v2-hotend/

    Some of them, I question. For example:

    The new white connection part seems to be designed to stop plugs and making the bowden tube connection less prone to errors. As the bottom part has a slightly thinner diameter then the brass tube on which it rests. This means any plug that tries to form is of a diameter that will fit back into the brass tube.

    I have made very careful measurements of the parts with micrometers and calipers and the Teflon tube discussed here has the same internal diameter and the brass tube on which it rests. The other beneficial claims for it are true, I believe.


    Yes I've read that but thanks to my experience I don't agree with everything also. Maybe this v2 head assembly is less prone to the plugs found before but it sure has other problems then. Just need to find out what exactly. If just a slight over temperature (hypothese only for now) is causing these jams then that would be an important warning at the instructions. Not to mention the official wiki has several different temperatures listed to start with.


    I am running the V1 nozzle and brass pipe in the V2 hot end, because I broke my V2 in the repeated wrenching I've done to take things apart and put them back together many times for debug. I'll provide more details later, but I found that a gap exists internally between the Teflon tube and the brass tube (regardless of V1 or V2 parts used in a V2 hot end).

    Exactly what I found after many taking aparts and cleaning etc.


    So I closed the gap by milling 0.011" (280 microns) off of my V1 nozzle. You could achieve the same dimensional change by milling (or carefully filing) the same amount off the bottom face of the PEEK where the flange from your V2 brass pipe seats against the PEEK. This will move the other end of the brass tube into the Teflon pipe above. If your parts have the same dimension as my parts, this should seal the gap between the Teflon tube and the brass tube. I milled enough to create about a 150 micron (0.006") "crush zone" in the end of the Teflon tube to seal it well against the brass tube. Again, my parts vary a bit. For example, I have two PEEKS and the depth of the recesses in the top end of the PEEKS (that accomodates the flange of the Teflon) tube varies by 100 microns between the two PEEKS.

    I don't have the V1 nozzle so I don't really understand how removing material from that part helps but I understand the rest of the story regarding the V2 parts and I do agree on that idea. In fact I had the same conclusion so far. Great minds think alike, isn't it :p

    You're really talking about microns here, probably not a good idea to do so by hand then. I'm at a fablab monday and tuesday next week with a real engineer (I'm only a software engineer, the soft kind that is). I'll check with him what's possible.


    However, I think your problem is likely to be assembly (mine quite possibly as well!). I was very, very careful in the assembly of my modified V1/V2 hybrid hot end. fluxline helped me to realize the possible importance of a step left out of the V2 instructions: The Teflon tube must be displaced from the wooden plate by the width of the small allen wrench provided in the kit. This is covered in the instructions. What might be equally important (I"m not certain about this), but not covered in the instructions, is the clip in the Bowden tube quick connect must be inserted before tightening the assembly together with the screws. The Bowden tube must be fully inserted into the Teflon tube (the pen marks line up) at this point too. This was required in V1 because the Bowden tube had to seal or it would leak plastic. In the V2, the plastic should be solid at the end of the Bowden tube, but we still want it to be hard against the Teflon pipe.

    At first assembly I followed these steps but I agree I might have been not precise enough at that point. Later on I redid the whole assembly with a better understanding of the need of all the steps so I did pay much more attention to details. I'm confident I did these steps correct that second time.

    I'm not sure however if running the head the first time could have cause damage or blocking PLA in the PEEK part. There sure is PLA in the tube now and maybe that is just bonding with the passing filament when heated causing plugs anyway. That is how I got to the gap between brass and teflon inside PEEK theory. Not how to remove that. I saw the teflon popping up at a certain point while jamming so I'm pretty sure material was inside.

    Let's say I get away too much of the PEEK material. Would it be a real issue if the plate on the brass screw, between the heated alu block and the PEEK, would be apart from the PEEK? As long as the brass and the teflon meet inside the PEEK I think it should work no?

    I'll be able to compare the PEEK and brass parts measurements once I have my spare v2 hot end assembly. I'm curious if that would introduce a lot of room for error.


    In my case, I think the finger pressure required to feed filament manually has dropped from 30-40N to about 20N. However, I also think that (after my modifications to the drive hobbed bolt and Delrin rubbing block, my extruder drive mechanism could now drive the previous 30-40N if necessary!

    If you feel the force required to push the filament though the hot extruder is excessive. I think you may need to reassemble the hot end very carefully with regard to above procedure.

    I definitely need too much force from the 3 layer on. So during the print.


    Much like the jamming wiki explains as a mod =>


    . If done that way nothing can get in between, no?

    In the V2, our Bowden tube terminates at the Teflon tube. This should not cause leakage problems because the plastic is solid there! However, my mod was directed at the equivalent junction in the V2--the interface between the Teflon tube and the brass tube. There IS a gap there in both my V1 parts and V2 parts (about 125 microns, but it varies between my sets of parts a bit). Is that significant enough to cause leakage and a jam inside the PEEK? I don't know. The nozzle orifice is 400 microns, in comparison. Some plastic was sticking to my internal PEEK threads so I know plastic was in the gap! My hot end requires less force to feed filament now, however. Is it because of something about my V1/V2 hybrid? Is it because I filled this gap? Is it because I was very careful and methodical about assembly. I don't know for sure. I'm pretty sure my printer would have function at least a little bit before (it would less fuctional than your printer), if my Delrin had valid dimensions!

    I agree on your findings, they match mine. Really a good thing yours is working now and many thinkgs for reporting back. Really appreciated!

  4. I don't think the small mod to seal the Teflon tube against the brass tube can hurt, but I suspect following the V2 hot end instructions precisely is more important. I was wrong and step 31 does say to insert the clip in at the appropriate time:



    I followed these steps closely. From my understanding step 30 and 31 will compensate for each other. By creating a gap the size of the blue horseshoe clip at the bottom, then putting the clip in place you push the tube up, that will be compensated once you assembly the long screws so the white part in between on the bottom is pushed up again and the 2 parts meet.


    Do you have access to a milling machine? It's often difficult to make accurate measurements where needed (make many and look for repeatability) but you could just take off 0.280 mm / 0.011" with a file. Lay the file on a flat surface (or your lap where it won't slide) and more the PEEK across it with your fingers, keeping pressure even and the PEEK square to the file. Measure your progress often and use the standard machinist's trick: try to remove no more than half of what remains to be removed after each measurement. Actually, lacking the benefits of graduated leadscews or digital readouts on a mill, you'd better go even slower than that at first! I could do it for you very precisely on my mill in about 3 minutes, including setup. I have an extra PEEK and we could swap after I send it to you modified, if you'd rather not modify your PEEK. I don't think this is super critical. You want a bit of force seal the junction but no so much that you significantly deform the Teflon tube end.

    No no milling machine here. Thanks for the offer but I'm in Europe so it would take a lot of shipping time and money. I'll try it once I have the spare. With a file should be doable very careful like you mention. Thanks for the tips!

    I was also looking at this thread:

    https://groups.google.com/forum/#!topic ... EmVIgFKRzY

    . Many familiar names by now. Looks like the same people are contributing a lot. The thread starts at a pre V2 hot end era so keep that in mind when reading about the tube thread tips etc. It's also talking about temperature measure variations up to 15-20°C and PLA bonding to PEEK very well.

  5. In the V2, our Bowden tube terminates at the Teflon tube. This should not cause leakage problems because the plastic is solid there! However, my mod was directed at the equivalent junction in the V2--the interface between the Teflon tube and the brass tube. There IS a gap there in both my V1 parts and V2 parts (about 125 microns, but it varies between my sets of parts a bit). Is that significant enough to cause leakage and a jam inside the PEEK? I don't know. The nozzle orifice is 400 microns, in comparison. Some plastic was sticking to my internal PEEK threads so I know plastic was in the gap! My hot end requires less force to feed filament now, however. Is it because of something about my V1/V2 hybrid? Is it because I filled this gap? Is it because I was very careful and methodical about assembly. I don't know for sure. I'm pretty sure my printer would have function at least a little bit before (it would less fuctional than your printer), if my Delrin had valid dimensions!

    In mij 3rd picture you can see that the green filament also got around the brass part in the PEEK. You can see the green ring it formed. Also the blob of filament there is too big to fit in the teflon part I believe. It looks like a jam. That picture is taken after the jamp but already cooled down.

    once I receive my second I can start modifying the head. For instance removing some material on the down side of the PEEK would allow the brass part to insert completely and touch the teflon white insert.

  6. What OS X version do you run? If 10.8 the instructions from the cura website won't work. I'm working with replicatorG for now and have hardware related issues. Once that's fixed I'll look into isntallation of cura on 10.8.

    If you're still on 10.7 or 10.6 then the instructions from the website should match. If not you can always get help here.

  7. Calinb: I feel your pain. Mine is a business investment also. Not return on investment yet though since it can only barely print 3 layers.

    The black stand offs were in a separate bag labeled motor stand-offs. I received the white ones also and these were indeed mounted like you describe. I have noisy cooling.

    Indeed since it works without head the tube ain't my issue either. Ebay has tubes listed in case yours gets bitemarks out of frustration.

    I watched mine closely while printing those first and only layers. The white teflon part on top of the peek got pushed up at least 1mm when it went wrong. I'm going to mark the bowden also to check if that gets pushed out or not. Just to make sure I'll also print at 240C.

    And I'm ordering a new head today. ultimaker is in business! If that one fails also I'm buying another hot end to mod on my UM.

    Edit: Some picture of my setup in attachments.

    Edit2: could less heat make an improvment? I'm testing at 210°C now. It looks like the tip just on top of the heated top brass part is swelling and causing a jam inside the white plastic (teflon?) part on top of the peek. Now if I would apply less heat it might be swelling less causing a better extrusion? Just a theory. Tests will be done this evening. I'll test again from 180 to 240 with manual pressure so I don't grind the filament down and don't need to clean up the mess in between all the time.

    If the issue is filament blocking between the parts stacked on top of each other, then why are there so many parts in between? Why isn't the tube mounted on top of the top brass? Much like the jamming wiki explains as a mod =>


    . If done that way nothing can get in between, no?

  8. I'm going to abuse this thread to collect info for myself also. It might help you. I was talking earlier about the pressure on the long threads that keep the head together. I have that wrong in my setup for sure. The first answer in this thread viewtopic.php?f=7&t=1317 has great info on why that tention has to be exact.

    The tube doesn't melt down but flexes when heated and then can deform making it harder for the PLA to come through. When I retract PLA I sometimes also have to use more force because the molted end is bigger and causes more friction against the tube.

    => edit: fixed this but didn't give any improvement.

    Somehow I think my extrusion went better in the beginning. That is when I had it assembled and running for the first time. I then had issues with the nozzle leaking so I didn't pay much attention to anything else. I think I had it running on 1000 rpm then without issues.

    While testing over the past days I also tried several heat settings and finally used some ABS on higher temp for sealing. I have to remount the nozzle closer to the alu block so I'll take it apart again for cleaning. And then tighten the top brass part with 2 bolts tightened against each other to drive it in completely against the nozzle for proper closure.

    I've read about people heating up the head and putting pressure on the bowden tube with a bike pump. That might be a good way for cleaning without remounting.

    My head sometimes kind of plops a bigger amount of PLA out at once like a plug was popped out. Not sure when exactly this happens but I'll pay attention to it from now on.

    I see metal parts on the white retention clips. I didn't see these on mine.

    => edit: I've got that metal in the clips also.

    Oh and might not be related at all but I had black tubes labeled as motor stands (or something like that) included in my kit. Comparable to the white parts used to mount the electronics board away from the bottom. Problem is that I never used them!? No idea what they are ment for.

    This thread also looks similar: viewtopic.php?f=7&t=601

    and info about an alternative head:


    edit: you must read this one also! Info on the bowden tube and alternatives etc. : viewtopic.php?f=7&t=902

    edit2: I was able to remove the first fast extrusions from my gcode so I couldn't print from the beginning without grinding. After 2 layers same problem again though. I checked the retention on the extruder and that is fine now, leaving only toothmarks. It's clear to me that there is too much pressure build up in the tube/head/nozzle causing the extruder to slip/grind after some time. Don't know why yet. Not sure if it's worth it to get an extra head. I check dimension of both filament and tube and that seems ok. Filament is around 2.9 while tube is just below 3.2.

  9. So you received the Bertho-style clamp in the drive mechanism? I did not receive that upgrade. Luckily, I received both a V1 and V2 hot end parts. Now I need the spares! :(

    Indeed got that bertho-style upgrade shipped. It provides better controller over pressure (I agree on that) and should compensate for differences in the filament (looks like it does to some level). Once printer works with the original clamp mechanism you can print one yourself. UM should work with original also. Or this completely new design:


    ... If only we could print :D


    Yep--those are my symptoms too, but I can't even get it to work at 250 or 500 rpm. I just get to the fail point faster at 1000 and I've not attempted higher. My two attempts at printing were also a waste of time and the same for all the plastic in these trials, because about 2/3 meter is wasted each time the drive chews it up and rams it up to the head!

    Yes cutting off another wasted length of filament is getting harder and harder to do.


    I believe the nozzle should touch the aluminum block because, in this position, the top of the brass tube that is inside the PEEK will just about make contact with the bottom of the Teflon tube. I think it SHOULD make contact with some pressure, to make sure molten plastic does not leak into the PEEK at this junction. As measured with my micrometers, I do not believe the dimension of the parts are correct to make this possible. There is about a 0.125mm gap between the bottom of the Teflon tube and the top of the brass tube. This junction is inside the PEEK, so it cannot be observed not measured directly. You can only measure the disassembled parts and deduce this gap.

    This link has good, and visual information on that plug issue:

    http://daid.eu/blag/2012/08/31/ult ... v2-hotend/

    I borrowed a picture from there and added some color codes to explain what I did (see attachment). The red line between the nozzle and the alu block is where I have a 1mm gap. This doesn't influence the gap between the top brass part and the PEEK though (green line). I have those 2 tight onto each other. Not overdone though. It's plastic so I didn't dare putting more tention on these 2.

    The white part is on top of that PEEK and the bowden tube goes in the white part as far as possible. I posted a link in one of my previous posts here about the long fasteners of the head that shouldn't be fastened too much. I probably over did these (will test this evening). That is what closes the gap between the parts at the blue lines.

    An important pat to prevent the leaking on the head for me was putting some ABS through (not included in my kit though) and fastening the 2 copper/brass parts against each other so they meet closely inside the alu block


    Again--all too familiar to me!. I don't have the patience to do it but I suspect that I could print successfully if I don't completely close the latch on my drive mechanism (this compensates for my Delrin adjuster that's still too tight with the adjustment screw backed all the way out) AND I just sit there and "assist" the feed with my fingers. The motor will change speed, as programmed by gcode, and my extra 20 Newtons of force will keep it extruding. Of course if my worries about the Teflon tube / brass tube hot end gap are valid, it still might jam eventually.

    Given the similarity of our printers' symptoms, I don't believe a solution lies in increasing the power (or speed) of the motor. There is plenty of power available to grid and distort plastic already! ;)

    I agree.


    Same print result here too. I haven't even bothered to assembly my Ulticontroller yet. It has no value to me w/o a working printer!

    I don't know what rpm is reasonable. I've focused down around 250 to 500 rpm and even that doesn't work.

    I'll let you know how my V1/V2 hybrid configuration works out. Keep in touch. I think we have the same problem--at least the same major root cause (there could be other contributors.

    I'll keep posting here if I find something interesting. I hope you'll find a solution to your problem soon (so you can post it and I can get mine solved also :p).

  10. So you have E commands in the resulting gcode? I had an issue before where these were missing and had to check the "dimension" > "activate dimension" option in the applied replicatorG profile.

    Can you get the motor running when you use the control screen in replicatorG? If that fails I would say it's a wiring/hardware issue for sure.

  11. I'd like to know the answer to this question also. My extruder also jams at that speed on a newly assembled UM kit. It works fine at much lower speeds like 500 rpm. 1000 rpm was also blocking eventually.

    @banana: check if you can push the filament through by hand. If that isn't possible it's more likely caused by the hot end blocking. Make sure to clean the driving bolt once this has happened since it will slip when not clean. I read that we should have just light toothmarks in the filament, that should help getting the right tension. Do you have the V2 or V1 clamp on your driver? There is a wiki page on jams, check the link on the troubleshooting wiki.

    @Ian: I don't see how other software can help here? I'm not saying cura isn't better but for running filament at 1000 or 2000 rpm through the hot end the software shouldn't make any difference.

  12. Do you have a recent kit? I received mine about 2 weeks ago and received V2 hot end only but both V1 and V2 extruder clamp mechanism.

    I have no tools to measure the required force to put filament through nozzle at this time. I'll try to get that done. I have a caliper so I can measure the filament diameter. I'll do that this evening and complete this post.

    The symptoms on mine are very similar. If I let the extruder drive filament through an open hot end it goes fine up to 2000 rpm, 3000 rpm got the motor screaming but that's not abnormal I understand. When I try to let it run through a heated hot end with nozzle it only goes well for a few seconds. Soon the extruder will begin slipping and grinding into to the filament making the problem even worse since these spots make it harder for the filament to get through the tube.

    This is what I've tried so far (spread over 3 evenings/nights):

    I cleaned and remounted the complete hot end. At first it was leaking a lot on top of the alu block where the brass part comes in. Turned out I had the nozzle bolted against the alu block instead of against the top brass part. That and running some ABS through fixed the leaking issue. As long as the 2 brass tubes meet in the alu block there is no need for the nozzel to touch the alu block? Or is that truely a requirement? Since mine now has the nozzle about 1mm apart from the alu block. Maybe needed for heat spreading?

    I also had filament getting up into the white plastic part between the PEEK and the bowden tube. That was caused because of a gap there between the bowden and that white plastic. Remounted that also and got that fixed. No more clogging there (I checked in between tests).

    I tested with several temperatures from 195 to 240. No real difference. Except for the difference in the palstic coming out. But still blocking eventually.

    At the extruder drive end I played with several tensions. From what I understand it should leave some toothmarks but not deform. I can get to that point so no issue there.

    Every time the extruder slipped I took it apart to clean up the driving bolt so it would be perfectly clean and ready for the next test. The bolt is in the perfect spot, the best part of it like explained on the assembly instructions.

    The big wheel can spin freely if the stepper motor is turned of. I can push filament up by turning the wheel by hand. As long as it doesn't get blocked once (starts grinding and deforming filament) I can push it through a heated nozzle this way. It's slow but it works. And from what I saw during the sparse printing time that is close to what it should keep doing during a print.

    The motor does get quite hot, still touchable but hot. Because of that I'm not very keen on increasing the power to that motor using the pot. Should I try that? It's not that the motor can't turn any longer, it's more that the motor starts grinding into the plastic instead of pushing it up.

    I did some tests with the control panel setting an rpm for the extruder motor. If I put it to something near 500 rpm (that is slow) it will keep going forever (or at least as long as I was willing to look at it wasting plastic). If I turn it up to 1000 rpm it will get blocked eventually. At 2000 rpm it gets blocked almost immediately after the first filament gets through the nozzle.

    I did try to print some things. During the print it seems to function until it gets blocked again and the filament stops running out of the nozzle. If I prepare for a print I heat up the nozzle with the ulticontroller and let the filament get to the nozzle. Once I start the build on my macbook I have to confirm the build on the ulticontroller (not completely sure on that procedure).

    First the build platform will go down (Z+) for about 5cm and the extruder start running fast (around 1000 rpm I guess). This is the part where the filament gets damaged. After that the build platform goes up again and the head starts print. At this point the extruder is much slower and it gets there for some time. But because of the damaged filament it gets into trouble quite fast. At first I can help it by hand (resulting in too much filament on the build) but eventually it will block up again.

    I believe that if I can prevent the fast extrusion at the beginning of the print I would be able to print something completely (or at least a lot more) since then the filament wouldn't be damaged from the beginning and as long as it runs as slow as during the build I think it could work.

    The documentation about first prints shows some intsructions on running filament through at 2000 rpm. So that should be possible without blocking?

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