Torgeir

Hi Bray, This is one of a special thing.. The last print looks very nice, question is; is this objects height less that the height were the "error" occurred on you full scale model? Cause the only common thing here is the Z-axes, so this is just a theory;. Suppose that the bed does miss two step -or more (hanging somehow), then assume a little lo torque on the X-stepper or high friction when hot(?). When the extruder then hit the print object, the X-stepper miss some step due to this collision (and now has got an offset), the heat bed move a little down and the printing process continue printing with this X-offset. A monitoring of this problem would be interesting to observe. Well, this is just a little theory, but.. Who knows. Thanks. Torgeir.

Great job Johan. Thanks. Torgeir.

Forgot one thing. There will only be smoke until it dry some up, then it will be fine, just went a little. Torgeir.

Hi Johan, OK., you should use shielded for the signal wire between those board. BTW., I've just checked the EMI from the two fans on the UM2, here there is two fan in series (12 VDC each. And 24 VDC feeding both). There was a lot of spurious (Lots of HF spikes) in the middle of the two fans. I've also tested with a 100 micro Farad capacitor, this capacitor removed all the spikes.. If you have an oscilloscope, you'll see it all. On an UM2, those spikes do not create a problem since the level of the signal from here is much stronger and do not need to be amplified that much. Good luck. Torgeir. (Edit: Sorry for the misspelling of your name.)

Hi Bray, This is kind or rare, -sure the slicer program can do strange thing, but so can the hardware.. A few missing "full step" on the x-axis at a certain spot will do the same thing! This is very true as the firmware only can synchronize at the X/Y and Z end switches, from there on it is only the number of steps that's the true reference. Also, is your R/H stepper (the X-axis) very hot, or just hand warm? Compare with the Y-axis stepper. Did you try to print this object (edit:) "sliced" in Cura without this issue? Just a thought. Thanks. Torgeir.

Hi Johanes, Come to think about those fans as they do radiate lots of pulses when we adjust the pulse width and some of them also radiate when at full speed (the max voltage). Sometimes we'll use ferrite bed, but this is mostly for high frequencies, so at lo frequencies we simply put an electrolyte capacitor as close as possible to the fan. For those fan we're using a 100 micro Farad / 25 VDC will do the trick. (PS. remember the polarity.) (This volatge advice is for UMO, for UM2 and like select at least 40 VDC.) This kind of "EMI" noise from the fan use the feeder wires to the fan as an antenna! Just my 10 cent.. Thanks. Torgeir.

Hi Folks, A last report about the testing after this modification. When I loaded a roll of black PLA (Verbatim), the usual thing happen and it started to extrude filament out of the nozzle, then I heard the feeder stepper started to skip. As I watch this, it seemed to have a little less flow than before and the feeder act as it was compressing a "strong spring"! Every time it skipped it moved about 90 deg. back, then started to compress again. I was wondering if there was any remains/gums etc. inside the nozzle, so I did a few "atomic Bob". To my surprise the filament broke of right at the top of the Teflon coupler, I've had to reload manually and squeeze out a little PLA. After this, let the temp go down to 60 deg. Celsius, then set it to 90 deg. C and when at 90 deg. pull.. Then it come out "almost as" normal, but -just about where the Teflon coupler is insulating the heat block from the upper "cold part" of the extruder there was a circle/section of the filament with less diameter than the filament diameter(2.95 mm). This set me somehow out.. After some thickening, I realized that I've lifted the heat block a little up. Aha., so I reduced the gap back to about 0.8 mm and made another test, bingo... The little fan improved the cooling so much that is also cooled more of the upper part of the heat block. So, the faster the filament was tried to be feeded through that passage the more energy was needed to melt the filament. So now I'll know how important the adjustment of the height of the Teflon coupler is. You're actually adjusting the width/sharpness of the hot/cold zone for the hot end. As a final test I printed the "extruder feed test", started with the temperature of 205 deg. Celsius and monitored the temperature until finish. When the temp descended one deg. I rolled it up one deg. more and so on. It finished at 207 deg, Celsius with no issue.. All in all, I'm very pleased with this result. Thanks. Torgeir.

Hi Tom, Thanks. Grate job in finding your problem. Torgeir.

Hmm, -no cure with the copper paste. As you tried to decouple noise on the thermocouple amplifier with the 4.7 micro Farad capacitor, you sure knows about the EMF that can be radiated by the small electronics inside the fan.. The thermocouple amplifiers input signal is in order of a few micro volt at lo temperature levels, so any noise/EMF around here may/will jam this small signal. I'm sure Neotko has a solution for you here, as he have plenty of experience and at last 3 UMO in various versions. As I have an UM2 with PT100 temp sensor, such problem is not an issue here. Good luck in your fault finding. Best Regards Torgeir.

Hi Tomty, I've had exactly the same problem as you describe here. But first thing to check is the hot end cooling fan on the back of the extruder, if this one is not working you'll have the same problem as you describe. As you did, I'll always remove the filament after the print and then put it in an airtight bag that have some dehumidifier keeping the humidity around 17 %. After a 12 hour print did finish when I was not around, the filament was stuck at the extruder. Actually the feeder become glued, due to ricing heat during cooling down. I'll think this problem is causing more problem than most people are aware of, myself included here! Have a look at this tread; https://ultimaker.com/en/community/17794-detailed-documentation-of-our-hardware-and-software-mods-for-reliable-printing Good look. Thanks Torgeir.

Hi Folks, As I've modified my spare extruder, now it's time to do the extruder that's removed from my printer. First, here is a picture of both extruders. The right one is the spare one, still have some issues to be fixed before I can use it on my printer.. You'll see the Alum tape I'm using to have the pressure center at the nozzle. Also you'll see how the wiring from the heater block shadow the inlet for the cooling fan. This next picture is after this modification on the extruder normally installed on the printer. First, this modification on the used heat block was not an easy task. So if you're going to do this modification you need to have some spare part aviable in case something break, because here it is very easy to breake the wiring esp. the one for the heater element. So do not rebend the wires, they should stay in same position as it have under the whole modification! I've had to power up the heat element in order to unscrew the adjustment screw for the Teflon coupler, as there was a sign of black plastic at the connection to the heat block. I'll think heating also is a good thing to do before trying to remove the heater element. As I added the copper paste into the heat block attatcment hole's for both the heat element and the PT100 from before started using it, there was a minor task to remove them. So, now you're warned about the problem that's may occur if you like to do this modification. OK., here is a picture of the split-ted extruder, just before I connected the heat element to an external power supply using 12 VDC only. Using this voltage brought the temperature up to around 130 deg. Celsius. The gap between the Teflon coupler and the adjustment nut is a little bit lo, only 1 mm.. Heating up to 130 deg. C. Here is the hot block attached to my "mini" vice. This block have more than 300 hour in printing, well, not much but still nice. You'll see I'm using the copper paste at the thread here as well. I've had to clean up the threads with this tool, no need for adapter here, only bare hands! Be very careful if you need to clean away plastic using this method. Here is the "essence" of this modification, the printed duct from James and related parts. I've somehow come to the limit of how much I could upload, so next time I'll compress the pictures. Just one more thing to mention is that I've had to make a cutout where the wiring going into the extruder plastic housing, the same way the Chinese did it on the spare extruder housing from China. Anyway, this is the way I did this modification. Thanks. Torgeir.

Hi Johan, Wow, you really made your lesson, great.. The measurement of your resistance is good, I'll think no problem here. The temperature graph is interesting as it normally should not jump that fast.. Just come to think about some more to consider, this might also be a bad thermal connection. The thermal connection between heat block and the thermocouple (assuming you're using the Chrome-Alumel thermocouple). I'm always using the copper paste when installing the "PT100 and the heater element", this to make sure there is a good thermal connection. Another benefit here is that the temp sensor and the heat element never get burned stuck into the block anymore. Well, maybe the PID tuning as Neotko brought up will do the trick.. Anyway, good luck. Thanks. Torgeir.

Hi Johan, There is two things here to be isolated, either the temp is wrong (high) -telling the system to turn power off, or there is an interrupted connection to the head reducing power to the hot end. Both reducing the temperature. I'll go for the latter, -but sure could be wrong. IMO, your indication is OK, but the power is not! How many hour does you printer been working? So, check the resistance to the heater element in the "hot end" when you're moving the "extruder head" manually around the bed. See if the resistance change during this moving action. Yes you will need an ohmmeter or any kind of "multi meter" that can read resistance to do this test. (Sure, here an ohm meter is connected to the "extruder heater" connector. as we like to see if there is any loose connection in the wiring from PCB to the "extruder heater".) We'll need to start like this to find out if this is a power interrupt or if it is an EMC problem. Anyway, good luck. Torgeir.

Oh no, -not brave, started with a cold iron to see if there was any problem... But, it's a very good insulator. BTW. also tested the high temp glue (1100 deg. Celsius). It worked on PLA and Aluminium foil! (Need (2-3) hour in room temperature to cure.) Torgeir.

Hi Ultiarjan, Thanks. The insulation material is «Absorbent of white fiberglass used as wick in ethanol stoves». This material have another good properties for us to use as it is an excellent high temp insulator. I've found this material some time ago, but did not have a good solution to prevent that the heath climb upward into the bowden tube and gluing the filament. -Well, until I saw this tread. I've found some items that might be useful for such high temperature related design. All of them is bought at «Biltema», a supermarket for almost everything that's found in the Scandinavian countries (originated from Sweden). There is a thermic glue that’s cope with temperatures up to 1100 deg Celsius! I've planned to glue some alum foil on the lo side of Laberns «dual fan duct bracket» in order to deflect some radiation heath from the heat bed. (Do not know how this will work on PLA or Alum foil, but will do some test later on.) The last one is a tube of high temp «instant gasket», that's also tend to vulcanize in room temperature. This silicone stand temperatures up to max. 310 deg. Celsius. Might be something to protect the nozzle tip with? (Reefer to another tread ongoing). As a little «prove» of that if this insulation might be good enough to be used for this purpose, have a look at the attached pictures. The tip temperature of the soldering iron is around 350 deg. Celsius. The brown area on the insulation “mat” is remains of the insulation sleeve at the thermocouple. NOTE. Another thing I forgot to mention yesterday is that, I did not have any problem to fit the fan duct adapter into place. No need to remove material in any way, just a drill bit 2.5 mm to clear the two attacment holes at bottom side. Thanks Torgeir.

Hi James, I have to say, this is one of the best report I've seen in this forum and cant really understand why this one is not more addressed! Here is a lot of tip of how to improve and what failed, ofc. we all may have different experience but most of the important things is in here IMO. (I'll have to say, I never had any problem with the feeder flow test, I could print the whole cylinder with a standard feeder and the standard extruder head with no issues. Maybe cause I used a 1.8 deg. (200) stepper motor geared down to 1/2 at the feeder wheel (more torque). ) I might have read this before, but missed the essence at that time, however, yesterday I've read it and today I printed the adapter for the hot end fan -and also installed it.. I have always wanted to do something with the partially blocked inlet (wires from heater and the temp. probe) side of the fan. Also the outlet had this issue, as the fan itself blocked some of the cooling ribs. This modification is much better than it seems to be, cause it will deliver better cooling to the cold part of the hot end -preventing filament to "glue stuck" on the cold side during cooling down, or during a long print. Also, if you plan to isolate the extruder in order to have more of the total energy for melting filament and not spread heat to the surrounding parts/environment, you must have better cooling on the cold part of the extruder. I have not installed the second (cheap Chinese) extruder head I have, on the printer, but I've printed Laberns Single nozzle heath scroud and installed this one as well with an Olson block well insulated in here as I installed a 25W heater element. Thanks Labern, your heath scroud do not need any alu tape to adjust the airflow, the pressure center is right in the middle of the nozzle. Well done!!! I've tested a few, but this is the best one -and best looking.. Here's a picture of the extruder. Thanks for sharing your experience James. Torgeir.

As the manual test is "proving fine", it does not confirm that the PTFE insulator is good! This might be measured carefully as we need to know how much filament is extruded pr a fixed number of E step. This is the only way to "properly" check the calibration or that the PTFE insulator is in good condition. You can find out how many hour you Ultimaker been running by checking the maintenance advance menu. As sugessted previously, check the PTFE insulator. This is one item we'll need to have as a spare parts "in our store box".

Yes, you could be right, this click or.. could be just when the feeder release and the feeder is moving back again. I thought this occured at the same point, but the two first click is approx at the same point but the last one in more toward the front side.. So this thing occure at different places on the track line. If this video last some longer, we'll prob hear this sound on the return track as well, may absolutely be caused by the feeder is pushed back due to the high pressure. Good suggestion.

Hi, Yes, I was listening and saw this video yesterday. There is something wrong in the X/Y linkage train as you can hear from this "alarming" sound. -Or is this from the feeder stepper motor??? An Ultimaker normally is humming without the "loud" rattling sound and the single click on the return from aft right corner in the middle of this track. Also note that the extruded material is completely loose as it moves when the extruder head “hit” and is returning from "front left" position along the diagonal path. To me it looks like the nozzle is to high above the bed... ? (Yes I've read all the post in this tread.) However, it might be caused by some mechanical problem. If this sharp rattling noise is from the printer, you have to fix this asap.. Are you using glue or heath bed or both for this print? Thanks Torgeir

Hi Dwardio, Again, I'm very much agree with Neotko here. I've been using s3d since April this year, -and I'll think s3d is great for analysing, -but not for slicing! I have 3 ruined prints sliced by s3d... And all of them in the first layer, got pictures of all of this. When slicing same file in Fusion 360 (AutoCad - you can have it for free) or Cura 2.1.(X )the print is perfect! And from my part, Cura is the best slicer! (If you're been using Solid Works and cant affort it anymore, look into Fusion 360!!!) So, use Cura and see the difference.. Thanks Torgeir.

Hi Edel, __________________________________ Neotko said; Also since you print pla and the part it's soo small. I would use bluetape and turn the bed off (you will need to readjust the level a bit). That allows you to get as much cooling as posible since the bed won't be heating the printed part. __________________________________ I'm very much agree with Neotko here. I've struggled a lot with printing small detailed objects when using the heat bed on. Doing so is almost impossible due to the high heat radiation from both, the heat bed and the heated nozzle. The details in the object is simply melted/boiled away.. :( So, turn off the heat bed, use blue tape or photo glue. For object/models etc, I do use glue when there is details with limited contact to the bed. Happy printing. Thanks Torgeir.

Hi David, Just finished a «deep dive» into the file: https://github.com/MarlinFirmware/Marlin/blob/RC/Marlin/temperature.cpp#L1 If you go down to line846, you'll find how the temperature is calculated for the thermocouple with AD595. This is a good place to look. Actually you can try to use heater 2 and just change the offset to 1.111 and gain to 10, then the temperature «may» be correct, I'll think. I could not find the PT100 and INA826 in there, but maybe you can, however; using this trick may work. Here's the part of this file of interest. 866 return ((raw * ((5.0 * 100.0) / 1024.0) / OVERSAMPLENR) * (TEMP_SENSOR_AD595_GAIN)) + TEMP_SENSOR_AD595_OFFSET; OK., Good luck with Marlin. Thanks. Torgeir.

Hi David, OK. David, those folks are the ones behind it! I was thinking this; if you have a kind of hardware fault/error, those people are the right ones to ask. Well, why not check what you have; what the hardware is giving by shorting the input to ground, measuring/note the value in deg. Celsius at your display. Then another test, in order to compare the room reference (the PT100 at room temperature) temperature to this value, and see if it makes sense! And what is the value in boiling water? We'll like to see that your hardware is working!!! Changing firmware and looking for the right values is not the right way to go! "Do not change the firmware, but use the right one referred to in the manual. Let's not make any correction for the filament feeder direction or the feeder speed, cause we know its wrong." Concentrate the focus on the heat bed and the temperature we're expecting. Theory is something what we calculate/expect we can get, the question is then; is it true, -or is it wrong? In other word, we'll need to know what the hardware is "telling" for a given input. This is how we find if it is actually working. Remember we (the forum) can't see your result/problem. Oh, I'm sorry, did not meant to be rude, but I'll think we're in need to “gear up” in order to improve. Thanks. Torgeir.

Hi David, I'm sorry to hear this. Just come to think about some thing, I might be wrong here but... I think there is "some" versions of UMO that's not compatible with this mod due to hardware issues. When you put up this one: #define MOTHERBOARD 7 I'll wonder if this type was motherboard 27??? Just a shot. Edit: Maybe you should describe your problem here: https://github.com/MarlinFirmware/Marlin/issues This is the place to go.. OK. as usual; Good luck. Torgeir.

Hi mkoening, I've also started my printing lately, and got some surprises when starting to print. First I used heat bed at temperature set to 60 deg. Celsius. (Yes, I'm using PLA as well.) I started by washing the bed, dried it and go, but as the model grow up it suddenly snapped off the bed and a lot of filament mess... etc. etc. Well, I learned this the bed have to be "super" clean, no remains of fingerprints etc. After this learning, the model never come loose like that again. Then I learned a new lesson; my printing was never that good, especially the part of the model close to the heat bed. So I learned this here in this forum (thanks to Nicolinux:)); I've stopped using the heat bed when printing PLA, just using glue stick! It stick very well to the bed glass plate and do not go loose, -but can be really hard to get off the bed. I do not know the "Elmer's purple glue", but the glue I'm using is the glue meant for using gluing photo into the "photo album". This is a glue stick and loose up easily in water, kind of like soap. Put a tiny layer where the print will sit, make sure to cover this place. I started printing at 210 deg. C as advised, but I'm now printing at about 192 deg C. You may find the correct temperature for your brand of PLA, I'm using Verbatim PLA. Edit: Forgot one important issue; level you heat bed very accurately, use a sheet of 80 g print paper (approx 0.15 mm thick). OK., Good Luck. Thanks. Torgeir.