paban

I've installed the BONDTECH feeder last week. It works fine. The only issue I had in the beginning, was that the small Gcode program didn't SAVE the new E-step setting in the EEPROM (it worked just for one print). Using Tinkergnome's "Motion Settings" solved the problem. I think, the BONDTECH feeder is a better choice than the UM 2+ - extruder.

@anders olsson Hi Anders Many thanks for your excellent video. You have a fine technique of measurements. I know, mine has to be improved and is at the moment below scientific standards. There are a lot of interesting informations in your video (e.g. the effective temperature in the nozzle ant the effect of the fans). The critical point seems to be (and is in my case) the small distance between the left corner of the "Olsson block" and the heater bracket. If i got it right (at 4'43" in your video), you rounded your block at this corner somewhat. I'm thinking about this too; it shoudn't make a problem. I would like to find your comment about that. I'm going to modify the mount of the bracket to lower the whole thing ca. 2 millimeters. My bracket is damn tight and since the screw holes are already on the edge, I have to elongate the attachment. The bracket is looking nice, but i think it's suboptimal in fulfilling it's purpose. I received the 35W heating element from 3Dsolex and run some quick tests yesterday. It seems to perform quite good. The temperature overrun when approaching the set temperature is below 5°C which is acceptable. The temperature controller does quite a good job. I'm planning to post some results, when I have made the planned modifications. Kind regards from paban

Sorry, there is an error in my last posting: The comment 1) in the table should read "It takes ca. 10 seconds until the Pt100 senses that the heater is on"

Hi gr5 Thank you for the feedback. I'm sorry for the poor labeling of my table and wasting your time. My first idea was, to produce a graph and do the proper labeling there, but the multiline graph function in the actual Excel is quite fussy when you are not used to it. So I stopped and presented that „quick and dirty“ table. To your questions: - I've just heated the nozzle again (during 3 min up to the "error point" (218°C). The green terminal block for the heater had 31°C (measured with an IR-Thermometer) at the end of heating. When touching with a finger it didn’t feel hot. I’m not surprised, when some folks have a problem there. When Ultimaker assembled my machine, they were just pushing the heater cables in the clamps, without any cable end sleeves. I’m not an electronics specialist, but I think this should be good manufacturing practise (even for a hobbyist). It’s quite difficult to attach it in this state anyway. It’s hard to see, if there are loose tiny wires whithin the loose isolating fibres. On my picture oft he mainboard, you can see, how it looked in the beginning ! I have changed that when I detached the cables the second time. - My installed firmware version is 15.02.1 - Yes, you were quite right in your insistency about an existing heat loss to the fan bracket (very good coaching, Sir !) I ran yesterdayday in the beginning a nozzle heat up without the bracket, which gave samewhat better values than I had last week (!?). I checked then the hotend / bracket geometry very careful. When I touched the bottom oft he bracket at a nozzle temperature of 200°C, it wasn’t very hot (about 40°C). I’ve no idea how it looks like on an unmodified UM2 (I obeyed the warning sign ;-D ). The distance between the bottom of the Olsson block and the surface of the bracket is ca. 1.5 mm. The smaller Allen wrench which Ultimaker supplied (1.5 mm) just got underneath. But on the side wall, between the nozzle and the left side fan it was non touchable hot ! It turned out, that there was very little or almost no space between the block and the bracket. I didn’t recognise so far, that Anders block is not only higher, but 1.4 mm wider than the UM2 nozzleblock. Since the bottom of the bracket has a slight „V shape“ (reduction from 35 to 31 mm wide) things became very thight. When I widened the hole for the nozzle to a diameter of 10 mm. I left the center oft he bore unchanged, just to prevent contact of the nozzle with the bracket. So, when I centered the nozzle, I had moved it even a bit closer to the metal wall. So, that was my mistake. Today I widened the hole ca. 1.5 mm towards the other (unused) nozzle hole. With some bending of the two bracket connectors it was possible to create ca. 2 mm distance at this critical place. This helps quite something as the new heating table shows. The „old“ heating element (which was checked in these measurements) is still not able to reach a block temperature of 250°C, so an exchange oft this part seems to be mandatory. I would like to see, how the heating curves look like on other UM2 printers (modified/unmodified. The easiest way is doing that by recording a video (good idea from Anders). I’ll install the 35W heater from 3dsolex as soon as it will arrive, test it and post the results. My goal is to print with higher melting filaments like ABS, Nylon and PC. The E3D nozzle assortment provides new opportunities with viscous polymers. Many thanks to you and everybody who gave me valuable information and advice. Frankly, I think the UM forum is the best thing Ultimaker has to offer ! It’s a great source of information. I’ll try to contribute useful information too. Kind regards Paul

Hi izzy Thank you for your comment. My situation is quite different: All this heating tests, which I posted above were WITHOUT the two product cooling fans running (NO extrusion too) made. The only fan running was the small hotend cooling fan. Even heating test with the double fan bracket removed (this to make changes on the hotend easier and to make sure, that there is no heat transfer to the bracket. As far as I see it at this moment, I have a problem whithin the motherboard, maybe a deteriorated electronic component in the heater power supply. Kind regards Paban

Seems, my pictures didn't find the way, so I try again [/media]

Hello again, Thanks a lot to everybody who gave me feedback to my questions. This forum is extremly helpful und many people do a fantastic job here, even a the weekend. I did my homework today and made some further checks und measurements at the printer. Here the results: 1. There were no loose connections at the mainboard (and it didn’t produce smoke or carbonisation so far…). By the way: There are no fixing screws anymore. For the heater cables there are clips (nasty ones, you should have 3 hands to attach/detach the cables); for the Pt100 sensor, there is a female Dupont plug. I attached a picture of my mainboard. 2. I measured the resistance of the original equipped heating element: 27 Ohm (so it delivers 21 W, which seems a bit low) 3. The voltage at the heater terminal is 24 V (and remains constant during heating up, until the error message occurs). 4. I measured the resistance oft he Pt100 sensor too and got 110 Ohm at 25°C (which is OK). I’ve added a temperature compilation of my two heater elements compared to the values out of Anders video (Thanks Anders !) Anders seems to have the best part of the three (and he deserves it !) If my spare heater is not at the low end oft he usual power range, it should be able to deliver the necessary heat (IMHO). So I hope to receive a comment from an Ultimaker electronics specialist , what might be wrong here, and if it’s possible to connect the heating element to the unused heater terminal 2 and what arrangements are necessary to do that (is it necessary to modify the firmware ? I think, the temperature sensor has to be moved to the terminal „TEMP 2“ in this case ). Kind regards Paul [media=1240][media=1239]

Hi Swordriff Thanks for your quick and helpful answer and the refresher of my physics (a long time ago, not to far from the middle of the last century I knew that too ;-D ) As I hate to approach the PCB again (with this cable chaos, specially to put it careful all together at the end), I'll wait until the 35W heater arrives and then measure the resistance of all three. So it takes some time until the community will hear about that. Kind regards from Switzerland Paul EDIT: I just measured the resistance of the new (spare) heater. The multimeter shows 24 Ohm. So, the heating capacity should be OK for the new part (which doesn't perform well too). So it doesn't explain what goes wrong.

Hi dim3nsioneer Thanks for your quick replay. The heater cartridge is rather thight (hard to push in). The sensor isn't "loose" too. I have no heat conducting paste available at the moment. As soon I get some, I'll try it. wish you a nice weekend Paul

Hi Anders Thank you for your quick response (and I still like your mod very much...). I forgot to mention, that I had the fan bracket NOT mounted during the heating tests. The firmware version is 15.02.01 Do you have any comments to the 35W heater (I have already ordered one from Swordriff) ? I wish you a nice weekend Paul

Hello everybody A few days ago, I changed the standard UM2 heater block against the custom block designed by Anders Olsson. The disassembly oft he hotend and the reassembly went quite good. The heating element was easy to remove from the UM2 block; the Pt100 sensor was somehow fixed. After some heating oft he block with the soldering iron it got out too. Both parts didn’t show any deformation from the fixing screw. I started with a 0.6 mm nozzle and the parts printed with PLA at 210°C and 50 mm/s pretty good. Later on I changed the nozzle with a 0.4 mm E3D nozzle with the goal to run some test prints to compare the modification with earlier results. So I run the extrusion rate test (3 – 10 mm3/s) at 210°C which delivered a comparable result (up to 7 mm3/s enough extrusion), although I expected it somewhat better. Then I ran the same test (all with red PLA from DUTCH FILAMENT) at 230°C. This was quite a short test: 3 mm3/s printed fine, but at 4 mm3/s the printer stopped already with the „Heater Error“ message ! I remembered that I have read in this forum, there is a safety function in the firmware, which stops the printer, when the temperature increase is too slow, when the heating is on. After cooling the hotend down, I started the „Heatup nozzle“ function with a temperature set to 240°C. At 230°C the „Heater Error“ occured again (which could be reproduced with further tests). I checked the hardware, if something went wrong during the alteration. Results: the heating element and the Pt100 sensor were both correct inserted; the nozzle didn’t touch the fan bracket (I had widened the nozzle opening to 10 mm). I checked too the connection of the two heater cable ends to the mainboard which was also OK. So I concluded that the heating element might have reached almost the end of its lifetime (with only ca. 200 printing hours so far; I got the UM2 in this february). The next step was connecting my spare heating element to the mainboard and the hotend and comparing the heating curves. The new heater has some more power, it heated during 125 seconds fro 25 to 220°C (the „old“ one needed 146 seconds). It can just hold a temperature of 250°C, but when it’s supposed to reach 260°C, it stops at ca. 252°C with the already familiar error message ! All this heating tests were done without extruding. These tests with the new heating element puzzle me quite much: - How about printing ABS and other high melting polymers ? - Is the new heating element just at the low end oft he power specification (whatever this is) or what else has to be blamed for this poor result ? Any ideas and comments from the members are very welcome. I have noticed, that 3dsolex offers now heating elements with 35 W (the standard one has 25 W). Who is already using this more powerful heater with what results ) Many thanks in advance for your comments and your time taking for that from Paul

Hi Labern I'm interesred too in your project. I'm awaiting delivery of an Olsson block. The present fan system is suboptimal for printing small parts (if you print only one small part like the famous "Marvin"). When Ultimaker decided to stop dual extrusion for the UM2, they should have offered at least an optimal single hotend (which I would even pay for). At the moment it looks, like UM2 product development goes towards customers (I remember the statement of Sander van Geelen; of course he didn't say this in my words ;-D ). But "tinkerers" can be quite innovative and successful. When a satisfactory shroud will be made of metal I'll order one too. Kind regards from Paul PS. When a lately removed the shroud, it gave me a hard time, since it was "glued" to the nozzle by ca. 1-2 cm3 of leaked (?!, I have no clear idea why / how it got there) brownish plastic mass. I had to remove it with the aid of a soldering iron.

Thanks to all for your comments, specially for the tips for printing voronois. Kind regards from Paban

@Kilian Thank you again for your answer and the pictures. Kind regards from Paul