UM2 starts shipping with Olsson block included!

[korneel 176]

also, the original head had a 25W heater to allow a secondary heater to be added. as we all know dual extrusion never happened so that additional power was never needed.

an additional advantage that has not been mentioned enough is that a larger heater will get you better quality.

to keep a nozzle at a certain temperature, let's say 250 degrees, you don't just set a dial on a heater. basically, the nozzle is on or off so the PT100 measures the temperature, and you see the temperature fluctuating. there is a complex algorithm that decides when to turn on the heater and for how long. you can use in certain situation things like alternation to fire up the heater in small increments but unsure if Ultimaker uses it.

anyhow, if you have a small heater, you need to take larger dips into account. in reality, setting the temperature to 250 will realistically lead to temperatures between 248 and 252. you;'ll undershoot and overshoot the temperature target. the more plastic you feed it the harde the heater has to work to get it to that temperature and the higher your temperature differences will be.

with a larger heater and a 35 watt heater is about 37 percent more powerfull, you have to apply heat for shorted periods to get to your target temperature, getting a more consistent temperature in your nozzle, leading to a nicer print. some filaments are highly impacted by temperature flucttuations. fluctuations that will be a lot less with a bigger heater.

so in short, a bigger heater is better for your print quality and your printer. but do you need it? no. do you want it? yes

[sambianchibazzi 9]

Yeah. It just never happened to me that the hot end couldn't stay stable at a certain temperature. That's why I wasn't thinking about it...

thankss

[cloakfiend 992]

@sambianchibazzi, trust me if the fan shroud is touching the heater block, it wont hold temps at all with any fans on....

ok i have my new sensor and 35w heater, so rather than just installing them i thought id ask a few obvious questions...

my last heater cracked completely along the line highlighted in the pic (still appears to work though), does that matter as the core is slightly exposed at the connector?, as it stuck out too much and the original metal shroud i bent down to get it in ended up smashing and grinding into the top left motor as a result and now my head wobbles a bit and i have a high pitch grunding noise from the pulleys or motor but only when the head travels left, not up and down or right.

also what do i do with the heater wires? which one is positive or negative considering they look identical, does it matter?

ive got the ob working with my broken heater and spare temp sensor, and only now do i realise the confusion with the temps, as i really ont know what to believe as the temp sensor is giving totally different readings than the last one, it appears 10-20 degrees less than the last, so what i would normally print at 185 i would print at 170 or something?

it turned out that the block was indeed touching the shroud somewhere, so ill just take the blame for that as i was focusing on the ob being 1mm away from the pfte which i have now ignored as that is far less relevant than the block not touching the shroud which is basically life and death.

here is a pic of the current heater that split where the wire met the heater. (25w). still works but seems more powerful than before, or the sensor is reading weaker than before?

basically changing my ob created a big headache when all i wanted was a better fan shroud. be careful what you wish for, lol.

if i ever manage to get it back to out of the box quality, im gonna leave it regardless of any future upgrades available. ive learnt my lesson. i've stopped caring about wanting the new fan shroud now. i just want to leave everything as it is, like marriage, for better or for worse. ive always tried to get the best out of my um2 and have come to realise i cant get better so that's that, its just in my nature to keep trying even if i break things. the ob is installed now but i think ive damaged my bearings or something that hold the head onto the rods as if i try to tilt it, it wobbles on one axis a bit.

gr5s tut pic is the best guide in my opinion. its what i ended up using as i am a big fan of arrows, it takes the guess work away.(below)

Edited February 9, 2016 by Guest

[qmaker 29]

Cloakfiend thanks for posting Gr5s picture, I hadn't seen that yet.

I am with you, ever since I replaced my hot end, temp sensor, ptfe and nozzle, I have had nothing but trouble. I wish my machine printed the way it did back in the early days...

Guess I better go check all of my gaps and clearances.

[SandervG 1,518]

Hi Cloakfiend,

Thank you for your write up.

If you could mention what areas you think are malfunctioning and why?

Like the bearing due to a wobbly head, maybe we can help!

Being an explorer is a valuable characteristic. It is what leads to innovation!

Sometimes it sucks. But when you succeed it is all worth it.

And about marriage, Ultimaker gets more attention than my girlfriend

[cloakfiend 992]

This was my final callibration result after trying to get everything as best as i could. numbered from left to right, no infill, good bridging, and smooth tops 3 and 4 look best so that will be my place of choice for my next print test.

from left to right in degrees, 55, 50, 40, 45. and some steeper ones underneath which i knew would fail. printed in UM silver it shipped with. 0.06, 175c (without the ob and using the other sensor would be 185) and all my usual settings.

when im done with my new model we'll see how happy i am with my 'upgrade'.

the odd one on the right is at 50mms the others are at 30mms

Edited February 10, 2016 by Guest

[avogra 68]

@cloakfiend, If your temp sensor shows lower readings than before, I would suspect that you now have to set higher values to get the same real temperature again?

I changed to the ollson block yesterday together with new pt100 and 35W heater and measured the actual temperature inside the nozzle before and after. Used a multimeter with one of those K-type thermoelements that have only a tiny solderball as the tip.

I was really shocked that my original setup set to 200°C actually was at 223°C And I usually printed at 205..210°C The new setup is at 208°C when showing 200°C. Same results with a different thermoelement + multimeter.

@SandervG, the tutorials for changing the Olsson Block and PT100 are really great!! Maybe you want to add one for the heater too? I was struggling a bit how to detach the heater cables from the PCB. I tried to look up the type of connectors in the schematic to see if they are 2 part and I just have to pull. But the schematic seems to be out of date as the connector was different. In the end, after detaching the pcb, everything went fine and my printer is running great again

[cloakfiend 992]

Im doing what works for me from now on. I dont care what any readings say, as long as they dont fluctuate i can just try to figure out my new setup, im going to try to print something today. im not going to turn the temperature up, whatever anyone tells me. Turning the temperature up is always a worse idea than turning it down if you arent getting underextrusion.

Actual temperature is totally irrelevant, its the result that matters.

Edited February 10, 2016 by Guest

[danilius 118]

@cloakfiend, I went through a horrible hour or two trying to free the thermal doohicky from the old, standard UM2 block, and failed miserably. However, having learned a great deal from previous life experience, I only undertook the change having spare parts at hand, which I of course eventually needed.

But it was worth it for several reasons. First of all, now I am no longer afraid of doing a head rebuild. It makes me around 20 minutes to strip everything down and put it back together again. Secondly, the Olsson block has made life much easier. Blocked nozzle? Take it out, put in an unblocked nozzle, clean out the old one over the gas cooker.

The thing is that when it comes to the unknown, you have to throw yourself into and convince yourself that it's easy if you know how. That's the hardest part. So don't just throw your hands up and say voila! I'm done! You didn't do that when it came to paint, did you? You bought a shedload of paint and spent hours experimenting and sniffing fumes. OK, the latter was a fringe benefit. Anyway, don't give up now!

[cloakfiend 992]

Yeah i only did it as i have a spare heat sensor as well, however i went into a panic as i thought i damaged my 25w heater which i may/may not have. I have a spare 35w heater now and a spare thermal sensor as well, as my main fault was the fan shroud. I can break the heater and sensor again and im still good in terms of spares.

Im not giving up, its just im hoping my current print will not fail, my attempt before fan shroud calibration and block height did fail and produced weaker layers. Acetone brings out weak layers immediately by splitting your object. I hope this model holds up. Its what i bought the printer for after all, everything before this has just been playing and practice. Im trying to stay away from sla printers due to cost, as i tend to print a lot of stuff for friends and family as well and i get a lot of free filament from some of my friends, which means i am incurring practically zero costs. If i can produce what i did before then i will be happy.

As for blocked nozzles, well seeing as i only use pla ive yet to meet a nozzle i cant simply clean, and now i understand how it works i believe blocked nozzles are a thing of the past as i dont print on the roll anymore. You only get blocked nozzles when the roll jams or the temps are too high when it gets stuck or.... The many other reasons, none of whoch i suffer from. Its a total non issue for me. In my honest opinion only people who print on the roll will get blocked nozzles, or beginners.

I am also aware that my posts are way too long, lol.

Edited February 10, 2016 by Guest

[LePaul 312]

Yes but those details help!

[danilius 118]

Im not giving up, its just im hoping my current print will not fail, my attempt before fan shroud calibration and block height did fail and produced weaker layers.

 

I rarely use the fans, even when printing PLA, since they only seem to benefit when printing really small areas. For most prints I simply keep them off entirely.

 

You only get blocked nozzles when the roll jams or the temps are too high when it gets stuck or....

 

...a host of other reasons. I print from a roll that sits on a custom holder I made with ball bearings. The only problem I encounter with that is a tangle, something more likely to occur when using loose filament.

[cloakfiend 992]

I have to disagree with you completely on the loose filament side of things, i've had many people say that to me for some reason, but i found them all to be careless, or you aren't laying it out correctly, because if you do then there is a zero chance of a tangle. Tangles are the sole reason i never print on the roll any longer. its why i don't do atomic pulls anymore, or ever get nozzle jams, or have any problems with the um2 printer feeder. Printing off the roll solves all these problems.

[drofnas 15]

Tangles are the sole reason i never print on the roll any longer.

 

Wondering if you can explain this a little more, or if you have a link to another article/post/video explaining the best way to work with off spool filament. Plus how you remove filament from a spool to it doesn't tangle during that process? I of course always "seem" to have issues when I get down to about 25% filament left on the roll, where the it's a bit tighter.

[cloakfiend 992]

do this at your own peril and dont blame me if anything goes wrong, but as long as you lay your filament on the back roll like this, you cant go wrong. It is physically impossible for it to get tangled. this is an early pic i keep posting as it was one of my first, but you can get up to 10 m worth of filament on the roll like this. All you need to make sure is its a perfect spring shape, which guarantees no tangles. If you just chuck it on after you randomly pull some from a roll and break it off, then its not different from printing on a roll if not worse.

I speak from experience on this one and over a year and a half of non stop printing with no room for errors, so telling me otherwise is futile because i am right and you wont convince me otherwise. This is the best method hands down. Period. Even safer than the UM2+ feeder as well as that can still tangle. But start as new thread if you want to elaborate as this is about the OB not the feeder/spool.

my latest print came out ok, ill keep testing to see the failure rate...

Edited February 10, 2016 by Guest

[SandervG 1,518]

@avogra, thank you! We did our best to make them conclusive.

The manuals have come from a long way

Are you specifically asking on how to remove the heater from your electronics board when you replace it by a 35W?

[cloakfiend 992]

Hey Sander, If there is a current guide to replace the heater with diagrams about the wiring end would be helpful just to know, before i unscrew th bottom panel just to know what to expect as i heard the ends differed?

The ob is working so far, fingers crossed, lol.

Edited February 11, 2016 by Guest

[avogra 68]

@avogra, thank you! We did our best to make them conclusive.

The manuals have come from a long way

Are you specifically asking on how to remove the heater from your electronics board when you replace it by a 35W?

 

Yes, that is the question. It is different from the PT100 as the heaters have open wires instead of a connector so there are some extra steps involved.

[cloakfiend 992]

Any guide for the extra steps?

[avogra 68]

@cloakfiend, I will have a try

In order to unplug the heater from the electronics board, you need access to the top side of the electronics. To achieve this...

1.) Remove the left motor cover. It is mounted with 2 screws, one through the back, one through the left side.

2.) Lay the UM2 on it's left side for easy access. Move the heated bed up to access the screws in the bottom.

3.) Remove the electronics cover cage, which is secured by 2 screws. ( You might already have done this for the PT100). Grab the nuts on the other side to prevent slipping.

4.) Open the 4 screws holding the electronics. They are the ones sitting in elongated holes. Be careful not to lose the small black spacers, maybe grab them with pliers while opening the screws. The electronics board is now loose but some parts like switch and power connector still stick through the backplate.

5.) Carefully pull the electronics board out of the backplate and swing it onto the table.  You see a green terminal block where the extruder heater and the bed heating are connected. There seem to be different versions of the terminal block. According to the assembly manual and the schematics on github the heater wires are fastened with screws. open the screws und pull the wires.

My UM2 from Oct. 2015 instead has a spring loaded terminal block. Use a flat screwdriver to push the first orange clip and while holding it down, pull the first wire. Repeat for the second wire.

6.) Make sure, that the strands of your new heaters wires are neatly in parallel or in other words, make sure there are no single strands sticking away.

7.) Press the first orange clip again and while holding it down, insert the first wire into the terminal and repeat for the second wire. If your terminal has screws, just insert the wire and fasten the screw. The 2 wires are interchangeable so it doesn't matter which wire goes in first and second place. Make sure, that all the strands go into the terminal insert.

8.- x.) remount the electronics and covers in reverse order. (I don't fell like describing it all the way back ).

[cloakfiend 992]

Thanks for the write up! Pics would be nice! Lol, but ill cut and paste this for a rainy day when i transition to the 35w heater. If im happy with my setup, then i may leave it be a while, but the heater does drop temps more rapidly than without the ob for sure. But seeing as i manually tend to lower them anyway its not that big a deal, maybe takes me a few minutes mor than before, i always print the first layer hot anyway and cool down progressively. Im sure i could write a gcode for this to sav myself the hassle, but it all depends on the clicks so gcode would be useless.

Im doing extensive testing at the mo with lots of different materials and high and very high resolutions just to see if im happy but sander said he would help in any case if i had issues so it more R@D i got this machine for character development so as long as i can print them in a moderate amount of detail im happy. And so far so good with 0.06, now 0.04 with the ob to test...

[cloakfiend 992]

I never thought the fan did that much before, boy was i wrong! Im not sure ive got it right with the ob. Some pics of the ideal arrangement with the old um2 fan shroud and the ob would be nice, as otherwise is hours of trial

And error. I still find the out of the box setup very good on the um2 side, tweaking doenst improve much in my opinion, its a well balanced machine from the outset.

My bridging appears much improved now, that is plain to see. Thats after some fine adjustments. Bending the fan too much here and there can seriously affect the print. I think i am happy where i am at, but for the sake of r&d im gonna try every filament i own.

Edited February 11, 2016 by Guest

[cloakfiend 992]

I also just screwed the nozzle in with my fingers and the metal thing without printing that whole device, is that a problem? Do i need to use the ob holder thing? Oh well i guess ill see...my problems seem to be over which is good, but my prints also look different.

[neotko 1,417]

You can't tight a nozzle with just your fingers, specially since when it goes hot it will expand and leave an area for the filament to leak, so it will work, but soon you will start to see filament 'drooling'. So just by hand, not a good idea. The olsson 'thingy' it's to help you tight just enough, because if you over-tight it you can break it.

[cloakfiend 992]

I did it by hand using the metal thingy trying not to overtighten, i printed the ob holder but am holding off using it as things now appear to be improving, first time i printed i heard a kind of hiss and pop, then drool of filament, but nothing since then. It appears to be getting better. just now I accidentally dialed in a 0.6 nozzle using a 0.4 one but the results look suprisingly good, even at 0.04? Weird, i must investigate this area more. The surface looks peculiar but ill see after it finishes.