What went wrong?
After your post, I'm almost afraid to show the print below:
What went wrong?
After your post, I'm almost afraid to show the print below:
Hi,
I finally couldn't find this kind of molex connector in any electronics shop, so I replaced them with another connectors. I modified Nicks design so it can hold a pair of 40x40mm fans. Nick if you give me permission y will share it (and of course give you credit)
Now I will try to make my first Ubis print (fingers crossed). I am worried about if the top part of the Ubis gets too hot during long prints because I don't have a crossflow fan. Have anybody tried a long print without crossflow fan?
I've made a 13 hour print this weekend wihout any fans, had no problems at all.....
What went wrong?
I really don't know and I'm starting to not care. It was like the temperature fluctuated wildly. At first I think I was printing too hot so I lowered it a bit, patches then looked dull (like it was printing a bit too cold) but all of a sudden there would be an area that became gooey and messy. All the while the temperature reported by Pronterface remained dead steady with only a single degree of fluctuations. This printer has been a solid source of frustration the past year or so. I think the only things I haven't changed/upgraded are the feeder (not counting the bolt and pressure assembly which I've also replaced) and electronics.
But, enough about my failures, back to the good stuff.
I really don't know and I'm starting to not care. It was like the temperature fluctuated wildly. At first I think I was printing too hot so I lowered it a bit, patches then looked dull (like it was printing a bit too cold) but all of a sudden there would be an area that became gooey and messy. All the while the temperature reported by Pronterface remained dead steady with only a single degree of fluctuations. This printer has been a solid source of frustration the past year or so. I think the only things I haven't changed/upgraded are the feeder (not counting the bolt and pressure assembly which I've also replaced) and electronics.
But, enough about my failures, back to the good stuff.
Sounds like you're getting uneven extrusion, maybe from a feeder mechanism that isn't working as smoothly as it should. Are things smooth when you handcrank some filament through the hotend?
And to the previous poster who made the fan mount of the hotend, please , of course share your mods with everyone else.
Also worth noting is that with the UBIS you can increase your retraction settings to get perfect, string free prints at all settings... I use 35mm/s and 4.5mm (with updated firmware) and get very clean results.
Could be Nick, I think it feels alright though.
Oh well, another day, another few tweaks and a test print. A bit better this time around. Certainly not great but better than the complete failure of last night.
And here's my beautiful cooling solution :lol: Might be part of the problem.
It's a shame they don't make them for 3mm filament anymore...
I suppose there's no news regarding that matter? No more 3mm Ubis hotends? :-|
It's a shame they don't make them for 3mm filament anymore...
I suppose there's no news regarding that matter? No more 3mm Ubis hotends? :-|
Here is the response I got from them last week......
no reply no-reply@printrbot.com
Feb 13 (4 days ago)
to me
Hi Carroll - Thank you for contacting Printrbot. At this time, as you know, we're out of 3mm hot ends and cannot promise that we'll have more for sale in the future. If we do, we'll put them back in stock in the store when we do get more. We apologize that we can't be of more help at this time.
So, they kinda left it open. I think that they will make them again...
I hat noticeable stringing, especially with PLA/PHA. Could you give me an example of your settings (material, temp)? I want to try again when I've got my modular printhead ready for the UBIS.
Could be Nick, I think it feels alright though.
Oh well, another day, another few tweaks and a test print. A bit better this time around. Certainly not great but better than the complete failure of last night.
And here's my beautiful cooling solution :lol: Might be part of the problem.
I'm going to assume that you have updated firmware installed, due to the custom hotend, but just want to make sure that you have the retraction speed fix. If so, maybe try the retraction settings I posted above?
Is that Printbl Emerald filament or someting else? What temps are you using? I'm usually around 205C / 0.1mm / 50mm/s with this UBIS.
If you think it might be a cooling problem, printing two copies at once is usually a good way to alleviate any print issues while you test that as a cause.
Sorry for grilling you with questions. I'm away from my printers now, so I can't give exact settings, but some of the last prints I did before I left were that pyramid, and they came out almost breathtakingly perfect. Zero strings, blobs, or curling, and an almost needle-sharp point at the top with no bulging from heat....
I hat noticeable stringing, especially with PLA/PHA. Could you give me an example of your settings (material, temp)? I want to try again when I've got my modular printhead ready for the UBIS.
I'll try to find a good piece of gcode but most of my prints are only on my SD card, far away from me right now. I've never tried PHA/PLA, but once I upped the retraction settings, stringing with PLA was completely eliminated... Will try to post something more specific than that tomorrow.
@Nick: That's PLA from Ultimaker. I used the firmware produced by the link in http://umforum.ultimaker.com/index.php?/topic/3786-ubis-hotend-on-an-ultimaker/page-4&do=findComment&comment=34578 But I removed the options for the heated bed and display/SD card.
That print was:
210C
0.1mm layers
50mm/s
40/4.5 on the retraction
I'll try moving the fan closer tomorrow and/or print multiples for more cooling and see if that helps, hopefully it's that simple. I'll also re-check the diameter on the filament (it worked fine on the UM2 though). I have to say though, man do I miss the glass bed of the UM2 now that I'm back messing with the UM1...
@IRobertl: you are not alone. I'm having a lot of problems with the UBIS too.
I printed a torture test (http://www.thingiverse.com/thing:33902) scaled at 0.5. This is the result:
I tried with temperatures from 190C to 220C and only at higher temperatures worked better (but not ok, with a lot of random under/overextrusion)
0.1 layers
40mm/s
35/4.5 retraction (also tried with 35/5.5 with no success eliminating the stringing)
Ultimaker PLA
Also tried enabling/disabling the fans, with no success
This looks like some overextrusion + too high of temperature.
I haven't tried the torture test, but I was printing some mockup electronics connectors that are definitely a challenging print for stringing and retraction:
As a scale reference, those screws are T7's and the columns are just under 1mm in diameter. There are 40ish of them. Came off the printer looking like this. Ultimachine Green PLA.
That print looks clean!
Would it be possible to share the stl of the green part. I can swap UBIS and Merlin within minutes now and would like to give both a try.
Sure - it's just some stock JST connectors on a circuit board we're using in an electronics assembly. STL is here:
https://www.dropbox.com/s/oizet1nofi5xx6d/Inner%20Housing%20v1.8%20-%20PCB.STL
You need to drop it 1mm or so into the bed or it tries to print the PCB floating in thin air.
As promised.
Disclaimer: Results cannot be generalized because printed with a 4 mm inner diameter bowden tube. I will repeat the test with the original tube mounted.
Merlin prints look excellent. I wonder what I'm doing differently to have such drastically lower stringing on the UBIS... maybe temperature?
A few more test prints from me. These were at 190C and 195C. Slightly better. Maybe it's the filament that sucks, I'll have to try another one.
It's difficult to see in the pictures (which are gigantic btw if you want to zoom in) is that top surfaces are very dull like it's too cold when extruding. But going much higher resulted in the mess I posted previously.
Merlin prints look excellent. I wonder what I'm doing differently to have such drastically lower stringing on the UBIS... maybe temperature?
I'll mount the original 3.15 mm ID tube tomorrow. My 4 mm ID tube gives an extra lag of about 1.5mm ( = 0.05 sec @ 30mm/s) before the filament starts to retract at the printhead and the pressure drops.
Hmm. I've also shortened my bowden tube by 5cm or so, since less of it is locked up inside this printhead compared to stock. Could be making a difference...
A few more test prints from me. These were at 190C and 195C. Slightly better. Maybe it's the filament that sucks, I'll have to try another one.
It's difficult to see in the pictures (which are gigantic btw if you want to zoom in) is that top surfaces are very dull like it's too cold when extruding. But going much higher resulted in the mess I posted previously.
Looking way better... it seems like there is a very slight amount of overextrusion happening. I generally try to do all of my debugging prints in non-transparent filament because of how much more difficult it is to identify problems with clear filament...
Yep, same here really, it was just I happened to do the first test print with this roll (it was the one closest) so I wanted to do a few more tests with the same roll to avoid adding more variables. I'll be trying another roll the next time now that I know the temperature seems to play a bit of a bigger roll than I'm used to.
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It's official, my UM1 is cursed. When I think back on how much time, effort and money I've put into this thing it makes me sick to my stomach.
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