RE: CORE One and soft TPU
yeah now that you mention it, I like the fact that prusa provides the upgrade path too. Both MK4S and Core One printers started as MK3S'es. I'm still waiting on the next rev of XL to come out. It's been long enough, and it's about time they did. Mine shipped assembled as 5 tool and with .6 nozzles lol 18+ months of waiting after preorder haha.
I'm glad you're taking precautions with that hd2.
Cheers!
RE:
Hello!
I'm currently trying to print TPU (step step from 95A, to 60A) and 85A was very difficult to load without removing PTFE and printing directly from the top extruder.
Does anyone have a tips for that?
Next step will be 70A and then 60A, but I think I will have to modify filament guide inside the head with something like THAT.
I will keep you in touch, 85A Ninjaflex was printed easily just by unscrewing idler tension a little.
I wish someone would post a video on YouTube about how to load TPU into the Core One. It's difficult to follow the process in pictures for me personally. However I appreciate you documenting it here. At least I know I'm not crazy. 🙂
RE: CORE One and soft TPU
I wish someone would post a video on YouTube about how to load TPU into the Core One. It's difficult to follow the process in pictures for me personally. However I appreciate you documenting it here. At least I know I'm not crazy. 🙂
I wrote a Printables article on how I print TPU Air which is a soft TPU: Printing Siraya Tech Flex TPU Air on a Core One in order to do this I had to install the two mods mentioned in the article and I remove the Bowden tube and feed directly into the nextruder.
That said, I've been able to print 95A without the mods and feeding past both filament sensors. The softer stuff (like 85A and below) is hard to impossible without these mods.
RE: CORE One and soft TPU
Worth noting I’ve printed 85A without mods on the core one unmodded. It’s a little annoying to feed the filament but it’s definitely doable.
it was a lot easier on the MK3 series.
RE: CORE One and soft TPU
The real benefit to the mods is the fact that you don't have to open your extruder and untangle the tpu from around your gears. The profiles for things like ninja flex are entirely too high MVS. I've found to get reasonably reliable prints with things like ninjaflex and chinchilla you need the mods to so there's no room in the filament path, and you have to go SLOW. I have the mods installed for my xl, my mk4s and my core one. The core one is not at all tpu friendly out of the box. My baseline MVS for ninjaflex and chinchilla is 1.19. It's slow, but it's reliable.I've got a second mk4s-> core one upgrade sitting here that I'm hesitent to do until I've had some more time with the core one. After some initial mishaps with the first core one upgrade though, I've got it printing pretty well. Tpu seems to be an afterthought on the prusas though. Those mods should be standard issue on the prusas. I've done some 92 and 95A prints on the core one with just the extruder mods, no filament sensor mods and that goes ok. I really find the idea of having to fiddle withe bowden tube just to print tpu annoying though. it's not bad on the XL since you just unscrew it and help the filament load and the put screw the bowden tube back in. the xl doesn't have that plastic part that fits over the connector.
RE: CORE One and soft TPU
The official ninjaflex profile actually worked fine for me. No tangles.
but one parameter I did change based on experience from mk3 days is de-retraction speed. Had to sl9w that down. Everything else can be default
RE: CORE One and soft TPU
yes, the retraction and detraction speed I set to 10. when there's extra room inside the extruder(i.e. the mod isn't installed) that' more chance to get tangled up in the gears. I may not increased MVS once I figured that one out. I never ever look for fast when I'm printing tpu, the 1.19 puts it on the bottom end of the ninjaflex recommended print speed, 3.0 is quite a bit faster than recommended speed. I also go 3-5C over the top end range because I print with the harden steel nozzle and not brass. Having gotten it to work pretty well on the xl, mk3, mk4 etc, there's not much magic for the core one. I wanted to get to the point where I didn't have to adjust the idler tension screws to switch between tpu and everything else, and I've gotten to that. I just wish the prusas didn't require so much fiddling and modification from the stock to reasonably handle tpu. If I switch my other MK4s to core one I'm probably going to bite the bullet and do the filament sensor mods and not just the bogie parts. The bogie parts, IMHO are a must have if you print with tpu at lot.
RE: CORE One and soft TPU
If I switch my other MK4s to core one I'm probably going to bite the bullet and do the filament sensor mods and not just the bogie parts. The bogie parts, IMHO are a must have if you print with tpu at lot.
The filament sensor mod (with magnets instead of spring) is easy enough and makes a lot of sense. Not sure why Prusa doesn't use this approach. The bogie mod is not just for TPU but I've found better overall for various extruder gear issues I was having.
RE: CORE One and soft TPU
yeah, I liked the bogie mod enough that I printed 7 sets and updated the XL, the MK4S and the CoreOne(that was upgraded from MK4s). prusa should make that standard issue. I don't see any reason at all you wouldn't want your filament guided precisely to the nozzle tube, especially for TPU, but in general for any filament. Was a good chance for me to print PC-CF the first time. I do plan to do the filament sensor mod as well. I' was hoping for a hardware refresh to the XL so I could update the sensors in those too. One of the very first things I did when I got the XL a couple years ago now was to take the ball bearing and spring out of the filament sensors by the spools since they created a TON of drag on Tpu and made it underextrude. why would prusa keep making the same mistakes.... lol oh well. I still like my prusas.
RE: CORE One and soft TPU
Hi everybody. Regarding the sensor mods.
I modded both sensors.
The mod for the side filament sensor works like a charm and it‘s done much easier than expected. I printed a lever with a slightly bigger „magnet“ hole. When testing with a spare one I noticed that the weight of the lower magnet is basically enough to work properly. So I left the upper magnet but put some pieces of lead into the hole.
I used only one magnet for the mod on the nextruder sensor. 2magnets as suggested had to much resistance in my opinion. So I added only one opposing magnet but put a small piece 2mm plastic behind. That way the sensor opens reliably,but now my setup is soft enough to push the Prusa tpu all the way through without disableing sensors or disassemble the tube
RE: CORE One and soft TPU
Hello all,
I was directed here from Scott's reply to my cry for help on Reddit (thank you @scott-18) when trying to print Ninjaflex 85A.
I don't know why, I thought after 5 years on a cheap Chinese printer with a Hemera extruder and amazing Ninjaflex prints that this would just work out of the box.
Anyway..I have made the idler and filament sensor mods and I had a successful print (4 hours). But there were a couple of zits in the side of the print.
The next print, it jammed and managed to do a wrap around despite the mod at about 3 hours in (same object).
For this one, I had slowed it down from MVS of 3 down to 2. I also set my retraction and detraction speed from the default (45?) to 10.
I am using the hardened nozzle as I do print CF too. My temps are 238/50.
I wonder if this is too cool, particularly for the hardened nozzle?
Thank you.
RE: CORE One and soft TPU
I will check my retraction settings to see if something changes. I will let you know.
RE: CORE One and soft TPU
Ninjaflex was/is notorious for wrapping itself arount extruder gears and otherwise being close to impossible to print. I would try a different formulation. Maybe give TPU or PEBA Air a try instead.
RE: CORE One and soft TPU
Also, make sure your TPU is well dried, it absorbs moisture quite quickly and can change his « softness » when printing it.
RE: CORE One and soft TPU
Thank you. I dried it for about 2 days at 75c (maybe overkill). It just finished another print.
This time I chose retraction and detraction speed of 10 and increased temp from 238 to 245. It doesn't look pretty but it succeeded (didn't jam).
I don't like the outer walls though. I need them to be smooth. This must be temperature related.
RE: CORE One and soft TPU
I've not seen the filament tangled around the extruder gear since I put in the updated parts that reduce the filament wiggle room. I still have yet to have good success with ninjaflex in the C1. It works well enough on the XL, so I've decided to go ahead and use the second mk4->c1 upgrade kit I bought last year and upgrade the second mk4. I've not had a chance to try ninjaflex again since I updated the first C1(upgraded from mk4) with the c1+ parts to reduce drag in the filament path. In general though 92A+ work ok in the C1. I don't think you can ever escape some amount of pain with such soft filaments. I have gotten chinchilla(75A) to print on the XL, but that is hit or miss.
RE: CORE One and soft TPU
My personal experience with flex filament on the Core One:
- I had a really great experience printing with Prusament TPU 95A!
- Then I tried Polyflex 90A… what a nightmare !
I dried the filament as much as possible, tested a bunch of settings, and in the end, I just gave up. but I’m still curious if anyone else had luck with this specific filament...
RE: CORE One and soft TPU
I may have to call time on my 85A Ninjaflex. It prints, but, not well enough and dialling in takes time.
I ordered some Sunlu 90A as 95A is a bit too hard for what I need it for.
Also, with a layer of Magigoo acting as a release agent, my part got stuck down so hard that it tore a little hole off and build plate 🙁
RE: CORE One and soft TPU
You should definitely try lower temp regarding stringing as you said you dried it well, it's not normal.
For gear wrapping issue, did you decrease idler tension at maximum?
Thank you. I dried it for about 2 days at 75c (maybe overkill). It just finished another print.
This time I chose retraction and detraction speed of 10 and increased temp from 238 to 245. It doesn't look pretty but it succeeded (didn't jam).
I don't like the outer walls though. I need them to be smooth. This must be temperature related.
RE: CORE One and soft TPU
I might have another go and bring the temp down to 235. In the failed run, I had not unscrewded the two screws with the springs on but for the next successful runs, I had by a good few turns. I think I will split the model up for testing as each print is about 8 hours now!
Thanks.
You should definitely try lower temp regarding stringing as you said you dried it well, it's not normal.
For gear wrapping issue, did you decrease idler tension at maximum?
Thank you. I dried it for about 2 days at 75c (maybe overkill). It just finished another print.
This time I chose retraction and detraction speed of 10 and increased temp from 238 to 245. It doesn't look pretty but it succeeded (didn't jam).