3D Printing Forum

Peek gives a lot of nasty fumes. You will need to print with very good ventilation.

i would say you are spot on..
but i could have also saved you some time

I've been working with UM on this for a long time..
i published my spring replacement about 12 months ago at https://www.youmagine.com/designs/ultim ... eplacement because i wa ssure it was the spring that was causing issues.. i have been testing the TFM coupler ever since.. i actually have one of the original testing TFM's still in my machine, having printed for about 7500 hours including ABS, XT, PLA and whatever you can guess.. i only replace the nozzles every now and then but no more maintenance..
so yes. i can confirm your findings

Ive been using Korneel's Spring replacement for about a month now and I must say it has improved things, the print head seems more stable especially when you have retractions.
As every thing is now nice and tight any over pressure from the feeder cannot result in filament ozzing between the coupler and the nozzle.
Hi Korneel welcome to the forum

korneel wrote:i would say you are spot on..
but i could have also saved you some time

In fact, I haven't had to spend much time on the PTFE myself since I used the I2K and rarely printed PLA, so dealing with the PTFE issue has been fairly low on my to-do list.
I just thought I would write up this summary because there are so many theories and rumors about the PTFE and some of the important information appears always to be missing.

Not sure if I have come across the TFM-coupler yet (I have a bunch at home that could be TFM, not sure where I got them), but your methods of testing them means I should get one because it will more or less have life time guarantee for my kind of use

Nice to see you here by the way

happy to be here

i would definitely recommend one of those.. I don't have spare ones lying around.. currently in the process of upgrading my UM2s to Um2+'s..
official retailers should be able to have spare parts soon.. but it's worth it..

Hello,


I have had consistent issues with the couplers going bad after only a few prints with my Ultimaker 2. Even printing a lower temp does not prevent it from eventually causing under extrusion. I was wondering if you would be willing to share your blueprints for the metal coupler you made? I think that could be the fix I've been looking for. Thanks for the great write up!

Anyone has ever had access to weird materials like this?
http://gajitz.com/new-ultra-slippery-al ... -material/

Even more slippery than teflon and almost as hard as boron!...

I once saw smelted gold bars, but this - never. Considering shaggy year of this note, and the fact that the alloy is still not used massively the possible falsification of data, as in the case with stem cells.

Art in 3D wrote:Hello,


I have had consistent issues with the couplers going bad after only a few prints with my Ultimaker 2. Even printing a lower temp does not prevent it from eventually causing under extrusion. I was wondering if you would be willing to share your blueprints for the metal coupler you made? I think that could be the fix I've been looking for. Thanks for the great write up!

Why don't you just print my original replacement?

https://www.youmagine.com/designs/ultim ... eplacement

So by changing from a spring to this printable "spacer" the UM2 printhead with an Olsson Block, it is basically the only thing you need to have a printhead with minimal maintenance for most "normal" consumer filaments?

Art in 3D wrote:Hello,
I have had consistent issues with the couplers going bad after only a few prints with my Ultimaker 2. Even printing a lower temp does not prevent it from eventually causing under extrusion. I was wondering if you would be willing to share your blueprints for the metal coupler you made? I think that could be the fix I've been looking for. Thanks for the great write up!

I would definitely start with a new TFM-PTFE coupler and the rigid spacer instead of the spring, as korneel suggests.

The Aluminum spacer was just something I made quickly in my lathe and I don't think it would have any immediate advantage over TFM+spring replacement in your case.

nilrog wrote:So by changing from a spring to this printable "spacer" the UM2 printhead with an Olsson Block, it is basically the only thing you need to have a printhead with minimal maintenance for most "normal" consumer filaments?

The key seems to be to combine the TFM-PTFE with the rigid spacer, so you should try to get both of them.

Great! We have an UM2 in our office that was fun to play with in the beginning. But now it is just giving me headaches when I want to print something. I think too many "chefs" in combination with this issue has degenerated it a lot. I'm going to suggest them to buy a new coupler and putting this spacer in place and see if it helps.

You have got to have just 1 person in charger of your printer and it's set-up, get yourself a big stick and take charge!

Hi,

Thanks Neotko for the link to this post. I've had some fun with failed couplers lately and I'd like to add a bit to the theory. My last coupler died after only 10 hours of printing with PLA. I have posted about it here. From the start I have used Korneels spring replacement but I might have put too much tension on the coupler.
What I don't understand about the new UM2+ kind of couplers and the spring replacement - how do you know how much pressure (how far the coupler should stick out from the metal ring)? I think with the wrong pressure, any kind of coupler could be destroyed very quickly (as my unfortunate test shows).

And looking at my failed couplers so far (I have a hand full), some dents do not look like they were produced by filament expanding outwards. Some dents are very thin and sharp. I have the nagging impression that it is also related to the atomic pull method. If there is a very faint dent and one pulls out the filament at 90°, then the entire bulge would travel along the entire coupler doing some damage.
What do you think?

Maybe someone could design a 'tester' with the correct height, so one can tight the stuff to an specific height. To remove the human error and lack of documentation about that, and be able to repeat it over and over.