Periodic maintenance for the UM2 in Ultimaker 3D printers Posted January 3, 2017 Fair enough I suppose, I do little retractions so Im still using the same coupler it shipped with but have a few issues now with uneven layers. I was meaning to buy new bearings and change the PFTE coupler, but never got round to it and that was months ago. I think Ill try and get some TFM ones, do they work with the UM2 btw? Well, I got mine with the 2+ upgrade and so I also switched to the Olson block. If you have that then certainly they should work. If not, then I am not sure. I would imagine it might be possible to request the correct one, or at least confirm it with your local supplier and/or ask on the forum. 3DSolex has their own version, not sure if it is the same, but I think they will adjust the size if you ask. (I think I got the idea from them!) If you do get TFM, I suggest you replace the spring with the spacer ring (again 2+). I am pretty sure you can get it too. The spring puts a lot of pressure on the coupler and can contribute to it deforming faster, that is why they switched to the ring, I believe. There are 3D printable spacer rings too, though. But metal is better. Anyway, wordy answer. But hope it helps.