Does hardware determine filament size?

[rlrcstr 1]

Is there a reason that they ship the UMO+ with the 2.85 filament? Does that size work better? Do you need to modify the hardware to use the 1.75? (I can find that locally, the 2.85, not so much...)

And is there anything specific you have to do to change the filament? Do you have to clean the head, between filaments, in any way, or something like that? (Or just print something small to get the old stuff out?)

Thanks.

[neotko 1,417]

You can print 1.75 with the stock but with many problems on the long run. I changed mine for 1.75 and there are many paths to do it.

You can not change a think and insert a ptfe 3/2mm inside the existing bowden and glue it with special glue for ptfe. Using the ptfe to go through the heat barrel or even inside the nozzle. On the long run ptfe with burn and you will start understruding, filament will flow and burn between the ptfe and the barrel.

You can do the ptfe think glued but change the heat barrel, nozzle and even the hoyend isolator coupler. Then after tweaking the extruder (it need's) I had to do some filling to get a proper grip and changed the delring clip.

There are many roads. I tested (I think) most of them. So far the ptfe 3mm/2mm glued inside the bowden works but It adds extra friction. I changed my bowdens to a ptfe 6/2mm. But it isnt easy to find and also changing the bowden means that there's some changing needed on the clamps that hold the bowden.

It's doable? Yes. It's worth? Well for my it was fun do adapt it. I learned a lot. But I don't think it's worth unless you go double extruders or you really really need 1.75mm filament.

Btw also. Most of the time companies sell 3mm that it's 2.85mm. So maybe you just didn't know this? Just wondering.

[neotko 1,417]

Btw tou are on usa. You could even buy it by amazon

[gr5 2,173]

I recommend printedsolid.com for filaments in usa. I've met the owner - great guy. He's on this forum somewhere or used to be.

Don't try 1.75mm filament - too much of a hassle.

It's fine to just switch filaments and turn the big gear until the old color is gone.

or you can do a cold pull like I do - when a print finishes, turn the big gear so filament isn't retracted (or reheat head to 180C and then extrude a tiny bit of filament). Then set temperature to 100C and let it cool. Then release the tension on the feeder and pull hard downwards on the filament to remove. If you need more than about 10 pounds of force raise the temp by 5C a few times - it should come out around 95C to 110c - somewhere in there. If you do it perfect the end of the filament is shaped like the nozzle tip inside including the .4mm channel at the end.

Now you can switch filaments and there will none of the old color plus you get any dirt/gunk out of the nozzle which is great maintenance.