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cloakfiend

Acheiving superior layer quality

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Well just printed a bust for a friend and was naturally disappointing to see large layer lines towards the top as im only used to high quality prints from my Ultimakers. I was printing from the roll (Which i used to never do until i got the S5 As my other um is a um2 with the black feeder), using some dutch orange I had lying around. At first I thought it could be a dirty layer screw because i had a few failures where the support was tangled and messed and possibly fragments might have fallen into the screw. but then i tried the exact same print off the roll, as i used to. And the pictures speak for themselves. So, In my opinion (as I thought before!), no matter the printer, and no matter how great your feeder is, the sheer tension during during a tangle during a print WILL cause layer deviation.

 

Basically, if like me you want as perfect layer height as you can get guaranteed every time, The ONLY solution is to print off the roll. People keep trying to change my mind on this, but now I know I'm right. Case closed! the improved feeder does has some advantages which ill get to in my next tut😉.

 

I'll let you decide which ones were printed on and off the roll. but its not very difficult to see!

 

 

 

 

 

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Well I have nearly always printed "off the roll" as I buy most of my filament loose to avoid entanglement. Now if I print Dutch Orange I do not use the rear holder and instead leave the reel on the floor but unwind a length and at the same time loosen the wind of the unwound length. This provides about 45 mins printing before getting near any danger of entanglement and so not absolutely great because it does require a visit to the printer every 45 mins or so, but does the job 🙂 Lol I certainly would not try to change your mind.

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You know where the quality is at!

 

Doing a big job just isnt worth the risk on the roll and adds tons of post time messing around trying to sand out a weak layer which takes longer than you'd think to sand out! 

 

For small jobs its fine on the roll but for the filament that isnt wound perfectly, I now wouldnt even risk it. 

 

There must be some kind of device that clamps down on the filament from the start to prevent ANY filament skips. Its the only thing i can think of. The pressure applied needs to be consistent though to keep nice beautiful layers.

 

I find the the last 10-15 percent of a tightly wound roll to be totally fine on the roll. I find TR colourfabb seems to be wound tighter or simply slips less than others perhaps to the texture of the filament? Eitherway ill probably off the roll it for important jobs anyways....

 

Smooth/slippery filament I imagine would tangle a lot. Its all down to how its wound and surface tackiness....imo.

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I do print "half on the roll": I manually unwind a bit of filament, and then wind it up in the opposite direction around a skater wheel (7cm diameter). And then I let it sitting on the roll, now very loose.

 

My print jobs rarely take more than 3 hours, which at 1m/h requires only 3m of filament to unwind and straighten. I do this while the printer is warming up and I am waiting anyway.

 

This has two effects: (1) it straightens the filament and gives it the same bending radius as the bowden tube, ca. 30 to 50cm. So resistance in the bowden tube and nozzle is almost zero. And (2) it completely removes the anti-unwind resistance of the spool, which would otherwise act as a very strong spring that resists unwindind. I also have replaced the spool holder with a frictionless holder with bearings, but I am not sure how much effect this has. I just disliked the jerky movements and sound of the original too much. My UM2 (non-plus) were sensitive to variations in resistance in the feeding traject.

 

I am not trying to convert you  :) , but for me this just works: while not perfect, it is good enough for our prototypes. The benefit is that I don't have left over ends of filament for each model.

 

But of course this is method would not work for long prints that take days, or for unattended printing.

 

See this photo where the filament is being bent in the opposite direction around the blue-green skater wheel. A couple of meters are already done and now sitting *very* loose around the spool. The yellow sliding clamp on the edge of the spool is to prevent the filament from falling off sideways. And to prevent it from "auto-unwinding" while I am straightening it.

 

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Not sure about the unwinding part. Its not clear enough for me but my jobs nowadays are at least 12hrs. But i personally find unwinding the filament off the roll and just laying it on the holder works just fine as the tension is the same as its like a spring so iys very light and only pulls at the front, the rest just follows. Ive done this with 20m of filament before, and i can easily just splice more filament on the fly anyway so it doesnt matter even if its 200m of filament!

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No, youre alright! i imagine that im just very unlucky and like to try to control my luck a bit. Printing high res all the time brings out any issues....speaking of which i tried to plate the bust but for the first time ever i couldng polish it! It wad just sanded eay too much! Who cares though i got a new batch coming in a few hours and 10 litres of gentile distilled water to shake it all up in! Boom. Its gonna be modesty next.

 

 But check your models for inconsistent layers @kmanstudios and if they have them then its the spools fault. I think I've seen them on your pictures. Not the baubles! The big white duck thing springs to mind, but i could be wrong and they are caused by something else. 

 

Ive been printing off the roll for over 4 years with perfect results everytime. The only time i havent got perfect results was on the roll. That kinda says it all to me. Also a dirty z screw! But clean that up and slap some green grease back on and bobs your uncle! Perfect layer lines again!

 

But dont get me wrong I am not trying to talk you out of printing on the roll! Just informing of my solutions to my 'occasional' imperfect layer issues! And my assumed causes. Im no engineer but just hyper observant. And hyperactive!

 

However if you are bored feel free to do a comparison of surface quality and see the results for yourself!! 

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Ohhh post production nice, i like! i'm also getting my new solution today...and using the spring method prevents tangles because...a spring doesn't tangle! unless you overstretch or squish it around. I have not have one tangle off the roll, as that is the entire point in doing it in the first place!

 

Im still ill unfortunately, but have areal nice sculpt coming!

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