Random 3D printing chatter

Soldato
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On the Bambu Labs printers it's all-in-one. The nozzle, heat-break and heatsink are one piece. You can order that as a part of the whole assembly that also includes the thermistor (temp sensor), ceramic heater and fan. Luckily it comes with a spare so I've reassembled the old heater, thermistor and fan onto new hotend.
Part came out ok but I'm going to have to try playing with temp and retraction to reduce dribbling that I had to chisel off. Also on the PLA-CF the support just fell off (literally) once cold. On the PETG-CF (much like PETG) it didn't and I had to take a hammer (gently) and chisel to it to get it off. Dimensions and strength both seem good though.
 
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Is there a difference between brands and colours of filament when it comes to bed adhesion?
It used to be more of an issue in the past but filament has got much better in my opinion. used to be noticeable in the work we were doing on white/yellow vs other colours but you could raise the temp a notch to overcome it
 
Soldato
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PETG has a tendency to string when it oozes out the nozzle while it's travelling (moving without extruding). Sometimes that builds up on the nozzle (it also like to stick to the nozzle) and eventually you get a blob deposited into a wall somewhere. This printer with its default settings was fantastic (at first) for PETG as it didn't string at all. This stuff has carbon fibre mixed in so it's different (and needs a hardened nozzle as it is abrasive) but I'm trying to get back to that perfect PETG print. You find a filament that works perfectly and suddenly it's not available and you're back to square one.
Support seems to break off PLA much easier as it's brittle. I suspect that PETG also spreads a bit more so the support is much more joined to it.
PETG was my go-to because I could run my last printer without the layer fan and just make do with the waft of the hotend fan. That was key as it was close to me whilst I was at work and Creality had done weird things with PWM that meant it was noisy and sort of crunchy - even with a Noctua.

A deburring tool is quite good for getting rid of brims if you are having trouble getting those off cleanly - again, more a PETG thing than PLA.
 
Soldato
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Is there a relationship between nozzle diameter and object print diameter?
E.g a 0.4mm nozzle printing 2.8mm diameter cylinder vs 3mm diameter cylinder since 2.8 is a multiple of .4 ?
 
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Yes and no, it’s good practice to consider your nozzle size but not really essential as the fluid material will flow round a slight overlap. It’s more of a concern for me in my day job where I use 20-50mm nozzle diameters.Not too much at home with 0.4/0.6
 
Soldato
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I know it sounds mad but concrete.
Doesn't sound mad...but those default 0.2mm layer heights you're using might be why it takes months to print a building! ;) Hope it's got power-failure resume and a decent webcam for watching it overnight! :D
Ventilation's no issue but do you need an enclosure for printing concrete filament?! :eek:
 
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The cage is 10x8x3m. I have found that layer height works as a function of nozzle diameter for our material, so 10-25mm. Wrapping the material post print for curing is the main concern to avoid micro cracks. No headed bed though that may be a step too far.
 
Soldato
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Nah, it's easy, you just flex it and your house pops right off ;) :D
Kind of interesting that the layer height is still about half the nozzle width even at much larger scale and very different material.
 
Soldato
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PETG has a tendency to string when it oozes out the nozzle while it's travelling (moving without extruding). Sometimes that builds up on the nozzle (it also like to stick to the nozzle) and eventually you get a blob deposited into a wall somewhere. This printer with its default settings was fantastic (at first) for PETG as it didn't string at all. This stuff has carbon fibre mixed in so it's different (and needs a hardened nozzle as it is abrasive) but I'm trying to get back to that perfect PETG print. You find a filament that works perfectly and suddenly it's not available and you're back to square one.
Support seems to break off PLA much easier as it's brittle. I suspect that PETG also spreads a bit more so the support is much more joined to it.
PETG was my go-to because I could run my last printer without the layer fan and just make do with the waft of the hotend fan. That was key as it was close to me whilst I was at work and Creality had done weird things with PWM that meant it was noisy and sort of crunchy - even with a Noctua.

A deburring tool is quite good for getting rid of brims if you are having trouble getting those off cleanly - again, more a PETG thing than PLA.

My fans are almost silent on my Ender hotend. What are you doing exactly? I decoupled my fan from the hotend and run it from the PSU directly with a voltage adjuster to get it where I want it.

I also put all my electronics, psu and screen in an external housing (making sure to run a ground wire to the frame btw), and use a large 120mm fan to keep everything cool in there, with the original fan hooked up to a temp sensor for backup.

CF you need a hardened nozzle, ideally 0.6mm to avoid clogs.

Do you dry your filament prior to use? I run a food dehydrator on my filament before printing.
 
Soldato
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I swapped the hotend fan for a Noctua and ran that off a buck converter. That's pretty quiet and doing that wasn't a problem as it's on all the time.
I did similar for the layer fan but left it controlled by the board. It's sort-of PWM but weird. The positive is direct so that's now on a buck converter too. The negative is what is chopped by the board but very roughly and that's what causes the noise. It makes it sound like there's gravel in the bearing. The answer is to swap the controller but I got as far as buying one and then bought a new printer when I realised I was never going to get round to it!
I stuffed a Pi into the original electrics case, two bucks (12V for fans and 5V for Pi), a network port, a switched outlet to run better lighting (24V COB LED strips on aluminium backing plate) and a 92mm slimline Noctua to keep it cool.

New printer is a Bambu and the 0.4mm nozzle is hardened. I do have a 0.6 that also hardened but haven't needed it so far. Tried it once and was disappointed that the print time was pretty much the same.

I've got a Filadry S2 and just went for the Kickstarter for the S4 that will dry 4 concurrently.
 
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I've got a Filadry S2 and just went for the Kickstarter for the S4 that will dry 4 concurrently.

How do you find the S2? Have just ordered one for short term, but also couldn't resist backing the S4. It seems the biggest issue with the S2 is allowing moisture to escape, will probably try propping the lid open slightly and maybe add a fan at some point.
 
Soldato
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Pretty much what you've found to be honest. It does help and some moisture may be able to get out the Bowden tube holes but maybe not a lot. I printed the desiccant holders that fit in the middle of the spool and half fill them with colour-change desiccant, then I spin the spool about every hour (or when I think of it!). Drying a few and maybe using it like a dry box seems like a good plan. Tried the vacuum bags and they're a bit hit and miss; some stay vac'd and some don't.
 
Soldato
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I don't need another dryer but opted to get the S4 kickstarter anyway lol.

I don't like that they aren't controlled by the printer though. Not aure about the S4, but having a smart dryer would be way more preferable than a timer you have to mess with.
 
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