How about a 3D printer section?

[nicobie]

If the nozzle was hitting the bed, you're going to need a new nozzle. The soft brass dents easy closing up the hole. Buy a bunch as they are cheap and I find that they wear out relatively fast.

 

[Alan B]

If you have an 0.4 mm drill bit you can clean out the hole if it is damaged. But new nozzles are fairly inexpensive (depending on how you buy them) and changing nozzles is often a way to solve various problems with clogging, etc. They do wear. I used one for a long time and when I changed it print quality improved.

 

[scianiac]

I haven't replaced a nozzle in years, I'm sure the one that's run many kg of NylonX through it is slightly worn but seems to print great. Tungsten Carbide nozzles on all my printers and cold pulls with PLA if they ever clog (wood filled occasionally clogs even with 0.6mm nozzles). Pros and cons vs cheap brass nozzles you replace often.

 

[goatman]

nozzles ok, it was a loose eccentric screw on the bed rollers, whole bed was wobbly

 

[nicobie]

Pros and cons vs cheap brass nozzles you replace often.

Yep, and figuring in the time it takes to replace, better to just buy a good one. I read that because brass is better at transferring heat that it might be better, but thinking about it, that doesn't really seem to apply. It's handy to toss them if they get clogged, but if everything is set up right you shouldn't be getting clogs.

That Voron Switchwire sounds interesting. I checked it out for a minute, am going to dive into it tonight.. Might be right up my alley.

Even though I've got some cf/PETG on the way. I can't resist trying that NylonX. After I finish screwing with my machine adding stuff I probably don't need.

 

[scianiac]

Yep, and figuring in the time it takes to replace, better to just buy a good one. I read that because brass is better at transferring heat that it might be better, but thinking about it, that doesn't really seem to apply. It's handy to toss them if they get clogged, but if everything is set up right you shouldn't be getting clogs.

While they can be hard to find I think the Tungsten Carbide nozzles are the best all around nozzle for many applications. Their thermal conductivity is actually a fair bit better than hardened steel, they are of course super hard, from my experience are more durable than the ruby nozzles that can break if you aren't careful and they are easy to clean/unclog. The fancy coated nozzles are cool but their coatings seem fragile sometimes (the nozzleX for instance recommends not to do cold pulls or you can rip the coating off). The thermal conductivity of the tungsten is fine for reasonable printing speeds and a well setup hotend. The copper and brass nozzles are certainly better if you're going to max speed but honestly I don't see a point in speed unless you're using it to test the machine limits. Super fast machines like CoreXYs I think are great because while they are "built for speed" it also means they print even better at more reasonable speeds. I've certainly learned some interesting things about printer design from watching the #speedboatrace which if you haven't watched videos of the top machines you're missing out.

 

[Alan B]

Tungsten Carbide nozzles could be excellent, if they are machined well. Some are very poorly machined, it is quite difficult to make a good one.

I've purchased a couple of hardened steel nozzles but haven't tried them as they are not needed for what I've been printing, and many folks report reduced print quality with them.

I have purchased both brand name and low cost brass nozzles and in both have found burrs and flashing inside, now I clean up nozzles before I use them with a drill bit. Not trying to remove material but just to get the rough edges out, and they always have rough edges. That would not work on the carbide nozzles unless one had a diamond tipped bit.

Once the burrs are cleaned out both the low cost and expensive brass nozzles seem the same. Right now I'm trying a plated copper nozzle on a dragon hotend that I bought before the patent dispute and it is fine, but I haven't seen much difference. Occasionally I get a clog and reportedly the Dragon will reduce that and minimize any heat creep. I'm still using the stock Noctua fan, but the Dragon allows a lot more airflow than the E3D V6's massive heatsink did.

The temperature on the Dragon does seem to be very constant, all that copper might help with that. In Octoprint I can watch the temperature and it is devoid of the occasional minor blips that I used to see.

If you have any recommendations on good tungsten carbide nozzles that would be useful. I use many carbide cutting tools and blades, and I bought a tungsten carbide wedding band to avoid the scratches the gold and titanium allowed. It always looks brand new.

 

[scianiac]

Inpsecting the two 3D Maker engineering nozzles I have here I would say they are passable, inside certainly isn't polished smooth (I think they are cemented and minimally machined after) but that's fine with me. I don't think the added drag will cause any issues or at least it's never caused me issues in the past but it probably also depends on other conditions. I don't print anything super fast, my direct drive Titan extruders have plenty of push and they are 0.6mm nozzles that already have less back pressure so the small surface roughness isn't an issue. I get jams very rarely and normally it's due to some other issue, barring something failing like the hotend cooling fan, it's always wood filled filament or this one spool of carbon fiber ABS that has a really absurd amount of carbon in it and extrudes like tar.

I guess I'll take the tradeoffs of the tungsten carbide for the durability. I may try lapping the inside with some diamond lapping paste though just to see if it works.

 

[goatman]

This are my suggestions for printing strong parts, most of the suggestions are in order to achieve maximum strength and they differ from what is normally used for aesthetic parts. As well there are some suggestions in order to improve parts printing speed.

- Nozzle diameter: 0.6mm to 1mm. (I use normally a 0.8mm)
- Layer height: 40% to 55% of nozzle diameter.
- Line width: 110% to 150% of nozzle diameter. (I use 150% for external perimeters, and around 112% for the other lines)
- Infill pattern: Gyroid. (If sliced in Cura activate “Connect Infill Lines”)
- Printing temperature: As high as the material allows without material degradation.
- Printing speed: Low to medium. (I use 30mm/s for external perimeters, 45mm/s for other perimeters and 65mm/s for infill)
- Use a volcano heating cartridge or similar so maximum volumetric speed can be increased. Test before increase. ( I was able to set it up to 20mm^3/s)
- Use minimum cooling or no cooling at all in order to enhance layer adhesion. (I use auto cooling, it only starts cooling if the layer time is under 30 seconds or at bridges lines)
- Use brass nozzle. (Not if you are using a FG or CF reinforced material)
- Use an enclosure if possible to avoid fast cooling and prevent high internal tensions and warping deformations. (YES even with PLA)
- Set bed temperature to maximum recommended for the material.
- Use some kind of adhesion enhancer in the bed like PVA stick or similar.

I use Sunlu PLA+ it is far more stronger and hit resistant than ABS and far more reliable for outdoor applications (It does NOT biodegradate or affected by UV as much as ABS). It has a softening point a bit higher than normal PLA. It needs to be printed at higher temperature than normal PLA. I recommend it very much for mechanical applications.

 

[goatman]

i have Sunlu PLA cf,
for strength, would you go 100% infill, connect infill lines, gyroid pattern?

 

[scianiac]

i have Sunlu PLA cf,
for strength, would you go 100% infill, connect infill lines, gyroid pattern?

Depends on how the part will be loaded, you're often better off increasing the perimeters before you start increasing infill, sometimes going all perimeters right to the core is stronger than infill. For instance if you have a flat part with two holes, all perimeters will be immensely strong in tension between the two holes. For many parts though 4-6 perimeters and a reasonably dense infill is nearly as strong as solid, sometimes more if you have less perimeters in the solid part. There is a great CNC kitchen video on the subject of infill vs perimeters. I also have been liking the infill locking feature in SuperSlicer that buries the infill to perimeter connections inside the perimeter with extra perimeters every other layer.

 

[nicobie]

I saw that video last night and it opened my eyes up, as do most of Stephan's videos.

 

[Alan B]

Or get the 3d printer that lays a fiber of kevlar along the print line, making things as strong as aluminum but lighter in weight.

 

[goatman]

hardened steel nozzle sure messes with the settings,
had to turn nozzle temp to 245
fan down to 60%
speed down to 40 mm/s
otherwise the regular PLA filament would jam
now the feeder doesnt skip at all on the filament

 

[scianiac]

Or get the 3d printer that lays a fiber of kevlar along the print line, making things as strong as aluminum but lighter in weight.

I have been doing some testing with ways to DIY one of these, since the commercial options are absurd money and I haven't seen other DIY options. My goal is to do it in a such a way to just make large compromises in certain areas to reduce complexity.

hardened steel nozzle sure messes with the settings,
had to turn nozzle temp to 245
fan down to 60%
speed down to 40 mm/s
otherwise the regular PLA filament would jam
now the feeder doesnt skip at all on the filament

So you have a silicone sock? These can help the temp gradient across the nozzle a bit, keep the cooling air off the nozzle.

 

[goatman]

silicone sock, yes
put new feeder on and it wouldnt shove the filament through, just chewed it up
brass nozzle no problem
so i used the ABS pre-heat at 250 and it worked
pla is supposed to be 235 i think

i thought the higher print temp was because of the carbon fiber but now i realize its because of the steel
pla cf is printing fine at the new settings i set for the pla

 

[nicobie]

Unless you have changed out your hotend to a all metal type you will get clogs printing at those temps because of 'heat creep' in the hotend/nozzle. Also your bowden tube will start to melt and emit toxic gasses. Be careful with ventilation until you switch out your hotend.

As always, take my advice with a grain of salt. I'm only repeating what I've read and watched on youtube. I'm as new to this stuff as you.

 

[Alan B]

Yes, teflon is dangerous if it gets too hot. Depends how far into the hotend it goes.

I have seen reports that steel nozzles require an increase in temperature, and others report that there was no difference. I wonder how much it varies with the type/quality of the steel nozzle and the design of the hotend.

I generally print PLA+ at the Prusa default of 215, and the label on the spool says 205-225.

 

[goatman]

1.5 hrs into the print, filament quit feeding, just kept skipping
tried brass nozzle, nope
new ptfe bowden tube 3inches longer than original
nope
put a new feeder on last night
thought id try putting the old brass toothed wheel back on
nope
different temps and speeds, no fan
nope


i put the filament in a Sunlu filament dryer at 50c and was feeding right out of it
it made the filament too soft and wouldnt feed
took it out of the dryer and mounted it on printer
so far so good :thumb:

 

[nicobie]

I'm using the same dryer with PLA+ @ 215C and everything is working fine.

Maybe you are getting clogs. What temps are you using and what does Sunlu recommend for the cf/PLA?

Carbon fiber is going to eat up brass.

 

[goatman]

im back to using the steel nozzle
did it again an hour later

had too much tension on the feed spring which made the filament ovalish on the way out
the ptfe bowden tube is a tight fit
backed it off 1/4 turn and its been just purring along since
wicked thunder booms outside, hope the power doesnt go out :lol:

thinking i might just preheat at 30C in the sunlu

 

[goatman]

24hrs into the new print it happened again. roommate called said it was skipping so i told them to unplug it from the wall

if you pause it autohomes and you cant get the fan screw out
it just thinks power went out and will resume when you plug it back in

contacted sunlu yesterday about a refund or new roll

the filament was at 1.9mm when it jammed the bowden tube







plugged it back in and alls fine again

 

[goatman]

and it screwed it up again thats it for sunlu pla cf for me
atleast theyre refunding me

going to try some duramic 3d pla + tough
https://www.amazon.ca/DURAMIC-3D-Filament-Printing-Dimensional/dp/B08LKQ1YN3/ref=sr_1_5?dchild=1&keywords=duramic&qid=1632314709&sr=8-5&th=1

yellows half the price of the other colours

 

[scianiac]

Having used my fair share of cheap filament when I was starting out in 3D printing I quickly learned it isn't worth it to me. There are tons of reputable filament suppliers and brands, many of them have economy lines that are nearly as good as their premium lines, most places have free shipping. Buying some no name brand off amazon that may work great (many times they will) or may be garbage (consistency is the problem) doesn't seem worth it to save a few bucks for the risk of hours of headache.

 

[nicobie]

I don't think your extruder even cares if +or- .2mm filament size. I'd pull the bowden off the hot end and make sure the filament slides freely. If it does I'd guess you have a clogging problem. If always happens after an hour or so into the print, you might be getting 'heat creep'. Maybe it's time to throw more $ at it and buy a all metal hotend.