I just had to increase my nozzle size in my slicer settings,

Carlton_Dodd · February 23, 2015, 1:42am

I just had to increase my nozzle size in my slicer settings, even though I haven’t changed my nozzle.
I’m not sure everybody knows, but pushing plastic through a nozzle wears the orifice. My 0.35mm nozzle has become 0.40mm with only sporadic use over a few months.
If your prints are starting to look sloppy or under-extruded, you may want to either check your nozzle’s orifice diameter, or trade it out for a new one.

paul_wallich · February 23, 2015, 2:03am

How many kg of material? I’ve run at least few couple kilos through my 0.35 nozzle with no change. Maybe something else is going on?

Joe_Spanier · February 23, 2015, 2:16am

What nozzle too? I could see this happening more with an aluminum nozzle then brass asc well

Carlton_Dodd · February 23, 2015, 2:25am

This is on my RigidBot, after about 3-4kg of almost exclusively PLA.

Joe_Spanier · February 23, 2015, 2:47am

wow. that shouldn’t happen. You have sand in that PLA haha. Im on 20+ with no noticeable wear or issues.

Carlton_Dodd · February 23, 2015, 3:23am

@Joe_Spanier
Hmmm… I checked it with a 0.4mm drill bit (without turning it); it wouldn’t fit in a new 0.35mm nozzle, but slipped right into the one I currently have mounted.
Maybe I’ve got crappy nozzles (at least I have a few spares!), but this worked for me.

Joe_Spanier · February 23, 2015, 3:34am

WOW Thats essentially how I am testing it too. Thats a shocking amount of wear though.

Whosa_whatsis · February 23, 2015, 5:30am

Slicers have an annoying tendency to assume that the extrusion width should be equal to the nozzle diameter. The ideal extrusion width is actually nozzle diameter + layer height. This way, there is a rectangular portion with the width of the nozzle, plus a semicircular portion with a radius of half the layer height on each side. Less than this, and the shape of the extrusion will be less predictable, and layer adhesion less reliable. In some slicers, to get this extrusion width, you have to lie to the slicer about the nozzle diameter.

Brook_Drumm · February 23, 2015, 6:21am

Plastic is extremely abrasive. It will absolutely wear on the nozzle. Plastic is not all created equal so ymmv. Metal type and design play into it a lot too… It’s a dark science, but you either have to track the wear by measuring the orifice and adjust in slicer or replace the nozzle every few months. I do know that the metal filled plastic is way worse on nozzles than regular stuff.

Ken_W · February 23, 2015, 4:14pm

Carlton, if its the IAP pla I suspect its colored with titanium dioxide. After measuring you have explained why mine had the sniffles. I went from .4mm snug to very loose .4mm. This is with an E3d. Time to change the noozle. I have been printing with mostly black ABS so who knows what was hidden in mine.

Carlton_Dodd · February 23, 2015, 5:37pm

@Ken_W
Actually, I just started with my first white IAP PLA filament. I’ve used almost 1kg of the IAP gray, and about the same of the IAP red. I have used several other brands as well.

Guy_Sheffer · February 23, 2015, 6:35pm

How do you measure the nozzle diameter?

Brook_Drumm · February 23, 2015, 7:14pm

I bought a set of precision feeler gauge / pins. But using drill bits works too.

Carlton_Dodd · February 23, 2015, 8:45pm

I have 0.35 and 0.40 drill bits. I used them for testing. You have to be very careful with them, though. Not only are they made to cut into things, but they snap off very easily (and they’re kind of expensive).