Nozzle replacement (Ender 3)

I am still very much a beginner at this 3D printing lark and barely beyond the nursery slopes of 3D CAD but I have a question about replacement nozzles for the Ender 3 printer.

On the internet they are for sale in multipacks suggesting they may not have a long service life - but what are the symptoms that suggest a nozzle might need replacing?

Thanks,

Nick

Not owning a 3D printer, my knowledge from first hand experience is nil, but I have done some research with a view to purchasing a printer at some stage. Part of that research involved purchasing "3D printing for model engineers", written by our own Neil Wyatt. In it he makes a number of observations regarding worn nozzles, notably those made from brass which should be considered a consumable. He suggests that they should be changed every two spools of filament. More often, if the more abrasive filaments, such as carbon fibre impregnated nylon ones, are used. More durable nozzles for this type of filament can be had with a ruby insert, for example, though they will be commensurately more expensive.

Symptoms include blobby prints and over-extrusion, apparently.

I can recommend Neil's book for the beginner - it contains a lot of useful information and guidance as well as set up advice and trouble shooting. And, no, I'm not being paid to say that!

John

Based on 5 years experience with my Ender 3 (about 35 reels 1 kg each of PLA plus filament) I'd suggest not buying further nozzles until you need to. I have changed nozzle ONCE in that time on my machine. (Like most people I bought a few when I started and still have all but one). Symptoms of nozzle issues I have had are poor first layer adhesion, or poor adhesion in later layers. If holes start being printed dimensionally too small it may mean the nozzle is worn internally and laying down an oversize width pass. Stringing has many causes but nozzle wear can make it worse. One useful improvement I made was to install a SeeMeCNC extruder, see link below. This worked much better than the stock Creality extruder which "skipped teeth" and mis-fed a lot, and after a while its' plastic frame was getting distorted (creep) by the spring tension behind the roller. I also installed a Creality glass bed about 6 months in as the magnetic build pad was cracking. I am told the stock build pads are better now. Again I suggest not buying a bunch of things to improve the machine before you get to know it.

The single most important thing I have found gives good results is good quality PLA plus filament. Some filament on the market is rubbish. Also important is to use the default settings for your selected material for a while in the Cura slicer. Several times I made things much worse by messing around adjusting settings without fully understanding the effect.

https://www.seemecnc.com/collections/parts-accessories/products/ezrstruder

I've had a lot of fun and done a lot of interesting prints for myself and printed a lot of toys for my nieces on my Ender 3, it was great value for money.

Do keep an eye on the conical axis guide rollers to aluminum extrusion fits - they loosen a bit over time and they need to be as close to 0 clearance as possible for good prints.