Nozzle Bores

I recently purchase some 0.4mm nozzles thus.

The ones I was sent were similar to thus.

I have plenty of the latter which I can manage with but are longer and not really ideal in my situation. hence the order for the shorter ones.

When I looked at these, it seemed to me that the bore looked considerably less than 0.4 mm. A check with a B&L Optical Comparator indicated more like 0.3 mm or even a bit less.

A #80 drill .34 mm wouldn't touch it.

However, every other 0.4mm nozzle that I have around (of various types) seems to be the same so it doesn't seem to be a case of mis-marking on this particular batch.

Am I missing something?

Edited By Bandersnatch on 01/07/2020 17:27:35

OOPs! Sorry ladies and gents. What I took to be a #80 drill was actually a #60. Failing eyesight ... symptom of current lack of infinity-breaks.

I can't find a #80 but the optical comparator info would still seem to apply.

Did you try is at operating temperature ?

Just a thought .

Edited By XD 351 on 01/07/2020 20:04:35

I didn't (difficult to do plus I never thought of it) XD.

However my quick calculation on the back of a tear-off from my Dilbert daily calender came up with 0.0015mm as the expansion of a 0.4mm hole over a 200 ºC temp range.

Not that I'm very good at those calculations any more (another sign) so feel free to correct me.

I don't think that's what I'm seeing. I'll look for a very small drill tomorrow and if I find one I'll run it through a nozzle and see if it resizes it - and if so, see if it make any practical difference to the printing (with Cura set to its current value of 0.4 mm).

Edited By Bandersnatch on 01/07/2020 22:29:54

You might find something interesting in this video By cnc ktchen regarding nozzle size ,tolerance and bore finish.

https://www.youtube.com/watch?v=Zi5gA_tDE4Y&feature=share

I wonder if a 0.4 mm nozzle cleaner for oxy torches may be better if they are available in that size ?
I run stainless Nozzles and can honestly say i have never even give the tolerance of the hole a thought !

I do know what it's like to run a .3 mm nozzle (by misteak) with gcode sliced for a 0.4 nozzle and the result ain't pretty.

(The video seems to be the kind Neil's complaining about so it may not last long).

Edited By Bandersnatch on 02/07/2020 01:29:57

(The video seems to be the kind Neil's complaining about so it may not last long).

Why?
I must have missed that post
It is a link to a very popular channel that does some amazing things with 3 D printing .

It is not my Channel and i have no affiliation with but i do subscribe to it along with a couple of hundred other channels !

If it is to do with the sponsor/ sponsors he has or any advertising of them I can’t rectify that , i just fast forward past it ! Unfortunately more and more channels are going this way as the mighty dollar and mankind's lust for it has ruined a lot of if not all of youtube !

Nozzles from E3D are low profile, if they are too spendy for you then trianglelab on AliExpress sell nozzles made to match E3Ds published drawings.

As for sizing, if they print OK then they cannot be too far out, try measuring a known good nozzle?

I have no knowledge of 3D printers or printing so I could well be talking gibberish, apologies in advance. Could it be that the nozzle diameter is designed with an apparently undersize nozzle/aperture to accommodate spreading of the the hot extruded plastic so that it actually lays down a track that is 0.4mm wide and the size given for the nozzle refers to the minimum wall/ track thickness that can be printed and not the actual aperture of the nozzle.

Hope this makes sense.

Martin

Edited By Martin W on 02/07/2020 11:09:47

Martin, I don't doubt there may be some spreading effect of the plastic but it wouldn't make sense for every nozzle manufacture to apply his own correction to the hole diameter if needed. Much better to drill the nozzle to nominal so that everyone is doing the same thing and have any correcting done in the slicer software. It's always referred to as "nozzle dia/size"

In any event I checked a number of nozzles today and all looked a bit small so I tried running a #79 drill through by hand. It went through quite easily and left me with a nice clean (and round) hole.

CE - this whole thing kicked off because I was dissatisfied with the print quality on one machine .

I've never questioned the size of 0.4mm nozzles. To me the ones I have look right but its very hard to judge.

An undersize hole is not critical, unless it limits the flow due to back pressure (it would need to be quite a bit undersize). Oversize (as I've found to my cost) is more problematic. What appears to happen is that it amkes teh delivery inconsistent and you counter-intuitively get symptoms of under-extrusion.

I find that with extreme wear the bore opens out and I get inconsistent results (I suppose I could try setting Cura for 0.5mm, but as nozzles are just pence...)

I've had a play with 0.1mm nozzles. Life becomes very slow and things like bed adhesion become very fussy.

This 100 tooth wheel took a long time to print, the top surface is really good. In the end I used one printed with a 0.4mm nozzle which isn't as pretty but works well. For the matching 20-tooth wheel the 0.1mm nozzle gave a much better result. I think 0.1mm nozzle with 0.5 or 0.25mm layers would give results to match resin printing, but very, very slow.

Here's something that I had recently. This was on a generally reliable machine with material (PLA) that has been good. (It's all supposed to be a single column). I hadn't expected trouble so I printed it again without changes. Exactly the same result.

When I investigated, I found that, instead of my normal, ubiquitous, 0.4 mm nozzle, I had installed a 0.3 mm nozzle in error. The slicer (Prusa) was set for a 0.4 mm nozzle.

I fitted a 0.4 mm nozzle, ran it again and the print was fine. (I could kick myself that I didn't leave the 0.3 mm nozzle in place and change the Prusa setting to match it).

I buy my nozzles from China in lots of 10. I always check the nozzles and thread, not had any problems (so far).

I have ran 0.2 nozzles and got a fantastic finish, but the time taken was not worth the compromise, likewise, a 1mm nozzle is fast, but the quality ain't good!

0.4 does seam to the right mix of speed and quality.

Jim

I've come to a similar conclusion ,though for small objects and figures the 0.2mm nozzle with a 0.1mm layer height is outstanding. Tip if the items are very small print 2 of them, gives one a chance to cool down between layers and cuts heat distortion.

I also came across an article [can't find the source now !] that recommended for printing flexible TPU type filaments to use a 0.5mm or larger nozzle to avoid high pressures in the extruder and failure of the extruder gear to feed the soft filament.

Edited By The Novice Engineer on 05/07/2020 00:05:27

Good advice. I tend to print a Ø20mm block when printing threads, as this does allow the layers to cool fully.

Jim

This has morphed into a very useful thread. Thank you.

You can also set a minimum layer time in Cura that has the same effect.

As for TPU - I find it a very reliable filament! These tyres featured in the latest Ed's Bench were printed in TPU, 3/4" thick, 2 1/2" diameter.

Neil

Neil,

what parameters did you use for the TPU - nozzle and thickness, etc?

BR
Simon

I must kindly disagree on this one Jim. -
It all depends on how you look at it.
I printed some 2+meter high models recently. I used a 1.5mm nozzle. These models are about 225 mm high and bolted together.
Yes you can see the layers, but seen from a distance it's ok. These SaturnV rockets I've printed are actually very good and pleasing to look at.
As a matter of fact, busy right now building a bigger printer to be able to print very high objects in combination with a 2 and even a 2.5mm nozzle...

It took me just under 48 hours to print these rockets, I actually printed 4 of these.