[Cerrado] .8mm nozzle tips with PLA  

Re: .8mm nozzle tips with PLA

.8 nozzle is huge why would you go with a larger orifice? I would think that that size of a nozzle would be used for a machine 3x the size. How is your printing going? I am curious.

Re: .8mm nozzle tips with PLA

Usually the wider and thicker the layer, the better the layer adhesion and the stronger the part (up to a point where it does not adhere).

However, there are limits for the V6 hotend and it seems to me as though you would be better off with a volcano for those line widths/heights.

The V6 is capable of melting (at higher temps) up to slightly over 10 mm^3 per second. If you do the math, you can work out the max print speed.

Also be aware that there is also a maximum extruder speed.

Peter

Re: .8mm nozzle tips with PLA

As a general rule, if you want to push more material through the nozzle, you have to increase the nozzle temperature to melt the extruded plastic.
If you don't increase the nozzle temperature, you have to print slow with the 0.8mm nozzle. But then it defeats the purpose of the wide nozzle.
Vojtech

Re: .8mm nozzle tips with PLA

and please don't use the "automatic" settings of the extrusion width in Slic3r. Rather put 0.85 or 0.9 everywhere. The way Slic3r defines the default extrusion widths does not work well with the Prusa I3 printer. Just use the default 0.4mm settings as an example and multiply everything by 2.

Vojtech

Re: .8mm nozzle tips with PLA

I've successfully used a 0.8mm nozzle to nearly double the speed of my Original Prusa i3 MK1. The larger nozzle obviously reduces the resolution, but it also makes it possible to use taller layers without sacrificing overhangs. I printed over a dozen Kendamas in PETG using a 0.8mm nozzle.

The simplest thing to do is first print successfully with the 0.4mm nozzle (since the community has more experience with that), then change to the larger nozzle and don't increase any speeds. In fact, you'll probably need to reduce speeds. In my experience, when using PETG with a 0.8mm nozzle, I had to limit all speeds to 30 mm/s (20 mm/s for outer layers), but I was able to increase the layer height to 0.25mm and use only 2 shells, for an overall reduction in time, an increase in part strength, and an increase in the amount of plastic extruded. I could probably extrude PLA faster.

You probably want to watch the extrusion temperature carefully when using a larger nozzle. Octoprint makes it easy to watch the temperature.

Re: .8mm nozzle tips with PLA

I am trying out a 0.8mm nozzle. It seems that the extruder settings need some fine tuning in regard to retraction and or speed settings. I am getting a LOT of stringing. Which I guess makes sense given that 4X as much material can flow through the nozzle. I also found that I was getting pock marks similar to printing with wet nylon. I suspect that may be due to the extruder not being dialed in and not keeping up with the amount of material being put down. But then again I was using 0.5 layer height so I may have simply been pushing the machine too far.

Re: .8mm nozzle tips with PLA

and please don't use the "automatic" settings of the extrusion width in Slic3r. Rather put 0.85 or 0.9 everywhere. The way Slic3r defines the default extrusion widths does not work well with the Prusa I3 printer. Just use the default 0.4mm settings as an example and multiply everything by 2.
Surprised to read this. I've got a range of profiles set up with automatic extrusion width set, and have been getting good results with every nozzle size from 0.15mm to 1.00mm. I do create "precision" profiles for detail prints with exact extrusion width settings, but 90% of the time, the automatic setting has been working very well. It also cuts down on the number of profiles I have to maintain when trying out different nozzle sizes. What do you mean by "does not work well"?

Re: .8mm nozzle tips with PLA

The printer works great with the supplied .4mm nozzle. And Joesph's Simply3d settings.
Recently switch one of the two Mk2 that I own to a .8mm nozzle.
Slow down the printer speed. Changed width of line to automatic. Changed Nozzle to .8 set layer to .64mm.
What else should I change?
If you're using Slic3rPE, you don't even have to change your speeds. Set the Max volumetric speed (MVS) and Slic3rPE will cap speeds to stay within the set MVS limit for you. I set it to 11.5mm^3/s in Print Settings->Speed->Autospeed and per-filament in Filament Settings->Advanced->Print speed override (e.g. 8 for PETG).

If you're using another slicer, you get to do some work with the calculator. The MVS for the E3D V6 is roughly 11.5mm^3/s (Advertised as 15, you'll find discussions of ranges from 10-15). If you exceed the maximum throughput the extruder can handle, you'll get extruder skips and jams. MVS is calculated as:

MVS = Layer Height X Extrusion Width X Speed

You can calculate speed as:

Speed = MVS/(Layer Height X Extrusion Width)

For the E3D V6 this equates to:

Speed = 11.5/(Layer Height X Extrusion Width)

So for an 0.80mm nozzle using 120% of nozzle width for extrusion width (0.96mm), you can use speeds of (rounding down):

You can increase temps a bit to exceed this, and YMMV as always. I've dumped my notes on printing with different nozzle sizes here and the relationship of nozzle sizes to print times versus "speed" here.

Works great on some prints. However, on others it appears to put out to much filament on the first layer. Did you re-calibrate your Live-Z setting after mounting the new nozzle? I do it after every nozzle change and generally get good results. I also usually use a 0.20mm 1st layer regardless of layer height on all but the smallest nozzle sizes.

Other problems are that layers are not ticking together. Make a point of keeping layer heights at or below 80% of nozzle size for best results. Any higher and you're printing cylindrical cross-sections which will have poor inter-layer adhesion.

I am having a lot of fun printing strong functional parts with a 0.80mm nozzle lately. Print finish quickly and are very strong. I've been able to print threaded parts on larger sized parts.

Re: .8mm nozzle tips with PLA

[...] I was using 0.5 layer height so I may have simply been pushing the machine too far.

At 0.50mm layer height and using a 0.96mm extrusion width, your top speed should be roughly 24mm/s using the stock E3D V6 extruder.