Effects of Increasing Printer Speed  

Re: Effects of Increasing Printer Speed

That works, to a point, but it's imprecise. A print might go along merrily at 150% for hours, then fail or jam miserably near the finish. If this is an ongoing concern, you'd be better off creating a draft print profile that does things like speed up while still respecting the hardware limits of the E3D V6 hotend on processing filament. This way you can go fast without worrying about needless jams and skips. You'll have more control over what is sped up. You can even slice with a lower resolution.

An even better technique might be to use a larger nozzle. On many prints, you don't come near your set maximum speeds. The printer has to come up to speed and slow down for turns. If you're laying down more plastic on those same moves, prints will complete much faster.

I've got some notes on the illusion of speed here.

Re: Effects of Increasing Printer Speed

Bob, that's a great article.

I was thinking that given I don't want to buy a nozzle, or change all the "advanced" settings (I pretty much leave everything as it is bar brim and infill), I would just up the speed, and the first line in your post calls me out on that!

Given I really do only have the one nozzle, and right now, not the time to to truly go through setting speeds on different parts of prints, or parts etc, is there any kind of very rough rule of thumb?

Like:

up to 120% everything is ok, very little quality loss
up to 130% some quality loss, for functional only parts, won't matter
up to 140% more quality loss, however no functional loss
up to 150% complex parts like gears may not work
over 150% there's a good chance your part will be deformed
over 180% there's a 1/10 chance your printer will blow up.

BTW: this doesn't mean I am not listening to what you say in your blog, as an engineer I am on board with that, given it's my 10th odd maker hobby, (woodwork, electronics, computing, robotics, video editing, graphic design etc....) I'm was just looking for an easy life on this one!

I feel it's down another rabbit hole for me though....

Re: Effects of Increasing Printer Speed

If you watch bobstro´s site closely you will find all profiles dialed perfectly in for nearly every nozzle size. Just download and import.
If you order nozzles via aliexpress, you get one for 30 ct including shipping. Give it a try.

Cheers

Re: Effects of Increasing Printer Speed

I've got some notes on the illusion of speed here.

This is a brilliant article. Thank you for sharing.

Now try to find the github page for the factory filament profiles and request that (at least for PLA) reduce the max volumentric speed from 15 to 11.5 so I don't have to constantly maintain a parallel set of profiles... Do you have a published source (even if it is your own data) for your ascertain that the real-world MVS of the E3D V6 hot end is 11.5?

Re: Effects of Increasing Printer Speed

[...] This is a brilliant article. Thank you for sharing.Thanks. I'm just trying to compile all my notes in one place so I'll remember it all in 6 months! I hope those pages are useful, but they're really nothing more than my living notebook.

Now try to find the github page for the factory filament profiles and request that (at least for PLA) reduce the max volumentric speed from 15 to 11.5 so I don't have to constantly maintain a parallel set of profiles.Good news: You can set it in 2 places: Your filament profile and under print settings. Take a look at Print Settings->Speed->Autospeed (advanced) and you can set it under Max volumetric speed there. I set it in my print settings to provide a system-wide maximum, then as-needed for individual filaments. Slic3r will use the most restrictive setting. I only set it for filaments where I need to slow things down further. You can verify this by adjusting the numbers, then checking out the View->Volumetric flow rate and Speed options in preview mode after slicing.

.. Do you have a published source (even if it is your own data) for your ascertain that the real-world MVS of the E3D V6 hot end is 11.5?
Nothing authoritative. I found scattered references to everything between 10 and 15 on the reprap forums and other places. 11.5 was commonly cited, and worked well in my testing. I really saw the difference when doing prints with large areas of infill where the nozzle could come up to speed. At the default of 15 combined with Prusa's aggressive infill speeds, I'd start getting extruder clicks, nozzle dragging and other issues. Notching the rate back to 11.5 cleared it up in most cases. You can probably tweak that based on your own combination of nozzle and temps. I personally err on the side of caution. I don't want to go "fast" only to lose a print at hour 8 of a 10 hour print.

I'm traveling this week, so won't be able to print at all. I'm hoping to spend some of my hotel and flight-time downtime (BOS-ANC) updating some python scripts that will make it easy to create Slic3r profiles in a batch, allowing profiles to inherit properties from a baseline profile. Slic3r already has the functionality built-in, but it's not available to users in the current versions.

Re: Effects of Increasing Printer Speed

If you watch bobstro´s site closely you will find all profiles dialed perfectly in for nearly every nozzle size. Just download and import.
If you order nozzles via aliexpress, you get one for 30 ct including shipping. Give it a try.
My profiles are under heavy development. I'm hoping to make them much more consistent in the near future. Apologies to anybody getting errors or inconsistency using them. At least you can get some basic nozzle profiles working with them.

FYI - I'm wondering if some of my stringing battles might be related to cheap nozzles. I've got some of the $9 cheapies, and they work. The wrench they provide is very useful. The nozzles are definitely craptastic. Triangle Labs on AliExpress has some really nice clone nozzles in a new(-ish) line out that is much more precisely manufactured. Their "fun pack" is only $16. I've got a set on order. I'm also trying out P3-D's nozzles.

I'm experimenting with the cheap 1.2 and 1.5mm nozzles, but those might be a bridge too far for the E3D V6 extruder.

Re: Effects of Increasing Printer Speed

[...] Given I really do only have the one nozzle, and right now, not the time to to truly go through setting speeds on different parts of prints, or parts etc, is there any kind of very rough rule of thumb?
Well, there is one feature that only Slic3r and KISSlicer have implemented that might fit your bill. It's a bit of a hack, but it may tickle your Engineering itch. It's the reason I went down the Slic3r rabbit hole myself.

Check out Print settings->Speed-> Autospeed (advanced)->Max volumetric speed. This lets you set a maximum volumetric speed (MVS) for any slicing done using that profile. This over-rides the actual speed settings in the same profile above. This means that Slic3r will use speeds up to those specified, but only so long as they adhere to the MVS limits. You can see this in action in Preview mode after slicing.

You could create very aggressive speeds, and just use MVS to keep them within the limits of your hotend. Want perimeters at 100mm/s? Sure, it'll work until you exceed MVS, then throttle back to avoid skips and jams without any further action on your part. Not very artful, but appealing in a brute-force sort of way. You can be a reckless as you like, but it provides a built-in safety to avoid frustrating nights of cleaning and disassembly.

You might also look at Print Settings->Advanced->Other-Resolution. I haven't done much with this myself, but the idea is that it avoids overly-fine calculations that won't show up in a physical print.

So to answer your question: Create a "draft" profile with fast speeds, restrict speeds with MVS to stay within the hotend limits, and tweak resolution to achieve the desired level of detail. Of course, I have no idea if any of this will make any real difference in print times, particularly compared to the time gained with a bigger nozzle!

I strongly urge you to go down the nozzle size rabbit hole. Once you start to see the impact even a slightly larger nozzle can make, it's hard to go back to 0.40mm. I've got nozzle swaps down to a few minutes, and it's always gratifying seeing the results. I guess it's the equivalent of putting a bigger bore engine in.

Re: Effects of Increasing Printer Speed

Good news: You can set it in 2 places: Your filament profile and under print settings.

I hadn't noticed it in the print settings. Thanx. I already maintain my set of custom print settings (tuned to the 0.04 magic number, enable 7x7 mesh bed leveling and associated re-ordering of startup steps, and my own custom end gcode to have the post-printing z height set to above 100mm).

I'll have to re-try the first few layers of something that I printed that was having trouble laying out enough filament on the infill until I slowed the print speed down. I want to see if the lower volumetric setting fixes that issue. (It was the tray that fits between the front y-axis extruded aluminum pieces that I found on Thingiverse, so it started with a rectangle the size of most of the bed. I chose "line" infill. I was getting cracking and popping from the bondtech gears during the infill layers and the second layer of infill was only bridging every other gap, leaving spikes on either side.)

Re: Effects of Increasing Printer Speed

You mean like this?

https://www.aliexpress.com/item/5PCS-3D-Printer-Accessories-MK8-Nozzle-Extruder-Nozzle-Brass-Nozzle-1-75MM/32830199323.html?spm=a2g0s.13010208.99999999.260.38c33c00BCTtoj

I didn't find a 0.8mm one, not sure if the designation CR10 or MK8 means it will work. A quick google (10 mins) left me none the wiser.

Thanks again!