How do you max out print speed?

Bambu Lab H2 Series
1

Hi folks,

I’m thinking about how to MAX out print speed on my H2D for some prints.

  • Single material
  • Mostly ASA

I’m wondering how fast I could get by optimising the filament/print settings, WITHOUT SACRIFICING QUALITY and without shaking my H2D to pieces.

I’m wondering if I could get a 24hr print down to maybe 6hrs…or even 4hrs…:shaking_face:

Before I waste time on a fools errand trying to dial something in, has anyone tried this? Any advice?

2

Find what you’re constrained by, then make that constraint’s number bigger. Repeat

You’re almost surely constrained by one of 5 things:

  1. Minimum Layer Time [cooling]
  2. Speed
  3. Accel/Jerk
  4. Quality related retraction settings [spiral is slower than slope, any is slower than none, etc]
  5. Max Volumetric Flow

A 0.6 nozzle at 0.3mm layer height being run at the same speed as a 0.4nz/0.2lh is firing off 50-100% more plastic with each pass, which will get your print done faster if it can keep up.

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3

Fast, cheap, good. Pick two.

If you want to go fast and can dial in the quality, in the long run you’re not going to have a machine that lasts as long. Physics isn’t optional, harder accelerations wear things down faster, period.

That out of the way, there are always lots of optimization levers that can be pulled that AREN’T “faster acceleration and top speed”, but it’s very dependent on the model being printed, and at some point you’re past the point of diminishing returns if it’s a single print situation.

In a crazy do or die situation where I had time and the print was the right geometry, I’d manually cobble together gcode so I could run a 0.8 on one nozzle and a 0.4 on the other. That could be good for 75% time savings one some prints alone.

Another example - I have one large rectangular part I make a lot of, with a solid base that’s two layers think. Since the first layer is always slower. I orient the part so it goes the short way across the base, then for the full speed second layer it can rip and go the long way across the part. Big savings from that one simple tweak.

4

I had a design that started at 15 hours, and it’s at 6 hours. I changed the design including changing different infills etc. I also used Jayo or Sunlu high speed petg and used the Bambu HF petg settings. Right now I’m between 6-7 hours as I’m trying to balance between number of layers, walls, infill and top surface pattern. Interesting as my print is 50% larger than my competitors, and I know they are at least at 7 hours with a weaker print compared to my 6 hour print. I know their print times as they use a free available print file.

I have one design that I decreased the print time from 11 hours to 4 hours by making one design change.

I have not touched any of the speed settings. So my advice is to beside the speed settings look at your design.

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5

Keep in mind: The biggest time saver is the 3D object itself. This is often seriously overlooked. It’s a shame you didn’t post a photo as an example.

Strangely enough, this first step is almost always overlooked. In fact, often the second step, too.

  1. Optimize the actual 3D object
  2. Positioning, alignment, quantity, etc.
  3. Printer Settings

You need to treat this like a project. All the relevant aspects need to be optimised. For example, what use are printer settings that only save you 10 minutes when you could optimise your object to save an hour? Of course, vice versa is also true.

In short, the first step is to make your 3D object “printer-friendly”.

You can’t skip this step if you want to save time and keep quality.

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6

Thanks for the replies folks, I can definitely look at improving the design. I wonder could I create an app that will modify my gcode to allow me single outer wall at 0.8mm and single infill at 0.4mm…that would be interesting if i can find the time. :thinking: Sounds like some serious time savings are possible if I put in the work to improve it. :flexed_biceps:

7

Besides optimizing the model as mentioned… run a max flow test with your filament and adjust the flow rate in filament profile, then tune the speed and acceleration settings in the slicer.

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8

Agreeing with Maxim, but adding more color:

  1. Optimize the model as people already suggested (beyond settings, also bear in mind that printing horizontally is faster than vertically, so try to make your prints shorter, use auto-arrange to keep pieces closer to each other, try to avoid supports, etc).
  2. Consider HF nozzles or higher layer heights (with appropriate nozzle sizes to support it). Just bear in mind that usually that stops yielding returns once you get to .6 HF. At this point flow rate and cool time becomes the bottleneck
  3. Try to use the hottest nozzle temperature you can without affecting quality (temp towers and oozing tests help you here). That will help maximize the flow you can get.
  4. Now find out what your real max flow is with a max flow test.
  5. For printers speed and acceleration, I tend to recommend the highest where you are still comfortable with the jerk, but don’t overdo it, as the benefits of this step tend to be very small. Your time is better spent improving the actual “layer speed” , which I don’t have a very objective test to recommend - I believe this one tends to be more filament and model specific

In fact, I’d be curious to see if anybody has a smart way to assess highest layer speed possible. Even though I’d also say that this is almost always constrained by max flow.

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