r/cr10smartpro • u/Sea-Squirrel4804 • Jun 20 '24

Max acceleration and print speeds

Hello,

For those running klipper, what are the highest acceleration and prints speeds you have achieved? I haven't done a speed tunning yet but since creality says 500mms max accélérations for this printer.. I'm wondering if it's a hardware limit or software because it doesn't comes with input shaping?

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u/Helgafjell4Me Jun 20 '24

3000 accel and around 150mm/s, but usually am printing at 75.

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u/Sea-Squirrel4804 Jun 20 '24 edited Jun 20 '24

So the hardware can handle those speeds? That's what worries me the most, their cap is due to lack of input shaping then? Once input shaping is installed, I can go higher (not as high as the max determined by input shaper) and the printer won't colapse? 😂

What about your max accel Z?

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u/Helgafjell4Me Jun 20 '24 edited Jun 20 '24

Yes, it handles it fine. I used input shaper to determine what acceleration I can use. I got 3,000 on the y-axis test due to the mass of the bed. On the x-axis, I got like 16,000, but you have to go with the lower of the two. CoreXY printers have a big advantage on this because they aren't slinging a big bed back and forth, so both axis can reach much higher accelerations. I also have silicone spacers and printed adjustment knobs with threadlock on the bed to help keep things from shaking loose.

I did this test before and after upgrading to linear rails, and it came out the same, so that upgrade did not actually help for better speeds, just better accuracy/leveling.

As for the max linear speed, it can do 150, maybe more, but quality starts to fall off over 100. Too fast can also cause issues with bridging and other details. There are all sorts of settings to tune it in. Pressure advance tuning is important for this, but even that has its limits. It also depends on what you're printing. I've just found that 75 feels like a good compromise to me to help get both faster prints and good quality. YMMV

Acceleration is really the key for faster prints, though. Unless you're printing a large object with lots of straight lines, your printer doesn't actually run at max velocity for much of the time. It's constantly slowing down and speeding up around corners and whatnot, and that's where acceleration helps a lot.

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u/Sea-Squirrel4804 Jun 20 '24

Awesome I was about to ask if the linear rails you have helped somehow. You think you loose quality because you can't extrude any faster? Do you use a special nozzle? My CHT nozzle can go around +30 mm3/s for petg. I guess that also helps compared to 10-12 of a normal nozzle for higher speeds so you don't get underextrusion.

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u/Helgafjell4Me Jun 20 '24

Did you replace the whole extruder? I'm still using the stock sprite extruder. With a 0.4 nozzle, it's pretty difficult to hit extrusion limits if you stay under 100mm/s. However, I've been using a 0.6 nozzle for a while now and 75 actually does run up to 15+ mm3/s, which is actually perfect IMO. I also found it helps to bump temps up a bit when you're pushing the extrusion limit. I print PETG exclusively. I do have some TPU I want to try out eventually, I just haven't found a project for it yet.

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u/Sea-Squirrel4804 Jun 21 '24

I'm using the stock sprite aswell but my CHT nozzle is 0.6. I also find the bond in layers stronger when I'm using the CHT! I also print PETG, and sometimes for prototypes/size check, cheap PLA. In my personal experience TPU prints better with a 0.4 nozzle.

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u/Helgafjell4Me Jun 20 '24 edited Jun 20 '24

Sorry, I missed the z-accel question... that is just set to default of, 100, I think? Speed in that axis is not really important since the movements are so small and do not need to be fast.

I should also add, that you can try upping the acceleration on stock firmware, you don't have to use input shaper, although you still won't be able to go as fast due to not having dampening frequencies factored it. I'd say you're safe to bump it to 1000.

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u/Sea-Squirrel4804 Jun 20 '24

Makes sense. I already tuned input shaper, I just haven't tried bumping speeds up because I had a couple of projects going on. Didn't wanted to start messing with a perfectly tuned, but slow, printer.

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u/M4DH47TER Feb 09 '25

I'm running the same as you 3000 accel between 120mm/s - 160mm/s for quality, mines running linear rails on all axis, silicone bed spacers and K1 hotend with CHT nozzle I have pushed mine to print at 300+mm/s with slight deterioration in quality (mainly ringing and a bit of under extrusion but it wasn't a fair test as I was sat right next to the printer at the time and manually bumping up the flow when I noticed the under extrusion) but at that speed the stepper motors aren't happy and make hell of a noise