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slic3r / Slic3r

Open Source toolpath generator for 3D printers
https://slic3r.org/
GNU Affero General Public License v3.0
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Input fan CFM instead of percent? #1369

Closed JoshMcCullough closed 8 years ago

JoshMcCullough commented 11 years ago

Instead of inputting the % min/max of the fan for cooling, what if we could specify the CFM of the fan and have Slic3r determine how much power to provide based on the CFM?

It seems much less arbitrary than just setting a percent. I've used three different types of fans on my printer for cooling the print: 80mm fan, 40mm fan, larger server-grade powerful 40mm x 40mm fan - the one I use currently.

With my fan, I set Slic3r to min=25%, max=40% because anything higher than that would cause some extreme cooling of the print and nozzle. But I'm just guessing at those percentages, would be awesome if Slic3r just figured it all out for me. :)

alranel commented 11 years ago

How would Slic3r know the properties of your fan, which I guess are needed to convert a CFM into a PWM?

JoshMcCullough commented 11 years ago

Maybe I'm over-simplifying, but if I told Slic3r that my fan is rated at 26cfm, couldn't Slic3r then adjust the voltage to the fan based on some simple algorithm? Slic3r, in theory, knows "how much cooling is needed" since it already decides what % of power to apply. This is just adding another variable, the throughput of the fan.

thecrazy commented 11 years ago

I have never seen a program let you set your fan speed in CFM. For every different fan you want to use you would have to provide slic3r with complete specs of the fan and not just its cfm rating, you would need to establish a graph of its cfm rating at every rpm increments cause its acceleration curve is most likely not linear.

I dont see how knowing the speed in cfm would be usefull anyways, even if you had the info, what would you do with it? Most ppl couldnt use the same cfm setting in their prints unless you all have a controlled print environment, same ambiant temperature, humidity etc...

JoshMcCullough commented 11 years ago

My thought was that 100% = 100% CFM...but true, the fan speed wouldn't be linear...