Nozzle Clearance Diameter setting in Fusion 360

[dbrub2]

I found the following definition in the Fusion 360 documentation. “Nozzle clearance diameter - The diameter created from the initial cut when the Water, Plasma or Laser is first turned on.” I assume this is the diameter of the pierce hole. I have three questions

1. How does this affects cutting, e.g. how does Fusion Manufacturing utilize this parameter in creating the tool path and what happens if this parameter is incorrect?
2. Since the pierce diameter is influenced by the pierce delay should you use an average diameter here?
3. Langmuir Fusion 360 setup videos say that for Pro to use 1” for this setting…why?

[TinWhisperer]

I thought of the nozzle clearance diameter as being the zone around the nozzle that fusion 360 keeps the torch away from hazards while calculating tool paths.

Right or wrong I had been setting mine to 1.4 with the 180 torch.

After dinner I’m going to have to fire up fusion and check for sure.
I assumed hazard clearance for the torch head was the reason.

[TinWhisperer]

Here is a context screenshot for anyone reading along.

ANSWERLESS AUTODESK THREAD

[dbrub2]

This issue has come up because a fella that subscribes to my Youtube channel said that he was having trouble with holes, slots, etc. being undersized and that after he changed the nozzle clearance diameter to 1/16" his cut sizes are now accurate!!!

Here is the link for the fusion 360 info on the nozzle clearance diameter and from the pics in the manual the example has the nozzle clearance diameter set to twice the kerf???
That is a whole lot less than the 1" suggested by Langmuir!! You may have to copy the link and paste into your browser.

https://help.autodesk.com/view/fusion360/ENU/?guid=GUID-AEF979DA-D97A-4275-89AF-976D7C8428A8

[TinWhisperer]

here is the clip from Autodesk.

I have a hard time understanding that sentence.
“Nozzle clearance diameter - The diameter created from the initial cut when the Water, Plasma or Laser is first turned on.”

the picture above shows the default setting as kerf as .08 and the nozzle clearance diameter as .16 .
the tip of that default waterjet is about .16 is the default drawing. the skinny part anyhow.

I set my to 1.4in, run almost hypertherm book setting and get very decent results.

but now i am wondering and going to have to dig some more.

interesting topic.

[dbrub2]

I’ve posted a question about this on the Fusion 360 “Manufacturing” forum but so far so replies!

[TinWhisperer]

Langmuir tool setup video.

about 1:40 they briefly talk about it.

They talk about tip up avoidance in conjunction with the keep nozzle down feature. which makes sense for a machine with two axis. (Crossfire)

But then he says also use 1" with crossfire pro with no further information but they’ll talk about the torch height controlling video later?

I’ll see if I can find that torch height video maybe it gets into it some more.

[sloanstar]

Any further updates on his topic…Where is Langmuir on this topic?

[dbrub2]

Nothing from Langmuir I’m afraid!

[MRudisill]

Not 100%, but having done a lot of CAM work, I would guess that that nozzle clearance diameter is factored into the tool pathing. Say you have a small hole and your lead-in distance puts your start right on the main cut path. Well if your starting point for the lead-in is right on the path for the circle, but the pierce diameter is larger than your kerf, that would leave a notch in the hole you cut.

Sorry if that is hard to visualize.

[Bigdaddy2166]

Set it to 1 inch…

[Joe103]

What is the name of your YouTube Chanel ? I’d like to look it up.

[JPep]

I don’t see where this setting makes any difference at all. If it does, what effect does it have?

[TinWhisperer]

I’ve never been able to find a definitive answer.
I’m on the AutoCAD form quite a bit and I haven’t seen an answer that make sense yet.

I believe it’s to let fusion know what some of the torch geometry is so it can calculate tip avoidance.

I think it’s main use is for CNC machines without a z-axis so I can develop tool paths that avoid areas with potential tipups.

In the langmuir instructional videos it’s used in conjunction with the keep torch down feature ( this is so it doesn’t raise between cuts)

This is as close as I’ve been able to surmise.

[dbrub2]

D & N Custom Creations D & N Custom Creations - YouTube

[Joe103]

ok thanks I had already found you and you have a great Chanel with fantastic info, keep it up!

[dbrub2]

thx for the kind comment

[BowmanRanch]

Can anyone update this? Looks like fusion 360 changed some stuff… Is “Nozzle diameter” the same as “Nozzle Clearance Diameter”. I believe they are different… but don’t know where Nozzle clearance diameter was moved to…

[ds690]

It’s really an unimportant variable. It seems like another holdover from milling, where something like this is necessary to prevent crashes.

At one point, fusion screwed up an update and the simulation was showing the nozzle diameter as the kerf width. People who wanted an accurate simulation had to set it to their kerf width.

[Kwikfab]

Nozzle diameter in my experience is an irrelavent field, just like pierce delay, amp setting, air pressure, etc.

The kerf value is the one that matters.