Help Needed: How to Properly Create Knurling from Drawing?

[jambrozy]

Hello Design Team! 😊
I hope you all had a wonderful Christmas and New Year! Wishing the very best for each of you!

I’m having some trouble with the knurling shown in the drawing attached. Could someone explain how to properly create it? A designer from another company sent me a 3D SolidWorks file, but it’s a whopping 155 MB. That seems insanely large, and in my opinion, it shouldn’t be that heavy. I’m not sure where the mistake might be, so I’d like to try drawing it myself.

I’d really appreciate any help with this. Thanks in advance!

Take care,
Dawid

[g-andresen · Accepted solution]

Hi,

follow the process in the screencast and in the timeline of the file.

günther

[Drewpan]

Hi,

I am not surprised at all that the file is so big - just think for a moment how much physical geometry is in a knurl

that has actually been modeled. All of those tiny pyramidical structures. The worst part of it all is it was done for

essentially nothing.

Why do you need to actually model a knurl? You want the appearance of the knurl in the fabrication drawings so that

the machinist can change to the knurling tool; you want the Tool Change G-Code for the knurl in the CNC code so

that the CNC machine can apply the knurl. What is the purpose of modeling the knurl again? Even the Design

Department will only use the appearance of the knurl in the advertising and production documentation.

Knurling is not usually modelled for the above reasons and because of the huge hit on performance fusion will take

in tracking all that stuff within the model. It is the main reason why there is an option to model threads or not. There

is an enourmous amount of calculating that goes on under the hood of fusion and this stuff just kills performance.

If you are lucky enough to have your own Server Farm you might not notice.

If you are desperate to model a knurl then it is easy to do. Scale down to the sub-millimeter view and create a tiny

pyramid or whatever shape you want on the surface you want the knurl. Use Rectangular or Circular Pattern tool to

make the 10s, 100s or 1000s of structures. Go and make a coffee while fusion kludges through all of the calculations.

Go and make another coffee while you wait for fusion to re-calculate everything because it wasn't quite "right" and

you had to change it. Repeat as many times as required. After you have done this make sure to have a book handy to

read every time you make an update to the file from now on. When you are finished the model - look at it proudly

and then delete the knurling as the CNC machine will go into meltdown trying to cut it or the machinist will just

laugh and change to the knurling tool.

Cheers

Andrew

[etfrench]

The lazy man's method is to use a triangular coil:

Cut the coil from the cylinder, then mirror it, and finally circular pattern it.

p.s. Sorry @g-andresen I didn't watch your video until after I posted😐

[jambrozy]

Thanks to all of you for your answers.

@Drewpan, I need to clarify something.

The only reason I modeled this knurling is that I need to machine it on my 5-axis CNC machine. Everything you wrote is true—I drew this knurling because I wanted to test if the manufacturing module in Fusion can generate toolpaths for this machine.

I have a good computer (i9 12th gen, 32GB RAM, RTX 3070 Ti), and after waiting around 40 minutes, it’s still working on the model. So yes, you’re absolutely right. However, the file size is about 1MB. In comparison, the original file I received from the designer in SolidWorks was 155MB, so the difference is enormous.

Now, I’m wondering how to create a line sketch with the knurling pattern and use those lines in the manufacturing module. Any ideas? 

@g-andresen thanks for your video, now I can do that by myself ! 🙂

[g-andresen]

Hi,

sorry, I forgot to attach the file  (8,42MB).

1. Here it is.

2. In the “optimized” version, I made a few more changes to fine-tune the pattern.

günther

[etfrench]

Draw a horizontal and a vertical line in a sketch. In the Surface workspace use the Sweep command to create a helix.

The helix can be used to split a face on a cylinder which can be used in Manufacturing.  You can also project the edge into a 3d sketch.

[jambrozy]

Interesting, when Fusion calculate my knurling i will check this solution, thanks @etfrench ! :))

[Drewpan]

Hi,

My only confusion is that knurling is usually done with a knurling tool which is typically some kind of roller with a

pattern in it. All you really need is a Tool Change G-Code and some kind of Tool Offset to get the depth correct. Other

that that it is the tool that makes the cuts. Strictly speaking, a knurl is not really a cut, it is a displacement. The "cut"

is made into the work piece that literally makes a groove by pushing the material out of the way. It doesn't actually

cut anything at all. The resulting knurl is a little bigger than the original diameter of the work piece as the material

"pushed" out of the way is displaced upwards as the tool imprints downwards. You could use a cutting tool to create

the knurl by cutting but usually a knurl is either decorative or functional for gripping so it isn't really a critical thing.

I would never have thought to actually model it and program a CNC to cut it.

Cheers

Andrew

[g-andresen]

Hi,

---

@jambrozy  schrieb:

The only reason I modeled this knurling is that I need to machine it on my 5-axis CNC machine.

---

A picture to @Drewpan  comments.

günther

[etfrench]

Actually there are two types of knurls, formed and cut.