# Cutting from the Center of a Hole: Fusion 360

I’m still learning Fusion, but I worked out a method to “Start cut from Center of Hole”. Since this has been a topic, and I don’t believe I’ve heard this answer I thought I’d post it. It’s not as simple as a single button click, but here it is using a .125 hole as an example:

Lead-in sweep angle to 90 deg: this makes the cut move in perpandicular to the circumference.

Lead-in Distance: Sorry… we got math. But its simple math. Radius - 1/2 kerf. In the case of this example I am making a .125" hole and my kerf is .055". So the radius is .0625".
.0625 - (.055/2) = .040
or…
.0625-.0225=.040.

Voila:

Note: for small holes like this, I have to set the pierce clearance at 0.

2 Likes

I’m not sure what the benefit of starting at the center is, if you are not spiraling into the circle to eliminate the defect where the lead in changes direction. With a 90 degree lead in, the effect of the sudden change of direction is the same, regardless of the length of the lead in.

Here is what starting at the center of a circle looks like in Sheetcam.

3 Likes

Well… Dang Thought I had something there. It’s doable on larger holes by using a lead-in radius and making the lead-in distance 0. The problem is that the math changes for every size, so I can only do it by trial and error.

Edit: Ii think I got it. Using a 180 degree Lead-in radius, and no Lead-in. The equation becomes:

Basically the same equation as above but divided by 2, because we are not doing the whole length of the lead-n, but the radius of a 180 degree lead in.

4 Likes

That looks great.

1 Like

I’ll have to give that a try, THANKS!

1 Like

You can do it easier in Sheetcam using a drilling operation !!! Have used it alot !!!

In Sheetcam, you just check the box for “start at center of circles smaller than” and input a value for the maximum size circle that you want to start in the center of.

2 Likes

For all you sheetcam lovers, this was kind of focused on Fusion users. ie: is there a Fusion alternative to the start from center command. We know this exists in sheetcam.

2 Likes

SheetCAM and Fusion360 dilemma

Similar to

Coke and Pepsi

(Coke from the can on ice is the best BTW)

Fusion 360 is like the borg from Star Trek,it will soon assimilate all the off patent good stuff from all the other programs.

3 Likes

Coke on ice…. Yup!

1 Like

By reading your posts, I know that you know Fusion…hence I would push back on you coke v. pepsi.

Sheetcam and fusion are not similar at all. And inferring they are is a disservice for folks trying to figure this all out.

Sheetcam, looks like it rocks for getting going and cutting fast, but the investment in learning Fusion is well worth it. I learned a long time ago that basic products have their place but I soon want much more and realize I have to move on and learn the larger more complex software anyway.

Just this weekend I “bent” up some sheet metal fixtures in fusion…flattened them out…cut them on my pro and that is just for starters.

2 Likes

I hear you, I was just comparing thier CAM environments. (Being that was the tone of the context of this topic)

Being sheetcam has no CAD I can’t compare that.

I am definitely a firm believer in Fusion 360 for rapid product CAD/CAMdevelopment.

Currently sheetCAM does have far more detailed options when it comes to CAM but it won’t be long till Fusion ends up with many of these options.

Having a parametric link between CAD and CAM is amazing and it’s where Fusion 360 shines against all other competition.

3 Likes

@DRotblatt

I used this method on Saturday cutting some 3/8” holes in half inch plate. Worked much better than the standard lead in/out I tried on the first set of holes.

I had intended to take some pics but I already installed them. Plates were guides for a home made log splitter my dad was trying to get back up and running.

Thanks for sharing!

5 Likes

Thanks @DRotblatt I can’t wait to try this out!

SheetCAM vs Fusion, Coke vs Pepsi, Budweiser vs Molson Canadian (@TinWhisperer shoutout), Football vs Basketball, … damn testosterone just won’t let us agree on anything!

2 Likes

Well, at least one of those is patently obvious, eh?

2 Likes

can’t you just select the center of the hole using entry position, then give it a small lead in radius?

As far as I can see, the “entry position” must be on the selected geometry, and the center of the hole is not selectable.

1 Like

you can leave a sketch with center points turned on in the manufacture page, and select the point as your entry position

1 Like

I’ll give that a try, thanks.

Did that work?