4th Axis Engraving Questions

[TZ250]

A couple of months ago, a member here (Jeff Peaslee?) made a really cool business card holder.

I'd like to make a similar version. Viewed in the XZ plane, it would have two 'mountains'. The engraving was on top of that, viewed on from the XY plane.

With a ballnose endmill, why couldn't I wrap the engraving over the top surface? That would require XYZ to move simultaneously. I was told that a 4th axis is required, but I'm not sure about that.

So, do I need a 4th axis for this type of engraving?

(I know my description is somewhat vague.)

[JPMach]

You can see the pic of my Cardholder on the examples page of my website www.jp-machining.com

I did it with a 3 axis Haas cnc mill, no 4th needed, not sure how a 4th would really help either. I used a small ball mill for the engraving. I think it was on the order of 1/32" or so. A regular v-shaped engraving bit won't work as it needs to be able to cut on the sides and the tip, so a ball mill is in order.

JP

[TZ250]

no 4th needed, not sure how a 4th would really help either.

Thank you, Mr. Peaslee.

That makes sense to me. I told that to the person that was sure that a 4th axis would be needed.

Now, I have some learning to do! My new software is on order. That will be my first project for true 3 axis milling (as opposed to 2.5 Axis).