Precise cutting/engraving repeatability issues - Nomad 3

Hi All,

I’m making several small discs with a pattern in brass.

I made a jig:

For the pattern, I run a toolpath using the Mcetcher.
Then, I run a simple contour toolpath to cut out the disc. The brass
plate stays in exactly the same place in the jig and has no wiggle room at all.
To ensure this I use the super glue/painters tape solution.

The problem is either the pattern or the contour toolpath doesn’t
cut in exactly the correct place… it’s off centre, leaving a border on one side
and none on the other.

I’ve scrapped a bunch of pieces and just can’t figure out how to make sure they’re
cut properly aligned.

Mirabelle.c2d (544.3 KB)

Hmmm. A bit of a mystery.

Some random thoughts:

(1) if you use mcetcher to on the same outline as the contour, does it do the same thing or is it better?

(2) is the offset the same on every part or is it somewhat more random in nature?

I do know from my experience with small surface area parts the painters tape/superglue hold down will squirm a little under pressure but not release. Not sure that is happening here.

2 Likes

Phil - thank you for your input.

I’m not entirely sure I understand what you mean about the Diamond drag bit doing the same as the contour? The offset, I think, tends to be polar so north/south.

As for the holding method, I have used this for a long while and have never had any issues, besides, the jig holds it very steadily without the slightest wiggle room.

Gunter

It would help those trying to help if you were specific about your holding method. I think Phil means if you were to do a trial run where, after doing the engraving part, you would perform the contour “cut” with the drag bit instead of a mill. This might help isolate the issue.

You say the offset “tend to be” directional, can you be more quantitative? It’s important to know whether it’s the same in all trials or not.