My Engraving and Micro-Machining Solution

[Boyan Silyavski]

Great setup Nick. So is that the spring that could be seen at the picture? It would be great to see some more pictures from different sides. So you say the brass one/ the sphere/ slides on the material?


I have been thinking "how to" and "what belt to use" to make the reverse for milling metal using the 3kw spindle.

[magicniner]

Boyan,
The spring in the upper right is the one under the micrometer and is the key to pressure adjustment for engraving uneven surfaces.
The friend who sold me the mill has seen this arrangement and plans to use something similar to run a spindle at slower speeds with reduction driven by his chinese spindle.

I'll make a video once I get the equipment and post it here to show what can be achieved with a setup like this,

- Nick

[lucan07]

Vinyl cutter tool holders are similar, have adjustment for pressure are easily modified best of all available for just a few pounds on eBay. I watched a guy engraving wine glasses on a 4 axis with a diamond tipped bit apparently engravers have been using them for years. Have not tried it yet my vinyl cutter is in the back of my lock up with the toolholders etc. Just have a look at the Roland toolholder knock offs from china etc they tend to be alloy so will have limitations but for fine work look ideal.

[magicniner]

Vinyl cutter tool holders are similar, have adjustment for pressure.

I suspect you may have misunderstood the setup I've shown, what you're describing is "scratch" engraving where the cutter dances across the surface, it's good for creating fine lines, possibly a couple of thou deep, but is incapable of any depth, my arrangement allows deep cut "milled" engraving to a fixed depth on curved and uneven surfaces.

To maintain fixed depth you need to
(i) Follow the surface, (this is what the ball nose on the engraving spindle does),
(ii) Have precise control of cutting depth (this is what the micrometer adjustment collar on the engraving spindle gives) and
(iii) Apply enough pressure to ensure cutting to the full set depth, not skimming over the surface or allowing the cutter to lift (this is what the spring pre-load on the ball slide is for)

- Nick

[lucan07]

Thats what the guy was doing with the Roland tool holder no spindle running just dragging diamond tip and scratch engraving the glasses some really fine detailed work.

[magicniner]

You can use a "burnishing" cutter in a rotating spring loaded holder to get wider lines than diamond drag