Fading memory - Vanguard (mechanical) engraver for uneven surfaces?

[John Noell]

I remember seeing an engraver for sale that went for about $10,000 used, and would do irregularly uneven surfaces. It did not use a spring-loaded engraving tip but it somehow sensed distance to surface and automatically adjusted Z height so the engraving depth was consistent. I thought it had Vanguard in the name. Can anybody steer me in the right direction? (I mentioned it in passing to someone who owns a pearl farm and they are interested in engraving their pearl shells with it. I used to enngrave their shells with my 45 watt Epilog before I retired but they always wanted more depth.) Thanks!

[Mike Null]

It is possible that you are describing a Newing Hall engraver where the spindle is air activated and can handle irregular surfaces within reason.

[Tony Lenkic]

John,
Vanguard series of engravers are New Hermes (Gravograph) machines.
Uneven surface can be diamond drag engraved by all machines equipped with automatic surface sensing.
Check out this clip.............https://www.youtube.com/watch?v=2ejg61a-hFE

[John Noell]

... irregular surfaces within reason.
Ahh, and the big question is, what does "within reason" cover? These shells are up to 6" wide and they want to engrave to a depth of at least 2-3mm.

[John Noell]

Thanks Tony. They want some pretty wide designs cut. Can diamond drag do that? I was thinking something with a rotary spindle would be best. No?

[Tony Lenkic]

It all depends on application it may be more attractive to diamond engraved.
You can get wide engraving with diamond drag using multiple line fonts. In case of graphics with closed objects you can hatch fill to get it done.
Awards plates look very nice and many people prefer appearance with diamond engraving process.

[Mike Null]

With the Newing Hall you can get about 3/8 of an inch or so in variable contours. I would be concerned about the diamond because of the brittleness of the shells. With the Newing Hall you can use the rotary spindle but if the diamond will do the job then that's what I would use.

[Kev Williams]

I've owned 3 NH Vanguard engravers for over 20 years, and if the machine in question "did not use a spring loaded tip", then it's likely not a New Hermes machine. The only way they CAN follow an uneven surface is with a spring loaded spindle. Even with them, they only have 3/16" (.188"/4.77mm), so if the surface varies more than that, there would be a lot of stop/re-zero/restarting going on. And depth gauges and spindles can only follow a certain amount of 'uneven'. Too much variance at once on an 'uphill run' and instead of the spindle raising, it can get caught- if this happens, one of several things can happen: the machine will be immobilized until the next movement in another direction (at which point any further engraving will be out of position); the machine will push the part out of its clamp; the part may break; part of the spindle may break...

And engraving shells 2-3mm deep? 3mm is an 1/8" deep, are the shells even that thick? Engraving virtually ANYthing that deep is difficult at best. And any depth past "superficial" can't be done with a diamond, a rotating cutter is necessary.

There may be a machine out there tracks the surface with a laser and adjusts the Z-stepper as needed, but I wouldn't know the first place to look I'm afraid!

[John Noell]

Thanks Kev. And yes, some shells are indeed that thick. There are some artists here in Fiji who hand carve them to that depth. (They come out beautiful!) I think the engraver I read about did something to track the surace and adjust Z axis on the fly. It had small x-y dimensions but able to engrave on uneven curved objects. Now it has disappeared into the dark shrouds of lost memory. :)