A monogram and engraving project

[simsmj]

The initial monogram design didn't take that long, only a couple of weeks on and off to make the 'in your face' Dragon 1, and a lot of that was mostly about tweaking the wings' phalanges. It was engraved before Christmas on my last blank head. I ordered more blanks from Etsy, and they were going to take several weeks to turn up, so I had the time to experiment with other variants. Some of the time was spent making simulations in Xara and Xara3D, often as wax impressions. One of the reasons for using Xara3D was to evaluate how well a shallow relief shape would be seen in different colours and shades of wax. The clear answer was that mid-toned colours work best, because they allow a wide enough contrast range for well-defined highlights and shadows. I also concluded that if it wasn't too much hassle, a two-colour wax impression would be nice. I haven't got the knack for single colours yet, so two will have to wait!

I did have a slight concern that an 'in your face' dragon being a monogram might get submerged, and that was what lay behind the Subtle Dragon track. But as a unique personalised image based on my initials, I think Dragon 1 still works, as I don't really think the resemblance of Dragon 1 to a monogram is that obscure that most people looking at it for more than a brief glance wouldn't notice it. Arguably Dragon 2 where the wingtips didn't hit the floor and the 'J' perch didn't have an obvious curve at the bottom, could make that a little harder to notice.
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The Subtle Dragon didn't take long at all to draw, only three text characters converted to shapes which needed only minimal editing. There were only two shapes to engrave having integrated the 'J' into the 'M', but my toolpathing app can only handle a single depth per shape, and in the wax I wanted the dragon's tail and the 'J' to swap over in the 3rd dimension so the dragon's tail appeared behind the bottom of the 'J's curve, while keeping the rest of the dragon's body in front of the rest of the 'M'.

So I needed to hand edit the gcode output from the toolpath app to get the middle leg of the 'M' to slope downwards into the brass, but it took longer it should because I'd forgotten that the toolpath app worked in centimetres, but the gcode output was in millimetres, so my search for the coordinates I'd recorded to identify them in the gcode for the relevant nodes/paths to tweak weren't found until I realised I needed to convert them to mm first!

As soon as I did they all popped up and the editing was then completed and checked in a gcode visualiser in under an hour, and the engraving was done the following day and went perfectly.

The subtle dragon took just over an hour to engrave, the other two took about an hour and 45 minutes each because their engraved area was larger overall. There is a rule of thumb when using a cutting bit, which is that the depth of any cut shouldn't exceed the radius of the tool bit, so to cut deeper you need to do it in stages. Because my cutter was only 0.5mm in diameter, I elected to make the step cutting depth only 0.2mm to reduce bending stress on it, and in Dragon 1 the deepest shape was 1.0mm down from the surface of the brass, so that shape was 'coloured in' with the bit five times over, dropping 0.2mm per pass. The shallowest was 0.6mm, so needed three passes, and a set of intermediate shapes needed four passes each.

[Egg Bramhill]

Following your post Mike I've looked at several videos re creating engraved seals for use with wax seals. It's a facinating subject. For one club I used to run we had a similar seal that when used embossed the seal on a paper documant.

[wizard509]

Following your post Mike I've looked at several videos re creating engraved seals for use with wax seals. It's a facinating subject. +1.

+1

[ss-kalm]

That looks excellent Mike. Brilliant work!

Could you 3D print a seal rather than engraving it. To test ... Obviously once perfect, engraving metal is better and much longer lasting, but for development purposes, would 3D printing work?

[simsmj]

Egg; I like the idea of an embossing stamp, but does that not require two interlocking stamps, and possibly shallower relief? I haven't looked into that, so that might be a silly question. It would certainly be a much less messy business.

ss-kalm; Once you have a suitable .stl file, you could print the stamp head in something that had enough physical integrity not to break. I think the weakness would be when levering the stamp off the wax. I've found that it can take some careful effort to release the stamp from the wax once it has cooled down. Layer separation can be a problem in 3d printing. Also the temperature of the molten wax would be similar to the melting temperature of the stamp itself, so distortion might be a problem too. I can see it being a finicky thing to get right, but plenty of people have been playing with 3d printers at a pretty deep technical level for some years now. In many ways it was the enthusiastic well-informed and innovative amateurs working in garages and back bedrooms for years with home made equipment that brought 3d printing to the masses. My CNC milling machine was itself designed by someone in a garage/basement/workshop at home, who eventually developed a thriving business selling kits and pre-built CNC milling machines. So it's entirely likely that someone has already done this.

I think you can already buy 3d-printed seals with sticky backs, and also actual wax seals with sticky backs? I have a 3d printer, which I recently bought, and I've only used it once so far, my son wanted a bust of Dante Alighieri for which he'd downloaded a .stl file. When I first opened the file up in the computer, I thought the file was empty, but noticed a tiny speck at the bottom of the screen. That was the model! It was only 1.3mm tall! But being a 3d vector file, I just scaled it up to about 11" which was the size my son deemed suitable, and printed that. But being my first time using it in earnest, I tested the model out at 5cm size, and that turned out well. The 11" one took about 4 hours from memory to complete, and it looked fine.

OK, that last was slightly off-topic! But I was going to say that it did occur to me that printing a seal itself would be pretty easy, and it could be made to look like an embossed blob of wax, or just be a clean disc with the emblem raised upon it. It would only require perhaps about five to ten layers, without looking into it. It would also be possible to print in wax itself if it had suitable properties that would allow it to be rendered into a filament that could be fed into the heated printhead nozzle with a suitable temperature.

Hah! Just googled it, and wax filament is a thing. I need to look into this further!

Edit, just checked my notes, the 11" bust took almost 26 hours!

[wizard509]

Utterly fantastic, I love your work.

[simsmj]

Why, thank you!

[gray]

That is amazing looking work.