About: ABOUT text engraving, logo engraving, patterns engraving, on wax model, on master, piece by piece.

Engraving of text, logos and patterns



The wax printing machines (rapid prototyping) of various types, the laser engraving machine (on silver master for imprint in the rubber/silicon mold), or the engraving piece by piece are not having the same resolution.
Depending on the stage at which we choose to make the engraving the minimum line width or distance between 2 lines are not the same.
When considering to engrave your jewelry you must take this fat in consideration in the level of detail of your logo, the choice of the font for your text, etc.




Engraving at 3D Design stage :
loss of detail:
1) The wax or resin model will be printed from that file by the 3D Printer.
2) Then casting of the wax into metal to becomes a master
3) Filling the master
4) Then fabrication of the mold
5) Then casting of the final piece
6) Then filling with sandpaper
7) Then polishing and plating

There is a loss of detail at each stage of this process since the engraving is already there from 3D Design. It will NOT be as sharp as an engraving made by laser on the master.
Nevertheless engraving in 3D file will be the best option for large text or large pattern because the loss of detail becomes negligible and the " floor of the engraving " will be flatter and will present a better surface than a costly laser engraving on the master.
* For large text or large patterns we might want to apply a sandblast effect on the surface at the bottom of the engraving to create an even texture. The reason for this is that deep engraved areas are difficult to reach with hand tools for clean or polishing without damaging the outline of the engraving.

Text Restrictions:
The text should be big enough. If the size of the text is small then avoid fonts that are too thin, we might have to use a simple font like "Arial".

Pattern/logo restriction:
RP printing Machine
(3D intricate designs presenting details in 2 or 3 axes):
- The smallest line engraved or distance between 2 lines should be 0.35 mm to obtain sharp text or drawing.

CNC printing Machine
(Rings with details on the outside only or object with unidirectional details 1 or 2 sided):
- The smallest line engraved or distance between 2 lines should be 0.35 mm to obtain sharp text or drawing.

Solid scape printing Machine
(Economical for very flat object, becomes very expensive on high objects because very slow) :
- Very effective machine for portraits, textures, and detailed reliefs.
- The smallest line engraved or distance between 2 lines should be 0.15 mm to obtain sharp text or drawing.
- The restriction is only for text or thin sharp lines and is not due to the resolution of the machine but more related to the mold and to casting. A deep thin line will have its negative on the mold represented by a thin raised border/wall which than break after a few injections. The wax might not reach or fill the entire gutter in the mold and same for the meal at casting which will result in incomplete casting, line interruption or line disappearance at polishing stage.
- No restriction for textures, portraits and other detailed raised or recessed reliefs apart from the fact that polishing will reduce the level of the details on Silver more than in gold products. So we might in certain cases avoid polishing too much, leaving the deepest cavities unpolished which can actually enhance the definition and contrast in a positive way.

 

Cold Silicon transparent Mold
For best result in casting very detailed lines, text or textures we might want to use a Cold Silicon Mold.
Such molds are created directly from the printing wax/resin so we will jump the Master (casting and cleaning) to reduce the steps and the losses of details.
- Such molds are a little more expensive (about 50%), but we have saved the step of the master in the costs..
- Cutting and opening the mold will most likely break the wax (which does not happen when opening a mold from a master in metal). So most likely we cannot re-adjust details on the wax for further corrections after the mold is made.
- No correction can be made to the master (because no master) meaning that in case of imperfection we have to reprint the wax from 3D (additional cost) and redo a new mold (additional cost).
- The Cold Silicon Molds have a shorter lifetime even if left unused (6 months - 9 months). Production of multiple injections of hot wax will accelerate this effect.

Impact on cost:
- This engraving is done only 1 time from the wax model
- Tracing and raising into 3D relief is included in 3D Design Cost.
- If the tracing in vector file (file with *.ai extension, Illustrator) is provided by the customer and is technically valid (line thickness, spacing, no cross over and closed lines only) then the 3D Design cost will be lower.


Engraving By Laser on the master :
loss of detail:
1) Fabrication of the mold
2) Then casting of the final piece
3) Then filling with sandpaper
4) Then polishing and plating

As we can see there are less steps causing losses of details than to have the engraving included in the 3D Design..

Text Restrictions:
The text should be 1 mm minimum. If the size of the text is small then avoid fonts that are too thin, we might have to use a simple font like "Arial".

Pattern/logo restriction:
The smallest line engraved or distance between 2 lines should be 0.15 mm to obtain sharp text or drawing.
If very fine the mold will not be able to produce many pieces and the master will be used to produce more molds as the production goes.

Impact on cost:
- This engraving is done only 1 time from the wax model - We must prepare the Illustrator file with continuous lines and closed areas only, to be passed to the engraving laser machine. This work is charged separately on case by case basis depending on the design provided. We can extract this filename.ai from a 3D file provided. We have to retrace it if an image (jpg) is provided. - The engraving has a cost starting at 10 USD or more depending on the size of the logo/text


Engraving by laser on each piece produced :
loss of detail:
1) Polishing and plating
There is fewer losses of details.

Text Restrictions:
The text should be 1 mm minimum to be readable. Any font is possible and the resolution can go as far as 0.1 mm or less.

Pattern/logo restriction:
- This is the sharpest method and a line can be 0.1 mm or less
- If very small the polishing/plating could alter the engraving and we could decide to engrave after the polishing on non-plated jewelry. It is also possible to engrave after the plating on silver and white gold jewelry plated with rhodium.

Impact on cost:
- Adding cost on each piece
Ex : Running 6 digits Serial numbers 999999 will cost around 1 USD per piece in lots of 100 pieces. .


Hydraulic Stamping:
loss of detail:
1) Light filling with fine sandpaper
2) Polishing and plating

There are few losses of details but the resolution of the details is not great from the beginning..

Text Restrictions:
The text should be 1.5 mm minimum to be readable.

Pattern/logo restriction:
- Can be used only on flat pieces with a thickness equal to 1 mm or below

Impact on cost:
- Adding cost on each piece for engraving
- If the jewelry is also made by stamping the production labor cost is reduced a lot.
- The cost to make the stamping head will start at $150 and can go up to $300 for large pieces like bangle.
- If there is cutting and engraving then each operation requires a different head.
- We recommend to start fixing the product (less precise) made by casting and invest in the stamping tools only once the product is really correct in all aspects to avoid paying for multiple head while modifying/optimizing the product..


Hand Stamping / Hand Engraving :
Text Restrictions:
The text should be 1.5 mm minimum to be readable.

Impact on cost:
- Logo or few letters (Cost for making the stamp is around 50 USD )
- Serial number: Letters or numbers applied 1 by 1 by hammer stamp is cheap but will not be perfectly aligned.
- For manual Engraving on masters or finish products we will provide the pricing on a case by case basis.


CNC:
Impact on cost:
Very costly method to put the tooling in place for machining a piece with this method ($500 to $1.000).
Usually it can be used in a less costly manner to engrave patterns on the master only.
It is also used to engrave patterns very shiny and sharp directly on gold rings and bracelets, but the production should be important enough to justify the costs. Usually done in specialized factories.

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