Acrylic - Engraving bit versus a Drag bit - I need a 101 lesson

I am about to start my first Acrylic project, I have wandered through the various post on this forum and learned a lot ! I expect to use the Contour and Texture tool paths in CC ( not Pro ).

What are the basic questions I need to ask myself in deciding which bit type to use ?
I understand the bit included angle effects the results.
I know the density of the design within a given area should direct me to some point.

While not an either/or, I do discuss using a drag bit at:

A drag bit is great when you are doing small fine work and doesn’t require much time to learn. However, it just scratches the surface and does not give much depth in appearance. Depending on what type of Acrylic you are using and your skill level in my view cutting the acrylic with the appropriate bit, speed, and feed is an art and a better look in most cases. Generally just cutting through acrylic of any kind is easy but engraving can be frustrating as it likes to melt. Even after you think all is well and you have completed several pieces all of a sudden you get a gum up and you have produced garbage. You should search further as this has been discussed many times on this forum.

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The Acrylic is Glowforge proof grade. No idea if that is alright. Found it at Micheals.

It appears to be cast which is much better cutting than extruded (less chance of melting). You will still create scrap in the begining so I would try to find some remnants to practice if you plan on cutting.

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Once in a while I actually don’t make scrap, every dog has his day.
Tally ho !

First engraving. This dogs day is today ?

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I had to try a drag bit on the acrylic. I used the 90 drag bit with default parameters from CC.
The results of the etch were good, I just picked the wrong photo to try out. Grand daughter in full thought while sketching.

Starting with the original picture, using Paint.Net I used the Effects > Artist → Ink sketch process.
I then used InkScape to trace the image to SVG entities.
I then used CC to create the paths.

Given that edges are the key to the presentation, organic surfaces are tough.

Here is another example ( which I have not cut yet ) that may work better.

In Paint.net
Crop and brightened to get more detail.


Used the Ink effect

At this point you can use InkScape or CC to tract the image.
It is trial and error for me to get a result I think will work.
Here is a PNG export of the SVG file. I have not cut this as yet.

I need to refine this process a bit more.

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Your paint.net link appears to be a dead link

This appears to be the correct link: https://www.getpaint.net/

The “Paint.net” link was auto generate by the web site.

Refined the process work flow.

Paint system
Crop original color image as required.
Adjust Contrast in color image to reveal detail in dark areas.
Run the Effects → Ink sketch
Save as PNG

Inkscape
Set document to inch units.
Import PNG file ( Do NOT scale )
Trace the image
Save the SVG

CC
Open SVG
Set stock size
Scale and translate.
Generate Tool path

Notes:
I am not sure if scaling and translate maybe more efficient in InkScape.

:ok_hand: :+1: looks really great!

Get acrylic cast, must have a paper protection layer (brownish not transparent!).
Best router bit is a “O-flute” type. Don’t ask me why that name. But those are specifically made to cut plastic: smallest available surface to rub on the plastic, just one “tooth” on the tip. And: to reduce heat on the bit cut with the lowest possible router rotation speed, and the fastest motion of it through the plastic to move away the heat from the site of cutting as fast as possible. Yes, needs some experimenting, and will cost you few router bits if you use very small ones. I did not try a drag bit yet.

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Here is an updated input image based on the above process.

It is definitely faster to scale/translate/rotate in Inkscape than in CC.
There are 360K nodes in the SVG file.

The density of the little features looks like noise, so I am going to cut this on as big a piece of clear acrylic that I can find on short notice ( 20 " wide" ) to spread the noise out.

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