I am trying to carve out some letters in acrylic and this is the finished look I am getting. What do I need to change to clean up the bottom?
1/8 upcut one flute
611 on speed 1
1/8 upcut one flute
611 on speed 1
Do you have an example of the look you’re going for? if the desired result is a smooth, clear finish, then some post processing like hand polishing may be necessary.
I just didn’t want to see the bit/cut path/lines
So it’s not a bit choice that’s wrong? it is set up right?
How are you mounting your acrylic down??
The Spiraled ‘O’ Flute: Ideal for Acrylic
Thin material may be lifted by the bit during cutting – this is a common cause of cracking and breakage.
Using double sided tape, adhesive spray, or a vacuum hold down will reduce flexing of your material during cuts. Take extreme care when cutting very fine and thin plastics. Double sided tape is a cost-effective method which proves to be very reliable.
it’s half inch acrylic. still should tape it down?
Its the tool marks I want to get rid of
First, I would remove the film from the side of the acrylic that you are cutting.
You can set the initial carve to about 0.005" shallower than the desired cut. Then, make a new workpiece that is full depth and a DOC set to the full depth as well. That will give you a very thin layer to mill off at the end. The thinner material being cut will place less pressure on the tool/machine allowing the bottom finish to be as smooth as possible.
As @SethCNC mentioned, post processing is going to be required if you want to get a smooth, original looking bottom. One thing that works well is to hit all of the carved areas with a little heat from something like a propane torch. If done correctly, this will make the finish clear again.
Would a heat gun do it?
Possibly… It all depends on getting it hot enough, quick enough, and then just removing the heat. You could try it on a scrap piece that you have cut to test it.
maybe a small butane torch (like the ones they sell in the vape shops) to get into those smaller areas and immediately remove the heat… it’s risky and it’ll be a learned skill… not something that’s perfect every time…
To get a more professional looking carve in cast acrylic use a diamond drag tool (70 bucks at amazon).
I have and order of 250 of these with LED lighting to illuminate the carve.
this is fresh off the machine, just pulled the protective film and double stick tape off the face (carve was done on back side of acrylic so face is smooth).
Something like this? https://www.amazon.com/DIAMOND-SPRING-LOADED-ENGRAVING-DEGREE/dp/B07DK1TWKG/ref=sr_1_1_sspa?crid=2LLWG3PIKFZST&keywords=diamond+drag+tool&qid=1645373529&sprefix=diamond+drag+tool+%2Caps%2C475&sr=8-1-spons&psc=1&smid=A18ECZVVODG54G&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExSVJST1haQ08xOE00JmVuY3J5cHRlZElkPUEwOTg4NTEwMU9HU0pPUkVWQzFMUCZlbmNyeXB0ZWRBZElkPUEwMzg4OTYwMVE0S0U5NFdMRk1SRiZ3aWRnZXROYW1lPXNwX2F0ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=
What were your cut settings IPM DOC etc?
Yup, you might want to consider the 60 degrees. also, replacement cutters are available at $30.
again, the spindle remains off while using diamond drag. max. “Z” 0.05"
flip your project so you are working on the back, the face will smooth.
now if your waste board is not parallel and/or surfaced it will affect your finish project.
So instead of the probe I would manually find 0 with a piece of paper since diamond is not conductive. And set the DOC no more that 0.05" both in cut settings and the project?
your design@ 0.05 diamond drag
your profile(project) cut out @ material thickness The Spiraled ‘O’ Flute: Ideal for Acrylic
@CDD, another thing to remember is that you need to flip your design horizontally if you plan on carving on the back of the acrylic and the design has any type of letter or anything else that matters.
Thanks for all that provided solutions. I did flip it horizontally and carved on the back and also did it in two workspaces with only taking off .005 the second pass @SethCNC @BrandonR_Parker I tried the butane torch, which on my test piece cleared it up but did actually warp it, may need to keep it clamped down.
@Ken4 may get that drag bit and try those out as well and spiraled O flute
Yeah, the torch thing works, but you have to just barely kiss it especially if it is thin acrylic.
You can use the torch as Seth said, and the edge cuts will return to clear. However, the large flat areas should be sanded first. I use this process on some of the cabinet shelves when we do kitchen remodels. We sand the edges then torch them and the look factory. I would have to assume the flat areas will be the same. I hope that helps and works out for you.