Basic router bit question: I'm a Newbie

Hello, Everyone. You’ve all been so helpful in the past. I wanted to ask a basic question.

I make this guitar accessory:

This shape is a very popular design, approx 32.5 mm tip to tip. We make these from very expensive industrial plastics that cut similar to acrylic. I’ve been cutting them with a laser, which words okay but leaves a bit of char.

I have a sheet of material that is 12" x12". If I set up my machine to cut these, I have two questions to start:

  1. How much material (kerf) loss should I expect to lose per cut?

  2. Could someone please recommend a basic bit designed to cut plastic, and perhaps paste a direct link to it? I don’t have a lot of moolah right now, so I can’t afford an entire bit set; I just don’t have the resources. But that will likely change a couple months down the road.

Thanks in advance for your expertise and suggestions.

All the Best,
Routing Success

2 Likes

Basically, the diameter of the endmill you are using (and probably a tiny bit more due to tool deflection and router runout). How thick is your material ?
Amana has fantastic “O-flute” endmills (single-flute specialized for plastics), some of those are included in one of C3D Amana kits:

Those are 1/4" (way too large) and 1/8" endmills (suitable but still too large for your usecase)
Amana has 1/16" O-flute endmill for plastics like this one:

But basically any 1/16" single-flute should do for initial testing (if you can initially get cheap ones, you should, as you are likely to break a few until you have your feeds and speeds dialed in)

Your first challenge is likely to be workholding, for a 12"x12" thin sheet. Double-side tape or (my preferred option) blue tape & superglue would seem to be adequate.

Of course, try your hand at a sample first, before you proceed to try and cut a ful sheet of those picks

4 Likes

Julien, thank you very much. These are great ideas. The 1/16" is probably about as thin as I think I can go. That is 1.5 mm. I might go a little thicker first time, to prevent breakage. The material is not terribly expensive, and with laser we usually figure 1.0-1.5 mm of lost material due to charring, so we typically cut those pieces about 1.0 mm larger.

Yes, I think we can secure the material on MDF board with a superglue gel or something similar.

Thank You!
Scott

2 Likes

Julien, hello again. You mentioned finding some cheap bits to practice with, assuming I will break a few. Would something like this work?

Thank You,
Scott

Hi @RoutingSuccess,

That example is probably the furthest away from what I had in mind :slight_smile:
(I don’t blame you, it’s very easy to get lost in the ocean of endmill size and types initially)
That link you included points to a gigantic 1/2" diameter endmill, made for cutting steel, and it’s 4 flute.
What you want to practice cutting plastics is a set of cheap small-diameter single flute endmills, here’s a random example :

Folks in the US will probably have much better references for you than I do, since I source my endmills locally in France. But this example should give you the ballpark price you should expect. In this example they are 2mm in diameter, so in between 1/16" and 1/8", but you should be able to find cheap 1/16" one too.