Woodsmith last issue Woodsmith current issue

Keep up to date with


Sign Up for Our FREE Newsletter

Give a Gift FREE Issue
URL:
https://www.woodsmith.com/article/episode-004-working-with-brass/
Share Page:

CNC Basecamp

CNC Basecamp logo
Proudly Sponsored By Inventables logo

Episode 004: Working with Brass

By: Chris Fitch
If you’ve seen a CNC router in action you know it can do amazing things in wood, but did you know that with the right techniques and tooling your CNC router can mill brass and aluminum with dependability, accuracy and consistency.

004 cutting aluminum If you’ve seen a CNC router in action you know it can do amazing things in wood, but did you know that with the right techniques and tooling your CNC router can mill brass and aluminum with dependability, accuracy and consistency. Is that cool or what?! Think of the possibilities! Milling these materials on a home shop CNC router isn’t difficult, but milling metal requires a different and a disciplined approach. Here is a basic formula to get you started: 1) Stick with easily machinable alloys. 2) Choose the correct bit for brass or aluminum. 3) Mill at an RPM and feed rate that is right for your machine. 4) Use a light depth of cut. 5) Lubricate the bit. 6) Clear the chips! The alloys
We want to choose an alloy that machines easily, is commonly available and is affordable. Aluminum alloy 6061 is a great choice to work with. Manganese and silicon are the major alloying elements. Alloy 6061 is strong, corrosion resistant, inexpensive and widely available, and can be easily machined on a CNC router. 004 cutting brass Ultra-machinable 360 brass consists of copper and zinc, and as you might guess from the name, it is made to be easily machined with the addition of lead. This attractive alloy stands up to high speed milling with minimal wear on tooling while generating chips that clear easily from the cut.

The right bit
The bit we’re looking for doesn’t deflect, minimizes lateral forces on your router and clears the chips quickly to give you a quality cut and longer bit life. The bit that accomplishes this for both aluminum and brass is a 1/8” diameter, 1/4” shank spiral upcut and with a length of cut that is 1/8” more that your max depth of cut, but not much more. The small diameter reduces lateral strain on your machine, which increases accuracy. The 1/4” shank and short length of cut reduces chatter and deflection while the spiral shape clears waste chips efficiently, but how many flutes? This is where brass and aluminum part ways.
Aluminum is a gummy metal that can cling to the cutting edge of a bit. Once that occurs, breakage is only moments away. What’s needed is a single-flute, highly polished bit that both clears chips quickly and prevents them from sticking. 360 brass is alloyed specifically to cut cleanly so a two-flute bit can be used. Two flutes offer the advantage of addition stability and more cutting efficiency. 004 end mills RPM and Feed rate
Speed and feed rate calculations give you an ideal set of numbers to cut metal. However, home shop machines suffer from a lack of rigidity. To compensate, we need to slow down the feed. I have found that a feed rate of 50 fpm at a speed of 19,500 rpm is a combination that will work well in most situations. Don’t go below this trying to baby the machine. Feed rates slower than 50 fpm cause the bit to rub needlessly, increasing heat, wear and reducing its life.

Depth of cut
Bit deflection, backlash, and frame rigidity are enemies of a clean cut. To counter these we need to choose an optimum depth of cut. For aluminum 6061 I have found .03” to work well and for 360 brass .05”. It might not seem like much but you will find your CNC router can clear a lot of metal in an hour’s time. Be patient. Enjoy the process.

Lubrication
No doubt you have had the experience of scorching some wood while routing. The dense structure of metal creates even more heat as the bit balances between cutting and rubbing so lubrication is critical to keeping the bit cool. A cool bit means a longer bit life and a better cut. To lubricate a cut there several options: wax, spray can oil, or an oil mister. If you’re cutting thin sheet stock in one pass, a wax stick makes sense. Wax sticks are less messy than oils and have the advantage of being applied once and letting you walk away. No babysitting. For cuts requiring multiple passes, the simplest approach is to use oil from a spray can at frequent and even intervals. Avoid using sprays that are designed for stopping squeaks and breaking frozen bolts. Choose a dedicated machining oil or an oil with some cling such as chain lube. The best approach that guarantees constant lubrication for the bit and no babysitting of the machine is to use an oil mister. It’s an easy add on and uses compressed air to suction oil from a reservoir and delivers it directly to where it’s needed – the router bit. 004 oil mist There are many specially formulated oils for machining, but in our situation the oil is not recoverable. Once it is sprayed it’s gone, so price matters. An inexpensive cutting oil that can be bought in gallon jugs goes by the name “Plumbers Lard” – not a glamorous name but it works. I also keep a spray bottle of this oil in my shop for metal drilling or CNC work when I don’t want to use the mister. Machining oils can be messy, but when delivered directly to the cut at the right level it doesn’t take much. None the less, keep a roll of paper towels handy. 004 lubricants Clear the Chips You know that milling wood produces a blizzard of chips. Milling metal can do the same. Chip buildup results in re-cutting the chips, increasing heat and stress. It’s the #1 cause of broken bits when milling metal.
So how do we deal with the chips? They can be blown out of the cut with an air wand or, if you have a larger compressor, by setting up a continuous air stream using a flexible nozzle attached to your router. (Take care to be very careful when using compressed air on metal chips – the chips can end up in electronics, or worse, in your eye.) A dust collector can help keep the workpiece clean, but metal chips are heavier than wood. You may need to fit a custom boot to increase air flow around the cut.

Cutting aluminum and brass with a home shop CNC router is an exciting process. By addressing the issues unique to milling aluminum and brass, you can mill with confidence. So, pick up cutting oil and the right bits, and open the door to a new world of possibilities for your shop.

Episode Downloads

Project PDF and DXF Files

Published: Jan., 5 2022
Share Page:
Topics: None

Product Recommendations

Here are some supplies and tools we find essential in our everyday work around the shop. We may receive a commission from sales referred by our links; however, we have carefully selected these products for their usefulness and quality.

WSM Sidebar Ad_EssentialsDVDs

WSM_zone58_PopWoodSubPromo_300x250

Related Articles

Reviews

Draw Knife – A Must-Have Gadget In A Woodworker’s Toolbox

Make It Simple With the Best Magnetic Wristband

Secure Your Work With The Best Clamps

The Best Cordless Dremel For Working From Anywhere

Best Router Lifts For Woodworkers

The Best Phillips Screwdrivers to Add to Your DIY Arsenal

An Ultimate Guide to Best Hole Repair Kit

The Best C Clamps for DIY Projects

Tighten Up With the Best Slotted Screwdrivers

Keep Your Area Clean With The Best Spray Shelter

Tools for Every Jobsite: Best Portable Table Saw

Precision in Cutting with the Best Portable Band Saw

Tighten Nuts And Bolts With The Best Nut Drivers

Fix Your Pipes With The Best Pipe Wrenches

Ace Your DIY Projects With the Best Hand File Sets

Best Folding Benches: A Must-Have For Everyone

The Best Japanese Saws for Flawless Wood Crafting

5 Best Drill Guides To Achieve Flawless Accuracy & Precision

Cut, Engrave, And Polish With The Best Rotary Tools

Cut Anything Sharply By Purchasing The Best Pocket Knives

Controlled Drilling With The Best Manual Hand Drill

The Best Rust Removers To Bring Your Antiques Back To Life

Work On Different Projects With The Help Of The Best Woodworking Dremels

Become More Than Amateur: Best Woodworking Kits

Create Beautiful Art With The Best Epoxy Resin For Wood

Get Them Started Early With The Best Wood Working Kit For Kids

Make Perfect Cuts With The Best Miter Saw Blades

Best Worm Drive Circular Saws: The Ultimate Cutters for DIYers

Best Allen Wrench Sets For Snug Fits

Best Pliers To Buy For Your Everyday Household Works

Best Electric Chainsaw For Safer and Quieter Cuttings

Our Team’s Review of the Best Chainsaw Mills

Get Rid of all of the Dust with the Best Dust Extractors out there

Best Dremels For Wood Carving

Cut Cleanly Through Wood With The Best Circular Saw Blades

Cutting is made Easy with the Best Plunge Router

Upgrade your Creativity with the Best Tap and Die Sets

Smooth Cutting with the Best Jigsaw Blades

Make Carpentry Effortless With The Best Saw Horses

The Best Needle Nose Pliers for your DIY Projects

Best Coping Saws for Coped Joints

The Best Mini Circular Saws For Perfect Cutting

Best Flooring Nailers for DIY Enthusiasts

Best Dowel Jigs for An Exquisite Woodworking Experience

The Best Drywall Sanders for Incredible Finishing

Best Roller Stands for Your Woodworking Projects

Best Strops For Knives To Polish Them Well!

Best Reciprocating Saws To Buy For Heavy-Duty Cutting

Best Air Impact Wrenches You Can Buy – A Brief Buying Guide

Best Gas Chainsaws for Trimming Large Branches

Enhance Your Woodworking With The Best Benchtop Thickness Planers Of 2021

Become a Home Improvement Hero With These Best Heat Guns

Improve Your Cutting Efficiency Easily With The Best Mobile Sawing Tables

Work On Irregular Wooden Structures With The Best Oscillating Spindle Sanders

The Best Electric Brad Nailer For Healthy Nails

The Best Respirators to Keep you Safe!

The Best Pocket Hole Jigs to Create Joints that Last

Take Your Sanding Projects To The Next Level With The Best Belt Sanders Of 2021

Smoothen Numerous Surfaces With The Best Palm Sanders Of 2021

Best Socket Sets For Day-To-Day Needs

Create Strong And Robust Interlocking Dovetail Joints With The Best Dovetail Jigs

Best Carpenters Tool Belts For Easy Storage Of Essential Equipment

The Best Dewalt Wrenches To Topple Every Project

Add the Best Vise Jaws to Your Workshop for Added Workpiece Stability

The Best Sawzalls; Cut Through Anything. Anywhere

Best Dewalt Tool Kits For DIY Home Project

Make Stapling A Breeze With The Best Pneumatic Staple Gun

Add The Best Dewalt Impact Drivers To Your Tool Kit

Effortlessly Thread Neat Screws With The Best Die Sets

Measure with Accuracy: Best Angle Finder

No More Cracks: Best Wood Filler

Enhance Your Woodworking Projects With The Best Plate Joiners Of 2021

Make Your Sanding Jobs Easier With The Best Spindle Sanders Of 2021

Best Scroll Saw For The Finest Cutting Results

See Through Walls With The Best Stud Finders

The Best DeWalt Drills and More For Your DIY Needs

The Best Drill Press Of 2021

The Best Wood Planer To Complete Your Woodshop

Make Every Cut Ideal: Best Router Table Fence

The Best Router Base For Furniture Manufacturing

The Best Allen Wrench to Get the Job Done!

Make Your Projects Effortless With The Best Ball Peen Hammer

Brushless Drills: An Incredible Addition to your Toolbox

Keep Your Cuts Clean With The Best Radial Arm Saw

Best Tap Sets For Your Workshop

The Smoothest Experience With The Best Random Orbital Sander

Carve and Create With The Best CNC Router

Upgrade Your Workshop With The Best Benchtop Jointer

Deal with Logs with the Best Wood Chipper

Blast the Tunes with the Best Woodshop Radio

Best Compact Bandsaws For Easy Cutting

Best Finishing Nailer For Durability

Best Mini Air Compressors To Buy

Our Team’s Review of the Best Propane Torches

Best Wood Carving Set For Hobbyist

Best Wood Lathe For Beginner

Use The Best Edge Sanders To Smoothen Any Wooden Surface

Seamlessly Cut And Chop Wood With The Best Hatchets

Woodturning Essentials: The Best Roughing Gouges

Best Shop Fans: Top 7 High-Velocity Heavy-Duty Fans for Garages, Worksites and Workshops

Preserve Your Valuables With The Best Linseed Oil

Best Rubber Mallets For Woodworking

Best Wrench Sets That Makes Work Easy

The Best Wrench Racks To Organize Your Tools

The 7 Best Calipers For Accurate Measurements

Best Marking Gauges For Professional And DIY Woodworkers

Best Folding Stools To Fit into Compact Spaces

Get The Perfect Flush Cuts Every time With The Best Edge Banding Trimmers

Best Deck Screws For Pressure Treated Woods To Make A Perfect Deck

Best Miter Saw Stands To Mount Your Cutting Tools On The Go

Increase Your Sanding Efficiency With Zero Effort Using The Best File Belt Sanders

Best Table Saw Fence 2021 for Smooth Cuts and Shapes

Sharpen And Shape With The Best Bench Grinders

Best Metal Clamps for Your Craftsmen Needs

Best Cordless Impact Wrenches for All of Your Mechanical Needs

Best Biscuit Joiners to Help Easing Your Woodwork

Best Estwing Hammers For Your DIY Needs

Use The Best Wood Moisture Meters To Separate Healthy And Damaged Wood Pieces

The Best Rail And Stile Router Bits: The Staple Of Hassle-Free Woodworking

Best Adjustable Wrench For Hassle-Free Work

Best CNC Router Bits For A Hassle-Free Woodworking Project

Achieve Precision with the Best Glass Cutter

Keep Things Sharp With The Best Sharpening Stones

The Best Sandblaster To Get Your Job Started Strong

Best Forstner Bits To Add To Your Woodworking Tool Kit

The Best Jointer For Every Type Of Woodworking

The Best Track Saw of 2021

Our Team’s Review Of The Best Spring Clamps

Best Rasp Files – A Versatile Woodcarving Solution

The Best Veneer Edge Banding: A Perfect Finish To Your Furniture

Catch The Dust Before It Catches You With The Best Dust Hoods

Best Depth-Gauges: A Staple For Woodworking Enthusiasts

Construct Your Projects On The Best Workbenches Available

Smooth Out Your Work Using the Best Sanding Discs

The Best Caster Wheels to Upgrade Your Equipment

The Best Furniture Levelers: Bid Farewell to your Furniture Woes

7 Best Flush Cut Saw That Could Change the Wood Cutting Game

Level-Up Your Portals With the Best Door Hinges

Organize Your Lifestyle With the Best Pegboard Hooks

The Best Magnetic Toolbars For Easy Storage And Organization

The Best Vise: A Staple In Every Workshop

Our Team’s Review of the Best Rolling Tool Chest

Organize With Ease: Best Pegboards

Make Better Cuts With The Best Table Saw Push Block

Cut And Shape With Ease: Best Router Table

The Best Plywood Jigs For Every Need

Reviewing The Best Taper Jigs This Year

Hit The Nail On The Head With The Best Hammers

Make Every Cut: Best Angle Grinder

The Best Wood Stain For Every Project

The Best Overhead Storage Rack For Convenient, Safe Storage

The Best Double Sided Tapes That Won’t Damage Surfaces

The Best Saw Dust Catchers For Shop Safety

Toolbox Essentials: The Best Sandpaper

Start Your Next Carving Project With The Best Scorp

Seal, Coat, and Craft With the Best Epoxy

Finding the Best Circular Saw in 2021

Reviewing the Best Drill Bits of 2021

Best Ratchet Wrench for Quick and Easy Repair

The Best Table Saw For The Everyday Handyman

Reviewing the Best Router Leveling Jigs

Tackle Screws Effectively With The Best Screwdriver Sets

Best Shop Vac For Those Heavy-Duty Cleaning Tasks

Best Tape Measures For Professionals and DIYers

The Best Handscrew Clamp For Gluing, Painting, and Building

The Best Wood Mallet For Your Next Carpentry Project

Revamp Your Outdoor Space With The Best Deck Stain

Smooth Out Edges With The Best Spokeshaves

The Best Carpentry Square For Precise Measuring

Protect Your Outdoor Entertainment Space With The Best Firepit Cover

Get The Right Measurements With The Best Framing Square

Best Wood Chisels For Impactful Wood Crafting

The Best Bird House Kits For First-Time Builders

The Best Wood Glue To Complete Your DIY Projects

Our Top Picks Of The Best Wood Burning Kits This Year

Reviewing The Best Moving Dollies This Year

Best Wooden Box Puzzles For Challenging Fun

Get Organized With The Best Racks For Firewood

The Best Landscape Edgers To Beautify Your Space

Endless Fun With The Best Wooden Puzzles

Our Top Picks Of The Best Blueprints This Year

Reviewing The Best Benches This Year

Never Lose Out On Warmth: Best Water Heaters

Make Cutting Easier With The Best Band Saws

Easy to Use and Efficient: Best Sanding Blocks Reviewed

Reviewing The Best Axes Right Now

Cordless Precision Possible: Best Compact Routers

Work Smarter with the Best Canvas Aprons

Convenience And Reliability: Best Tankless Water Heater

Create Clean Slices using the Best Low Angle Block Planes

Craft Wood Effortlessly with the Best Carving Chisels

Make Storage Seamless With The Best Extension Cord Reel

Review: The Best Cordless Drills

Don’t Let Handtools Slow You Down: Best Drills

Get Your Home Looking Sharp With The Best Wall Paints

The Best Table Saw Stand For Easy And Clean Cuts

Keep Your Tools Running Smoothly With The Best Lubricant Oil

Review Of The Best Hacksaws Right Now

Strong and Soft: Best Shop Towels

Stay Sharp With The Best Electric Pole Saws

Get Up-Top With the Best Step Ladders

The Best Deep Toolbox For Maximizing Your Space And Time

The Best Porch Swing Will Sweep You Off Your Feet

Tackle Any Project with the Best Chop Saws

Review of the Best Portable Generators

Secure Woodworking with the Best Bench Vise

Precise and Durable: Best Measuring Tape

Enhance Your Cuts Using The Best Miter Saw

Create The Best Firepit For Your Backyard

Keep Your Work Organized: Best Toolboxes

The Best Electric Log Splitter For Great Cuts