Archive for the ‘CNC Kits and Plans’ Category

Hobby CNC
Hobbyists get into CNC for many different reasons.  It really has a lot to offer as a hobby.  There are many challenges to it and that is what draws in many people.  This is not something you do just to pass the time.  There is a result in mind.
Some people make it to Hobby CNC through a side door.   They come from areas like Combat Robot and RC Modeling.  There are many small, precise parts in these hobbies, which CNC is perfect for.  There are also many enthusiasts that like to customize things so they need a way to make unique parts that they can’t get anywhere else.

Here are a few elements that have brought people into the CNC Fold:
Electronics – There are many electronic components you can build yourself.  Do you like to solder together power supplies, cooling fans, drivers and processors? CNC would appeal to you.

Design – Do you like to think about things in your mind?  Then conceptualize them into a computer.  Do you have a little inventor inside of you trying to get out?  CNC would appeal to you.
Manufacture – Do you like to make things in a process fashion?  Step by step, process by process.  Do you like to optimize and test and make processes more efficient?  CNC would appeal to you.
End Design – Do you have a result or end design in mind?  This is what happened to me.  I knew where I was.  I knew where I wanted to go.  I then used CNC as a bridge to get there.  If you have an end design in mind that is repetitive, then CNC would appeal to you.
Money – Do you like money?  Boy is that a question.  Many hobbyists get into CNC to make some extra money or start their own business.  Yes, you can make parts and sell them.  Guess what, after you design the part, you never have to do that again.  You can just call up the program and make some more.  Months and years later…forever.  CNC appeals to people who want to make money.
Challenge of Building a Machine – Some people just get bored and want a project to work on.  Building a machine that does something appeals to them.  Think of the Model Builders, Woodworkers, Metal Workers and any other type of builder you know.  CNC appeals to the builders of the world.
The Entire CNC process – I fall strongly into this category.  I started into CNC because of a problem, but stayed because I love the whole process of it.  I like to design things.  I like to build things.  I like to make money.  I like the challenge.  I like the whole enchilada.  That is what I want to share with you.

What personal attributes will help you with CNC?
I get this question a lot.  How do I know if CNC is right for me?  Guess what, I have seen it all.  Many types of people show up in CNC.  Here are some common skills I see often in the field. 

Computers – Do you like working with computers?  If you said yes then that will help you out.  CNC is really computer intensive work on the front end of the process.
Software – Can you learn multiple software packages?  If you said yes you probably have a flexible software mind.  That will come in handy.
Shop Skills – If you have skills in the shop, you will be ok.  It doesn’t really matter if it is metalworking, woodworking or anything else.  Being comfortable getting your hands dirty will help.
Engineering Mind – I usually think of this as a problem-solving mind.  Trying to isolate things and pin them down.  If a problem come up, you test different ways around it.  Keeping track of things will help.
Artistic Mind – Can you imagine things?  Think of the products you create.  Guess what, creating is very important.  Using you mind and thinking of unique possibilities will help.
Crafty Mind – I don’t mean in a devious way, more in a building way.  Can you take things apart and put them together in your head?  Can you see a finished product, and then back track the processes to make it?  You will be well served if you can play with things in your mind.

“Wait, wait, wait,” you might say.  “I don’t possess all these skills.”  You don’t have to.  Having some of these skills will only help you on your quest to learn CNC.  Again, I have seen all types of people get into and succeed in this field.  Your desire to learn and get out there and do it will be the deciding factor.

CAD (Computer-aided design)
Geometry authoring tool that involves software and sometimes special-purpose hardware. Current packages range from 2D vector based drafting systems to 3D solid and surface modellers.

CAM (Computer-aided manufacturing)
Considered as an NC programming tool wherein 3D models of components generated in CAD software are used to generate CNC code to drive numerical controlled machine tools

CNC (computer numerical control)
Refers specifically to a computer "controller" that reads G-code instructions and drives the machine tool.

CAD/CAM part programming
The computer calculation and creation of a toolpath based on part geometry information created in CAD.

Canned cycle
A predetermined machining sequence used to simplify programming.

Data
Information processed as the basis for calculations.

Database
Computer storage that holds data and is searchable

Detail Drawing
A drawing of a part giving a complete and exact description of its form, dimensions, and construction

Dimension
The desired measurement of a part

Documentation
A CAD process in which a part design is converted to a computer file or hard copy for reference and storage purposes.

Drawing Exchange Format
DXF. A standard storage format for personal computer-based CAD/CAM platforms

Driver
That portion of the electronic package that receives the stepping sequence from the translator and provides the switching of the windings in the stepper motor.

G-Code
Common name for the programming language that controls NC and CNC machine tools

Geometric Modeling
A modeling process in which a designer creates lines and text that represents the shape of a desired part. Geometric modeling is the first step in CAD.

Geometry
The measurement, properties, and relationships of the lines and points of an object that make up its shape

M Code
A code used to signal an action from a miscellaneous group of commands. M codes change cutting tools, turn on or turn off the coolant, spindle, or work piece clamps, etc.

Machine Control Data
Manufacturing instructions defined in CAM and enacted on a CNC machine.

Machine Control Unit
A small, powerful computer that controls and operates a CNC machine

Machine Tool
Powered mechanical device, typically used to fabricate metal components of machines by machining

Machining
The selective removal of metal or material

Numerical Control
The use of computers and special program instructions to execute the sequence of machining operations to make a part.

Part Program
A series of numerical instructions used by a CNC machine to perform the necessary sequence of operations to machine a specific work piece.

Personal Computer
PC. A computer designed for an individual user and commercial software. Desktops, laptops, and notebook computers are PCs.

Plotter
A large printer used to print blueprints. These output devices support vector graphics, unlike dot matrix and laser printers.

Post Processor
A software link in the CAD/CAM chain that communicates instructions from CAM to a CNC machine

Preliminary Blueprint
A design representing the rough dimensions of a specific part

Primitives or Primitive
Basic shapes such as cubes, spheres, cylinders, blocks, and cones that are combined in solid modeling to create a model of a part.

Prototype
The original test model of a part

Raster Image
A form of graphics in which closely spaced rows of dots form an image on a computer screen. Also known as bit-mapped graphics.

Ramping
The process of controlling the pulse frequency to accelerate or decelerate a stepper motor. Ramping increases the ability to drive larger loads at greater speeds by slowing the first series of pulses allowing the motor to overcome inertial loads and reduces overshooting by slowing the motor down more gradually than an unramped motor.

Scanner
A computer device that converts hard copy drawings into digital form

Software
The coded instructions, formulas, and operations that structure the actions of a computer

Solid Modeling
A type of geometric modeling based on solids in which all visible surfaces of a part are shown. In addition, solid modeling describes interior volume, mass, and weight.

Sub-Program
Acting as a part programming shortcut, a part program sequence that is called on as needed. Also called a subroutine.

Surface Modeling
A type of geometric modeling based on geometry only, in which all visible surfaces of a part are shown regardless of volume definition.

Step Angle
The angular increment the motor shaft will turn each time the windings (coils) are energized. The angle is specified in degrees. For a 200 step per revolution motor the step angle will be 1.8 degrees.

Step per revolution
The total number of steps to rotate the motor shaft 360 degrees. For CNC, 200 or 400 steps per revolution are usually used.

Stepper motor
A device that translates electrical pulses into precise mechanical movement. The output shaft may deliver rotary or linear motion.

Title Block
A portion of a blueprint that contains information such as the company name, part name, part number, designer, scale, and material.

Tolerance
A blueprint specification indicating an unwanted but acceptable deviation from a given dimension

Toolpath
The series of coordinate positions that determine the movement of a tool during a machining operation.

Translator
An electronic device that converts pulses into the correct switching sequence, which will operate the motor one step for each pulse received.

Unipolar
A bifilar wound motor. The current flows only in one direction through each winding. Normally there are two winding per bobbin and eight bobbins per motor. Usually is a 5, 6 or eight wire motor. One or more common leads are used per winding. Has less torque than a bipolar stepper motor but is simpler to drive. Bipolar stepper motor- just two windings. The electronic controls reverse the current alternately between the coils. This motor has more torque but requires more electronic controls.

Vector Graphics
A form of graphics that uses geometric formulas to represent images. Vector graphic images are more easily manipulated than raster graphics when dealing with CNC.

Wire Frame Modeling
A type of geometric modeling in which the edges of a part are represented by solid lines

Working Drawing
A drawing of a part providing data for manufacturing

X-Axis
An axis that is left or right. All movement left of a zero point is minus (-X), all movement right of the zero point is plus (+X).

Y-axis
An axis that is at right angles to the X-axis and intersect the zero point of the X-axis. All movement further away from the zero point is plus (+Y). All movement closer than the zero point is minus (-Y).

Z-axis
An axis that is vertically perpendicular to the X-Y zero point. All movement above the zero point is positive (+Z) while all movement below the zero point is (-Z).

By Eric Dykstra

Not long ago CNC (which stands for computer numerical control, by the way) machines were so expensive that only large companies could own them. But we’re in the middle of a full-fledged CNC revolution, reaching all the way down to the grassroots level. Now a dedicated average Joe whip up a precise fabricating tool with little more than some plans, basic tools, and a PC.

The internet abounds with plans like Rockcliff Machine’s router design. They claim their design can be completed for as low as $300 — though luck is a factor. You’ll have to shop sales and scrounge materials to hit that number, and settle for common materials like MDF.

Controlling this marvel of modern technology involves software, but luckily the open source community has created free (as in speech) software like EMC. The EMC package offers most — if not all the features of commercial software — without the price.

More specialized gear like stepper motors and polished guide rods and bearings will make up the bulk of the cost of the machine. But sites like CNCzone.com offer links to suppliers as well as a whole community of folks willing to answer questions and give advice.

A whole world of computer controlled tools has been opened to the do-it-your-selfer. Don’t miss out; get out there and give it a look!

The operators of the present-day CNC cutting machine demonstrate many of the same skills as those possessed by various traditional craftsmen. The operators of the CNC cutting machine include the men and women who design and make cabinets, woodwork, signs, and a whole range of metal, solid surface and plastic objects. The manufacturers who employ these operators know how important it is to have a good quality CNC cutting machine.

A good quality CNC cutting machine has a cutting table that covers the area bounded by a length of four feet and a width of eight feet. A quality table can handle satisfactorily a standard 4 x 8 plate of metal, wood, plastic, glass, or stone. A table that lacks a sufficient length or width will make it necessary for the operator to repeatedly reposition the plate. Operators of the CNC cutting machine refer to such repositioning as indexing.

A good basic CNC cutting machine does both plasma and oxyfuel cutting. Refinements on a basic cutting machine might provide it with the ability to perform other functions, functions such as:

-spotting holes for drilling
-drilling aluminum
-cutting a shape in the sides or end of tubing
-routing wooden shapes.

Other modifications on a CNC cutting machine might be directed at installation of the equipment for laser or water jet cutting.

The selection of a CNC cutting machine will be primarily determined by the nature of cutting that will be performed by the machine operator. For some operations, it will be necessary to do only straight cutting. For other operations, the cutting machine must perform bevel cutting. Bevel cutting allows the operator to trim, reduce, shave, and pare the material in the plate.

Both types of cutting will subject the CNC cutting machine to a fair amount of wear and tear. The manufacturer therefore needs to purchase a machine with adequate customer support. Such support should include the availability of spare parts. An absence of spare parts could require that the electronics of the CNC cutting machine undergo a retrofitting.

A need for retrofitting would deprive the operator of important production time. The need for retrofitting would diminish the quantity of goods that could be sold to the consumer. The need for retrofitting leads to a decrease in the amount of time that the operator will be spending at the CNC cutting machine. That is why the availability of spare parts for a malfunctioning CNC cutting machine remains one of the two chief concerns of the manufacturer. A second prime concern is the size of the cutting table.

The operator of a CNC cutting machine that needs to spend a large percent of time indexing will not have much time to spend on the actual cutting. Hence, the manufacturer will have much less product. Fewer products from the manufacturing facility translate into fewer products on the shelf. Consequently, the need for operators to spend time indexing can prove a detriment to the company?s bottom line. A good sales volume reflects the well-planned purchase of a CNC cutting machine.

About the Author: Peter Vermeeren is the owner and webmaster of: Machines and Tools and Airsoft GOT | Tactical Gear | Military Supplies

Design – thinking and planning what you want to build

CAD – translating it into the computer

CAM – converting it into machine language

Controlling – directing your machine’s motion

Machining – building the part to specifications

These five elements are really the building blocks to a CNC project.  As you see them above, that is generally the order people associate them in.  For example, you can’t control until you have a design.  You can’t use your CAM software before your CAD software.  One of the main things you need to address is how these elements interact with each other.

Right now this may seem confusing.  Over time, it will seem very basic.  The more you use these elements with one another, the more their order will become second nature.

Electronics – There are many electronic components you can build yourself.  Do you like to solder together power supplies, cooling fans, drivers and processors? CNC would appeal to you.

Design – Do you like to think about things in your mind?  Then conceptualize them into a computer.  Do you have a little inventor inside of you trying to get out?  CNC would appeal to you.

Manufacture – Do you like to make things in a process fashion?  Step by step, process by process.  Do you like to optimize and test and make processes more efficient?  CNC would appeal to you.

End Design – Do you have a result or end design in mind?  This is what happened to me.  I knew where I was.  I knew where I wanted to go.  I then used CNC as a bridge to get there.  If you have an end design in mind that is repetitive, then CNC would appeal to you.

Money – Do you like money?  Boy is that a question.  Many hobbyists get into CNC to make some extra money or start their own business.  Yes, you can make parts and sell them.  Guess what, after you design the part, you never have to do that again.  You can just call up the program and make some more.  Months and years later…forever.  CNC appeals to people who want to make money.

Challenge of Building a Machine – Some people just get bored and want a project to work on.  Building a machine that does something appeals to them.  Think of the Model Builders, Woodworkers, Metal Workers and any other type of builder you know.  CNC appeals to the builders of the world.

The Entire CNC process – I fall strongly into this category.  I started into CNC because of a problem, but stayed because I love the whole process of it.  I like to design things.  I like to build things.  I like to make money.  I like the challenge.  I like the whole enchilada.  That is what I want to share with you.

My Itital Thoughts on CNC:

I thought, “If I could build a CNC Plasma Cutting Table?”

I could hook my plasma cutter to it

Create a program of the part I wanted

Cut out multiple parts to my hearts content

Save a lot of time

And Finally…

Save my wrist from the dreaded Carpel Tunnel Syndrome.

        I really wasn’t scared of the technology to start with.  I grew up in fabrication shops across the Midwest and had seen these machines in action.  These machine “Operators” were always held in high esteem at the shop.  They always made more Money and always had as much Overtime as they wanted.  I decided if they could do it, I could do it.

        CNC hobby projects were not cheap at the time.  I figured I would have to invest $4,000 – $5,000 to build my table (they have come down considerably).  Keep in mind this was in 2000-2001.  For some reason that didn’t scare me off.  I always liked a good challenge and this was it.  With blind faith, I ordered up a CNC Controller and went down to my local steel yard to fill the back of my truck with steel.

Little Did I know…

        There was a steep learning curve with CNC.  Building a frame for the machine is only a small part of the project.  Today it is much easier.  The software, components and suppliers are better.  There is an entire cottage industry that has sprung up around CNC to support it.  Some of the best people in the world make their livings servicing CNC Hobbyist needs.

        For some reason I figured if I just build this machine it would spit out parts whenever I wanted it to.  Simple, Simple, Simple ran through my head.  Over time, I started to get it.  I didn’t have a teacher, but I started to learn the ins and out of what I was doing.

Other things I had to learn along the way:

CAD Software

Designing Parts

CAM Software

Preparing parts for machining

Simulating Machining

Machining Basics

Cleaning parts

So, where am I at today?

        Today I have multiple CNC machines that I work with.  Each have their own nuances, software, capabilities and functions.  The point of it is that they are all CNC.  They all follow the same basic process.  That process is pure gold if you know it.  You can move from machine to machine and know what is going on.  That is what I want to teach you.

        One day I knew I had a problem.  I just spent 4 hours with my plasma cutter in my right hand.  I had been cutting out patterns I had traced onto a sheet of metal.  These shapes were going to be my new coffee table.  Everyone complained to me that I didn’t have a coffee table.  I thought, “I’ll show them” and began to build one.

        Why make a coffee table out of metal you ask?  The quick answer is that I wasn’t much of a woodworker at the time.  On the other hand, I used to weld professionally and knew I could make anything out of metal.  That is how it all began, making a coffee table out of metal.

        Now if you knew me, you know that I can’t just make something normal.  My brain is the scheming type that has to do things differently then the norm.  I wanted to make a table that would knock people’s socks off.  I thought a funky looking table, made out of metal, with casters and lights would do the trick.  You know what?  It did. 

I really had a ball making this table.  I mean I had serious fun.  So much so that I started to design others.  I began showing photos of my work to everyone I knew.  On top of that, I was getting good feedback.  I had just found a new hobby, furniture making.  Who would have ever thought I would pick up furniture making as a hobby.

        While making this first table a problem arose.  It is the one I mentioned above with my right hand.  After plasma cutting all those parts my wrist really began to hurt.  While welding professionally there was always the threat of Carpal Tunnel Syndrome.  Welders are constantly afflicted by this injury and others because of Repetitive Motion.

        If you repeat something over and over and over and over, your body gives out at some point.  After cutting up these table parts, I knew I couldn’t go on doing this for a hobby.  I knew something would have to change or the new hobby would break my body.

        That is when I began investigating Hobby CNC.  I call it “Hobby” CNC, because that is how I found it.  There were small groups of enthusiasts on the Internet that were building these machines for the fun of it.  I thought this was the ticket. 

        CNC as a hobby has really seen a huge growth spurt over the last 8 years.  I think I stepped into it about two years after it started cooking in the late 90s.  When I jumped in there were a few CNC Groups going already and about three different CNC Plasma Tables available at the hobby level.  I don’t know where the other machine types were at the time because I came in through the plasma path.  I would guess they were further behind as CNC Plasma Cutters was one of the first areas of CNC to take off in the Hobby arena.

        Most of the growth I would attribute to the Internet.  Groups formed, ideas were shared.  Feedback was given.  People started making “chips” and didn’t look back.  The Internet brought a very expensive technology into garages across the country.  When I built my $4000 CNC Plasma Table a hobbyist class machine was around $10,000 and a commercial machine was $100,000 to as high as you wanted to go.

CNC Plasma Cutter – My first machine.  A good first project if you want to build a CNC machine.  Born out of necessity.  She is a little rough around the edges, but a solid friend.

Vinyl Cutter – This is a unique type of CNC Machine.  This machine uses a small knife to cut out vinyl in any shape or size.  Think “sticker machine.”  You know the stickers on the back of every jacked up truck you have ever seen.  You know, “P_ss on Chevy, Ford, Dodge, etc.  So a vinyl cutter is actually a “Redneck sticker-making machine.”  I actually bought it to cut sandblast resist, which is a whole different story.

CNC Milling Machine – My third machine.  This one I purchased.  It is actually a CNC Bridgeport Clone if you want to get technical.  It is funny how addictive this hobby is.  I bought this machine to make the parts for a CNC Wood Router.  “Wait, you bought one CNC Machine to build another CNC Machine?”  The answer is…. YES!  I love this hobby.

CNC Wood Router – My fourth machine.  My father likes woodworking and I like steel working.  This is kind of a bridge machine for me.  I have found woodworking with CNC to be really cool.  It has gotten me into 3D milling on the cheap.  Think of the cost of 3D milling a brick of aluminum or a block of wood into a shape.  That’s right.  No Brainer.  Wood is free in comparison.