how to build a cnc router - all day fencing instructions.pdf · cnc router construction guide and...

How To Build A...

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CNC ROUTER ....................................................................................................................

This guide remains the property of Sigem Property Development. Illegal copying or distribution of this material is strictly prohibited.

Contents

1. Introduction 3

2. CNC Basics 5

3. Construction 7

4. Drive Train 17

5. Electronics 21

6. Motors 24

7. Software 26


Definition

What is a CNC machine? (wikipedia)

Numerical control (NC) refers to the automation of machine tools that are operated by abstractly

programmed commands encoded on a storage medium, as opposed to manually controlled via

handwheels or levers, or mechanically automated via cams alone. The first NC machines were built

in the 1940s and 1950s, based on existing tools that were modified with motors that moved the

controls to follow points fed into the system on punched tape. These early servomechanisms were

rapidly augmented with analog and digital computers, creating the modern computer numerical

control (CNC) machine tools that have revolutionized the manufacturing process.

In modern CNC systems, end-to-end component design is highly automated using computer-aided design(CAD) and computer-aided manufacturing (CAM) programs. The programs produce a computer file that isinterpreted to extract the commands needed to operate a particular machine via a postprocessor, andthen loaded into the CNC machines for production. Since any particular component might require the useof a number of different tools-drills, saws, etc., modern machines often combine multiple tools into asingle "cell". In other cases, a number of different machines are used with an external controller andhuman or robotic operators that move the component from machine to machine. In either case, thecomplex series of steps needed to produce any part is highly automated and produces a part that closelymatches the original CAD design.


1. INTRODUCTION

FORWORD:

This guide is designed to simplify the process of building and operating a CNC router. Many hours havebeen spent in testing various designs of machines to make a woodworking CNC router table that is not onlycheap to build, but easy to program and use.

Building a CNC router has some challenges. There are 3 steps to the construction of a CNC router;

1. Construction,

2. Installation of motors and electronics, and,

3. Software.

As a carpenter, electronics and computers are not my speciality, and the process to design and build thismachine has been a long one! I have researched many designs before settling on this simple gantry stylebench. The components for the bench are easy to obtain from local builders hardware stores. Theelectronics, gears, rollers, bearings and all other parts can be found online using the links provided.

The purpose of this guide is to introduce you to the easiest and most cost effective way to build a CNCrouter.

When I planned and built my first CNC, I did a fantastic job of the build but I purchased the wrong motors,used the wrong gearing and also purchased 3 lots of software programs that I did not require. My mistakescost more than $800! The aim of this guide is to steer you in the right direction. To help with the design,electronics and software.

In my research I have found various free editions of software that can be meshed together easily(instructions provided) that can provide a detailed drawing, toolpath and cutting program that is easy forcarpenters, hobbiests and tradesmen alike! Some of these are trial programs and some are free or limitedand free software. The point is these will get you from plan to part quicker than expensive programs.

The 3D drawing interface plugin allows CAD drawings to be exported as toolpath files. Sound complicated?Well its not with the right advice.

Several stages of the build are referred to an external CNC site which can provide excellent informationon build and techniques. They can also supply the electronic kits and gears and a wealth of knowledge onthe construction of CNC machines. However the software in their manual is complicated and does notwork with the free programs.

The software process described in this guide is tested and proven and can be installed with a minimum ofcomputer knowledge.

The drawing program is easy to use with simple commands and 3D drawing capability. Its also free andusing the plugins we provide can be used to export files as .dxf format for processing by the tool pathprogram.

IMPORTANT FIRST STEP

***Once you have downloaded Sketchup 8, please email me for:

1. a set of these plans in 3D, you can amend these plans to any size you require.

2. Plugin file for dxf format. This plugin file will allow sketchup8 MESHED

TRIANGLE drawings to be exported as .dxf files. Once you have added the plugin

file to SKETCHUP/PLUGIN file, you will have an option to export files as dxf. The

option can be found under the 'TOOLS' menu in Sketchup 8.

Richard Berckelman, Master Builder BL Qld NSW, Sigem Property Development Pty Ltd


CNC BASICS

a CNC machine is probably themost useful tool a hobbiest can own...


CNC BASICS

A CNC machine is probably the most useful tool a hobbyist can own, but the price for a CNC machine onthe market is way more than the average hobbyist is willing to spend. Build your own CNC explains how tobuild, program and manufacture your own products on your own machine.

There are 3 steps to the project, Construction, Software, Manufacture.

This design can be amended and would suit machines from 2400mm x 1200 down to 1200 x 900mm. The quality of your fittings, bearings and other motion hardware is important. As your machine is used itwill wear slightly and it is necessary to design each join to be adjustable. It is also important to design theroller chain setup to be adjustable, so the table and gantry can be squared and adjusted as required. Inour design we have included adjustable bolts at either end of the roller chains so finding 'square' is easy.Our design also incorporates a steel tensioning bar that is supported by springs and adds constant tensionto the chain drive.


How To Build A

CNC Router

Construction Guide and Plans

3D Plans available: email [email protected]


Step by Step guide to construction

Step 1. The 'X' AXIS (table length)

The first step is to build the base for the worktable. The base needs to be large enough for the piece youare wanting to cut, plus clearance for the gantry. If your gantry is 600mm wide and you want to cut apiece of timber 1500mm long, then your worktable should be 2100mm long.

I used two skins of customwood separated by 50mm battens. The gap in between can be connected to anair extraction system, and, combined with holes drilled through the worktable top can be used as avacuum hold down table.

Cut a sheet of 22mm customwood to the worktable size required. Glue and screw 50mm x 50mm battensto each edge. Cut and fix cross battens spaced at 350mm as shown.

The worktop is the last thing to be installed. It should only be fixed down with screws so it can bereplaced easily if required.

STEP 2, CNC Rails and tracks

A CNC machine has three axis. The X, Y and Z. These represent the worktable. The x axis is the movementin the direction of the length of the table. The Y axis is width and the Z is vertical movement. When a CNCmachine works the computer instructs the cutting bit to move in all 3 axis.

Our plan uses V shaped rollers for all three axis. A total of 16 rollers is required for the whole machine. 8


rollers are required for the axis, and 4 rollers for both the Y and Z axis. The rollers run on the edge ofaluminium channel or aluminium plate as shown in the drawings.

These are specialized bearings that are used in many linear motion systems. The v-groove bearingsgenerally ride on a rail or track. Purchase these bearings from:http://buildyourcnc.com/bearingsproducts.aspx.

The first step to construction is to cut the timber and aluminium support rails as shown in the plan below.The rails are constructed from 140mm x 40mm primed and treated pine. A rebate 16mm x 16mm is cutinto both edges of the timber to allow for the aluminium channel.

A slot is cut into the end to allow for a tensioning rod which will be added later.

Front: The rails should be 140mm longer than the work table to allow for fixing pointsfor the chain drive that you will install later. (see diagram above)

Step 3 End Beams

The end beams tie the structure together while at the same time provides fixing pointsfor the chain drive system and safety covers.

The end beams are made from 70mm x 40mm timber and contains a cutout for thetensioning bar. See below diagram.


Back: The rails should also be 140mm longer than the worktable to allow for the fixingpoint of the chain drive. Fix both end beams in place with screws and glue.

The diagram below shows the safety rail fitted to the outside of the end beams. Thesafety rail can be added last. It is necessary to prevent interference with the chaindrive.


*Please note: these machines are very powerful!! KEEP FINGERS AND OTHER BODY PARTS CLEAR WHEN IN OPERATION.

STEP 4, The Gantry

The gantry is easily constructed using plywood and threaded rods.

Use a high grade exterior plywood for the gantry sides. The gantry is mounted to thetracks using the 'V' rollers described earlier. Dimensions for the gantry can be taken fromthe 3D plan or the 2D drawing below.

Gantry Fiqure 1


4 rollers are required to keep the gantry on the track. Note in the drawing above, the bottom rollers

are positioned on a separate piece of timber, this is to allow the rollers to be adjusted to the rails.

See diagram below for construction details.

The gantry sides are joined by timber battens and threaded rod for strength. The layout and size of

the battens are important as they provide the track for the Y AXIS travel. View the diagram below

for details of the bracing and structure for the gantry.

STEP 5, The Y AXIS

The Y AXIS is constructed similar to the X AXIS with the use of 'V' groove bearings and 16mm x

3mm aluminium channel.


Screw the above assembly together. For added strength rebate the frame above 6mm deep into the

gantry sides.

The sides are secured together with 10mm threaded rods. Do not over tighten rods to prevent

distortion of the gantry structure. Use 40mm x 40mm timber as spacers (as shown in drawing

Gantry frame 1, above).

ROLLER AND CHANNEL

Cut a front plate from 19mm plywood to help brace the gantry diagonally. (as shown in drawing

Gantry frame 1, above).

Rebate the edge of the battens to take the aluminium channel. Screw the channel to the battens as

shown above. Assemble the gantry sides and frame using 4, 10mm threaded bolts running all the

way from side to side. Provide a nut and washer to both sides of the gantry side, eg; each rod should

have 4 nuts and 4 washers.

STEP 5, The Z AXIS

The Z AXIS is the up and down movement of the router.

Construct the Z AXIS using aluminium plate 5mm thick. 2 pieces are needed. The back piece runs

along the Y AXIS while the front piece travels up and down, (Z AXIS).

BACK PLATE shows 30mm wide straps used to make the plates adjustable. The slots in the 5mm

plate allow the rollers to adjust to the rails as required.

The front straps allow adjustment from side to side, and the back straps allow adjustment up and

down.


FRONT PLATE shows the holes required to mount the router and dust extraction mounts.

VERTICAL SECTION - shows the front and back plates, plus the positions of the rollers. The back

rollers move the whole section from side to side. The front rollers allow the front plate to move up

and down.


Gantry Plates showing rollers.

The 70mm hole in the centre is for the router and the 2, 50mm holes on either side are for the dustextraction pipes.Z AXIS ASSEMBLY

The diagram above shows the 2 plates together with rollers. If the unit is assembled correctly it shouldprovide adjustable tensioning screws to keep the rollers firmly on the rails.


Fix the base plate of your router/trimmer to the Gantry plate by drilling and countersinking the bolts fromthe bottom.

The dust extraction (optional) is installed using 40mm PVC pipe. Make sure the pipe extends up highenough above the gantry to hold the dust hoses clear of the unit when operating. Fix the dust extractionpipes to the front plate only.


The completed gantry pictured below shows the orange dust extraction pipes connected to flexable hose.The hose is suspended above the machine allowing movement of the gantry with strain on the extractionpipes or machine structure.

STEP 6 Drive System - X AXIS

The X AXIS uses a chain and sprocket drive train to transfer power from the motors to the gantry. Thepicture below shows 3 yellow sprockets and a black line where the chain goes. The rollers are positionedto keep downward pressure on the gantry.

The top sprocket is connected to a steel rod that joins the drive train to both sides of the gantry,(pictured in yellow)


The chain needs to be adjustable and have tension for accurate movements.

Use a 20mm square steel rod as a tensioning bar. Fix the ends of the chain to eyelets with long

threaded shanks that can be tightened when required and also used to square the machine.

Use a 10mm bolt and spring to hold the steel bar and chain in tension. The picture below shows the

tensioning bar and eyelet bolt holding the chain under equal tension. This bar also absorbs shock

and backlash during operation.

The tensioning bar and chain eyelets are very important to the performance and accuracy of the

machine.


The X axis uses a #25 chain and sprocket drive. These items can be purchased here..http://buildyourcnc.com/CNCMachineMechanicalParts.aspx.The chain needs to run the length of the axis on both sides including around the sprockets as shownbelow..

Use a #25 drive sprocket to connect the motor to the drive sprocket. The Y axis can be driven by chain andsprocket or threaded rod. Use anti backlash nuts for threaded rods to eliminate movement.Join each side of the gantry power drive with a piece of 20mm square steel. Weld a bolt to each end andsuspend from side to side on bearings. Weld a sprocket to each end so power can be transferred from oneside to the other.

See picture below,

Mount the motor on the inside of the gantry with the drive shaft pointing outwards. Fix a sprocket head tothe shaft.


BASE The base is not really included in the instructions, however you can make a timber frame

as shown below or use an existing workbench. (note emergency stop button)


SAFETY FIRST

IMPORTANT SAFETY ADVICE

Provide easy to access emergency stop buttons to stop both the program and the router should an

accident happen.

Provide safety covers for the chain and sprockets. (see above). These machines are very powerful

and it is advised to keep all valued body parts well clear!!! The picture above also shows aluminium

channel used as a dust protector and safety guard bolted over the gantry rollers.

Turn router off at power during blade changes.

Use hearing protection when operating machine.

Abide by all advised safety instructions as provided by the manufacture of the router/trimmer or

other cutting mechanism.

All Day Fencing accept no liability, no responsibility nor financial loss for any damage or injury caused as a

result of the use of these plans and instructions.


How To Build A CNC Router

ELECTRONICSincluding;

MotorsDrivers

Breakout BoardAdapters

Wiring Tutorial


4. ELECTRONICS

MOTORS

Wow, big learning curve! I purchased 2 lots of motors before I realised the size and strength of the motorsI needed. In the end I used the 463oz motors to power all three axis. The motors are quite and strongenough to cut most materials (including aluminium) and will give years of trouble free operation. You willalso need 3 drivers a power supply and a breakout board.

Here are the electronics that you will need to make the CNC Router move!

You can purchase a bundle of components including three stepper motors, three stepper motor drivers, apower supply, and a breakout board (fan is not included but is recommended if the system is enclosed)here.. http://buildyourcnc.com/electronicscombo.aspx.

MOUNTING THE MOTORS


The above picture shows the motors (in purple). One motor is mounted on the gantry side to drive

the lead screw for the Y AXIS. The other motor is fixed to the inside of the gantry frame, with the

shaft pointing out to power the X AXIS drive chain.

Attach the lead screw to the motor shaft using flexible connectors. These connectors correct thealignment of the motor to lead screw at the same time as reducing vibration. Connectors can bepurchased from: http://buildyourcnc.com/couplings.aspx.

The motors can be mounted on bolts to provide clearance for the connectors as shown.

Most of the tutorials on this site are created in response to the difficulties users have with machinesmechanics, structural dimensions and the electronics that drive their CNC machines. Overwhelmingly, the


electronics pose the most difficulty with new users.

For an easy to follow wiring demonstration view the videos available here;http://buildyourcnc.com/CNCElectronicsandWiring.aspx.

The installation video explains the wiring instructions that demonstrate a methodology that begins with asimple and straightforward wiring of only one driver and motor and follows with the remaining driverswhile testing throughout. The steps per inch for many forms of mechanical option are also explained indepth.

I have used a direct link to this site as it is best you get the information from the horses mouth! I havetested many tutorials and easy start guides only to find they are not compatible with the motors orsoftware I wanted to use. This tutorial works really well and is explained in simple steps. Regrettablyhowever the software they recommend is both very expensive and not compatible with suitable CAMprograms and their measurements are in imperial making torque calculations extremely difficult. They dohowever sell the best quality motors and electronics at surprisingly cheap prices so it makes sense to use alink to their tutorial.

Once your motors are running follow the software instructions below to get drawing and toolpathprograms for your machine!


How To Build A CNC Router...

SOFTWARE Made Easy!

Including specially designed plugin file

To obtain the plugin file please email me at [email protected].


5. SOFTWARE

After months of reviewing software options, (there are over 60 options) including the 'wrong' purchase ofseveral programs that were not compatible, I can refer to you the cheapest, easiest and best software touse.

This software can be downloaded and tested free! The software relies on a plugin file specially designedto convert normal 3D drawing files to compatible DXF files.

The software toolchain can contain three software applications.

Firstly, a drawing program such as Auto CAD that can manufacture 3D drawings, second, a program thatcan convert the drawing into a toolpath, CAM, and thirdly software to convert the toolpath intomechanical motion. Sound complicated? Well it is up until now!

AutoCAD retails for thousands of dollars, CAM programs start at around $1000 and most do notsatisfactorily work. The final program will cost around $300 but you can get a FREE trial to test yoursystem.

So all up, with the information in this manual you can download and start manufacturing FREE!!!

Software Explained. What to use...

Use Google Sketchup to draw your designs in 3D. Google sketchup is free. Download the following softwareand save to your computer.

DXF Files

Make and name a new folder on your desktop for the DXF files you create.

CAM program.

Artsoft manufacture a program named 'MACH 3' that can convert the G Codes into signal to be sent

to your motors.

The MACH 3 console above is the control centre of your CNC router. In Mach 3 you can load a G

Code and run it. You can configure motors, workbench size and many more options.

Download a FREE limited edition of

Mach3 R3.043.022

from: http://www.machsupport.com/downloads.php.

1. Draw in google Sketchup

2. Under 'tools', export as a DXF file

3. Open DXF file in Meshcam

4. Set toolpath and save as (G Code) .nc file

5. Load the G Code into MACH 3.

When you hit the program start button the machine will execute the toolpath set. It is highly

recommended to connect your power to an emergency stop button!

Perform a dry run before cutting material.

WARNING!!

KEEP HANDS CLEAR, DANGEROUS FORCES AT WORK!

*All Day fencing accept no liability for safety or performance of the work outlined in this manual.

CNC machines can be dangerous, metal and flesh don't mix! We advise the use of professional

electricians for the electrical connections.


how to build a cnc router - all day fencing instructions.pdf · cnc router construction guide and...

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