FAQ – CNC Routers



  • 1.Router Uses and Capabilities
  • What's the difference between "ball-screw and rack and pinion" drives?
    MakerspaceNZ01-12-2016

    We get asked this question quite a lot when people are comparing different 3rd party machine pricing to our own - apples with apples we say, so here goes:

    A ball screw drive uses a jack screw (think like on a car jack for instance) to move the gantry around the machine -and although very accurate suffers from being relatively slow in operation (approx 3-4x slower than rack/pinion using stepper motors). A ball-drive can also suffer with 'whip' when used on long tables at high speed where the long threaded rod bounces around as it's rotated.

    A rack drive uses stepper motors (or servos) to drive a pinion wheel which engages onto a toothed track (helical on our 1212/2412 and larger machines as opposed to straight cut which means a quieter operation). These types of drives systems are much faster than ball-screw drives and can attain speeds of upto 60m/min (60,000mm/min) on servo drive machines. Most of MakerspaceNZ CNC routers (and indeed lasers) are stepper motor driven and they operate in the 0-18000mm/min speed ranges.

    Both systems have great repeatability and reliability and are very easy to care for.

  • What sorts of materials can I use with a CNC router?
    admin14-09-2016

    Our CNC routers can process many sorts of materials from MDF or manufactured board, natural timbers, marble/stone (required direct cutter-watercooling), plastics e.g. Acrylic or PETG through to soft aluminium or other soft non-ferrous metals (if you're prepared to do the clean up!)

    Makerspace NZ has machined everything from polystyrene (for making full sized human sculptures) to milling tracks and drilling holes in tiny precision PCB's from in house electronic projects.

     

  • What size materials can the machines process?
    admin14-09-2016

    Material size is expressed in terms of width x length x thickness (in Z plane, or up and down).

    The bed size and gantry clearance (thats the bit between the bed and the cutter at the top of it's travel in real terms) and generally the smaller the machine the less gantry clearance and smaller the bed size will be - so the size of materials will be limited.

    Transmission type (ball-screw vs rackdrive) is also a consideration & the physical strength of the drive motors (i.e. bigger is generally better). The power rating of the spindle and size of the collet - which holds the cutter also dictates the cutting speeds & the smaller machines have less power than their larger cousins, but will still process thicker and harder materials - it'll just take longer.

    Also the larger machines travel faster due to their transmission types (rackdrives) and hence cut faster using bigger cutters without stalling the motors.

    To process metals and stone you'll need a coolent feed and waterbath which adds to the cost of the machine too as the complexity goes up.

    There are many options including suck-down (or vacuum) beds, stepper vs servo drive motors and aircooled vs watercooled and autotool change spindles - but we like to keep things simple to learn and tend stick to the basics.

  • How safe are CNC Routers?
    admin14-09-2016

    Much like any other workshop tool, when used properly a CNC is relatively safe, and our CNC's are equipped with a number of safety features to ensure that risk to the user is as minimal as possible. A few of the potential hazards (and the safety features that protect the user) are listed below:

    Electrical Hazards
    The electrics in all of our CNC's are completely contained within the cabinet, and most of our models include keyed locks to prevent direct access. However, if these physical barriers are bypassed, contact voltages inside the cabinet range from 24 volts DC to 240vAC, and are potentially lethal. While this does not pose a hazard to the typical user, it does mean that servicing must be done by qualified individuals.

    All of our CNC's are equipped with standard electrical safety mechanisms such as circuit breakers, physical insulators, and electrically grounded casings.

    Dust Hazards
    During cutting the resulting dust particles are a potential hazard and should be treated as potential carcinogin or irritant as all dust should be. To help minimize risk and ease of connecting to your dust extraction system- all of our CO2 laser cutters and engravers come standard with dust extraction hoods fitted to the spindle.

    Whilst Cutting Hazards (flying objects/debris/noise)

    The CNC uses an ear-splitting, rapidly rotating spindle to hold cutter at  upto 24,000rpm. The cutter can break sometimes (if the operator isn't paying attention with setup) or cause cut material to be expelled at a terrific rate - so we advise that simple shields be used when cutting and keep away all no essential people when the machine is operating to avoid crushing of hands in the moving parts & all cutter dust-shrouds should be in place and hearing & eye-safety be in place. No gloves are to be worn when using the machine.
    There is also the danger of creating some really awesome stuff - so beware!
  • Can I machine 2D or 3D with a CNC?
    admin15-09-2016

    The real answer is - it depends upon what machine you have & whether it's a 3-axis, 4-axis or 5-axis.

    3-axis machines have a Y, X and Z-axis

    4-axis machines have a Y, X, Z-axis and also a rotating C-axis (think like a lathe)

    5-axis machines are really expensive and have X, Y, Z axes - and the head can rotate in 2 directions so undercut machining can take place without replacing the workpiece. The software required for 5-axis machines tends to be complex and expensive too.

    All the machines are capable of 2D machining which is machining simple shapes out of solid flat stock material - all the way through. 2.5D is the same principle but the machine can 'pocket' to a set depth as well as cut through using the z-axis.

    3D machining isn't really 3D as such - it's still 2.5D, but uses the Z-axis and other axes to machine smoothly and can create complex organic shapes like faces - but with undercuts becasue the tool is straight and can't 'undercut' where recesses or ledges occur - for that 4-axis and 5 axis machines are required - or the workpiece can be flipped and moved manually in the the case of a 3-axis machine and suitable software for 2 or 4 sided machining.

    2D/2.5D machining is much simpler to perform. 3D machining can be tricky and requires some experience before great results will happen.

  • What software do I need to run my CNC router?
    admin15-09-2016

    The CNC router comes with a DSP (digital system processor) pendant-type controller which runs off a USB to actually provide the motion control -although other controllers are available, some even run direct from a Windows PC via serial connection - but we think the DSP is more reliable from experience. The DSP requires instructions to do anything useful and needs a software package that can take designs and change them into bunch of numbers which the machine can understand when it moves around machining a job. The bit that does this is called a "POST PROCESSOR" within the CAD/CAM (computer aided design/Computer aided manufacture) you'll need.

    For design and creating your artwork (CAD) and that important "post processing/toolpathing" (CAM) depends what you want to do, might require different software for each type of work & it is important to understand what machining methods you will need in order to produce your work.

    When it comes to software there is a significant difference in both features and price on the multiple software titles out there & depending on what type of work you are doing, you may be able to get a simple cheaper package that will do everything you need.

    E.g If you plan on making wooden Signs or 2D parts Vectric's VCarve Pro is as good a program with heaps of features but there's also a cheaper option in the form of Cut 2D Pro from the same website.
    If 3D (2.5D) is what you are looking to do- VCarve Pro is also a good choice although it's not a true CNC machining package like Autodesk HSM for instance, but it'll still be great for most jobs on your CNC router.

    Other sofwtare packages work as well -and there are heaps available- though MakerspaceNZ will be less able to assist with developing a workflow that works for you.

    If you already use CAD software for developing your stuff... e.g. AutoCAD or Illustrator, Sketchup etc, all your drawings can be imported into VCarve packages as a dxfs. This makes it simple if you're already using CAD drawings & will keep you from having to redo all the work you already have invested time into.  Then it's only a matter of importing these drawings into your CAD/CAM software to produce the G-code (postprocessed or toolpath code) and run your job.

  • What size machine will I need?
    MakerspaceNZ15-09-2016

    This is probably one of the biggest questions you will ask yourself while looking at purchasing a CNC router.

    What kind of work do you want to do now? How about 3 years from now? If you are in a small workshop and you only want to make small parts, a small TE6040R machine will likely do you just fine, but if you want to cut full sheets you will do well to look at a TE2412R or larger machine.

    If you plan on getting by with a smaller machine and stretch the machines capabilities it may be fine in the beginning but when you get a few jobs and as your experience grows, cutting down material to fit your smaller CNC will be extremely time consuming and as a result time-expensive.
    Buy your second machine first. This is a statement you may have heard or read when it comes to CNC machines. This is not a sales ploy, it is a very important piece of advice to those new to CNC that may not see the big picture yet. Buying a basic CNC is great for hobby use. But when it comes to a school or workshop that wants to use a machine in production, even light production, this can be a huge set back.

  • What support do you offer?
    MakerspaceNZ15-09-2016

    Makerspace NZ pride ourselves in giving a suburb and trouble free experience when purchasing new technology as we know it can be daunting. When you buy a machine we will deliver, install and train you until you completely comfortable and only then will we be happy and if you need Professional Development or Classroom support - we can help with that too - some of us are ex-teachers and understand your pain!

    Our support technicians are available by phone, internet (remote service or via Q&E/email or servicedesk) or at your facility (although some fees may apply if we come onsite).

    Additionally, each machine is pre-configured for remote desktop support & this enables us  to troubleshoot your CNC via an internet connection no matter where you are located. The machines are pretty robust and we have had very few issues with breakdown once installed and basic maintenance is followed.

  • 2.Router Servicing and Maintenance
  • Will my machine be hard to maintain?
    MakerspaceNZ01-12-2016

    Certainly not - we think our machines shouldn't be workshop Queens - they should be covered dust and be working constantly!

    Of course preventative maintenance is always the key and all the machines ask is that they are wiped down and vacuumed occasionally -including the electronics cabinet and the cooling intakes dusted (switch off the power before doing this!).

    The spindle requires no maintenance - well other than maybe just checking the connector hasn't come lose once in a while- and the bearings are sealed. As part of our maintenance program, a small amount of tool oil is squirted liberally on the square linear bearing rails and she's ready to go!

    If any component fails - which is rare indeed from our experience- we normally have spares in stock and they can be readily swapped out buy any novice mechanic or electrician in only minutes (or we can do the work too if you prefer)!

    Above all - Keep your cutting tools sharp (blunt tools not only squeal and work the machines harder than normal, they also give substandard finishes!) and don't machine into your clamps!

  • 3.Router Troubleshooting
    There are no questions in this category