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An introduction on how to use the noisy machine in the corner of G10

Induction Required

This equipment requires an induction prior to use. For your own safety and to avoid damage to the equipment do not attempt to use it until you have been inducted.

Loud Equipment

This equipment is extremely loud. Ensure that you and those in the room are wearing ear defenders. Hearing damage is permanent and debilitating.

How do CNC machines work?

  • The following videos give a much better explanation than this author can
  • Where Mach3 is mentioned, we use bCNC

What is it?

  • A modified ICP 4030 CNC mill
  • A computer-controlled, spinning cutter
  • It can move in three directions:
    • Linearly in X, Y, Z
    • A fourth, rotary dimension (A) is planned
  • It can cut many things:
    • Tested:
      • Aluminium
        • lubrication is critical
      • Titanium
        • the hackspace logo on the door was machined from titanium
        • lubrication is critical
        • slow cuts can cause work hardening
      • Steel - a small experiment has been carried out, more attempts needed
      • Wood, quite easily
    • Not tested, yet:
      • Plastics
      • Carbon composites
      • Human Fingers

Machine Overview

What do all the buttons do?

  • Power buttons
    • Box on the side of the machine
    • Controls power to the entire machine - including the computer
    • Hit the off button if a catastrophe is happening
  • Cover
    • Hold the button to unlock the door
    • This only works when the machine has power
    • The spindle motor is interlocked to the cover - it will not turn when the cover is open. The cover
  • Other buttons
    • They do nothing
    • Ideally, they will do something one day, but this is a low priority, so may not happen

How do I use it without dying?

  • Don't cut your finger off
    • Don't touch the spinny bit
    • Don't open the cover when it is spinning
    • The spindle power is interlocked to the door. However, interlocks can fail!
  • The mist cooler creates an oily fog
    • Don't breath this in
    • External extraction is planned
    • An interim solution has been to use the portable sawdust extractor to catch the cloud from the top of the machine. The filters/dust inside seem to work well at removing the (very small volume of) oil from the air
  • Dust clouds can be flammable
    • Especially true if cutting wood
    • The portable dust extractor can remove the dust cloud from the top of the machine. A better attachment is needed (want to be amazing and help the space? create this attachment!)
  • Metal chips can scratch your eyes
    • They will likely get stuck to the door and then fall on you when you open it. Watch out for this!
  • If you tell the machine to move, it will move, regardless of whether your fingers are in the way
  • The compressor is extremely loud, and will probably start as soon as you power the machine on
    • warn others in the room, so they can use hearing protection

How do I make something with it?

  • Have you watched the videos linked further up the page?
    • watch them
  • design your part in Fusion 360 - or CAD software of your choice
  • use CAM (computer-aided manufacture) software to create the g code (.nc file) - ideally use Fusion 360 for this as well
  • transfer this to the CNC mill computer
  • on the desktop, press “run bCNC”
  • Connect to the machine through COM 4 (probably)
  • press home
  • zero each axis on the workpiece
    • you did set the origin to a sensible point didn't you?
  • press play
  • you will have made a mistake in your setup, accept this
    • PLACE YOUR HAND ON THE KILL SWITCH, READY TO PREVENT THE INEVITABLE CRASH!!!
    • grumble to yourself and others
    • try again

Feeds & Speeds

The result of poor Feed/Speed selection!

  • Feerate: How fast the spindle is moved accross the workpiece (mm/min)
  • Speed: How fast the spindle turns (RPM)
  • The combination of these factors, along with the cut depth determines the forces on the tool
  • The free mobile app FSWizard is very useful for selecting the right speed/feeds in an intuitive manner. https://app.fswizard.com/
  • Because of the cheap spindle motor driver, the mill has very low power below 10'000 RPM. Therefore, it is better to use smaller tools, which use higher spindle speeds.
  • Maximum spindle speed: 24'000 RPM

What is a collet?

What a lovely collet Drawer full of collets, nicely lined up

  • A collet holds the tool nicely in the spindle
  • Select the correct one for the diameter of the tool shaft
  • Ensure it clicks fully into the holder on the spindle
  • Insert the tool
  • Tighten the holder onto the spindle using the big spanners

Oh dear, not properly inserted Nicely seated The collet goes in the black part Big Ol' Spanners

Lubrication/Coolant

Spindle and Mist cooler

  • Compressed air is used to spray a fine mist of cutting oil on to the material to be cut.
    • This is known as Mist coolant
    • For some reason, the control board thinks it is controlling a flood coolant system (where lots of liquid is dumped onto the part, like on our lathe)
    • Therefore, we must go along with this fiction, by telling Fusion 360/bCNC to turn on/off flood coolant, when we need the mist to operate
  • Some materials (Aluminium, Titanium) absolutely require lubrication, as they try to stick to the cutting tool
  • Other materials, e.g. wood, do not require it. However, the air blast will help to avoid chip recutting

Coolant Controls

  • These two screws control Air and Oil flow
  • If lubrication is required, it is desirable to use as little as possible
    • Using more than necessary probably won't improve the cut, but it will make a mess, and increase the risk of inhalation
  • There is also an adjustment knob on the air compressor
    • LEAVE THIS AT OR BELOW 1
    • Experiments showed that turning this any higher resulted in the compressor overheating and seizing

Interesting and nerdy article on coolant strategies https://www.cnccookbook.com/cnc-coolant-system-mist-high-pressure-through-spindle/

What is the build volume?

  • 400x300x140mm (XYZ)
  • The table is larger: 600x375mm

Am I allowed to/how do I/would it work if I?

  • Yes, probably, or possibly no
  • the machine is extremely versatile, so all eventualities can't be covered on a Wiki page
  • don't be afraid to experiment, but be sensible when you do
  • someone on youTube has probably done it. take a look

Oh no, I've broken the CNC mill!

  • This may happen at some point
  • Clearly, you're smart enough to make the machine move. Therefore, attempt to repair it.
  • Put a post on the google group
  • Put a label on the machine

Induction Process

  • Design the thing that you want to mill
    • Use Fusion 360 as it is easy to transfer designs from this into machine code
  • Ask for an induction on the google group
    • The induction will be tailored around the part you are creating

Maintainers

  • Alex R
  • Felix H
  • Mark P

Useful Information for Maintainers

Spindle / Spindle Mount / Inverter / Cooling Pump:

https://www.aliexpress.com/store/product/2-2kw-Water-Cooled-Spindle-CNC-wood-Router-2-2kw-220v-110v-VFD-80mm-Clamp-Water/214974_32965019931.html

https://zhonghuajiang.aliexpress.com/store/214974

Manufacturers Website

ICP 4030 CNC Manual

We appear to have these Stepper Drivers:

DM556T Stepper Driver Manual

This is the operating manual: ICP4030 Operating Manual

And this 5 Axis breakout Board:

5 Axis Breakout Board

Supporting Files

There is also an Arduino Nano controller with GRBL firmware in the cabinet:

Stepper motor information:

  • Holding torque: 1.13nm
  • Voltage per phase: 4.2a
  • Step angle: 1.8° (200 steps per revolution)
  • Angle error: ± 5
  • Connection lines: 8

steps_per_mm = (steps_per_revolution*microsteps)/mm_per_rev

  • equipment/cnc_mill.1590953109
  • Last modified: 3 months ago
  • by alexrowe