Differences
This shows you the differences between two versions of the page.
| Both sides previous revision Previous revision Next revision | Previous revision Last revision Both sides next revision | ||
|
equipment:cnc_mill [2020/04/25 22:17] alexrowe |
equipment:cnc_mill [2020/06/14 19:43] alexrowe |
||
|---|---|---|---|
| Line 5: | Line 5: | ||
| <callout title="Induction Required" type="warning" icon="true"> 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. </callout> | <callout title="Induction Required" type="warning" icon="true"> 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. </callout> | ||
| + | <callout title="Loud Equipment" type="warning" icon="true"> This equipment is extremely loud. Ensure that you and those in the room are wearing ear defenders. Hearing damage is permanent and debilitating. </callout> | ||
| ====How do CNC machines work?==== | ====How do CNC machines work?==== | ||
| - | The following videos give a much better explanation than this author can. | + | * The following videos give a much better explanation than this author can |
| * Where Mach3 is mentioned, we use bCNC | * Where Mach3 is mentioned, we use bCNC | ||
| - | * [[https://youtu.be/YBGqknN3gGs|CNC Basics 1]] | + | |
| - | * [[https://youtu.be/J4bMAIEFCYU|CNC Basics 2]] | + | {{youtube>YBGqknN3gGs?medium}}{{youtube>J4bMAIEFCYU?medium}} |
| ====What is it?==== | ====What is it?==== | ||
| Line 19: | Line 20: | ||
| * It can cut many things: | * It can cut many things: | ||
| * Tested: | * Tested: | ||
| - | * Aluminium, carefully | + | * 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 | * Steel - a small experiment has been carried out, more attempts needed | ||
| * Wood, quite easily | * Wood, quite easily | ||
| Line 25: | Line 31: | ||
| * Plastics | * Plastics | ||
| * Carbon composites | * Carbon composites | ||
| - | * Titanium?! - approach with extreme trepidation | ||
| * Human Fingers | * Human Fingers | ||
| Line 40: | Line 45: | ||
| * Hold the button to unlock the door | * Hold the button to unlock the door | ||
| * This only works when the machine has power | * This only works when the machine has power | ||
| - | * There is an intention to interlock this to the spindle motor, but this hasn't happened yet | + | * The spindle motor is interlocked to the cover - it will not turn when the cover is open. The cover |
| * Other buttons | * Other buttons | ||
| * They do nothing | * They do nothing | ||
| Line 52: | Line 57: | ||
| * The mist cooler creates an oily fog | * The mist cooler creates an oily fog | ||
| * Don't breath this in | * Don't breath this in | ||
| - | * External extraction is planned | + | * The portable dust extractor can plug in to the horrible jagged hole in the top of the enclosure. This seems to do a good job of filtering the oily mist |
| - | * 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 | + | * Did I mention that the hole is jagged and horrible? |
| * Dust clouds can be flammable | * Dust clouds can be flammable | ||
| * Especially true if cutting wood | * 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!) | + | * The portable dust extractor can remove the dust cloud from the top of the machine |
| * Metal chips can scratch your eyes | * 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! | * 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?==== | ====How do I make something with it?==== | ||
| * Have you watched the videos linked further up the page? | * Have you watched the videos linked further up the page? | ||
| * watch them | * watch them | ||
| - | * design your part in CAD software | + | * 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) | + | * 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 | * transfer this to the CNC mill computer | ||
| * on the desktop, press "run bCNC" | * on the desktop, press "run bCNC" | ||
| Line 77: | Line 85: | ||
| * grumble to yourself and others | * grumble to yourself and others | ||
| * try again | * try again | ||
| + | ====Feeds & Speeds==== | ||
| + | {{:equipment:20191129_173024.jpg?400|}} | ||
| + | |||
| + | 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?==== | ||
| + | {{:equipment:single-er-11-collet-6-00-5-50mm-swiss-quality-116523-en-g.jpg?400|What a lovely collet}} {{:equipment:20200530_121457.jpg?400|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 | ||
| + | |||
| + | {{:equipment:20200530_121543.jpg?400|Oh dear, not properly inserted}} {{:equipment:20200530_121555.jpg?400|Nicely seated}} {{:equipment:20200530_121510.jpg?400|The collet goes in the black part}} {{:equipment:20200530_121618.jpg?400|Big Ol' Spanners}} | ||
| + | |||
| + | ====Lubrication/Coolant==== | ||
| + | {{:equipment:20200530_105004.jpg?400|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 | ||
| + | |||
| + | {{:equipment:20200530_104947.jpg?400|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?==== | ====What is the build volume?==== | ||
- equipment/cnc_mill
- Last modified: 4 months ago
- by alexrowe