Revision as of 21:08, 5 April 2013

Equipment / Laser Cutter

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Our LS6090 PRO Laser Cutter

Summary

This is our LS 6090 PRO Laser Cutter. It has a working area of 900mm by 600mm, and is powered by a 60w CO2 Water Cooled Laser Tube that can engrave and cut through materials such as wood, plastic, card, leather, fabrics, up to about 10-15mm thick (note, it can not cut metal). The laser cut is approximately 0.15mm wide, and a job can take a few seconds through to tens of minutes depending on material thickness and design complexity.

We have a dedicated PC running LaserCut 5.3 software to import, prepare and download jobs to the Laser Cutter. It can import various formats, with DXF being the most commonly used, so various software packages can be used to create your designs.

Here are some examples of laser jobs we've run (please add a photo of yours any time you do a job!)

Using the Laser Cutter

The laser cutter is a great way to easily produce accurate and complex 2D forms in various materials, and can be designed for with limited experience in various drawing or CAD applications. At the same time, it is an expensive tool with real risk of injury and fire, so is very important you know how to use it to avoid damaging yourself and the machine. You must only use the laser cutter if you have been trained, and if you are ever in any doubt about something, please ask for assistance.

Owners

The Owners are those who have volunteered to be in charge of the equipment, organising maintenance, training others to use it, and generally being a point of contact. The current Owners of the Laser Cutter are:

• Simon Ford
• David Barham
• Nick Johnson

If you have any questions, problems or concerns around the laser cutter, please use the mailing list thread:

• Log : Laser Cutter

Training

To get trained on the laser cutter and be added to the qualified user list, you will need to arrange for a training session with one of the Laser Cutter Owners.

If you'd like to arrange training, please see:

• Laser Cutter Training

Health and Safety

The laser cutter is a potentially dangerous piece of equipment which must only be operated by members who have received appropriate training and who take due care. The top things to always remember when using the laser cutter are:

• ONLY USE THE LASER CUTTER IF YOU ARE ON THE LIST OF TRAINED USERS
• NEVER LEAVE THE LASER CUTTER RUNNING UNATTENDED
• KNOW WHAT TO DO IF A FIRE BREAKS OUT
• NEVER CUT MATERIALS THAT YOU DON'T KNOW ARE SAFE

As a trained user, you should be very aware of the following risks and how to deal with them:

FIRE (under normal operation) - Cutting at the wrong speed or the wrong power can result in the material igniting

• You must watch the cutter at all times and be prepared to abort the job if problems occur
• Small flashes of flame that don't hang around for a fraction of a second are acceptable, but any more is rare and not acceptable
• If a fire does take, this is the process you should follow (from minor to major):
  • Press "pause" (the same button you started the job with) - This will turn the laser off so no more heat enters, and assuming the flame goes out, you can press "start" for the job to continue where it left of
  • Open the lid - With the job paused, you can open the lid to blow out the flame. Again, it is possible to re-close the lid and continue where you left off
  • Move the material from under the laser head assuming safe to do so (so it doesn't damage the optics; alternatively send the laser to home/datum), and smother with a spare sheet of material or blow out
  • Use the workshop CO2 extinguisher to extinguish the flame
• You should also make a note in the log if any of this happens with associated materials and settings so we can keep track of any particular materials/settings we should look at

FIRE (abnormal operation) - If the head gets stuck or something else goes wrong, ignition could happen much more suddenly or intensely

• You must watch the cutter at all times and be prepared to abort the job if problems occur
• If the head gets trapped (e.g. tomb-stoning of a piece, mechanical failure) or any other problem occurs that causes or could cause fire, this is the process you should follow:
  • Hit the emergency stop
  • Open the lid and move the material from under the laser head assuming safe to do so (so it doesn't damage the optics)
  • Blow out, smother with a spare sheet of material, or use the CO2 extinguisher to extinguish the flame as appropriate
• Ensure a Maintainer looks at the machine before it is brought back in to action if it is not obvious what went wrong and all is ok
• You should also make a note in the log if any of this happens with associated materials and settings so we can keep track of any particular materials/settings we should look at

FUMES - The laser cutting process will release different smoke and fumes depending on the material.

• Never cut PVC or a material you are not sure is safe. When PVC is heated it releases chlorine gas, this mixes with the moisture in the air and the result is hydrochloric acid which is toxic to humans and corrosive to machines.
• Ensure the filter is on and the cutter lid stays closed for a while after a job to allow the fumes to clear.
• If you are feeling strange, think the fume build up is too much, or for any other reason you are unsure, stop the job.

TRAPPING - The head and bed of the cutter can be moved by the front panel menu or programs in the machines memory.

• Be careful when working inside the cutting area or with the lid open not to trap hands, hair, clothing or anything else.
• Always check the machine for unexpected items that may have fallen in before closing the lid.
• Do not attempt to climb into the machine!

LASER BURNS/LIGHT - A 60W laser can do real damage.

• The laser should be safe within the confines of the machine, and cut-off automatically when the lid is open (although this should not be relied upon). The top window is safe to look through during a job, but do not attempt to interfere with these windows or the laser or in any way invent some way to look at the laser.
• Do not tamper with the laser cutter, or any interlocks. All side panels of the laser should always be closed and locked whilst the machine is plugged in.
• Do not put metal in the laser cutter.

Instructions

To use the laser cutter, you must have been trained and have had your name added to the trained user list; these instructions are not a substitute for this training. See the training section to understand how you can become qualified to use the laser cutter.

Although not a requirement, it is recommended someone else trained is also present when using the laser cutter. Having two pairs of eyes helps avoid forgotten steps, allows for double checking, clarifications and discussions, and ensures a greater pool of experience is both present and being built up as the laser is used.

Power Up

Give the machine a quick visual check. Make sure that there is nothing left on the bed, the water reservoir is normal, and that the equipment has no obvious damage or signs of being out-of-action. If the bed looks like it has residue on it, give it a wipe with IPA and a cloth.

Turn on the air filter system to the right of the laser cutter using the green rocker switch. It should power up, make a decent amount of noise, and the lights should indicate the filter is in good condition (i.e. no need for replacement).

Make sure the lid is closed. Turn on the laser using the key on the right hand side. The inspection lamp should come on, a satisfying hum start up, and the cutter go into doing its self-checks and start the cooling water feed pump.

Before doing any job, the laser should be left to warm up for 4-5 mins. While the machine warms up, power on the adjacent PC and start the LaserCut application from the desktop.

Load your Design

The PC software has an import facility which seems to be happy taking AutoCAD 2004 DXF files and other formats. The workspace of the laser bed is represented as the workarea in the LaserCut software. If the import doesn't do what you want size-wise, you can select the whole image and then use the 'size' command from the drop down menu to set the dimension you want. Clicking on the three dots ... symbol will adjust the other axis in the same proportion (keeping the aspect ratio fixed). Selecting the 'centre on bed' option will locate your imported drawing on the centre of the machine's cutting bed.

Assign Settings to Colours

Each part of your drawing that is assigned a different colour can have a different cut action assigned. Each colour will appear on the menu on the right hand side of the screen with numbers related to power and speed of the laser which will be used for the colour.

The main options are to Cut (line) or Engrave (raster fill). A marking on the material is a Cut. For each material and cutting depth required, a corresponding speed and power must be entered. The handbook provided with the machine gives suggested values for various materials but these should be considered as a starting point for a test. See the Power and Speed Settings section for our guidelines and experiences for these settings.

Download to the Cutter

Your drawing will feature a blue dot which represents the starting point of the laser; this is by default on the top right corner. In general, you will want to use "immediate" mode, which means this point represents wherever the laser is positioned when you start the job. You can also run the job in absolute mode by unchecking the box, making the job use absolute positioning on the workspace.

To download, select Download and Download Current; the download option will by default call the file on the laser cutter 'LASER'.

Set the Focus

Before each job, the focus needs to be checked and set by adjusting the height of the bed, and thus the work piece, from the lens. The critical dimension here is 41mm and several gauges made of perspex will be left around the machine. This gauge needs to be a fit between the top surface of the material you intend to cut and the white plastic 'flap' on the lens piece. The height of the table is adjusted using the UP and DOWN buttons. Failure to set the distance correctly will result in an out of focus laser and much bigger (but lower powered) cut line. Always ensure there is clearance between the material and laser head before the head moves.

Aligning and Testing the Job

The cutter's menu will show the most recent downloaded file highlighted. Pressing the 'test' button will make the head travel along the square maximum extends of the cuts. This shows you that you have the material in the right place, and you have enough of it! You can do this repeatedly, moving the work piece by hand or the laser head using the arrow keys (after hitting ESC), until you are confident you have things where you want them.

Cut the Job

When happy with the location of the material, close the lid and press 'start' to start the cutter. Watch the head and at least at first be prepared to press the 'stop' button immediately if you find you are burning massive holes in your work piece! This goes back to doing some tests on a sample of your material and making sure you are happy with the cut speeds and power you have selected. You should stay near the cutter at all times and be prepared to pause it or stop it in the event of fire.

DO NOT EVER LEAVE THE CUTTER UNATTENDED

Finishing

The end of the job is signified by a beep. Waiting a few moments for the exhaust pump to clear any remaining smoke is a good idea, especially with wood, and will limit the build up of smells in the rest of the workshop. Remove your work piece, ensuring that all parts are cleared from the bed of the machine.

Power Down

The cutter is turned off using the key switch, then the air filtering system with the green rocker switch. Shut down the PC and double check that everything is left in a safe state for the next user.

Clean the bed of debris using the soft brush, then wipe down the bed using IPA and a cloth.

Go away excited by what you can make and come back with lots more drawings!

Power and Speed Settings

In due time we will try to build up a large sample stock of materials and record the values which work best. Here are the sample material tests we have so far:

• 

  3mm Acrylic

• 

  10mm Acrylic

• 

  9mm MDF

Tips & Tricks

• If the laser cutter's user interface does not seem to respond/do what you want, hit "ESC" to return to 'normal mode'.
• The opaque white acrylic needs slightly stronger settings for surface cuts as they are not as visible as in the transparent acrylic (i.e., for similar effect you need a deeper cut). Otherwise seems to cut equivalently to transparent acrylics.
• If you want a tight fit of pieces or very accurate sizing, keep in mind that the laser beam has a width of just over 0.1 mm (maybe 0.11 or 0.12 mm). So all exterior cut lines should be offset by 0.05 mm; you can do this very easily in the LaserCutter Software with the "Offset" tool (units are in mm, so enter '0.05' and select 'Outer').
• The DXF file format stores values only (not values and units). The internal units in the LaserCutter are in mm. If you set your document's units to mm in the exporting CAD system it should work fine, but generally it is a good idea to have a piece of geometry of known length, e.g. a line 100mm long, or a box of known size around your design. This makes adjusting the scaling a lot easier.
• If you want to export a DXF from Inkscape (which is a great, free vector drawing package), then make sure you do "Object to path" from the Path menu for the whole object and then during the export stage, enable "use ROBO-Master type of spline output". This should make sure all the curves and so on work.
• There's now a page to help with Inkscape and our laser at Equipment/Laser_Cutter_Inkscape

Maintenance

The maintenance of the Laser Cutter is carried out by the Owners, with some basic maintenance being carried out by Users on every job.

Maintenance Schedule

Continuous Maintenance (Every job, done by all Laser Cutter Users)

• Clean the laser bed with IPA and cloth
• Clean any debris off laser bed and surround using soft brush

Basic Maintenance (Every week, done by Laser Cutter Maintainers)

• Clean the laser lens with IPA and cotton buds
• Oil the 3 runners with 3-in-one light oil
• Thoroughly clean the laser bed with IPA and cloth
• Check the water level in the cooling tank
• Clean and remove debris from the machine base and catchment drawer

Full Maintenance (Every 4 weeks, done by Laser Cutter Maintainers)

• Check the water is clean in the cooling tank (i.e. no contamination/organic build up)
• Check filter unit for filter renewal
• Oil the 4 rise and fall lead screws with 3-in-one light oil
• Check mirrors and clean with a disposable sachet lens cleaner cloth (only if needed, mirror coatings are delicate)
• Work through mirror alignment procedure to check alignment of mirrors

Maintenance Log

Reactive Maintenance

• 15th Jan 2013, Simon Ford: Laser cutter not powering up, with switching on via key gives no activity whatsoever. No recollection of it cutting out during a job (Alexis), so assume it just stopped turning on at some point. Filter box and power sockets confirmed OK. Diagnosis: RCD in right back panel of Laser reset to off, no obvious reason why. Switching back on brought everything back to life OK.
• 22nd, Simon Ford; 29th, Nicholas - same again.

Regular Maintenance

• Week Number, Date, Type, Owner (Notes)

2013

• January 7, Full, Chris @ HPCLaser
• January 14, Basic, Simon Ford
• January 21, Full, Simon Ford (running better than new :)
• ...various maintenance events happened...
• April 5th, Full, Simon Ford

Maintenance Shopping List

• 3-in-one light oil
• Cotton Buds
• Lens cleaner sachets
• Soft paint/cleaning brush
• Thermometer for water tank
• Hand held CO2 extinguisher

Further Information

• LS 6090 PRO Laser Product Page
• HPCLaser Technical Info
• Laserscript Forum

LaserCut 5.3

• Homepage
• Manual

Installation

Purchase

Full Purchase, Delivery and Installation (£6865.00+vat = £8238.00)

• LS 6090 PRO Laser engraving and cutting machine, 600mm by 900mm 60W (£5250.00+vat)
• Laser Fume Filter (£1250.00+vat)
• Delivery (£190+vat)
• Installation/Training (£175+vat)

Repairs

We expect to have to change the following parts for general maintenance:

• The laser tube (guess every 6-12 months)
• The filter (guess every 3-6 months)
• The optics (guess every 6-12 months)

Maintenance and Spares:

• 60 watt C02 laser tube (£275.00+vat)
• 50 mm Focus Meniscus Lens (£75.00+vat)
• Estimate for Call Out (£200.00)