A Video Diary: Laser Cutting and Engraving Videos 01

• Introduction to the machine
• A look at what you get for your money
• The DIY water tank
• Tour of the machine
• A look at the engineering quality
• Doubts about the aluminium table
• Laser Cutting and Engraving Videos

• Laser light theory
• Laser head description
• Laser focus point
• Absorptivity table for metals
• 3 main cutting mechanisms with the laser
• Hazardous fumes from cutting plastics and some woods
• Warning about VERY high voltage

• Loading RDWorks
• Useless stuff on the CD.
• This link will take you to the latest version of RDWorks.
• But a better source for a good stable well tried version with added items in the cutting parameter library can be found at http://www.thunderlaser.com/laser-download Download at least items 1,3 and 4
• Install the USB driver but put a USB stick into a USB port first or it may complain (in Chinese that you won’t understand). THEN press install to load RDWorks.
• Configuring your work area to match your table size
• Quick first look at drawing a figure
• Use of Control key.
• Simple use of coordinates to align objects
• Quick look at layers and cutting parameters
• Cutting power…you are witnessing my ignorance. DO NOT FOLLOW IT. Set your max/min power at 60% /60%
• UNTICK THROUGH POWER.
• Layer order. regardless of order, SCAN always takes precedence over cut layers

• Nail bed mark1
• Fitting the water pump and tubing
• Powering up the machine in stages
• Using the focusing tool
• Red dot pointer
• Finding out where machine 0,0 is
• First test pulse
• Seeing the invisible laser beam
• First power down

• Dangerous materials you should not cut
• Places to go and find out about plastic materials
• Loading your first test program
• On machine parameter editing
• Exploring the machine keyboard
• Running first test program
• The effect of air assist……not a good idea to turn off air assist as there will be a chance of fogging the lens.
• Note I am using 80 and 85% power BAD NEWS. I should not be using more than 60%
• Why you need to set the focus correctly.
• Laser Cutting and Engraving Videos

• Making a focus setting gauge
• Testing beam power and size of beam with different focus distances
  • in a block of acrylic
• Depth of cut tests with different speeds and no air assist (not recommended as there is a risk of fogging the lens)
• Depth of cut tests with different air assist pressures
• Beam penetration results (more air assist pressure=shallower cut) True for acrylic but not all materials
• In my ignorance I mention using 100% power. I didn’t know at this point that 100% power was there but NOT to be used!!!!

• Setting Config file to give a page size the same as your machine table
• Setting the blue arrows to match your machine 0,0
• Setting head position (the green square) At this point I did not understand the datum scheme. See https://youtu.be/CWZvQXxbR_E
• Setting node menu
• Drawing a line and using the Ctrl key to fix ordinate positions
• Drawing Poly lines
• Drawing Circles and ovals
• Drawing squares and rectangles
• Using the Text tool
• Quick look at Bezier curve tool
• Laser Cutting and Engraving Videos

• Drawing a marquee round objects
• The X and Y coordinate position of object centres
• The X and Y dimensions of an object
• Using the padlock tool
• Using the % scale windows
• Using the rotation tool
• Getting to rotation handles with a double click

• Move your object to work area corners
• Last drawn or selected object become the “anchor” object
• Use of EDGE alignment tools
• Last selected (using shift key) object become the “anchor” object
• Using mouse key to zoom in and out.
• Resizing and spacing objects tools.
• Moving an object’s location coordinate

• Draw simple test object
• Use of layers to separate scan and cut functions
• Setting layer parameters for cutting/etching
• Assessing depth of cut to guess cutting speed.
• Is Blowing? Is actually not relevant to our simple machine. It’s a feature of the controller that allows you to program the extractor on and off so that it only extracts when you are cutting if you answer Yes. You fan is NOT connected to this system, so the question and the answer are meaningless
• Through mode. I now know this to be not very important for our machine Through Power should be used in conjunction with OPEN DELAY. Normally the program starts cutting immediately. If you tick Through Power, specify a Through Power % and set the OPEN delay to say 10ms. The head moves to the start point, turns on the Through power % for 10ms. After 10ms the normal power and program begins NOTE!!! Make sure you set OPEN DELAY back to zero if you untick Through Power
• Error Don’t set power to 85% limit yourself to 65%
• Layer cut order. You can select cut order BUT machine will an ALWAYS do scanning layers first
• Preview your program
• Save your drawing as a .RLD file
• Save your machine program via Ufile button as a .RD file.
• Load .RD file via a USB stick into the laser machine

• Look at different plastics you can and cannot cut
• Hammer test to identify safe ones
• Places to go to find out about material hazards
• How to edit parameters on the machine
• How to run your first program

• First attempt at graphics in Photoshop (failed)
• Importing graphic from internet
• Building a picture away from RDWorks
• Import into RDWorks
• Create final object
• Break object into 2 layers. One for cut and one for scan
• I set power to 85% power WRONG!!!!
• Use preview screen
• Connect PC to machine to transfer program
• Use of Track button
• Examine finished project
• Laser Cutting and Engraving Videos

• Designing a cut test program
• Copy and paste duplicate objects
• Use even spacing tool
• Use horizontal alignment tool
• Put all objects on different layers
• Assign parameters to each layer
• Run the cut test to show results are now worse
• Some ignoramus mistreating a lens!!!!
• This is how to remove the anti-reflective coating. Ignorance is bliss. DON’T do it this way.
• Despite my attempt at wrecking the lens, all’s well that ends well

• Import a BMP picture
• Using the bitmap handle
• Examine the picture in the Bitmap Handle window
• Experiment with lots of settings
• Add text to picture
• Add layers and assign parameters for each layer.
• Cutting at 90%??? WRONG!!!

• Producing the horse graphic on acrylic using NET GRAPHIC.
• Set the focus a little into the material
• Not the most successful graphics test

• Reworking the horse picture as DOT GRAPHIC
• Produce 2 copies
• Zooming the screen to examine the finished dot picture
• Invert image to a negative for the second picture
• Examine both with preview.
• Cut both pictures and compare end results
• Examine pictures close to look at the dotting
• Modify resolution to improve picture?

• Disconnect Y axis plug and plug in rotary device
• Orienting the rotary device onto the machine table
• Discover direction of keyboard arrows
• Understanding 90-degree rotation of program
• Designing and programming a test program with 150mm reference lines
• Set rotary device true to table
• Power machine on and find the roller 0,0
• Laser Cutting and Engraving Videos

• Align Head to work centre
• Understanding slippage
• Align work by using track test
• Cut test program and measure reference distance (162mm)
• Don’t mess with vendor settings
• The maths off calculating a correction factor
• Designing another calibration check program
• Verifying Calibration number with a smaller tube.

• Designing acrylic targets to aid with beam alignment
• Quick check of beam alignment at each mirror
• Check beam centre through nozzle in two axes

• Prepare bitmap for rotary engraving
• Set to negative and modify y axis to 92.6%
• Someone suggested engraving through wet kitchen roll
• Repeat test with NO kitchen roll
• Be careful of glass shards
• Clean off glass shards

• Preparing a photo by mounting it to backboard
• Method of cut design
• Programming the cuts
• Cut optimise
• Preview cuts
• Order cuts by layer order.
• Test cuts to see how corrugated card does not cut well
• On-machine editing caution. Only one layer at a time
• Looks like cut success but in reality, rubbish.

• Picture remounted on 2mm acrylic for 2nd attempt
• Maybe substitute tri wall card for honeycomb
• 3rd attempt 95% power (NO!!!!!!!)
• Finally, success
• Stupid test…… engraving sliced bread!!!

• Preparing program
• Setting parameters 95% power (NO!!!!!)
• Cutting the parts
• Assembling the sculpture (click together)
• Add some led illumination
• Final success
• Laser Cutting and Engraving Videos

• Create some power loss test programs
• Run the test program
• Note. At the end of each sweep the beam cuts a groove in the piece of vertical white acrylic
• Conclusion that power loss is from the laser itself.
• MODE burn tests prove varying laser output

• Running program to produce test strips
• Finding out that power recovers quickly when beam switched off
• Mode burns at 1-minute intervals
• Examination of mode burns to show magnitude and speed of power loss

• Realization that RDWorks is an INTERFACE program NOT a CAD or DRAWING program.
• A drawing with multiple parts that need cutting in a specified order.
• Discovery of the cut optimise list
• This is the tedious LONG way to order cuts (It’s not until session 29 that I discover the BEST way to use this tool)
• Assembling the acrylic construction
• This jig was a great vehicle for learning about cut control, sadly the jig itself was useless

https://www.youtube.com/watch?v=C7Su7RZvKdQ

• General design of card.
• Edit cut property examination
• Cut optimise set up
• Struggle to find the correct order
• Cut optimise set as “inside to out”
• Examination of original nail bed. Binned
• Mk 2 pin bed…fully adjustable
• Cutting the Xmas card
• Assembling the finished card

• Explanation of the cut order I am looking for
• Cut optimise setting
• A different approach to SET CUTTING PROPERTY.
• Reversing the list
• Test with preview to check order….wrong.
• MUST remove tick from Path Optimise to allow ME to take control.
• Fix the Sue problem
• Further refinement of ordering the Set Cutting Property list
• Setting pin positions for good paper support
• The final personalised Christmas card

• An attempt to use conventional calorimetry to measure tube output power
• Laser Cutting and Engraving Videos

• Final testing of original rubbish tube prior to changing it.
• Introduction to my crude calorimeter
• Calorimeter calculations to establish power absorbed
• Results show lower average output form higher % power setting
• Conclusion. Yes, a rubbish tube. Needs to be replaced

• Emptying the water from the old tube
• Removing the old tube
• Remove the HV connection. (Wire wrap connection!!!!)
• Modifying the brackets to suit new larger tube
• DO NOT ATTEMPT TO SOLDER THE WIRE ONTO THE POST like this. It will NEVER work and will invalidate any warranty that may be on the tube. Stay with the wire wrap method.
• Connect water and check air bubbles move out
• Mode burns to verify better output
• Quick check the beam is through centre of nozzle
• New beam cut quality
• Quantitative assessment of power with mode tests
• Results hint at 65% power being max power output
• Calorimeter results assessment of power.
• No Power supply issues
• Graphical confirmation that you don’t run at more than 60% power setting

• Chinese laser advertising fraud
• Benchmark tests
• Design test program
• Run perfectly timed mode burns to see power characteristic of your tube.
• Confirmation that 60% power setting should not be exceeded.

• Import artefacts as RDWorks brings in fine detail
• Solution is to export at 10 times full size
• Import and then scale down to 10%

• Here is a suitable temperature relay (with sensor) plus this ammeter.

• Wire in the ammeter and check polarity
• Check what %power is the allowed max drive current (75%)
• See efficiency of extraction system
• Test cut with 4mm plywood
• Fitting NTC probes to measure temperature of return water into the tank
• Revised max power is now 65%power
• Test cut in 4mm
• Demonstration of how the excess power puts marks on the acrylic base plate

• Bit maps revisited
• Photograph onto wood ….a failure
• Convert photo into a line drawing sketch
• Import as bitmap
• Use Bitmap Handle to modify picture even further.
• Add a cut out feature
• Cut/engrave the coasters
• Finish them off with a wax polish

• My experiences and modifications so far
• Laser Cutting and Engraving Videos

• Order the parts with reversing method
• 65% power cutting for 10mm acrylic at 2mm/sec
• Cutting 10mm acrylic with a 1.5” focal length lens
• Cutting 3mm acrylic
• Assembly of knife block
• Squareness of edge ……. A problem?

• Draw a test program
• Remove the Y axis plug
• Auto run mode burn test
• Turn off power to reconnect Y axis

• Simple look at the CARTESIAN co-ordinate system
• Explain machine 0.0
• Explain program 0,0
• Explain position of OBJECT 0,0
• Explain machine ORIGIN button allows you to fix the program 0,0 at a position of your choice in the workspace.

• A radically simple approach to controlling cut order
• Clear the CUT OPTIMIZE window
• Turn off PATH OPTIMISE
• Use of the SHIFT key to help with SELECTING separate elements into a GROUP
• Press the GROUP button
• Review and order the SIMPLIFIED Edit Cut Property list
• Cutting the program
• Assembly of the finished card

• Cutting 10mm plywood…..very cleanly
• Keyboard wear observed
• Keyboard cover
• Fire hazard note
• Note about edge squareness

• Constructing a compact laser pointer
• Collimating the beam
• Laser Cutting and Engraving Videos

• Examine the positional error of the focus point when the laser beam is off centre to the lens or off angle to the lens
• Fixing the laser pointer to the water jacket
• Steering the mirrors accurately
• Out of squareness found?
• REMOVE the laser pointer and check with the real beam
• Test cut to show resetting head to perpendicular has fixed the squareness issue with cutting.

• Using the laser pointer to set the mirrors
• Checking the dimensional accuracy of the CUT
• Understanding diagonal errors

• Making a target holder and targets for checking that beam is coming out of the nozzle perpendicular to the table.
• Remove mirror 3 and modify holes to allow more float
• Move the head ONTO the beam centre and reset it square and true.
• Discovery that lens is fitted “wrong” way
• Now easier to get beam vertical

• My power meter arrives!!!!
• Examination of what I got for my money
• Do I trust it? Yes
• Designing a test program to set the beam on for an EXACT period to fire at the power meter
• Quick check of laser output                  37.0 watts!!
• Check power after 3 mirrors                 31.0 watts!!
• Check after lens                         30.5 watts!!

• Design of edge lit sign…. but solar powered
• Scanning ALWAYS happens first regardless of layer order.
• Engraving and cutting sign
• Quick test of “look” with temporary LEDs

• Making the aluminium base tube
• Fitting the sign to the base tube
• Testing the solar lights…..rubbish
• Testing a much higher price LED set…Looking good
• Fitting LEDs to sign
• Test of durability and “look” ……seems successful

• Last minute modification to make a mount for the solar collector integrated into the sign mounting post

• Design a set of clamps for my 2nd laser tube to replace the dodgy modified original clamps.
• Cutting the clamps
• Assembling the clamps
• Check clamps fit the tube

• How does my laser tube work?
• Simple atomic stuff
• Pictorial description of how the tube works.

• Description of how the carbon dioxide depletes inn your tube.
• Final proof graph of why your tube dies.
• Parallax confirms “dissociation” as the cause of death for a tube.
• Examination of my old tube to try and find out why it was so bad.
• Fit original tube back into machine for testing
• Add heat transfer grease to gap on mirror
• Did it improve its performance? Is it worth keeping?

• Fit 2nd tube back into machine
• Must seal HV terminal to prevent coronal leakage
• Fitting temperature probes to protect tube against freezing.
• Powering up the tube again
• Example of my new tube trying to strike at low current
• Example of my tube struggling to strike properly at full/mid-range current
• Power characteristic for my 2nd tube
• Laser through mode ….possible work around?

• Revised version of the laser pointer
• Different registration system
• Reference scorch mark
• Elastic band fixing method
• Checking mirror settings
• Cutting 10mm acrylic with 30 watts
• Laser Cutting and Engraving Videos

• Assembly of Mk2 adjustable clamps.

• Another attempt at making a laser pointer
• Assembly of the pointer
• No collimation required
• Rubber band fix ….again
• Sausage shaped mark (not a sharp dot)
• The Y axis beam instability problem we noticed with the mk1 pointer is still there

• Examination of the wandering beam and the effect it could have on the cutting accuracy
• Mirror 2 mount seemed to be the root cause…very flimsy and being twisted by torque from the cable guide chain
• Stiffen the bracket with additional screw
• Discovery that mirror mount limits bracket adjustment.
• 10mm plywood test cut at 6mm/sec.
• Check on power at cutting surface 27 watts!!!
• Quick look at the heating / anti-freeze system

• Realization that my machine is fitted with a 1.5” focal length lens
• Comparing 3 lenses that we can fit to our machines
• Spot diameter is very important (energy density
• Longer focal length puts the nozzle further off the work. That degrades the airflow into the cut area.
• For acrylic you do not need much airflow but for wood you need lots.
• Depth of cut changes with focal length
• Depth of cut in acrylic can be shown to decrease with excess air assist.

• How does temperature affect the power output of the tube.?
• Discussion of how my tank and tube are protected against sub-zero weather and how the DISTILLED water in the tank has remained pristine
• Examination of graph to verify the winterisation of the machine was a success
• Look at the graph to see the overall result. No significant loss with temperature increase.

• Infra-Red ….what is it?
• Laser beam is IR “light” that we cannot see but we can feel it.
• How dangerous is IR
• How various metals react to IR light
• The dangers of reflectance
• Steel bed plate advantages
• Phenomenal copper reflectance
• Laser beam danger assessment
• Materials that absorb IR including human tissue.
• Safety glasses http://www.hivis.net/132/Personal-Protection-Equipment/Safety-Spectacles/Clear-Lens/
• Laser Cutting and Engraving Videos

• Power tests to check power losses across mirrors
• Important to set the power meter back to ROOM TEMPERATURE
• Summary of results for mirror losses
• Discussion of results
• Examination of my mirrors
• Difficulty getting access to mirror 2
• Mirror 2 needs a dramatic clean
• Recheck power losses
• Improvement after cleaning mirrors? NO.
• Decision to make copper mirrors.

• Check power loss with copper mirror and original mirror
• Making of a prototype set of copper mirrors
• Significant reduction in mirror losses by using copper mirrors
• Discovery that my mirrors are molybdenum

https://www.youtube.com/watch?v=2gUjIExQI64

• More mode burns to check power after each mirror
• A few hiccups with my “bipolar” tube performance.
• Understanding that mirrors are oval when the beam arrives/leaves. Must be very accurate with beam alignment
• Modifications to mirror 2 screws
• Using the red beam pointer to aid mirror adjustment.
• Hacking the machine to access the mirror adjusting screws
• Relative power of mode burns A good checking method
• Decision to make better copper mirrors.
• Final test demo of cutting 15mm acrylic

• Death of the hard disk mirror myth
• Make a hard disk mirror
• Compare the hard disk mirror with the copper mirror
• Make a new mirror that also shows better performance.
• Further hacksaw work on the machine case.

• Look at changes I have made to make beam setting simple
• Case changes
• Mirror 2 modifications
• Make an adjustable bracket for the head mount
• Modify mirror 2 mounting bracket
• Remove mirror 3 and set up a line of sight back to the laser.

• Burn mark misses mirror 3 Why?
• Adjust laser tube alignment, NOT a mirror
• Pulse test and align the mirrors
• Move the head onto beam centre, you may have to make your own bracket.

• Pin Bed manufacture (8mm acrylic)
• Setting pins to give edge location
• Setting a typical pin arrangement
• Cutting demo of a gift box using the pin bed 2mm stainless dowels http://www.pts-uk.com/Products/Pins_Dowel_Pins_Metric_A2/A70232
• Laser Cutting and Engraving Videos

• Even more copper mirrors!!! A different manufacturing method
• Making 3 mirrors at once
• Change the lens for a new HQ lens
• Do a scorch mark on mirror 3
• Turn the laser and add the laser pointer to the tube
• Replace 1 mirror at a time and use the laser pointer to reset each as you go
• Power checks good until mirror 3
• Mirror 3 has always been a problem Why?
• Detail drawing of the head shows mirror is not central to the entry hole
• Adjust the HEAD to catch the beam in the correct place.
• With all the new mirrors and HQ lens Examination and discussion of results

• Quick tour of the machine to look at all the changes I have made
• Ammeter essential to maintain good tube life
• Look at the way I have winterised the machine against freezing
• Distilled water still pristine
• Importance of my power meter in developing the machine.
• Head mount special adjustable bracket
• Mirror mount and adjustment modification
• Laser pointer.
• Dangers of the laser beam
• Hard disk mirror myth
• DIY copper mirrors …very, very good.
• Bad design of mirror 3   position.
• Demonstration of my “laser KISS” to get the machine run properly
• Run out of patience and have ordered a new 60watt tube and PSU
• Look at the new pin bed

• Yet another variation of the laser pointer to suit different machines
• This version s magnetically mounted on its own bracket and stands free of the laser tube.
• Design. Cutting and assembly of parts
• Testing

• Cutting and building the extension box parts

• Unpacking
• Removing the old tube and power supply
• Fitting the new 60-watt tube and power supply
• Move the position of the HV end tube clamp to reduce unsupported length
• Powering up the tube
• Checking the power output. WOW 73watts!!!
• Laser Cutting and Engraving Videos