Menu For The Top Ten RDWorks Learning Lab Videos

The Countdown, Starting from 10

These are the RDWorks Learning Lab Top 10 YouTube Laser Tutorials videos ranked by average number of views per month.

10 – RDWorks Learning Lab 206 – Experiments to Test the Lens Cutting Theory

  • Some  people did not fully comprehend my theory of how lenses cut so I recap with a revised diagram.
  • I re-run the test of cutting through 26mm hardwood with a 2.5″ GaAS lens at 3mm/s
  • I then change the setup by removing the hardwood but leaving everything else set the same but this time burning a track on a piece of so that its surface mimics  the BOTTOM surface of the hard wood  We are trying to see what the beam is like at that point 
  • By changing the speed we can filter out the lower power from the outer part of the thick beam 
  • I then demonstrate that a 4″ lens will cut through the 26mm hardwood but at 2mm/s i.e. 33% less speed….but why?
  • I examine the reflections off the curved surfaces of various lenses to assess the  degree of curvature. The flatter the lens surface the greater the “projected” focus (according to my theory) and it illustrates why the 2.5″GaAS cuts better than the 4″ ZnSe. 
  • I take a less than perfect lens  and test it with my penetration test. Then I begin to brutally modify it in stages. I test at each stage  to asses the performance change. Eventually drill  right through the axis  and destroy the  cutting ability
  • I finally test this non-cutting lens to see if it will still focus and engrave.
  • Important safety warning about working with zinc selenide.
  • Top 10 YouTube Laser Tutorials

09 – RDWorks Learning Lab 051 – Beam Setting for Beginners Part 1

  • Must ensure that mirror mounts 1 and 2 are true 45 degrees and same distance off the Y axis rail
  • Must set the laser tube parallel to the back and bottom face of the enclosure by using packing blocks.
  • Check entry into mirror 1 is central.
  • These tedious setting will only need to be done once.

08 – RDWorks Learning Lab 059 – Marking Metal

  • Cannot etch or engrave metal with our low power
  • Marking metal by heat bonding a chemical into the surface
  • Quick test and scratching to show durability
  • High cost of Cermark
  • Low cost of Molybdenum Disulphide spray lubricant
  • Breaking all the safety rules
  • Running a matrix of tests
  • Looking at hazards of using these products.
  • Comparison of results

07 – RDWorks Learning Lab 054 – Acrylic beam drag and flame polishing

  • Explanation of and demonstration of Through Hole Power
  • What is beam drag?
  • How do I get rid of it?
  • Set focus onto surface and close air assist to almost off   
  • Modify the focus depth to 3mm below surface
  • Great flame burnished edge
  • Increase speed…….cut success
  • Examination of cut characteristic
  • Non-square faces explained.

06 – RDWorks Learning Lab 214 – Setting Z to a New Zero Position

To be updated Soon


05 – RDWorks Learning Lab 115 – The Russ Formula for Photo Engraving

  • This formulaic approach has been designed and tested for organic materials such as wood, card, leather and low formaldehyde content MDF.. It may work on mineral materials but that has yet to be researched.
  • Choose the shortest focal length lens that your machine will take.
  • Choose your material
  • Important to understand the principles of binary dot engraving.
  • The ratio between the dots and the background is paramount for a crisp picture
  • Organic materials have a scorching colour range where as something like clear acrylic does not. It’s a binary material that engraves white. This is the opposite of burning and hence when working with acrylic you have to make the image a negative before engraving .
  • Set your lens to the ideal focal position
  • I have designed a test pattern to help determine the smallest spot size.
  • I use step gauges to set/test the best focus point.
  • Use a magnifier to view your results
  • How to decide on the dot size by using the test pattern.
  • Converting that dot size back to a Pixels Per Inch resolution.
  • Modifying the brightness and contrast of a picture
  • Resizing and setting the resolution of the picture and dot dither.
  • Setting the interval is very important
  • CALCULATE the speed …..DONT guess it
  • Reset the head position in the config system settings
  • Explanation of what happens if you ignore the resolution rules.
  • Testing to find the best power setting
  • Cross flow of air and almost zero air assist is essential
  • Examination of a very good end result.
  • A look at another picture done on the Lightblade machine. One picture done with a 2” lens and a second with a 1.5” lens. Big difference. 1.5” lens wins
  • Top 10 YouTube Laser Tutorials

04 – RDWorks Learning Lab 075 – What have I learned from 1 year of owning a Chinese Laser Engraver

  • My early mistakes with eBay tubes
  • My great experience of buying a new tube and power supply
  • Chart of tube power characteristic sowing 70watt output.
  • Non linearity of tube output.
  • Understand your tube current limits and fit an ammeter to monitor it
  • Summary explanation of how tube works
  • Don’t use 100% power EVER. If no ammeter then stop at 65%
  • Discussion of axis speeds
  • Converting the machine into a “dream machine”
  • Cheap temperature control relays
  • Look at my ONE YEAR OLD distilled water. Still pristine.
  • Look at the water temperature control system.
  • Failed bouncy castle fan….motor burn out
  • New fan very noisy. Needed a silencer.
  • New air higher volume assist pump for future fitting
  • Quick look at my home made copper mirrors
  • I would not have learnt as much if the machine had been perfect
  • Top 10 YouTube Laser Tutorials

03 – RDWorks Learning Lab 005 – Cutting first program

  • 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

02 – RDWorks Learning Lab 215 – AT LAST!!! I understand how lenses cut.

To be updated Soon


01 – RDWorks Learning Lab 202 – More Laser Cutting Investigations

Top 10 YouTube Laser Tutorials: Number 1
Top 10 YouTube Laser Tutorials: Number 1 More Laser Cutting Investigations
  • A recap on the previous session
  • We look again at the remarkable results from my compound lens tests where despite the focal length of the bottom lens and the spacing from the top 7.5″ pre-focus lens nearly all the cutting speeds were the same at 17 or 18 mm/s.
  • We have to conclude from this that the light INTENSITY through each of these many different lens types must be exactly the same to produce the same amount of damage. How is this possible?
  • Is it to do with the difference between a normal parallel beam hitting the lens or is it caused by the converging pre-focussing lens?
  • Quick mode burn test followed by a comparative burn with a 190mm Fl lens but set 110mm above its focal point to simulate its use in the compound lens tests.
  • This clearly demonstrates that reducing the footprint of a beam dramatically increases its intensity and damage capability.
  • I wondered if I took two matching lenses placed flat sides to each other and with a special spacing between, could I make a parallel input beam exit as a smaller parallel output. Theory says yes but in practice it failed.
  • I carry out a series of cutting tests to see if I can find any useful patterns that may guide my thinking.
  • Just going round in circles, I conclude I must be trying to look at lenses in the wrong way. Just measuring their cutting capability sounds logical but is very one dimensional.
  • I write a new lens test program based on DOTS and DOT MODE. The aim is to standardize the cutting parameters for lenses. I use the same power for every test and a series of fixed exposure times. Measuring the depths of cut for each exposure time will produce a cutting profile for each lens.
  • With the focus set to the top surface of a special test block I run a test on a 4″ lens. The data in this format is not easily understandable so the penetrations were plotted graphically.
  • When we examine the graph, it becomes obvious that I only need to see a small part of the graph to represent the performance at REAL cutting speeds.
  • I use the same 4″ lens to cut a 25mm square and then measure the block and the hole to calculate the cut width,
  • Then I use the 4″ graph to find out how long it takes to pierce 10mm deep. I use the kerf width to build a series of touching holes (kerf diameter) to fit into 1mm.
  • This allows me to predict a cutting speed for 10mm acrylic with this lens. The speed is about 5mm/s. In practice 5mm /s was easy and it just about made a cut at 6mm/s. This may prove to be a good cutting speed predictor (for my machine only).
  • I run a whole series of similar tests on all my lenses and then examine the graphical results.
  • I then chose the best performing 1.5″ lens and added the 7.5″ lens above it to see how the combination performed the same test. This clearly shows no difference 
  • A similar no benefit result for compound lenses also existed for the 2″,2.5 and 4″ lenses.
  • I then use the graphs to see which lens focal length I should use to cut 10mm thick acrylic for example. Now comes an interesting observation The longer the focal length the quicker it will cut.
  • This kills the myth that you need more power to use a 4″ lens.
  • We have finally proved no benefit for having a compound lens.
  • Top 10 YouTube Laser Tutorials

Recommended

Why not try out one of our other video series such as:

The Tangerine Tiger Series where Russ has purchased a new 500 x 300mm, 50W laser machine from eBay with a view to modifying and upgrading it. In fact, he rips out the glass laser tube and high voltage power supply and replaces them with an RF laser source and PSU from Cloudray. Find out how the expensive RF laser source compares to a glass CO2 laser tube and prepare to get your hands dirty!

The Lightblade Learning Lab is a series of videos that Russ did for Thinklaser Limited based on using the Lightburn 4060 Laser Cutting and Engraving Machine. The Lightburn 4060 has a 400 x 600mm bed size and was supplied with a 60W EFR laser tube.

The Fiber Laser Series is all about Russ’s adventures and investigations with a 30 watt fibre laser, loaned to him by Dean at Lotus Laser Systems. If you are looking to engrave metal, without the fuss of using coatings such as Thermark, Cermark or Molybdenum Disulphide spray, then this is the series for you.

The Lightburn Software Series is probably the best generic laser cutting software available (I use it for almost all of my laser work). This series has tutorials, hints and tips as well as the occasional speed comparisons between it and RDWorks. My thanks to the team at Lightburn for allowing me to embed their videos.

The Top 10 Ranked RDWorks Learning Lab Videos


You may also wish to consider checking out The Concise RDWorks Learning Lab Series that condenses all of Russ’s work into an easy to follow encyclopaedia of laser knowledge.


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