Techniques/jigsaws

From rLab Wiki

Jigsaws can be made at rLab either by using the scroll saw or the laser cutter

Scrollsaw cut Jigsaws

Details to go here

Laser cut Jigsaws

Tony's report on making laser cut jigsaws

I've now got a couple of workable options for jigsaws made with the laser cutter. They are in no way 'hassle-free' but do result in usable jigsaws.

  • The output from https://cdn.rawgit.com/Draradech/35d36347312ca6d0887aa7d55f366e30/raw/b04cf9cd63a59571910cb226226ce2b3ed46af46/jigsaw.html works great, as long as you remember to ungroup it before converting to DXF. Each vertical and horizontal line is cut as one.
  • Choice of substrate is vital, some woods and MDF will create a very sooty jigsaw that is almost impossible to clean up. If the material isn't strong enough the lugs just snap off when against the grain.
  • If you are etching as well as cutting, then the pieces will have to be at least 30mm in size. I tried 15mm pieces and you can't see the image due to the noise of the piece cutting.
  • You will need to use 'dot' mode on the horizontal and vertical piece cuts or the jigsaw will collapse as it cuts. The degree of 'tab' needed depends on the media, too much and the tabs will get ripped off when you separate, to little and the pieces drop down and get singed by the laser.
  • You shouldn't be tempted to cut your pieces on a thick bit of 'waste' board to stop them falling apart, it will be messy, and more importantly a HUGE fire risk.

My recommendations:

  • Use a more laser friendly media to reduce ash/soot
  • Consider using the paper tape to make clean up easier
  • If you are combining laser etching for the 'image' with cutting for the pieces then use larger piece sizes 30mm+
  • I suspect that a printed image, laminated onto either 1.5mm ply or 1.3mm mount board will create the best jigsaws with the minimum of dirt/mess/hassle

Substrates

  • Quality mount board (cardboard) is a cheap option that has minimal ash creation, mine was from Hobbycraft
  • BR grade plywood either 1.5 or 2mm (from www.kitronik.co.uk)

Images

  • Direct etching by laser (but not too deep)
  • Pre-printed images (magazines, gift-wrap, wallpaper etc)
  • Hand drawn images on quality paper/card (better to use waterproof inks / colours)

Process

  1. Prepare your surfaces BEFORE you cut them, you will not have an opportunity for post processing
  2. For etched ply, sand and either wax or lacquer, allow enough time to dry/cure
  3. For applied images, laminate paper/board/ply with PVA, allow to dry (and keep flat), then add a protective coating to image surface varnish/lacquer/spray sealant, allow to dry
  4. Coat both sides with low tack masking tape, press down firmly
  5. If engraving do this first, lower power 'colouring' works better than deeper etching
  6. Otherwise cut jigsaw lines with the appropriate power and gaps of 0.3mm every 30mm (depending on size of pieces, in this case between 10-15mm)
  7. Cut the outer line without dots for easier removal from laser
  8. Once complete lift whole jigsaw out of machine in one go and transfer to a board / table top / mat
  9. Carefully remove masking tape from both sides
  10. For etched images you can use a steel rule to encourage the small bits of tape off
  11. For paper images you will need to be a lot more careful so you don't damage the image
  12. Any de-lamination can be fixed with a cocktail stick and some more PVA
  13. When de-taped the pieces should come apart with some flexing