Small CNC for guitar inlay work - general thoughts

[fwm891]

Small self-build CNC machine for guitar inlay work – General thoughts

Three of the questions I’ve been asking myself about why I want to build a small CNC machine:

1. My hands no longer give me the level of control I need to cut fine inlays in Mother-of-Pearl etc, and their associated housings in a variety of hardwoods
2. I get some of the MoP inlays cut commercially at present which is expensive
3. Some inlays require me to make a pattern for a homemade pantograph using 8x (size) patterns and 1mm cutters in a dremel fixed to a home made pantograph – this is time consuming at best.
This also requires a reversed pattern to cut the housings with the pantograph too

Took me quite a while to admit to the first point, the second point is simply one of cost. MoP and other shell inlay blanks are quite cheap and offer a greater range of sizes which in turn offers more flexibility in the designs I can use. Point three shows that I can currently cut inlays and housing but the process is drawn out in having to make enlarged patterns to cut out shapes.

What materials do I work with:
Inlays – normally in a shell of some sort, bone, resins, various hardwoods, rarely metal (brass or aluminium)
Inlay housings – normally cut into various hardwoods
Sizes: logo typically 38 x 18mm to 45 x 21mm. Headstock veneers upto 200 x 75mm. Rosettes 90mm upto 140mm diameter either as complete circles or partial arcs.
Cutting depths for inlays typically 1.3 – 1.7mm, for the hardwoods 1.5 - 2.5mm max, for softwoods (soundboards) 2mm max.
Rosettes are currently cut with a Dremel on an adjustable radial arm which rotates about a fixed pivot at the centre of the soundhole.

So I’m looking to build a small CNC with X, Y and Z movements covering a working area approximately 250 x 150mm (minimum) and a working height of upto 30mm. Cutter sizes I’m guessing will be between 0.4 – 3.0mm in general with a max of 5.0mm.

Initial thoughts are towards a fixed gantry machine, it’s axles being screw driven in X, Y and Z.
Base frame and gantry built from aluminium (mix of extrusion and bar/plate). Working platen aluminium.

These are general thoughts at present. I’m a complete newbie with regard to CNC so guidance from the forum members will be appreciated in all aspects of the design. I’m guessing that some will favour the fixed gantry others will opt for a travelling gantry…

I have some image examples of typical simple inlays I’ve made with the pantograph/Dremel and a commercially made logo.
Francis