Mechanics is built in 19mm medium density "synthetic" wood. The guidance of the carriages is performed by slides of drawer (4 big ones for X and 2 small ones for Y). The reaches accuracy is better than the tenth of millimetre (measurement made with the comparator)!
Two sets should of course be built symmetrical...
do not make the same twice ;o )
screwed stems are assembled floating. They are solidarized to the motors by pieces of plastic tubes (here Fischer ankles) blocked by rings out of copper tube with a tapped hole.
The support of the hot wire bow is made of aluminium corner.
Other side, you need a support to avoid the swing of the arc.
The drive is done by simple nuts welded onto a piece of metal sheet . The play is, in my opinion, negligible for the precision that we seek.
Here is a schematic plan to build your own machine. Have the wood cut in your do-it-yourself shop, the assembly job will be more easy ...