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 ...
