Jonathan,

You have an interesting point on the back lash, when i used one of these it was with back lash compensation, once i had set it up i never had to adjust it - it seemed very consistent.

I can not argue with your maths but seems a lot higher than i experienced in reality! Remember these are German, made in Germany so the quality is very good and the specification very conservative.

If you are still interested I am open to offers.... And we can combine shipment with the bolts, screws etc....