[Coogrrr]

So I read this thread and I figured my .0002 is as good as any so here goes.

It is irrelevant as to the design you choose. The relevance is in the products quality of parts. I attach a drawing of both the lean back and straight verticle examples (crappy i admit). Please note the little red circles...

Theses circles are some examples of where load stress can occure and then result in a problem. if the verticle machine is made of better materials and built more sound the lean back is irrelevant if the lean back is made as well then yes it would afford some tighter tolerances but at some point you run into the uncontrollable items like the quality of the router itself the deflection of the bit used the product being milleds deflection etc etc.

Now I say all that to mean this wether you use double gantry or lean back or a regular jgro build the deflection is ZERO at no movement or should nearly be if the bit is straight. The deflection is crippling when you feed 12349ipm (ok little far fetched) but the better built the machine regardless of design means more IPM with less deflection is all and likely a well built lean back or straight down or double gantry machine will give you great tolerances.

If you need more then .001 or .005 lets say then think of building a very solid machine that moves slower like the guys over in the jewelry section they build what I think are engraving machines that will shame any attempt I may make. I however am not trying to engrave fine jewelry and art onto the head of a pin. I take my hat off to those guys WOW. I will be doind some custom wood stuff that will get fairly tight like maybe 0.001 and I would be very happy if I can make that with my machine but wont cry if it only gets me to within 0.01 as a hundreth is real nice!

I think the designs on this thread are awesome and I am interested in the leanback design just for the sake of X travel.

just my .0002 worth