Please forgive a double post, I just noticed this forum and it seemed more applicable than the one I posted in previously.

I have a small (20" X 14") CNC Crafter router. It is very well built running 4 to 1 ball screws with delrin (?) nuts with 300oz/in steppers. Up until now I have had a Porter Cable 690 router as a spindle, and I have seen this CNC machine with Porter Cable 7518 3.25hp routers (12 pounds in weight) mounted on them successfully. I just bought a real 1.3hp spindle to put on it (not a router) and it weighs an unexpected 16 pounds. I have a concern about the weight on the Z stepper and whether the X and Y steppers will be able to deal with the extra weight. I don't think the mounting or the bearings will have any problem.

Any input will be appreciated.

Donn