AlfaGTA
Diamond
- Joined
- Dec 13, 2002
- Location
- Benicia California USA
Well time has come to do some needed heavy repairs on my trusty FP4NC.
Here is my tale: For some time now i have been having some trouble with my machine. The symptom is that from time to time i get positioning errors on the "Z" axis. The trouble is that the slide "sticks" when going down, the axis servo adds more power to make the move and the slide moves and overshoots posioion and then recovers. You can see the effect by placing a dial indicator on the machine and indicate the position of the vertical slide. Make a "-Z" move with the electronic handwheel and all is fine. Make a "+Z" move and the slide junps too far down and comes back.
I have done the ovious stuff: replaced the "Z: axis thrust bearing on the screw and had the ball screw rebuilt. These repairs helped but did not cure the trouble.
I have spent some time adjusting the axis gib and that has has sone effect but not enough.
Coarse measurments indicated that the ways were worn on the inside faces (that is where the table "rock" is controlled). There was also some gauling visible on the surface of the inside way opposite the gib. (that is the surface that is iron on iron)
I made the decision to repair the slide and fit Turcite to give a good sliding surface.
First step: remove the work table, the "X" slide and the vertical slide.
I am having a professional do the scraping as this is a bit more than i want to tackle.
If you look carefully you can see the gaulling on teh vertical way surface. This was not visiable when the machine was assembeled.....
More later as at the momnent the machine is lying on its side to facilitate the way scraping.
Cheers Ross
Here is my tale: For some time now i have been having some trouble with my machine. The symptom is that from time to time i get positioning errors on the "Z" axis. The trouble is that the slide "sticks" when going down, the axis servo adds more power to make the move and the slide moves and overshoots posioion and then recovers. You can see the effect by placing a dial indicator on the machine and indicate the position of the vertical slide. Make a "-Z" move with the electronic handwheel and all is fine. Make a "+Z" move and the slide junps too far down and comes back.
I have done the ovious stuff: replaced the "Z: axis thrust bearing on the screw and had the ball screw rebuilt. These repairs helped but did not cure the trouble.
I have spent some time adjusting the axis gib and that has has sone effect but not enough.
Coarse measurments indicated that the ways were worn on the inside faces (that is where the table "rock" is controlled). There was also some gauling visible on the surface of the inside way opposite the gib. (that is the surface that is iron on iron)
I made the decision to repair the slide and fit Turcite to give a good sliding surface.
First step: remove the work table, the "X" slide and the vertical slide.
I am having a professional do the scraping as this is a bit more than i want to tackle.
If you look carefully you can see the gaulling on teh vertical way surface. This was not visiable when the machine was assembeled.....
More later as at the momnent the machine is lying on its side to facilitate the way scraping.
Cheers Ross