[22lambo]

I have an import "Bridgeport" that's a little worn out, I would like to convert it to CNC with ball screws and instead of working with sloppy dovetails I was thinking of mounting a pair of some linear rails to the bottom of the bed and 4 linear bearings (2 each rail) for the X axis and the same for the Y axis. Am I crazy for trying to do it? Is the machine rigid enough for it and worth it? I don't want to sink all the money and work into it to find out it works as a sub-par CNC. I was to make some aluminum car parts with the setup, like brackets and mounts with it so tolerances don't need to be too crazy but I would still like some nice surface finishes and repeatedly results. Any input and advice would be really appreciated, thanks!

[Jim Dawson]

Never heard of it being done before, but I can't think of a reason that it won't work. My Haas has linear rails and seems to work fine.

Be sure to post your build thread with lots of pictures.

[peteeng]

Hi Lambo - I think there's a dovetail to rail conversion somewhere in here try a search - Peter

No reason for it not to work but have a very good look at it to make sure your rails do have places to land and cars do too etc. May have to machine lands for rails...

[mactec54]

I have an import "Bridgeport" that's a little worn out, I would like to convert it to CNC with ball screws and instead of working with sloppy dovetails I was thinking of mounting a pair of some linear rails to the bottom of the bed and 4 linear bearings (2 each rail) for the X axis and the same for the Y axis. Am I crazy for trying to do it? Is the machine rigid enough for it and worth it? I don't want to sink all the money and work into it to find out it works as a sub-par CNC. I was to make some aluminum car parts with the setup, like brackets and mounts with it so tolerances don't need to be too crazy but I would still like some nice surface finishes and repeatedly results. Any input and advice would be really appreciated, thanks!

If it is that worn, then it would cost more to redo the ways than to do the linear rail build make sure you get preloaded linear rail bearings if you do this

I have done many of them there was one posted here on the Zone somewhere, but was not one that I had done, I mostly did the Y axis the last one I did I made a new saddle as well which kept everything at almost standard height

When I said I have done many of them I have not done a clone only the Bridgeport Boss machines which have a heaver and wider Knee than a standard Bridgeport mill

I also add an extra 2" travel on the Y =14"axis when I have added the linear rails

I'm building one now that will have a added horizontal spindle as well as the normal vertical spindle, but with 16" of Z axis travel, with a total of 24" with the Knee

[ianagos]

I have an Excello with round linear rails that was done sometime in the 80’s it’s ok but the round rails are not the greatest.

[machinehop5]

...the price of CNC machines these days and lots of them for sale....you might be better off buying a real CNC machine.

[ianagos]

...the price of CNC machines these days and lots of them for sale....you might be better off buying a real CNC machine.

You could buy a real working vmc for the price of the rails and screws. Then sell the Bridgeport for the price of the vmc