I Need a Yoke (and/or dims) for a Bridgeport

[mxtras]

Terry (vmax549) -

The screws are on their way to you along with the dog bone and the nuts. I hope they work out for you. If not - let me know and we will work out their return. I understand your machine is smaller than the one these came out of.

I bought the HiWin rolled screw kit and installed it last week. It would have been a very simple thing, but I ran into a few issues. Without any issues the installation might take 2 hours, but with the issues OI encountered, it took me more like 9 hours. The end result is really nice. I have not done a final adjustment on the gibs, shimmed the support bearings or taken B/L readings yet. THese things will be done a bit later when the controller is assembled and installed on the machine. The motion is really smooth with no noticable slop in the crank handle.

One issue with installation was interference. The table nut contacted the bottom of the table. I hate to bust out a grinder and take it a brand new precision component but that's exactly what I did. A 3/8" chamfer on one corner and the interference was gone.

The other issue was alignment. The yoke is a pretty critical thing and it just was not made identically to the stock bracket. This is a very long story and I spent a lot of time debating on what to do to resolve the issue - I did not want to immediately blame the new bracket but it sure did look to be the problem. The bottom line is I ended up elongating the mounting holes so that my stock X and Y bearing supports would line up and work without modification with the screws in alignment to the ways. The pain was that my mill was torn down so I had to go to a local machine shop to elongate the holes. They were gracious enough to allow me to use one of their mills. If they had not, I would have spent a few hours putting mine back together for a 10 minute job, then tear it back down. I was glad the guys on the floor remembered who I was (I give that shop a lot of work through Mitsubishi).

I used the original location pins to locate the nose of the Y axis screw and aligned from there, using a small amount (.0015") of shim under one side of the bracket to maintain the Y screw perpendicularity to the support bearing mounting surface.

I will post pics and a write up of the ball screw installation in a seperate thread - hopefully later in the week. My time is very limited these days....



Scott