A trip to the hardware store got me the bolts I needed. Reinstalling them was pretty straightforward.
The rails & bearings took a little over a week to get here. The replacement steps were as follows (sorry no pictures):
1. Remove 3 or 4 bolts holding the rail to the frame.
2. Park the gantry over the missing bolts.
3. Put blocks under one side of the gantry. Shim it until it is snug.
4. Unbolt the bearings and slide them off the rail.
5. Remove the rest of the bolts holding the rail to the frame.
6. Slide the rail out.
7. Slide the new bearings onto the rail (it’s easier before the rail is mounted).
8. Slide the new rail in.
9. Install all the accessible bolts.
10. Position the new bearings on the gantry and bolt in place.
11. Remove the blocking under the gantry.
12. Relocate the gantry to install the remaining bolts.
13. Repeat for the other side.
Just to be safe, I loosened the three bolts I had just installed on one side of the tie plate. I gave the gantry a little wiggle and retightened the bolts. I did this just in case the new rail/bearing sets were a slightly different size. If that was the case then I could have been putting some extra stress on the bearings.
Here’s a shot of the new rail/bearing setup.
Next is the new limit switch. Here’s a (poor quality) pic of the old one (connector off). I used a piece of tape to mark the location.
It is glued in place. It has to be pried off and the glue cleaned up. ShopBot uses cyanoacrylate. I used several applications of Goo Gone to clean it up.
I connected the new switch to the cable and put a coat of Gorilla Super Glue on the back side. I lined the new switch up with my location mark and held it in place for a minute or so.
At this point I moved the gantry by hand to verify the switch placement. Then I turned the system on and checked each drive. I wanted to make sure I had not dislodged and cable connections during the repair. Then I ran a test file as a final check. Since everything looks to be in order I can get everything put back together.
