View Full Version : How to repair t-slots??

Rookie machinist
01-25-2008, 09:25 PM
The T-slots on my mill table have a few spots where the nuts stick, what is the best way to repair the slots. I am also wondering can the table top be "trued up" using a face mill or fly cutter? The previous owner hit the table in a few spots and I would like to clean up the rough spots.

01-25-2008, 09:27 PM
Use a die grinder down in the slots where they are smashed inward. Or a file.

On the table top I would use a good file and hit the high spots.

I have ground mag chucks on a surface grinder but never cut on a mill table. Thats a bit extreme.

01-25-2008, 09:52 PM
Stone the top with an indiastone. It will knock the high spots down. A few low spots won't matter beyond looking ugly.

It's a good idea to lightly stone the table top and the bottom of the vise (or fixture/part) whenever putting it back on. you will be able to feel any dings as a drag and give them some more attention. I was taught to use a figure-8 motion. Wipe them table with a rag and then your hand. Your hand will feel debris better.

01-25-2008, 11:44 PM
I once saw a fella mount a cup wheel onto an arbor, and basically "Surface Grind" a mill table very lightly.
The table was in bad shape to begin with.
Some moron had milled a 1/2" slot down the length of the table.
The slot was filled with weld, milled 'close', then ground.
Of course, tramming the head dead-nuts was VERY critical before grinding.

01-25-2008, 11:51 PM
I've used the file trick. What I do is take a pass one way, making sure the file is held flat to the surface. Then take a pass the other way, then once more the first way. If the file was any good, you'll have knocked off all the proud spots and removed much of what I'll call micro burring, material that's been wiped into the pores of the metal from the file stroke. Anything that fits the t-slot closely will be able to slide either way without binding. If you use the t-slot for anything that has alignment tabs, you won't be wanting to remove much material at all, just enough to wipe off the crater edges.