Question About Installing New Table Feed

[jmarkwolf]

I'm installing a new power table feed on my Bridgeport 9x42 table (See POTD).

The table end caps on my mill have roll pins for aligning the end cap with the center line of the lead screw.

The roll pins for affixing the new table end cap are provided, but they didn't drill the holes in the new end cap.

Two questions:

1. Are the 4 big allen head cap screws adequate or is it really necessary to install these roll pins? and...

2. How can you properly locate the holes in the new end cap for these roll pins?

 

[John_Dennis]

The roll pins are there in case the bolts get loose more than for strength. They also help maintain alignment.

You could make a jig using 3 blocks of metal. Drill a hole in each one for the roll pin or lead screw. Put the blocks on the mill bed roll pins and leadscrew and clamp them to a straight piece of stock. now you can remove the blocks as one piece and you have a jig to align your roll pin holes. This will take some shims and a little figuring to make the alignment work but should be simple and accurate.

If the roll pin holes on the bed go all the way through you could just use a transfer punch.

 

[Low tech]

This may work . Remove roll pins from table and replace with short dowel pins ground to a point . Ease on the new end cap and using the Allen bolts pull into place until the the dowel pins just come into contact with end cap . Then tap end cap lightly ,hopefully transferring the dowel pin marks onto the end cap . This would require snug fitting dowel pins to work. Hope you get the new power feed going.

 

[jmarkwolf]

You could make a jig using 3 blocks of metal. Drill a hole in each one for the roll pin or lead screw. Put the blocks on the mill bed roll pins and leadscrew and clamp them to a straight piece of stock. now you can remove the blocks as one piece and you have a jig to align your roll pin holes. This will take some shims and a little figuring to make the alignment work but should be simple and accurate.

If the roll pin holes on the bed go all the way through you could just use a transfer punch.

Interesting idea John. I have the original end cap, with roll pins, that I could use to make this jig you speak of.

I'll have to check if the transfer punch idea will work also.