Z axis yoke - a bit of machine fitting

Still a bit of work to be done in terms of actually fitting the yoke to the machine. For one thing, the special (fine thread) hex socket cap head bolt that secures it to the quill requires some work to pare it down and get it to fit without fouling the ballnut. I only have one of these bolts (the original), so I need to work carefully.

First, remove the DRO scale so I can remove the original feed trip mechanism:

May as well remove the auto feed mechanism. Not needed, they get in the way and I certainly don't want the feed to accidentally engage.

Here we are. The bracket fits!

Firstly the head diameter is too large to fit the (counter)bore. I can't simply open out the hole to clear it, as the body of the yoke isn't wide enough without it breaking through. And the main through bore is a little too tight for the bolt to pass through cleanly. 

Turn down the bolt head. I run the machine backwards and use a boring bar. This is a CCGT (ground) insert which is better for fine finishing operations than the blunter CCMT inserts.

The old trip bracket was modified (by me) to provide a means of mounting the DRO head.

That's it. Fits nicely, clears the ballnut and doesn't foul any of the other features:

I need to remove the feed mechanism. This is what remains once the trip lever is removed. It sticks out a fair way, so needs to come off too:

Around the side, removing the feed rate selector lever and the feed clutch mechanism reveals the gear clusters and the worm drive to the feed lever. I need to remove some of this - probably just the final worm drive but I'll have to check the manual to be sure. Then fit cover plates over the openings.

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