Very little action going on, so I will get this one back on track.
If you remember from last time, I had to mount my vice so I could get a hole drilled nice and square in the side of it.
I used my brass t-slot blocks that I made up ages ago, they are a nice tight push fit in the slot (see arrowed item). The angle plate was then pushed against the blocks, and clamped down. So the plate is now perfectly square to the t-slots.

The vice was then clamped under it's own pressure with the moveable jaw against the front machined face of the angle plate and the fixed jaw was tight against the back casting but with a piece of round brass between the jaw and the angle plate, this is to take up any minor irregularities. At the same time, the vice was tapped to a perfect upright position by checking with an engineers square against the top of the jaws. The jaws on my vice are parallel to the vice base, others may not be. If you don't know what an engineers square looks like, follow the arrow.

Now I have a vice whose base and jaws are square to the quill. Just what I was after. The setup isn't super rigid, but perfectly secure and safe for the jobs I will be doing on the vice.

First off I found an area on the vice side that, if drilled into, wouldn't hit any area used for mounting anything, plus in a nice beefy area of the casting.
I now needed a nice flat area for later additions to sit on, but the casting in the area I wanted to drill was all shapes and angles.
So the first thing I did was put a spot face cutter in, larger than the area needed, and cut down until I had a nice working face. You will see that in later piccies. You could use a large slot drill to do it at this stage, or a face mill if you have already drilled the hole. But take it steady.

The DRO was zeroed up so all the following actions were done in the same spot.

With a tapping drill the right size for 8mm coarse thread, I drilled to 20mm deep.

This was followed by a fairly deep countersink, I don't want the block I will be putting on here being held off by the threads. In this shot you can plainly see the spot face I put on earlier.

The hole was then hand tapped to depth, making sure the tap was kept truly vertical.
All machining jobs on the vice were now finished, so the setup was stripped down and cleared away.

I was going to use a piece of ali for the main support bar, but thought better of it, so after a rummage in my steel box, I came up with a crappy bit of hot rolled steel.
I only want the backstop to reach about 2" into the jaw opening width, so it was cut to rough length. If you want it to reach further, cut the bar longer.
The vice was remounted to the table, and squared up. The RT was put back at the same time.

After a run in with a cutter on the mill, the crappy black bar miraculously turned into a bit of accurate crappy shiny bar, complete with marking out blue and three pop marks and a rough slot shape scraped on the surface. There are no measurements for these, they were guestimations by laying it alongside the vice and marking where the holes should go.

The centre of the width of the bar was found using an edge finder, and by using increasing sizes of drills, all three pop marked holes were brought up to 8mm diameter.

Now for the slot.
If you want an oversized slot, plunge in with the correct sized cutter, and hack away. Not only will you end up with an oversized slot, it will most probably end up all rough with wiggly sides as well.
You have to caress a slot to the right size, this is how I do mine, others might have a different method.
I found an unmarked end mill (not too worried about plunging because I will be going down the pre drilled holes) that was just under 8mm diameter (I don't know exactly, about 0.4mm undersized, most probably some sort of imperial one).
The cutter was fed about 1mm down the hole, and a cut was taken until it reached the other hole. Another 1mm cut and fed again in the opposite direction. This was done until the complete slot was done.

The cutter was then changed for one of 8mm and plunged all the way thru the hole, and a very fine feed with a lot of cutter speed was put on until it eventually reached the other hole.

I ended up with a slot which when an 8mm rod was fed along it, it was like silk, with no sign of side to side wobble.

A 5mm hole was drilled half way across the width and half way across the single hole, and it was duly tapped out 6mm.

After a bit of cleaning up and rounding over, the major part of the job is finished.

Just a bit of turning, and a tiny bit of milling to be done, and the job should be ready to be used.
Bogs