Fitting & machining of bracket pads blanks on a No#4

[BrianLara400*]

Latest update:
Have finished the fixture to hold the action, as the pads are installed and the interfaces for the telescope bracket are machined.
Its bit of my own variation on the other fixtures I'd seen on the forum - should be plenty rigid & finely adjustable for collimation.
Will work with either the "plunged shell mill" method of forming the spigot or the radial method (though bringing the whole thing into line with the dividing head spindle axis, will no doubt be "fiddly").

- the levelling feet will allow the bolt way centreline & rear sight pin axis to be plumbed up, and the fixture is in turn dogged down to the faceplate.

- the jacking screws bare against the side directly resisting the thrust forces of the drilling/milling operations and in combination with the securing points on the vertical face contribute to the overall rigidity of the work piece. the mandrel itself just rests in place and is a very neat slip fit in the ways

- The faceplate is underway, its been flame cut from 25mm PL x ~400 Dia (rougly as large as I could swing without removing the gap bed - should clear the column of the milling machine by 30mm). Tigg'ed an ASAB bar boss on to it, now just have to go and skim it all true and thread it M45x3.0 to accept the dividing head spindle. - the whole thing should be a "goer" after this and I can get on with the actual project itself rather than all the ancillaries.

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[BrianLara400*]

Had a productive afternoon:

The combination of the fixture & dividing head made it quite easy to plumb the actions bolt way true to the x-axis.


*Skimmed the surface of the action in the area's that are to receive the bracket pads,

*drilled & tapped the 4BA holes, (was on egg shells when using such a small tap for the holes to afix the rear pad as this coincides with the hardened area, but wasn't nearly as "steely" as I had anticipated)

*With the front pad I also decided to counter-bore both halves of the equation to accept a hardened bushing, which will prevent any possibility of it "breaking away" after a pro-longed hammering from recoil.
Its most definitely over engineered, but my preference will always be to avoid potential headaches down the track by doing things as best I can in the first instance.
"consider it over egged"





The bushes Dia is pretty much size for size, I just need to de-bur a little and then fit the halves together and its ready to be soldered (note the track on the bushes to allow flow of solder - as per Peter's book).