Here we go again . . . MK4

[routercnc]

OK, so I need to bore this hole out to just over 80 mm to give a nice sliding fit on the WC spindle:


To give you an idea what is required here is the finished fly-boring cutter mounted on the lathe. Chuck is removed, an MT4 dead centre put into the head stock end, an MT2 live centre (rotating on bearing) put in the tail stock end, and drive provided by a long bolt from the drive flange running through a lathe carrier (lathe dog). This may look precarious but it has been done like this for years:


So here is the walk through to get to that point. First off I sketched it out:


Then I needed a single point cutter so started with an old 10mm HSS cutter:


Then marked the tool, roughed it out using an angle grinder with an inox blade. Then used the bench grinder to ground the required shape. Still a bit of finessing required:


Marking out the tool carrying bar with 2 scribe lines - one in the middle (where the tool, clamp bolt, and adjust bolt will be), and one further down where the edge of the vice will be. This is to keep it aligned when machining the features:


I needed to make a rotary alignment tool (don't have a rotary axis):


Setup for first op:



Then used the alignment tool to rotate it 90 degrees:


Aligned to edge of vice jaw:


rotated for 2nd op:


rotated again for 3rd op:


Over to the drill press for the dia 10 pilot to 40 mm depth:


Then reamed (very slow, lots of oil):


Holes tapped:


Assembled and checking the fine tune screw was going to advance the tool in the range I needed:



Mounting between centres:


Then onto the lathe carrier:








The last part to make is a fixture to hold the spindle mount in place on the lathe cross slide. This will bolt down onto the T-slot nuts, and bolt up into the underside of the spindle block using the existing M12 tapped holes. The key feature is that it will have M5 grub screws at each corner to provide adjustment vertically (bore centre MUST be aligned to lathe centre height), and to provide adjustment in tilt in 2 directions. Essentially a tramming plate to get it all lined up. Here is the CAM:

Flip side will be counter bored:


Machining under way: