Topics include, Machine Tools & Tooling, Precision Measuring, Materials and their Properties, Electrical discussions related to machine tools, setups, fixtures and jigs and other general discussion related to amateur machining.
Pete the Barbarian wrote: Since rmac said the tolerances are quite loose and the material is aluminium, I would put the rod in a bench vise, take a 5/8" cartridge roll in a die grinder and sand it to shape. The barbarian in me would have it done in the time it takes me to put an end mill in the mill and the part in the vice.
Well, maybe not quite that loose! The joint shown in the picture is all I was trying to do. RussN's suggestion worked great, even with a not-so-sharp mill. The ratty concave surface left by the mill butts up against the larger cylinder where it won't bother anything. All is well.
Unpopular opinion here, but on parts where I don't have an em of the desired size, if the fitment needs to be good but the actual surface isn't super critical, I'll go with the closest, but smaller, em I have and do a circular hole pattern inside the radius. Discing of the plunges is determined by the depth of the scallop that's allowable. I also do this when machining a pocket manually if it has corners. Way easier and faster than setting up the boring head or rotab. Looks like you got your part made, but maybe somebody will benefit from this someday.
A 5/8” end mil should do the trick if .525” is clos enough. Odd ball and oversized radius can be achieved by making first cut with nominal size cutter then inserting a pc of shimstock under one jaw of a 3-jay chuck or using a larger endmill holder and making an offset insert ( adapter) in your 4- jaw chuck.
The joint shown in the picture is all I was trying to do. RussN's suggestion worked great, even with a not-so-sharp mill. The ratty concave surface left by the mill butts up against the larger cylinder where it won't bother anything. All is well.