D1-4 Slotted Faceplate

[petertha]

I think I understand now. The spindle nose & vertical face are intended mate to their surfaces simultaneously. Dang, that's not much room for error. I need a lapping plug!

 

[Bob Korves]

Dykem and sandpaper will do the job... If you try to cut it on the lathe, it is very easy to cut it too much, resulting in radial runout. Note that the dimensional tolerances you posted the files of are metric measurements. .001 mm equals .0004 inch. It is very easy to overshoot while fitting the tapers, making the fit too loose. Wear will gradually make it looser yet. On a faceplate, ultimate concentricity is not important. Repeatablity IS important should you ever want to remove the part and faceplate together from the spindle for additional ops and then return it to the lathe.

 

[petertha]

My update & happy ending. BTW, everything Bob said was 100% exactly my situation. The only difference being for some reason I had more material to remove on the tapered bore than just a skiff. The daylight gap is a bit deceiving. I was concerned about introducing a bad profile by hand sanding so what I did was used one of my nicely ground & perfectly fitting chuck backplate adapters kind of like a mold guide. I applied a releasing agent to the spindle taper & pressed in some epoxy putty. When this hardened & cured, it gave me a good angle shape to then wet/dry sand the undersize faceplate bore. I blued it & checked progression & repeated until there was no more gap. Sorry I didn't take a final picture but its now smooth & shiny. It sits perfectly tight on the spindle nose & requires a just mild mallet thwack to remove. Once this was established I took some facing cuts to true up the plate. Now its elevated from doorstop status to useful tool.

I immediately put it to use & made myself an adapter plate.
http://www.hobby-machinist.com/threads/chuck-adapter-plate-for-rotary-table.52934/

 

[Bob Korves]

Glad to hear you got it working correctly, Peter!