Todays Project - What did you do today?

[PixMan]

Got about 4-1/2 to 5 hours in the shop today. First order of business was to make a HSS internal threading tool for the 1-1/4"-5ACME nut I have to make out of 660 bronze for Darren's Kondia machine rebuild. As seen in earlier posts, the mating threads on the screw itself is done and that will act as the thread gauge.

I roughed it out by hand on a bench grinder, then went to work on my surface grinder. Using the 5" sine bar grinding vise I'd made as my senior class project in vocational school (1976-1977), I first ground the two 14.5º angles. Set the 2" long 1/4" square blank in the vise jaws at 14.5º with my Starrett No.359 precision bevel gauge, then tipped it with the sine feature. One of the few times I get to use the No. 154 adjustable parallels. Here's a photo of the final surface, the tip. It's set square in the vise, then tipped 18º as that 2-1/2º extra clearance below the cutting tip.



I have ground tools like this by hand many times before, but now that my eyes need help with looking close and I have a surface grinder, wheels and tools....
Here's the tool, though I did later add a pair of grooves on the top for the set screws to grip in the homemade bar I'll be using:



Now to rough out the bronze. I chucked the 6" long Ø 3" blank, faced it off, turned both the 42mm and 70.9mm diameters, drilled, bored and chamfered to 1.280". Since I used a flat-bottom carbide insert drill, no excessive waste on the blank!



Turned it around, faced to length and chamfered the opposite end:



Tomorrow I'll set-up the new threading tool and have at it. Hopefully, this one comes out right the first time, not like the screw that took 3 tries to get it right. If I get the lathe work on this bronze nut done I'll try and get the holes done, then finish the work on the fixed end of the screw and SHIP IT!