Chapter 6

Left Side Operations

This chapter will be relatively short due to the incomplex operations that needed to be done. I still used my CAM program though, just out of pure laziness of not wanting to handwrite more code. I did, however, use the CNC mill in MDI mode and just typed in the operations for drilling. Since those were quick enough just to do by hand, it wasn't worth writing a program.

This is also the first time I had used solid carbide tooling in my mill. In some of the other operations the HSS cutters I was using wore out a lot quicker (due to my machine not being able to push them fast enough and torque through a proper cut) and deflected more than I liked. I know with carbide you're supposed to push them faster then HSS, but I figured with carbide I'd at least get longer tool life. Plus I get to dump more money into tooling and try new avenues! Enco had a sale on carbide tooling (as they do every month) so I purchased some quality Atrax solid carbide end mills and went to town. The deflection was a LOT less, practically zero, they cut very nicely and leave a beautiful finish. I was also able to plunge a lot easier than I was able to with the HSS cutters I was using before. I may have to look into getting more carbide end mills and using them for more of my machine work.

Since I'm approaching the 80% mark on machining the forgings I'm only going to finish out one lower completely. I'll save the rest for future projects when I decide what I want to do with them. That way I'll just have one finished lower to keep track of and the rest are just some fancy looking paperweights - for the time being.

For the indexing I used one of the jig plates and used the same indexing pins used in previous chapters. To clamp the lower to the plate (which was locked in the vise) I just used two 1" C-clamps and clamped inside the magwell and FCG well. While I don't like clamping on machined surfaces, its hidden, didn't mar the finish and gave me an operation plane clear of fixturing and clamps. This also made indexing a breeze - just as I had intended it to be by using the indexing pins.

Here's a pic of the setup before any machining was done.

Throwin' some more chips:

I didn't get too many pictures of the machining process on this chapter, but nothing too interesting or intensive was done here. Just some holes, slots and a triangle half-pocket. For the safety selector I first plunged with a 1/4" end mill and followed it by plunging with a 3/8" end mill. This gave me a tight tolerance and no wandering when it broke through the radiused FCG pocket.

Here's a pic of the finished left side still on the mill:

And a pic of it on the benchtop:

I couldn't resist putting some parts on it! (just to make sure they fit, you know)

Well, thats it for the left side! Told you it was going to be short. Next stop is the right side, then bottom, and then comes some more funky angled setups. See you there!