Tricks for moving feedneck?

[DocsMachine]

Four thou of interference is a LOT. I typically fit less than half that. The feed necks I press into Vee-Twin bodies- hollow necks, so they can 'collapse' easier- are fitted to .0015".

Doc.

[flyweightnate]

Well, yeah... I eventually did realize just how much it is. I'm used to taking twice that out of some joints, but didn't think about how much bigger they are (and hydraulics, and taper drive up, and all the other helpful features).

My body measured .867-.871 across the feedneck hole (a little messy), so I went with .873 to get it snug. It's VERY snug.

[Siress]

I hope you slapped it and said "That ain't coming out."

[flyweightnate]

Just did!
Machinery's handbook lists a FN2 as +1.4 to +1.9 for this size. Lesson learned! Bearings I've worked with recently are +11 thou interference, +50% if the journal is hollow... lost my sense of scale.

[Jordan]

[DocsMachine]

Old Joke:

The boss of a machine shop was walking by, and saw this younger fellow at a manual lathe, taking a very small cut.

He gets angry and says "That's not how we do it here! Time is money, son! This machine can take a MUCH bigger cut than that! Here, let me show you!"

He dials in an impressive infeed and soon large chips are flying off the part. The lathe hardly notices.

"See?" He tells the younger guy "that's how you remove metal. A couple of those and you'll be ready for your finish pass in no time!"

The young fellow says "that was my finish pass."



Doc.

[flyweightnate]

Finally got around to finishing this. Or at least this part of it.

Idiot marks here and there - climb milling on a mill/ lathe with backlash will do that - but functionally, it does what I want. It actually feeds the ball into the barrel, which is a bit of a novelty on a Sterling, and shot 277 with a .685 on HPA. (The .691 was 260.)

Now for a detent, an extended aluminum rail (botched the first one since it's longer than the travel on my cross slide), and some plumbing.

[Frmrspec]

Looks good.. a little bondo and a duracoat and the world will be none the wiser. I’m guessing you made that valve housing?

[flyweightnate]

Thanks - certainly needs the filler! The valve housing was easy; the 3-in-1 is lots more lathe than mill. 1/2-20 threads, IIRC, which was far more convenient than if it were metric.