I made boiler feeding check valve. Some changes were made from above drawing. The procedure of turning is bit complicated. At first 2mm blind hole was drilled to 10mm AF brass hex.

ボイラー逆止弁を作る。ただし図面からいろいろ変えてある。作る手順は結構めんどう。まずは10mmの真鍮六角棒にΦ2の盲孔を開ける。

Remaining hex at the centre, both sides were turned down to 8mm.

六角部分の前後をΦ８に削る。

Parting off.

突切り。

The work reversed and held by collet. The valve part was turned. I used a parting of bit only. For small brass turning it is enough.

ひっくり返して、コレットで咥え直し、弁部分を切削。削りは突切りバイトだけで行った。真鍮の小物ならこれで十分。

Threaded.

ねじ切り。

Outlet hole was drilled on the mill.

フライスに移して出口孔を開ける。

The valve body was held by a fixture and turned nipple part.

切ったネジをヤトイにねじ込みニップルを形成。

Finished check valve.

これで逆止弁ができた。

Silicone tube was installed as valve.

シリコンチューブを弁体を挿入すれば完成。