Boring Bar: Driven Between Centres, with a Set-Screw Cutter (Yates, 1922)

A home-made boring bar for holes too long for an ordinary boring tool, which would spring. A short, stiff bar runs between the lathe centres, driven by a dog, and carries a hardened tool-steel cutter locked in a cross-hole by a set screw. The work is bolted to the lathe carriage and fed past the turning cutter. Result: a boring bar, plus the small short-cut bar of Fig. 110. Source: R. F. Yates, Lathe Work for Beginners (1922), pp. 134-136. Unknown: bar diameter and set-screw size. Picture: Figs. 110-111 of the book.

متوسط

Unknown

التعليمات

Turn the bar

Turn a bar no longer than the job needs; the shorter it is, the less it twists under the cut. Drill both ends for the lathe centres. For short cuts, the small bar of Fig. 110 is 4 to 6 inches long with a round shank and a squared end. Ours: mild steel round bar. Not given: the diameter.

المواد لهذه الخطوة:

قضيب مستدير من صلب طري1 boring bar

الأدوات المطلوبة:

مخرطة معادن

أبعاد غير معروفة

Fit the cutter and set screw

Drill a cross-hole through the bar for the cutter and drill and tap a hole into it for a set screw that locks the cutter. Make the cutter of tool steel, grind its point with proper clearance, and harden it.

المواد لهذه الخطوة:

قضيب مربّع من فولاذ العدد1 cutter

معدن غير معروف1 set screw

الأدوات المطلوبة:

مثقاب عمودي

طقم أدوات قطع اللولب

حجر سنّ دوّار

فرن المعالجة الحرارية

حوض تبريد الحدادة

Bore with it

Bolt the work down to the lathe carriage carefully and securely; carriage bolts of several sizes are handy for this. Drive the bar between centres with a dog and feed the carriage. Run very slowly when boring cast iron, and keep the feed light so the bar does not spring.

الأدوات المطلوبة:

مخرطة معادن