In this video I continue to machine the over arm bracket casting for my Adcock and Shipley 1A milling machine. This requires three precisely sized and orientated bores in this iron casting. Since the support bar has already been made I have a dimension to work to for the largest bore. Machining starts with facing 4 sides. This requires some care in setting up to help with subsequent operations.
Sand casting leaves a hard outer skin which was challenging to get through with the high speed steel bit used for the boring operations.
Apart from the machining I take some time out to look into bar sag and whether it is a significant factor in the structure of the overarm support.
00:00 Introduction
00:58 Calculating bar sag of the overarm support
05:50 Rough boring of casting
07:50 Making a custom stud to enable better clamping
08:43 Better clamping of casting on mill
11:58 Rough boring of journal
14:00 Boring small hole for cotter
17:23 Tool regrind
18:29 Finish boring of hole for cotter
19:05 Setting up for final boring of main bore
20:03 Finish boring of main bore
23:13 Trial fitting of support bracket on bar
25:28 Next video
Related video on producing the casting for the support bracket: [ Ссылка ]
Music used with permission from You Tube library: "Smokey's Lounge" by TrackTribe.
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