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25th December 2018, 09:10 PM #1Most Valued Member
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- Aug 2015
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All For Naught ( A Milling Mishap !! )
A while back I picked up a shell end mill arbor along with a saw arbor from Fiora Machinery that would have accompanied my mill but somehow were misplaced prior to my purchase of the 13. The shell end mill arbor suits a 3/4" bore cutter which was probably a fairly common size back in the early Sixties.
IMG_20181009_141944794 (Large).jpg IMG_20181009_142516729 (Large).jpg
Searching online revealed that they are now uncommon but I was able to purchase a Dormer 2 1/2" cutter in "excellent condition" from C-Tool on eBay. Turns out the excellent condition simply means not completely f....d. Every edge was chipped which was sad because the cutter had never been used.
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To install the cutter correctly on the arbor required the making of a spacer and a spanner. The spacer took two goes. The first attempt unravelled when a new Goliath 3/16" BSW tap snapped off while tapping the second hole.
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A trial cut with the chipped cutter provided unexpectedly good results so this moring I thought I would have a go at making a pair of boring bar holders for my boring head. A couple of years ago Michael G had sent me photos and dimensioned drawings of the accessories that accompanied his Kaiser Piccolo. I had made a left hand boring bar previously ( with Michael's help ) and realised the other day when working on the Douglas vice, that these bar holders would be a useful addition to the Kaiser's kit.
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My plan was to turn a spigot on each end of a 75mm long piece of 28mm diameter 4140 then use the shell end mill to cut the remainder of the bar 18mm square.
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Easy I thought to knock it off before the crowd arrived for lunch. 100 RPM with a 1mm depth of cut provided a neat finish. Then BANG !!!
Two horsepower will search out the Achilles's heel in any setup and the heal must have been the tightness of the three jaw on the 10mm spigot. The bar rotated and cutter tore the bar off the tailstock centre snapping the very end of the centre off. The cutter is pretty much useless with the face of one tooth sheared off and two other teeth badly chipped.
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A lot of work down the drain but it could have been worse.
I hope you all enjoy the remainder of Christmas day !!
BT
Attached Images
- IMG_20181225_103958394_HDR (Large).jpg (222.3 KB)
- IMG_20181225_103912357 (Large).jpg (140.9 KB)
- IMG_20181225_103935081 (Large).jpg (128.1 KB)
- IMG_20181225_103742380 (Large).jpg (140.8 KB)
- IMG_20181225_103736185 (Large).jpg (139.7 KB)
- IMG_20181225_103534366 (Large).jpg (166.5 KB)
- IMG_20181225_103525500 (2) (Large).jpg (156.8 KB)
- IMG_20181225_101337126 (Large).jpg (140.6 KB)
- IMG_20181225_102528371 (Large).jpg (145.1 KB)
- IMG_20181225_101211434 (Large).jpg (160.2 KB)
- P1020272 (Medium).JPG (85.4 KB)
- IMG_20181117_134711677 (Large).jpg (156.8 KB)
- IMG_20181209_094313912 (Large) (Large).jpg (126.3 KB)
- IMG_20181208_150429493 (Large).jpg (168.0 KB)
- IMG_20181207_053203238 (Large).jpg (118.7 KB)
- IMG_20181207_052843368 (Large).jpg (225.6 KB)
- IMG_20181203_125746281 (Large).jpg (233.5 KB)
- IMG_20181118_111202817 (Large).jpg (139.4 KB)
- IMG_20181202_143549142 (Large).jpg (159.1 KB)
- IMG_20181009_141944794 (Large).jpg (153.6 KB)
- IMG_20181009_142516729 (Large).jpg (158.2 KB)
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