Thank you for checking in and the kind comments everyone
Jim, I'm particularly happy to see you active my friend
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Eric, going by stereotypes, the only time a redneck is quiet is after too much 'shine
Jerry checked in on the site today
I don't know if that's still from the bridge of that ship he went sailing along with, or if he's back in the shop and about to add some more interesting posts
On to the cylinder...
I found a small offcut of 12mm plate in the scrap supplies bin - the cylinder actually needs to be 12.7 x 14.3 x 25.4mm (1/2 x 9/16 x 1"), but using 12mm instead of 12.7mm won't matter too much... Here marked out for the 14.3mm width:
The black permanent marker's dried out now, so I grabbed a blue one)
Milled to the line:
And the 25.4mm length marked out - with an X on the off-cut side:
Off to the band saw - taking care to set the blade so that it will run on the marked off-cut side:
On to the mill and on one of my home-brew parallels. Note that I stuck the off-cut section in the left side of the vise to keep the jaws parallel:
Some lay-out on one end to mark the bore center. Note it's not centered on the width - it's offset from one side by 8mm (5/16") - OK, technically, that should be 7.94mm, but 8mm is close enough here:
That got a decent center punch... In two steps; first a light tap and check to make sure the light one was on center, and then a good whack to deepen it:
I snipped a bit of drinks can up - fortunately my brother-in-law had been visiting and I kept the beer and soft drink cans he and my sister used. One of my personal "peculiarities" is that I detest drinking anything from cans... so I never have empty drinks cans around unless visitors happen to leave empties:
Some more snipping, and that fit the workpiece fairly well:
Off to the lathe, and with the drinks can snippet wrapped around the workpiece very roughly located in the 4-jaw chuck:
Next I aligned the center pop to be visually "centered" - if one were to draw a cross through the centers of the chuck jaws, the punch mark is about in the crossing point:
The reason I made the deep punch-mark in the workpiece was so that I could use a spare MT2 center supported between the revolving center in the tailstock and the workpiece to center the workpiece with my favourite dial indicator:
I'm not going to go into detail about the centering process... - there's a couple of very good write-ups on that around.
The hole was center-drilled:
The cylinder has a blind bore 24mm deep, so a way to drill to the correct depth was needed. My lathe's tailstock is calibrated in imperial units, with one inch between the long markings:
As the bore wasn't a full inch deep, it would end between markings as the tailstock handwheel was advanced. This can be a bit disconcerting to guess while drilling, so I set the tailstock to the "difference" (1.4mm beyond the first marked line) before starting to drill...:
And moved the entire tailstock along the lathe ways to put the tip of the drill bit in line with the face of the workpiece - using eyeball mk1:
Then it was just a matter of drilling till the second "inch" line appeared on the tailstock. The first drill was a 6mm one - I followed that with a 9mm drill using the same method.
To get rid of most of the cone in the bottom of the bore left by the drill tip, I used a non-center-cutting 8mm milling bit chucked up to remove most of the material with a very light feed - also reading the depth off the tailstock calibrations:
I don't have a suitable machine reamer to finish the hole to size, and I was too lazy to make up a D-bit reamer. What I do have is a small boring bar made from silver steel:
A quick rub or two over the fine side of the oilstone it's lying on in the photo, and the cutting edge was razor sharp and smooth as silk. You can see the small shiny are where it was honed:
That was then mounted on the lathe and set to center height using the height gauge I made up as one of my earliest turning exercises:
To finish the hole bore to depth, I used the home-made stop block with an el-cheapo (US$14.00) long travel dial indicator to check the depth while I worked:
It may be a cheapy DI, but it works so well, I actually bought another one shortly after this one arrived in my shop...
The plans show a generous chamfer at the end of the bore - rather than faff around with the topslide, that was added with a sharp 3-flute countersink bit:
It's hard to photograph into a small blind bore like this, but in this one you can just about see the nice finish that home-brew boring bar left:
My reamers can't hold a candle to that...
Long post... Time for a break again
Kind regards, Arnold
