mbrown
Elder Statesman
Posts: 1,719
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Post by mbrown on Mar 3, 2019 21:57:34 GMT
Many thanks Brian - interesting. Once you had silver soldered the two tubular pieces together, I guess the rest was just like machining a casting. The fillets between the two tubes don't seem to have any complicated passages cut in them or anything like that. It's a much simpler arrangement than most fabricated cylinders I have seen.
Malcolm
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Post by richard2018 on Mar 4, 2019 9:46:58 GMT
Hi Richard, That's the dimension given, I assume its for 2 turns of 1/8" square packing. At least that's what I'm going to do. Paul So it is.....I obviously didn't read the " words and music" carefully enough! I can't see any mention by LBSC of what goes in it though, either in Doris or in Maid of Kent (which ran in ME at much the same time and where he used the same slot shape).
Thanks for the reply.
Richard.
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Post by mr swarf on Jun 15, 2020 16:10:41 GMT
Its been a while with various life events getting in the way but I thought I was time to do a bit more on Doris. I managed to buy some rear cover castings but they were very tight on some dimensions. The distance over the guide bars is 7/8" & the casting measured 900 thou so just over 12 thou to come off each of the flats but i'd give it go. The register was turned to a good fit in the bore, then the outside diameter. Next I drilled through and finished with a 7/32" reamer. IMG_20200608_142701338 by Mr Swarf, on Flickr To drill for the gland I made a pin drill from silver steel 3/8 x 32 tapping drill size. I wasn't sure I had the angles right but it seemed to cut well. It was then tapped 3/8 x 32. IMG_20200608_150934431 by Mr Swarf, on Flickr The flats were then milled using a 7/8" round bit of steel screwed in to the gland to act as a guide as per a previous suggestion. Just about got the skin off with the small amount that needed to come off. IMG_20200608_155814378 by Mr Swarf, on Flickr At this point I could see something wasn't quite right and setting a square against it showed the flats were not in line ! IMG_20200612_145055920 by Mr Swarf, on Flickr Not sure what I did wrong but after a bit of thought I turned the boss down to 1/2" diameter and machined a new boss on the end of some bronze bar & parted off. The two would then be silvered soldered together. IMG_20200612_194739719 by Mr Swarf, on Flickr Here are both covers after soldering. IMG_20200613_124738167 by Mr Swarf, on Flickr I did the same on the other casting without trying to machine it as I could see there was something not quite right about the position of the boss and with so little metal to come off it would probably gone the same way. Got there in the end, I blame the casting Paul
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timb
Statesman
Posts: 512
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Post by timb on Jun 15, 2020 16:45:14 GMT
Nice neat solution!
Tim
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Post by mr swarf on Jun 15, 2020 20:48:41 GMT
The covers are fixed with 8 x 6ba bolts. I usually use the bull gear on the myford for quick & easy 3 ,4 & 6 multiple divisions but at 60 teeth I can't do that for 8. So I dug out a change wheel divider I made when I had an old ML7. Luckily it fitted my newer Sigma 7. The first wheel out of the box which would give 8 was a 40 tooth so that was mounted up. I made chalk marks every 5 teeth so I could keep a check during the rotation and to be sure. IMG_20200615_195501790 by Mr Swarf, on Flickr 8 holes were then drilled tapping size for 6BA taking care to miss the steam ports. IMG_20200615_195610472 by Mr Swarf, on Flickr Then the holes are transferred to the cylinder, ensuring the guide bar flats are square to the mounting face, and tapped 6BA. IMG_20200615_210406731 by Mr Swarf, on Flickr That's the 1st one done, only 31 more to go. Paul
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