The Bolton -Bertinat -Bailey Triple expansion engine

Charles Lamont

Reply #15 · 16 Jan 2025, 11:15

The red and green markings suggest that the engine will be installed with the HP cylinder abaft?

steam guy willy

Reply #16 · 17 Jan 2025, 21:56

Quote from: Charles LamontThe red and green markings suggest that the engine will be installed with the HP cylinder abaft?

yes , very observant of you !!! hopefully the fitters will also be sailors !!
Willy

steam guy willy

Reply #17 · 23 Jan 2025, 20:11

Hi all the next job is to complete the cylinder covers... one of them was missing but I have a 2" slab of brass to complete it .. the IP and the LP covers have 14 bolting heads that is quite difficult to divide by 360 degrees ..!!however I do have this item that has all the faces accurately milled from 3 to 9 flats that I can use ?!! so we will see how this goes .....Here are the pics...

Willy

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internal_fire

Reply #18 · 24 Jan 2025, 03:04

Quote from: steam guy willythe IP and the LP covers have 14 bolting heads that is quite difficult to divide by 360 degrees

I know about "rivet counters". Are there also "bolt counters?"

The original engine reportedly used by Bolton as the basis for his design had 16 bolts for the LP cylinder head. There are a few photos floating around of the Australian ferry engine that Bolton modeled.

Gene

steam guy willy

Reply #19 · 24 Jan 2025, 17:41

Quote from: internal_fire
Quote from: steam guy willythe IP and the LP covers have 14 bolting heads that is quite difficult to divide by 360 degrees

I know about "rivet counters". Are there also "bolt counters?"

The original engine reportedly used by Bolton as the basis for his design had 16 bolts for the LP cylinder head. There are a few photos floating around of the Australian ferry engine that Bolton modeled.

Hi Gene yes thanks for that and I suppose that the size of the bolt heads is also taken into account .....
"W"

steam guy willy

Reply #20 · 30 Jan 2025, 18:54

I am now making the cylinder bottom covers and after turning the bore dimensions, rather than making three of the suggested fixtures for the different sized bores I have used a plate attached to the standard faceplate and will bolt the smaller HP cover first with the recess and then increase the bored size to accommodate the IP and the LP covers, I have also incorporated a brass bolt to stop the cover from rotating on the jig...I have also been looking at some of the recent Cabin Fever videos and there are so many lovely models there quite a few modern casting set models from the UK. Also a very old Marion shovel engine !!
Willy

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steam guy willy

Reply #21 · 31 Jan 2025, 03:18

the HP bottom cover has been attached with some clamps and the central fixing turned to enable the gland dimensions to be finished , The jig plate is then enlarger to 1.5" to receive the IP cover and has been turned to thickness and the outside gland part to 13/16ths ready to clamp up and the inside part will be drilled and bored to the 7/16th recess . Just wondering about 7 and 9 cylinder areo engines ...how do they manage to get the actual crankcase positioned for machine the flats and bore the recesses as 360 degrees idivided by 7 s 51.463829036823654 etc etc etc degrees ??!!!!

Willy

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Roger B

Reply #22 · 31 Jan 2025, 08:02

That's an interesting pineapple like dividing tool

Do you know it's origin?

steam guy willy

Reply #23 · 31 Jan 2025, 14:50

Quote from: Roger BThat's an interesting pineapple like dividing tool Do you know it's origin

Hi Roger, yes , a car boot sale ?!!!! Actually no , think it was a home made one as there are no markings on it It has 3 to 9 faces on it !

Cheers

crueby

Reply #24 · 31 Jan 2025, 15:34

To position the case for machining they would have used either a dividing head or a rotary table, I would think. In mass production, they may have had a bespoke positioning setup too?

steam guy willy

Reply #25 · 31 Jan 2025, 17:15

Quote from: cruebyTo position the case for machining they would have used either a dividing head or a rotary table, I would think. In mass production, they may have had a bespoke positioning setup too?

Thanks , so on CNC equipment are there buttons to divide the 360 degrees by 7 or 9 to rotate the part accurately ? I have never used CNC myself ...I do have a DRO and VRO (Visual Read Out )..to obtain accuracy mostly !!

"W"

crueby

Reply #26 · 31 Jan 2025, 17:38

Quote from: steam guy willy
Quote from: cruebyTo position the case for machining they would have used either a dividing head or a rotary table, I would think. In mass production, they may have had a bespoke positioning setup too?

Thanks , so on CNC equipment are there buttons to divide the 360 degrees by 7 or 9 to rotate the part accurately ? I have never used CNC myself ...I do have a DRO and VRO (Visual Read Out )..to obtain accuracy mostly !!

"W"

I was not thinking of CNC machines, but the older manual ones before CNC. On a CNC machine, they could just program in whatever angle they want and the machine would do it. When I make gears, I use a little rotary table that turns 5 degrees per full rotation of the handle, and the handwheel is divided down into 50 segments, so even with that I can get down to a small fraction of a degree quite accurately. More professional machines would likely have even more resolution on the angle. Then there are dividing heads, with interchangeable plates for different degree combinations - they are very repeatable and with the proper plate installed, you can do any angle.

steam guy willy

Reply #27 · 1 Feb 2025, 18:48

Hi Chris , thanks for this and yes One just as accurately as possible drill up a dividing plate .... I don'y actually have a dividing plate head and have used the 60 tooth bull wheel in the lathe headstock !!

cheers
Willy

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steam guy willy

Reply #28 · 6 Feb 2025, 02:10

The top and bottom cylinder covers have been turned to size and are ready to have the 12 and 14 holes drilled using the acorn gauge

Willy

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crueby

Reply #29 · 6 Feb 2025, 03:14

Looking good!

The Bolton -Bertinat -Bailey Triple expansion engine ▦ 11 Jan 2025

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