The Bolton -Bertinat -Bailey Triple expansion engine

[Charles Lamont]

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

[steam guy willy]

The 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]

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

[internal_fire]

the 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]

the 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]

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

[steam guy willy]

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

[Roger B]

That's an interesting pineapple like dividing tool  Do you know it's origin?

[steam guy willy]

That'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]

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]

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?

 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]

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?

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]

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

[steam guy willy]

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

[crueby]

Looking  good!