Author Topic: Vickers Inverted Engine  (Read 2479 times)

Offline Michael S.

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Re: Vickers Inverted Engine
« Reply #15 on: January 11, 2025, 09:26:14 PM »
Excellent finishes!
It looks absolutely good.

Michael

Offline Jasonb

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Re: Vickers Inverted Engine
« Reply #16 on: January 18, 2025, 07:03:33 PM »
Thanks.

Next job working my way up the engine were the columns. As with other engines to save materials I opted to machine spigots at either end to locate the bases and capitals which were machined separately. I could then hold the 12mm diameter steel by the bottom spigot and with a boring head offset in the tailstock the taper and mouldings could be turned.



The bases and 2 part capitals were fairly straightforward with a mix of form tools and files to create the mouldings on the end of a bar before parting off and repeating the process. The squares were cut from the waste material out of the base end plate arches.



After glueing the bits together with epoxy and allowing a day to set the columns were all machined to one setting ensuring they all came out the same overall length.



An old aluminium casting was machined up to 7mm thick and to the overall sizes on the manual mill before transferring to the CNC. I used that to form the four raised bosses for the column nuts, to bore the large 39mm dia hole and also drill the other various 3, 4 and 5mm holes.



Then back to the manual mill to cut the coved detail to the underside of the edges



A 7mm hex was milled onto the end of a piece of 8mm dia round and then a form tool from a previous job was repurposed to form the acorn nuts which were then sawn off, faced and tapped M4.



Starting to look more like an engine.






Offline crueby

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Re: Vickers Inverted Engine
« Reply #17 on: January 18, 2025, 08:36:02 PM »
Beauty!   :popcorn:

Offline Michael S.

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Re: Vickers Inverted Engine
« Reply #18 on: January 18, 2025, 08:57:45 PM »
A temple for a steam engine! It looks perfect!

Michael

Offline Jasonb

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Re: Vickers Inverted Engine
« Reply #19 on: January 26, 2025, 06:30:41 PM »
I was in two minds whether to fabricate the cylinder from Brass and Bronze using silver solder to hold it together or to JB Weld fewer pieces of cast iron. In the end the cast iron option was the one I went for.

A piece of 50mm bar was roughed out externally, faced and then bored to 30mm diameter.



I then used a parting and grooving tool to set out the position and depth of the various diameters that would become the flanges and decorative beads.



Further cuts with this tool removed most of the waste material and also cut the 1mm x 1mm step either side of the beads.



I then made a form tool from silver steel to form the 2mm radius beads around the cylinder.



A round nose tool took care of the stepped fillets at each end to complete the turning.



With the cylinder held horizontally a flat was machined to locate the central port face and also two blocks that would form the steam passages to each end of the cylinder which you can see sitting in place.



The inner face of these blocks and that of the port plock were milled out to form the passages and some further work done on the port block to form the undercuts and the exhaust boss. These were all then bonded into the slot with JB Weld and given 48hrs to set.



The port face could then be skimmed flat, the ports milled with a 2mm dia cutter and the stud holes drilled and tapped.



Each end had it's pattern of holes drilled and tapped and a notch was milled to link the passages to the cylinder.



Offline scc

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Re: Vickers Inverted Engine
« Reply #20 on: January 26, 2025, 06:55:09 PM »
Lovely  :ThumbsUp: :popcorn:     Terry

Offline pirmin

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Re: Vickers Inverted Engine
« Reply #21 on: January 26, 2025, 07:19:05 PM »
Beautiful Cylinder jason ! I am sure you get this engine done before my Upper Casting is safed :facepalm:

Offline redhouseluv

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Re: Vickers Inverted Engine
« Reply #22 on: January 26, 2025, 07:43:16 PM »
Looks like a cast cylinder, only better! I've never seen one of those round nose tools before, that certainly makes the finished look in my opinion  :ThumbsUp:
Best regards

Sanjay

Offline Chipswitheverything

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Re: Vickers Inverted Engine
« Reply #23 on: January 27, 2025, 09:23:52 AM »
Just caught up with your amazing fast-track build of this interesting engine:  the elaborate moulded base looks terrific, and features some ingenious practical solutions. And has a crispness of detailing that no small castings could approach, even with considerable fettling and re-working.  A very interesting build log, thanks.  Dave

Offline Michael S.

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Re: Vickers Inverted Engine
« Reply #24 on: January 27, 2025, 12:38:57 PM »
The cylinder looks absolutely good. A good example of how it can be put together from several parts. And I have never seen tools from Škoda! I only know cars or steam locomotives.

Michael

Offline Jasonb

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Re: Vickers Inverted Engine
« Reply #25 on: February 01, 2025, 06:40:02 PM »
Thanks for the comments from those following along.

With the cylinder complete the various bits that fit to it were next.

The lower cover is fairly straightforward turning, it is a bit thicker than your usual cylinder cover as there is an 8mm thick boss on the bottom which locates in the large hole in the entablature.





The top side just has the usual shallow spigot to locate the cylinder and was reamed 5mm for the piston rod



Some holes finish that part off, the two tapped holes in the thicker section are to take the crosshead rod guides



A quick modification of my beading tool by grinding one edge to 45degrees allowed it to be used to form the 4mm balls on the ends of the 5mm guide rods.



The top cover is rather busy with a lot of fine moulded detail to the "cast" part



The main turning was done on the lathe but rather than fiddle about with small form tools to turn the detail I used the rotary table to rotate the cover while I used various milling cutters to form the shapes including a 6mm dia bull m=nose cutter with 1mm convex corner and a 1.5mm radius corner rounding cutter.



The valve chest and it's cover are much the same as any other just being rectangular bits of cast iron with some holes drilled in them.



A couple of minutes each on the CNC had the elliptical boss and gland shaped on the end of the chest and a decorative recess in the cover.




Offline redhouseluv

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Re: Vickers Inverted Engine
« Reply #26 on: February 01, 2025, 10:49:09 PM »
Those ellipitical glands look perfect, both the valve chest and brass part - are they machined together?

I need to make a similar shaped exhaust flange for the engine I'm working on; pencil, paper, some round stock and a file unless theres a clever way of making ellipitical shapes using a rotary table??
.
Best regards

Sanjay

Offline Jasonb

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Re: Vickers Inverted Engine
« Reply #27 on: February 02, 2025, 07:25:16 AM »
Yes i did them together.

There are several options, rotary table, boring head, jig on the lathe. The later two require some filing of the small radius at each end

Though are the Centaur ones actually elliptical or a flattened diamond with rounded corners? In which case the rotary table can be used.

Post a photo of the mating surface in your thread and we can take it from there.

Offline gbritnell

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Re: Vickers Inverted Engine
« Reply #28 on: February 02, 2025, 01:28:51 PM »
Beautiful work Jason! The cylinder looks like the one on my Mary beam engine. Elegant looking engine!
Talent unshared is talent wasted.

Offline redhouseluv

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Re: Vickers Inverted Engine
« Reply #29 on: February 02, 2025, 09:49:59 PM »
Yes i did them together.

There are several options, rotary table, boring head, jig on the lathe. The later two require some filing of the small radius at each end

Though are the Centaur ones actually elliptical or a flattened diamond with rounded corners? In which case the rotary table can be used.

Post a photo of the mating surface in your thread and we can take it from there.

Yes, will do, thanks - once I have have overcome the current issues  :)
Best regards

Sanjay

 

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