Author Topic: ᐌǁ 'Vulcan Variation' Mill Engine ǁᐍ  (Read 3351 times)

Offline gary.a.ayres

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ᐌǁ 'Vulcan Variation' Mill Engine ǁᐍ
« on: July 16, 2021, 12:07:23 AM »
Thus far I have avoided attempting to build an engine with a proper valve, but the time has come for me to face this challenge. I considered various - and quite diverse - options before settling on this:



I was drawn to it for various  reasons:

(1) the plans are metric

(2) I wanted to bulid another fairly large engine, and the plans are for an engine big enough for me to take the dimensions from them without making any conversions

(3) the plans include clear, simple build notes for each part

(4) the designer encourages a flexible approach to materials, methods and the appearance of made parts.

It was that last point that really sold this one to me. My previous two engines have taken serious aesthetic liberties with the designers' ideas. However, Andrew Smith positively encourages builders to make their own unique versions of the Vulcan. For my part, I intend to go further in that my interests do not lie in making 'models of' traditional engines. No disrespect to those who do, and there are some stunning examples on this forum and elsewhere of model engines reflecting the aesthetics of the great days of steam, but my thing is to try to build something a bit 'different' - hence my verion beng called the 'Vulcan Variation'.

So, I will stick fairly faithfully to Andrew Smith's mechanical design specifications, but in every other aspect I will feel free to do my own thing. What that will turn out to mean I don't know yet, but it may have a combination of contemporary and traditional-looking elements, and it may include some recycled bits and pieces if the look and dimensions are right, but it will still (hopefully) be recognizable as some kind of a mill engine.

Although this is a relatively simple mill engine, it is nevertheless another step up for me (as a beginner) in terms of challenge, so I'm a little apprehensive.

But here goes...


Offline crueby

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Re: ᐌǁ 'Vulcan Variation' Mill Engine ǁᐍ
« Reply #1 on: July 16, 2021, 02:20:25 AM »
Looks like a great choice, enough added parts to learn with, you should do great with it!

Offline Dave Otto

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Re: ᐌǁ 'Vulcan Variation' Mill Engine ǁᐍ
« Reply #2 on: July 16, 2021, 02:23:17 AM »
Cool, looking forward to a new project!

Dave

Offline propforward

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Re: ᐌǁ 'Vulcan Variation' Mill Engine ǁᐍ
« Reply #3 on: July 16, 2021, 02:26:12 AM »
Following along Gary. Looks like a great choice of engine.
Stuart

Forging ahead regardless.

Offline gary.a.ayres

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Re: ᐌǁ 'Vulcan Variation' Mill Engine ǁᐍ
« Reply #4 on: July 16, 2021, 09:15:29 AM »
Cheers guys!

Offline gary.a.ayres

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Re: ᐌǁ 'Vulcan Variation' Mill Engine ǁᐍ
« Reply #5 on: July 25, 2021, 10:55:44 PM »
I started off with photocopying, sellotape, a sharpie and coloured pencils to make a user-friendly version of the plans:



Then I gathered together materials which I already had in my shop that will be useable in this build:



I was a little disappointed as I had hoped that I would have stuff to make more of the parts with than I actually do. A visit to the scrap bin at a local machine shop is indicated, and a few orders from suppliers will be required too. However, there was enough here to get me started, and I decided to get going with the flywheel, the materials for which are scrap bin salvage.

The main body of the flywheel will be made from the large steel disc, and the hub will be from the smaller brass one.

I began by facing both sides of the brass disc in the lathe:



It was then centre-drilled, drilled and reamed to 12mm. The final diameter of this hole will be 16mm but I don't have a 16mm reamer yet so I went with this to get me started and give me a reference:



The large steel disc was given a rough cleanup with a wire brush and although there is still some surface rust it's all pretty smooth and quite workable pending it being properly cleaned up in the lathe.

The centre was marked approximately using the centre-finder attachment of a combination square:



The centre was then punched. It will be interesting to see how accurate this turns out to have been when it is mounted on an arbour in the lathe.

The disc was clamped to the mill table and the central punch mark was located with a wiggler:



The central hole was centre drilled, drilled and reamed (again 12mm but to be opened to 16mm when the tooling arrives). I then used the DRO to centre drill and drill a 6-hole bolt circle:





Cap-head screws have been dropped into the holes, just for fun. Behind the chuck you can see a flywheel casting hanging on the wall. This was kindly given to me by our fellow forum member Peter, aka gas_mantle, who hasn't been on the forum for a while. I was originally intending to use it for this engine, but it's an inch smaller in diameter than specified on the plans. I'll use it for something else in due course. The steel disc I have used is a little bigger than the plans call for, so it will tolerate losing a little diameter when it's being trued up.

I'm going to leave this setup in the mill until tooling arrives for me to widen the central bore and counterbore the bolt holes.


Offline steamer

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Re: ᐌǁ 'Vulcan Variation' Mill Engine ǁᐍ
« Reply #6 on: July 26, 2021, 01:02:11 AM »
Have I mentioned I like steam engine!? 8) :DrinkPint:

Watching along.....
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline Dave Otto

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Re: ᐌǁ 'Vulcan Variation' Mill Engine ǁᐍ
« Reply #7 on: July 26, 2021, 01:24:42 AM »
Looks like you are off to a good start Gary!

Dave

Offline gary.a.ayres

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Re: ᐌǁ 'Vulcan Variation' Mill Engine ǁᐍ
« Reply #8 on: July 26, 2021, 09:57:56 AM »
Many thanks guys!

@ Steamer - no, you haven't mentioned it. Being a bit of a Sherlock Holmes, though, I cleverly figured it out...  ;)

Cheers,

gary

Offline gary.a.ayres

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Re: ᐌǁ 'Vulcan Variation' Mill Engine ǁᐍ
« Reply #9 on: August 01, 2021, 11:40:34 PM »
The holes in the flywheel bolt circle were counterbored to a depth slightly greater than the length of the heads of the cap-head screws which will hold the two parts of the flywheel together:



The hub was then located in the mill using a piece of 12mm round bar to find the central hole. This was as accurate as I felt it needed to be at this stage, given the approximate nature of my centre-finding on the main body of the flywheel:



The DRO was then set up to create a bolt circle in the hub to correspond with the one in the main part of the wheel. The holes were centre drilled...



... drilled...



... and tapped M6:





The two parts of the flywheel were then fixed together using M6 cap head screws. Despite my best efforts I ended up with a slight misalignment of the central bores of the two components to the extent that I was unable to push a test piece of 12mm round bar through the bore of the assembly. I'm not too worried about this at this stage, particularly as the final bore will be 16mm.

The assembly was chucked in the three-jaw in the lathe, with the jaws gripping the outside diameter of the hub (which is smooth and regular but as yet unmachined by me, so I'm not worried about the jaws marking the surface):





On setting the lathe running, a significant degree of wobble was apparent. This was unsurprising, given that to find the centre of the main part of the wheel I had used the centre finder of a combination square set. It's even possible that the steel disc that I'm using for the wheel is out of round. No matter - it can all be trued up in the lathe:



This flywheel is about eight inches in diameter, which is pretty much as big as my lathe can handle. Turning it so that it runs true is quite a time-consuming job. I made a start today; hopefully I'll make a bit more progress tomorrow...


Offline propforward

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Re: ᐌǁ 'Vulcan Variation' Mill Engine ǁᐍ
« Reply #10 on: August 01, 2021, 11:44:00 PM »
That's going to be a plenty big engine Gary! Very much enjoying the journey!
Stuart

Forging ahead regardless.

Offline gary.a.ayres

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Re: ᐌǁ 'Vulcan Variation' Mill Engine ǁᐍ
« Reply #11 on: August 01, 2021, 11:48:29 PM »
Cheers Stuart!

And - somewhat unusually - this is the size specified on the plans.

If I had the space and big enough machines (and of course the know-how), I'd build full sized engines!

This is pretty much as big as I can go, though, unless I win the lottery or something...

Offline Jasonb

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Re: ᐌǁ 'Vulcan Variation' Mill Engine ǁᐍ
« Reply #12 on: August 02, 2021, 07:03:18 AM »
Looking good, at least it won't suffer from too small a flywheel like the uniflow originally did :)

One suggestion for the next time you do this , if you used the 4-jaw you could have set the steel disc to run true so just a light skim to clean up. Bore at the same setting so it will run true on the crankshaft. Then you just need to correct any wobble on the outside of the hub which will be a lot quicker to do.

Offline gary.a.ayres

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Re: ᐌǁ 'Vulcan Variation' Mill Engine ǁᐍ
« Reply #13 on: August 02, 2021, 10:16:51 AM »
Hi Jason -

Thanks for looking in, and yes - this time the flywheel *should* be big enough!

Very useful tip about using the 4-jaw to centre the main disc. This is where my inexperience shows. Will bear that in mind for my next one...

Offline gary.a.ayres

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Re: ᐌǁ 'Vulcan Variation' Mill Engine ǁᐍ
« Reply #14 on: September 16, 2021, 09:43:24 PM »
Not a lot of progress currently. Been busy, then away, then busy, then away again, going away yet again soon, and will be busy again when I get back...

However, I did get the flywheel pretty much finished. It's eight and a half inches in diameter and pretty heavy. It runs true. Most of the markings you can see are just stray splashes of layout fluid. Some of them are tiny holes in the steel which would take to much metal away from the wheel if I tried to get rid of them:



Part of my aesthetic for this engine is to use whatever bits and pieces I have as far as possible. The plans call for the baseplate to be made of 6mm steel. I didn't have any of that, but I did have some 6mm aluminium plate, which will be fine. It's set up ready for milling square. In the original design, the base is short and the cylinder overhangs it. I'm going to keep mine longer to give the engine a more 'grounded' look:



I didn't have any pieces of solid steel the right size for the main bearing supports, so instead I'm going to fabricate them out of these odds and ends:



It will be time-consuming and probably no cheaper in the end, but it will be fun.

Sporadic appearances from me for quite a while longer...

gary