Author Topic: Alyn Foundry CHUK 2  (Read 2412 times)

Offline RayW

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Alyn Foundry CHUK 2
« on: January 19, 2022, 03:30:31 PM »
Graham has very kindly supplied me with a set of CHUK 2 castings for my next project. The build will definitely be interesting, as there are no detailed drawings, just 10 pages of Graham's handwritten notes and sketches.
I have been reading and re-reading the various build threads here, but if anyone who has already built a CHUK 2 has any helpful tips or suggestions, they will be very welcome.
I do not intend to make this a detailed step by step build thread as that has already been done before, but I will make progress reports from time to time, as various milestones are reached.
Ray

Online Jo

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Re: Alyn Foundry CHUK 2
« Reply #1 on: January 19, 2022, 06:03:22 PM »
Nice castings  :pinkelephant:

Jo
Enjoyment is more important than achievement.

Offline Jasonb

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Re: Alyn Foundry CHUK 2
« Reply #2 on: January 19, 2022, 07:37:03 PM »
Yes hopefully all from the new foundry so they should be nice on the inside too ;)


Offline Twizseven

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Re: Alyn Foundry CHUK 2
« Reply #3 on: January 19, 2022, 09:22:22 PM »
I note the bearing housing has Grahams latest pretty top.

Colin

Offline Alyn Foundry

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Re: Alyn Foundry CHUK 2
« Reply #4 on: January 20, 2022, 12:26:27 PM »
Glad to read they arrived in good shape Ray.

Yes, they’re nice castings, all done at the new Iron foundry. The bearing housing and top were done by the Brass foundry I’ve used for over 30 years, now run by daughter and son-in-law.

Here’s a picture of one I built last year, stripped down for cleaning.

Cheers Graham.

Offline RayW

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Re: Alyn Foundry CHUK 2
« Reply #5 on: January 21, 2022, 03:11:33 PM »
Do I assume, Graham, that the brass bearing housing cap serves no actual practical purpose and could simply be glued in place?
Ray

Offline Alyn Foundry

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Re: Alyn Foundry CHUK 2
« Reply #6 on: January 21, 2022, 03:56:21 PM »
Good afternoon Ray.

Of all the vintage engines in my collection the Barker “ B “ type is my favourite where the Brass works are concerned. The Pagoda style top finishes off the oil boxes beautifully. So yes, it’s merely a purely cosmetic feature and will hide the two Allen screws that hold down the bearing housing to the pedestal.

CHUK 2 has been evolving since its development over 20 years ago.

I still have a few sets of castings available for this model.  If anyone is interested, please drop me a PM.

Cheers Graham.

Offline RayW

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Re: Alyn Foundry CHUK 2
« Reply #7 on: January 21, 2022, 08:44:54 PM »
The new foundry certainly seems to be producing some nice castings. Lets hope they machine as well as they look. The only minor blemishes I have noticed were on some of the fins, where the metal has not quite filled the mould, and one small blow hole in the central boss of the flywheel. All easily rectified with good old JB Weld!
Ray

Offline RayW

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Re: Alyn Foundry CHUK 2
« Reply #8 on: February 10, 2022, 12:35:42 PM »
Base and cylinder have now been machined, and the bore honed and polished to a good finish. The flame port slot has also been milled. A shallow double boss has been machined on the base of the cylinder, the larger diameter locating the cylinder on the base casting, and the small diameter being lapped to provide a flat surface against which the flap valve will seal.
I have opted not to machine the cylinder fins as I prefer to retain the cast look.
Ray

Online Jo

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Re: Alyn Foundry CHUK 2
« Reply #9 on: February 10, 2022, 04:09:26 PM »
Coming along nicely  :)

Jo
Enjoyment is more important than achievement.

Offline Alyn Foundry

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Re: Alyn Foundry CHUK 2
« Reply #10 on: February 11, 2022, 01:05:19 PM »
Your cylinder finish is excellent Ray.

 :cheers: Graham.

Offline RayW

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Re: Alyn Foundry CHUK 2
« Reply #11 on: February 21, 2022, 04:47:02 PM »
All the main castings have now been machined, with the pedestal having been secured to the cylinder with Loctite 648. The flame port face has been lapped to a mirror finish to provide a good sealing face for the shutter.

Now time to move on to the "fiddly bits", ie the shutter and operating mechanism, and the flap valve and spring. There are a few rough areas and holes on the flywheel that will require a bit of fettling with body filler before painting. I have left quite long bosses on the flywheel, crank web, and cam at this stage until I see exactly where each of them need to be positioned. The crankshaft will also be cut to length, and the crank web attached with Loctite.
Ray

Offline Alyn Foundry

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Re: Alyn Foundry CHUK 2
« Reply #12 on: February 21, 2022, 08:58:19 PM »
Nearing the home straight now Ray….

 :cheers:  Graham.

Offline RayW

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Re: Alyn Foundry CHUK 2
« Reply #13 on: February 21, 2022, 09:15:11 PM »
Just remembered, a con rod would also be useful!
Ray

Offline RayW

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Re: Alyn Foundry CHUK 2
« Reply #14 on: March 02, 2022, 04:09:20 PM »
Continued progress, with all major components now completed. The con rod is waiting for the little end to be added once I get the bearing that is on order. The shutter mechanism works well, with a ball race serving as the cam follower, and a lapped Stanley knife blade as the shutter. The flap valve, which locates in the base casting, is made and just needs lapping to ensure a good seal with the base of the cylinder.
I am following Grahams idea of three coil springs to support the valve, with the springs each being located in a recess in the base.
Ray