CHUK, yes another one

[Jo]

Having built a couple of steam engines recently we decided it was time to do a different type of engine and I was lucky enough to be handed a set of Alyn Foundry CHUK 1 castings 

With all of my builds I like to start with the history of the model so I have copied over Graham's description of how CHUK's came about from our Two little CHUK's thread:

CHUK was originally designed as a kit of castings to be sold alongside the various machine tools marketed by Chester UK, now Chester machine tools. I worked for them for several years as head of the engineering department.

My inspiration came from a deal with a friend who twisted my arm for a recently completed A&T engine, cash and an Ernst Planck vacuum engine came my way. The Planck was a non runner initially, it would draw in the flame, partially rotate then stall. Upon closer examination I discovered that the taper pin that located the crank web onto the shaft had sheared internally   so that when the vacuum occurred the valve timing would alter to stall the engine. Within a few minutes the broken pin was removed and replaced, I had a runner.

The Planck is a lovely piece of engineering lots of parts pressed together, my job was to simplify its composition to ease construction.

I decided upon a simple " A " frame to support the cylinder, probably helped by my recent IF Allman build, I cut down a pattern to suit. CHUK 1 was born.

Cheers Graham.

The set of 10 castings supplied by Graham should be the Engine base, Flywheel, an Air cooled cylinder, the Cylinder head, a Piston, a Cam disc, the “A” frame, a crank web, a pair of cast brass Bearing support Pillars.  but it looks like someone has lost his cylinder head so I will use a bit of cast Iron for that.

The CHUK drawings can only be described as an Art work and of course they are metric 

Time for some casting Fettling 

Jo

[Johnmcc69]

 
 Good looking castings!
 Any chance you could post a snippet of part of the drawing?
 You know I'm a engine drawing junkie....
 
 John

[Alyn Foundry]

It's OK Jo, you can let them see.

 

The CHUK range is rather " exclusive " as we never got into any serious production with them. Due to the closure of Rhuddlan foundry production ceased and a draftsman was never sought after or ever found.

My hand drawn sketches ARE, quite literally, the drawings.

Cheers Graham.

[Jo]

My hand drawn sketches ARE, quite literally, the drawings.

They are better than that they have useful instructions on them as well 

The later ones don't have as much character.

Jo

[Craig DeShong]

Nice project, but how did you ever get them by Sirius?

[Jo]

Nice project, but how did you ever get them by Sirius?

A box of snicker Ice creams for now, three more boxes had to be ordered for Wednesday (it would have been more but thankfully purchases are still limited to 3 of any item ) and a promise he can have the running Horizontal Engine for his collection by the end of the week.  Castings are only allowed out one by one for fettling until he has the Horizontal 

I'm going to be busy 


Jo

[crueby]

Maybe cross-stitch a picture of him holding a casting set, might distract him long enough to snag a few more of them from his vault...

[Alan Haisley]

I think this will be fun to watch in more than one way.

[Jo]

I think this will be fun to watch in more than one way.

Signs are not looking good the three ordered boxes of snickers are unavailable   There is a major risk the castings will go back into Lockdown this afternoon once someone realises he is not getting his treats 

Jo

[Jasonb]

Sounds like you supplier has different thoughts on what is essential shopping to your casting monitor

[Jo]

Warning: The cylinder on this engine fits the other way round to the one on the CHUK 2 so if you are comparing the machining sequences between the two engines please do not get confused: The top is now the bottom and the Bottom is the top 

The cylinder is first mounted in a three jaw held squarely but most importantly so the outside curve of the top runs true because this way the bore will be concentric to the outside so the cylinder head, which will be on the top, will also be true to the outside surface 

Now we have a nice flat surface we can turn the casting round and mount the cylinder in a four jaw chuck, truing up on the bottom of the cylinder so that the fixed steady has something to rub against. I am sure most of you know how to set up a fixed steady but for those that don't: We start by bringing the steady up with the fingers withdrawn up to the work, lining up so that the fingers will rub on the newly machined surface once they are advanced and clamp the steady down. With the Lathe chuck out of gear so that it runs freely, each finger is slowly brought up to just touch and clamped into place. If like me you have a fixed steady that opens up don't forget to clamp it together before adjusting the top finger. Finally to prevent the fingers from rubbing a little Anti-scuffing paste is applied (other lubricants are available)

After lunch I am ready to start the boring bit 

Jo

[Alyn Foundry]

Hi Jo.

The tailsock centre? An added safety precaution ?

Cheers Graham.

[Jo]

Yes, I'm a wimp 

Jo

[steamer]

Yes, I'm a wimp 

Jo

    Once you face the end, put a pressure pad on the face and bump up on it with the TS center....helps a lot with "sketchy" setups, though in honesty, that chuck looks pretty stout from here.

Just a round disk with a center hole in it flat on the work side.....keep a couple handy...very useful.

Dave

[Alyn Foundry]

Yes, I'm a wimp 

Jo

 

" A little help's worth a lot of pity " Simple precautions make a great deal of sense particularly with large overhangs. I keep a few various sizes of " ball races " to use as " extra " packing because they're perfectly square. 

Cheers Graham.