Finescale - of a sort?!

[Peter Insole]

The brief outage notwithstanding, I'm afraid I have been doing more worrying brass and solder rather than writing again!

A little bit late in the day, I have collected a fair few photographs of progress to share now:

The straight connector and one of the nuts previously mentioned would prove to be almost perfect for the task...



A couple of small, rubber discs from some pipe end stops will hopefully provide material for the valve seals later too?!

I have shifted from the original design slightly, in that the thread for the lever cap is on the exterior of the barrel, instead of being on a narrowed section. Using the existing nut and leaving a remnant of the matching thread seemed to be a slightly easier option, as well as providing a bit more clear access for later operations?

While I was still considering the best way to proceed, a start was made on the cap itself by filing down the nut and chopping a bit more off a remaining stub of another old donor 10mm coupler:




I have left the inner ring section rough cut for the time being, as I want to solder that, whatever I can find for a hollow centre fitting, and the operating lever clevis in a single, messy operation!

The symmetrical coupler barrel has a reduced diameter pipe stop section in the centre, beneath the former hex, which I felt could be handy for pressing a separating barrier plug into - but that turned out to be a bit of a fiddle:



It did make drilling the apertures for the two vertical tube connections rather a nether clenching exercise... but I got away without any serious mishaps, or missing bodily bits!!

Making a really tight, press fitting plug to fit a hole with an unspecified, and difficult to accurately measure internal diameter required an amount of trial and error... plus a fair wind blowing in the end.




It might not look like it in the last image above, but the plug was sufficiently snug to require a bit of gentle "persuasion" before it settled in the correct position.

I wanted this essential barrier section to hold firmly in place during subsequent soldering up of the two, vertical branches and the front end fitting to come later.

Not only was working out the appropriate order of shaping down, drilling, tapping and cutting the branches tricky and troubling enough...



but on the lower, feed section, I was down to my very last bit of brass hex of the right size in the box...!



Wow! There really was just enough length to spin the shaft to shape when the piece was held in the chuck jaws - so not a millimetre to spare for any errors there!

I will admit that I am somewhat reluctant to order any more brass sections, particularly bearing in mind that I am now so close to completing all the plumbing jobs, that it would a shame to end up with any new lengths of odd size materials. for the sake of a single part!



By the way, the vee shaped cuts filed in before separating the pieces from the stock bar are necessary to fit with the sections left open above and below the centre plug - and having those angles inside the barrel would also provide a flat surface to commence drilling the connecting airways.

I felt it was preferable to drill those airways after soldering up, rather than finding that the angle might be slightly too steep, and then having difficulty trying to clear the tiny holes again of any runaway solder?!

There are more pics and words to bring this bit up to date, but I will save them for later!

Pete.

 

[Peter Insole]

It was a bit of fun trying to ensure that the cruciform remained reasonably square during soldering up, and I did have some trouble with solder not flowing quite where I wanted it - requiring a second dose of flux and waft (or perhaps more accurately a blast) of heat to make sure that the plug was thoroughly airtight all round the edges!



The view above was taken before cleaning up the excess solder, while the two below show how the angles act as both a shaped fillet, that doesn't intrude too much into each chamber, and as previously mentioned, would then provide one, small, flat section for drilling an angled passage connecting with the main column bores at top and bottom.



Once again, I was so busy faffing about with it all that I quite forgot to take pictures of the new holes, so the best I can do is describe them! The front chamber (upper view) has the inlet hole leading down into the branch with the hex and male thread, while the rear chamber (lower view) has the outlet hole leading upwards into the short, stubby, top branch (female threaded for the whistle).

A 2.5mm (max. dia.) valve rod and larger seal should (hopefully) hold the air in the front chamber, and then when pushed in against a spring, allow air to pass through the 3mm hole in the plug, thence into the rear chamber and to atmosphere via the screaming fipple!

That's the theory anyway! I still have absolutely no idea if it will work... but the learning curve is a steep and rather adventurous journey!




Ah well, if it doesn't, I suppose it will still be as a golden ball, sitting pretty and surmounting the glorious dome?!

To bring the tale up to date; I have now soldered in the front ring, and more or less sealed the fate of the front end. Any alterations there are by no means impossible... but I fear it would be very easy for me to get the whole thing in a terrible mess when attempting to sweat any part back off!



It is all a bit tight in there, as the maximum diameter of the valve, (to fit against the plug) is 6mm, so I had to drill and tap the hole in the cap at an awkward M7. This also was at the maximum to allow the valve to be fed in, while still leaving just enough metal all round the cap for a hex screw head to finally seat and seal it up.



I found a handy little fibre washer that was exactly the right size for the whistle joint, but only after screwing it fully home on the valve body I discovered that one, or both of the hand cut threads was on the wonk!

Damn it and sigh!

We will just have to imagine that the exalted object copped a wallop at some time on it's host's travel on the lines around Horwich Works... (probably not a particularly unlikely scenario?) and that it has never been quite as straight as it's fellow bellowers ever since!!

Pete.

 

[timbowales]

Pete, I am in awe of your brass bashing, as usual! Wonderful stuff and don’t worry about the wonkyness, that’s just a little bit of character

 

[simond]

The “Screaming Fipple”.

Would this be some kind of Hammer Horror 1970’s vampire-like monster, or an ideal name for some kind of whistle-based folk band?

 

[Peter Insole]

Ah, I was just in a silly mood last night, as well as getting bored with typing ordinary words!

Trying to be as poetic as I could manage, I thought of an alternative that I was quite pleased with... was utterly convinced that I had inserted it... did a read through just before posting... and spotted a peculiar, empty space in the text. (?!)

For the life of me, I could not remember what the little gem was... so "screaming" was an act of frustration... being as I was, by that time, dog tired and just wanting to click post before heading off to bed!

Pete.