The problem fitting, how to overcome

[Michael CallaghanParticipant @michaelcallaghan68621]

Hi, today I got to the part of fitting the boiler with the smokebox, and connecting the superheater feed to the cylinders and the blower. Both fittings are a true pain in the backside to connect. After almost turning the air blue I managed to get the cylinder feed connected. However when trying to connect the blower I had that sinking feeling that it had come loose at the boiler fitting. Space inside the smokebox is limited and the design of the fittings do not help.

my question is, is there a way of sealing the blower boiler connection without taking the whole lot apart again.
thanks.

[Nigel Graham 2Participant @nigelgraham2]

Unfortunately most miniature locomotive designs do seem made to prevent easy access to the smokebox fittings.

You could try making, or modifying, slotted-ring spanners or sockets shaped to suit.

I would suggest slacking the blower-ring connection, if that is rigid to the blast-pipe and not simply a “halo” that rests loosely around the nozzle. Then tighten both unions a little at a time so the boiler connection is tightened fully, first.

I can’t suggest how to deal with the superheater without knowing the design.

It may help if you can add a photo or a scan of the drawings. Identifying the loco type would also help, as others here may have built the same design.

++++

On a general point I admit not very helpful to you in this instance, some model engines have smokeboxes divided along their horizontal cntre-lines with a cover-strap on the inside of the joint, and discreet countersunk screws in the upper part. These might be obscured by handrails, or the ejector-pipe (even that is a dummy fitting.)

My 7.25″ g. loco is a heavily freelanced version of an already-freelance published design (it’s a doubled-up LBSC Juliet). I discovered in its previous ownership a long slot had been cut in the bottom of the smokebox to allow it to be slid forwards and off the loco completely without disturbing any pipes – though re-sealing the slot is not easy.

[noel shelleyParticipant @noelshelley55608]

Hi Michael, It seems that when locomotives in small sizes were designed only at the last minute was any consideration given to all the pipework in the smokebox and in most cases you are on your own ! Sometimes a longer pipe taking a circuitous route and gentler bends may help. Making or bending spanners to access difficult fittings could help. Since by the time you get to pipe it up the starting point and finishing point are already fixed, being a juggler or magician is your best choice. Good Luck. Noel.

[Michael CallaghanParticipant @michaelcallaghan68621]

Noel, I do believe being a juggler with four hands looks like the best idea. In the mean time I have taken it apart again. What a pain.

[parovozParticipant @parovoz]

What locomotive is it? What is the diameter of the smoke box? The smaller it gets the thinner your fingers need to be and they need a few extra joints:-(

Even with a 9″ diameter smoke box I had to be careful with the design to make sure I could fit everything in ‘layers of assembly’ in the correct order so as not to restrict access at the wrong point.

The main rough rule is to make pipes as long as possible and put in as much potential ‘strain relief’ as possible. So for a blower pipe, don’t route it directly but take it out to the wall of the smoke box then bring it back in to the blower ring, or put a full loop in it ‘like a spring’. That way when making the connection to the blower ring, it does not twist or torque the joint you have made to the front tubeplate hollow stay, those joints are normally the first layer of the onion and the link to the blower ring can be the last layer…. with five stages in between….

All the best.

 

 

 

[BazyleParticipant @bazyle]

We need a Chinese production engineer. “Make these connections as quick and easy to connect as possible. Don’t worry about maintenance that is the second owner’s problem”.

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