Finney7 47XX Build (started during Lockdown)

[simond]

Paul,

I’m afraid I can’t remember which spacers I used for mine, probably the same as you. I can measure across the frames if it would help.

It was my first brass kit, and I do recall it was a bit of a challenge to get it to run across a Peco crossover, which I determined to be a very adequate test of “it’ll run anywhere if it’ll do that” but I got there in the end.

Atb
Simon

 

[Focalplane]

Simon

The middle size spacers are 24mm across, ie the inside dimension of the frame.

Thx Paul

 

[mickoo]

Medium sized spacers will easily go around 21" radius.

Wide sized spacers copes with 24" radius easily enough.

Your biggest issue is the front frame extension over the pony truck, even though it's tapered you will still need to remove the half etched fillet to allow more swing on the pony truck and prevent shorting.



Cut back to the full thickness arched profile and you'll be fine.

You need zero side play on the leading driver as it's tight in there between the leading crank pin and slide bars/crosshead, then spread your side play out on the other three axles, preferable having the least on the trailing one to try and keep the rear end in line with the tender.

 

[Focalplane]

That’s great advice, thank you. Have already cut out the arch for the bogie, it’s something you also have to do on David Andrews’ kits as well. The washer spacing makes sense but naturally I wouldn’t have done it that way!

I am waiting on the extra crankpin, it hasn’t arrived so far today, so it will be Monday, I hope. Then I can proceed with axle springs etc. after checking everything out. I have blued the driving wheels though. I can start on the pony truck or the cylinder assembly next.

 

[simond]

24mm does seem to be “it”



and, as Mick says, a bit of relief around the pony truck wheels



And happily I spotted the tender pickup connection needs plugging back in. Took the opportunity to put a drop of oil on the gears & axleboxes, and turned her the right way up again.




one day I will replace the chip with a sound one. Might disguise the portescap whine!

Atb
Simon

 

[Focalplane]

I have made a start on the cylinder sub assembly. So far the instructions make sense (to me!) and the bits fit together a lot easier than on the David Andrews’ Castle (though I should add that I am using full size wheels on the Castle which makes life more difficult). I like that the slide bars run through the cylinders rather than a weaker butt joint. The piston rod also runs through a tube soldered into the cylinder chest. Nice!

I am making a complete dry run of the parts except where the parts are laminated, etc. A lot of fettling is needed to make the laminated slide bars look solid. The cross heads are not castings, by the way, but built up from etches.

 

[mickoo]

Some notes on the cylinders, that may help, if not already too late.

Excuse slightly blurred images, it seems I can no longer hand hold down to 1/3oth second lol



The drain cock lever goes on the inside of the fittings, note the activation linkage is toward the front, I've yet to add the cross frame connecting rod.

There are half etched points on the back to press out to represent the pivot bolts, I didn't bother as previously such things on such a small scale just end up distorting the etch.



Fit the piston tube front and rear faces before you fit the tube, much easier to dress and make smooth, in face my piston tubes are still not secured, if I opt to solder I'll just add a blob to the top, more as likely I'll add a drop of super glue and give them a little twist to spread it around the joint.




Take care with the stuffing gland etches, they're very small and once the cusp is removed, very fragile, note they are handed left and right.

Add the upper slide bar oil pots before you fit the slide bars to the cylinder, obvious really watch out for the motion bracket, there are etched recesses in the slide bars for the motion bracket, they're too big so it's easy to get the motion bracket all sixes and sevens.

I tacked the top joint first, the bent, twisted and cajoled the bracket straight and true and gave the lower joint a good dob of solder. Once secure I fully soldered the top.

Make sure the motion bracket is flush with the slide bars at the rear or else the cross head will smack into it later, and, it won't pass through the front side either!

There's a little clearance section on the front side of the motion bracket top and bottom to clear the cross head flanges as it slides past, make sure all the cusp is off this area or else the cross head will foul.

Not sure which instructions you're using, if it's the Finney7 ones then be aware they are work in progress, we are revamping them with information and photos from my build, whilst not perfect, they are better than the originals.

In the Finney7 ones it notes the piston rod is 2.0 mm dia nickel silver, in reality it isn't, it's 1.6 mm, please do not try and bore out the brass piston tube, it will only end in bad language, ask me how I know!

I do need to get back and finish mine, it's beginning to tarnish badly now, but other work precludes it at the moment.

 

[Focalplane]

Thanks, Mick, not too late! I’ve made one blue language error so far, I laminated one of the top slide bar etches on backwards, it would have made the motion bracket look a bit off! Thank goodness I bought a butane torch as an essential part of the lockdown kit.

I am indeed using the Finney7 instructions, supplemented by accessing the download of the Hall instructions.

So far this morning I have been doing other things but once the cold front arrives. . .

Calling it a “cold front” is a very North American thing, I experienced my first “blue norther” in Oklahoma during a conference. The morning coffee break saw us outside shivering as the temperature had dropped 30°F in 2 hours. On another occasion I flew from Houston to Dallas, leaving Hobby Airport in 80°F. It was snowing when the plane touched down at DFW. The flight continued to Calgary where it was around 50°F as a warming Chinook had drifted over the Rockies!

 

[Focalplane]

Cold and windy but some progress has been made:



The cross head is not level because the piston rod has yet to be fitted. Still some fettling and cleaning up to be done but I am well pleased with today’s work. Not much to show for a lot of work “behind the scenes”.

 

[Focalplane]

The cylinder sub-assembly is nearly complete, just some small brass fittings and the wrappers to complete. I will leave the wrappers until later because there is some polishing work to be done on the slidebars, etc.





The sub-assembly has not been fixed to the frame but is a good tight fit.

No deliveries yesterday so it is probably on to the pony truck next.

 

[SimonT]

Paul,
please read Mickoo's build on this. The pony truck can be a pig to fold correctly.
Simon

 

[Focalplane]

Simon, yes you are right and I have not only read Mickoo’s thread I have printed some of the posts so as to be prepared. I will keep the build as simple as possible.
Thx, Paul

 

[Focalplane]

The spare crankpins etc. have arrived from Slaters and the errant crankpin has been replaced and glued. Now waiting 24 hours before the big test of the chassis alignment. I never did start on the pony truck! But some progress was made nonetheless.

Not such good news today about the planned purchase of a UK house. Not surprisingly the sellers have withdrawn their house from the market so we are again searching for that elusive "house for the rest of our lives". Thank you, Boris et al. for allowing us to check out a few villages in Hampshire that can replace the "forever home". Progress was made, mostly in ruling out some locations that really won't make the grade. But one did, subject to more careful examination. The rear garden is flat enough for a garden railway and there is space to store at least 2 vintage cars - fingers crossed!

 

[Genghis]

I think you are going to find that there is no space on the leading crankpin to use a standard Slaters' 12BA nut arrangement. This is definitely a candidate for the inverted threaded 10BA bush treatment.

The kit includes two pony trucks: it's a good idea to practice origami on the one you think you will not use first!

Dave

 

[Focalplane]

Thanks Dave, for your input. First, I take your point about the clearance behind the crosshead for the front driver but would this still apply if using the 24mm (medium width) frame spacers? I guess I'll find out the answer soon now the crankpin is bonded to the 8th wheel. In which case, could you shed some light on the inverted threaded 10BA bush treatment?

Yes, two pony truck etches, I think I'll choose the wider track as the guinea pig.

Paul

PS Re-started the house hunting yesterday which will take time away from the 47xx build.

 

[mickoo]

The frame width makes no difference as it's the crank pin nuts that foul the slide bars and that width remains constant unless you're going to model a narrower gauge.

Using narrower frames will allow more lateral play on the axles and actually increase the chance of the crank pin fouling, hence my suggestion to ensure zero, or close to zero side play on the leading axle.

Inverted top hats is easy enough, usually you fit them with the flange facing the wheel, add the coupling rod and then a nut. Inverting them means adding a thin washer first, then the coupling rod and then the Bush with the flange on the outside.

To do this you need to thread the top hat brush but if you use standard Slaters pins you cant. Standard pins are 12BA and the top hat slides over and is not threaded, throw them away, tap the crank pin hole in the wheel 10BA and then counter sink the rear, add a counter sunk 10BA screw from the rear.

Tap the top hat 10BA and then screw on.

It's one if those easier to show than explain and right now I dont have access to photos to show.

 

[SimonT]

It's all even easier if you use the CPL GWR Loco crankpin set. There are two front wheel crankpin nut/bushes for exactly this job.

 

[oldravendale]

Mick's is the technique I use on front driving wheels for all locos with outside cylinders.

There are some cases (notably for me the Black 5) - this is really teaching grandma..... - where the conn rods are so close to the slide bars and general round and round and up and down gubbins that it's desirable to countersink the flange on the bush in to the wheel. For that I use a counterbore. The sizes are 3.8 x 1.8 mm, the smaller being the hole size. It's a bit smaller than than the bush so it rattles a bit. Best into some mdf whilst cutting the countersink in the rod.

I usually use a 7BA washer behind the rod to space it off the wheel. It'll need opening out to 10BA for the screw, though, but I'm sure that presents no problems.

Hope that makes some sort of sense.....

Brian

PS - I don't claim any sort of originality for this. It was taught to me by Bob Alderman.

 

[simond]

I have used the same method as Mick describes since I did my 47 back in 1998.

Piccies of the nuts on my Duchess thread here:

Second hand Duchess

hth
Simon

 

[simond]

Mick's is the technique I use on front driving wheels for all locos with outside cylinders.

There are some cases (notably for me the Black 5) - this is really teaching grandma..... - where the conn rods are so close to the slide bars and general round and round and up and down gubbins that it's desirable to countersink the flange on the bush in to the wheel. For that I use a counterbore. The sizes are 3.8 x 1.8 mm, the smaller being the hole size. It's a bit smaller than than the bush so it rattles a bit. Best into some mdf whilst cutting the countersink in the rod.

I usually use a 7BA washer behind the rod to space it off the wheel. It'll need opening out to 10BA for the screw, though, but I'm sure that presents no problems.

Hope that makes some sort of sense.....

Brian

PS - I don't claim any sort of originality for this. It was taught to me by Bob Alderman.

it’s got good prototype credibility Brian. I had to do that with my 1366. It’s a pain to get the nuts on the crankpins, but once on, they’re fine. ideally, you’ll want a milling machine to counterbore the rods.

I didn’t need to do it on my 47.

Atb
Simon