Focalplane's Workbench (mostly 7mm)

[Simond]

David,

 

I'm sure we're in violent agreement!

 

I think the term "connecting" is a bit vague, as it could clearly be used for any rod that attaches things together, but it is certainly always used for the item that transmits the force from the reciprocating bit (piston in small i/c engines, crosshead in big i/c & in steam engines) to the rotating bit (crank or big-end bearings) on the crankshaft, crank axle or crankpin on the driven wheel.

 

The term "rod" is perhaps misleading too, as in most cases it suggests a slender cylindrical object, whereas conrods are normally anything but: they may be very short, typically fatter at one end than the other, and are probably "H" shaped in cross section as they must contend with potentially huge inertial forces in high revving engines, not that this concerns us greatly with model locos. I have seen cylindrical rods on large stationary engines, where the rod may actually be built up with separate end pieces, presumable as forging technology was not able to make the whole rod at that time.

 

Which is all very well, but has very little to do with Paul's loco build, so I'll shut up!

 

Best

Simon

[Focalplane]

Despite there being good weather yesterday (an unexpected bonus) I did manage to complete the hornblocks and add the additional parts to the frames.

 

The Poppy's Jig was used to set up the hornblocks before soldering them into place.  This is the result:

 

 

I tack soldered only two frame spacers, one at each end.  With the axle rods and coupling rods in place this gave enough stability.  It was important to weight the chassis down while setting the hornblocks.  I simply used my hand while tack soldering each hornblock in place, essentially compressing the springs.  Also, note the thin wire holding the two parts of each coupling rod, it would have been easy to forget this and screw up the distance between the two axles.

 

Once the 6 hornblocks were tack soldered I undid the chassis and applied solder to secure the hornblocks properly.  Then I added the various etched parts to the frames, including the laminated springs and the modified (post 5013) front bogie arch.  It is now stronger than it was before I butchered it (see earlier posts).  Then a clean up and a quick going over this morning with a fibreglass brush and scalpel blade to produce these photos:

 

First the frames looking at the insides:

 

 

Then the same view but reversed:

 

 

Already the model is beginning to feel heavy.  Each hornblock has a vertical movement of just over a millimeter - my digital caliper says 1.2mm.  That is almost the same as the movement on my 14XX's beam compensation.

 

This is a good place to stop and pack away the kit for the travel north.  I may keep the tool box handy though for cleaning up the coupling rods while waiting at the ferry terminal!

Edited March 26, 2017 by Focalplane

[Simond]

Paul,

 

This looks very good.

 

On my King, and I think, on my Castle, I made the pressed form in the frames from black plasticard, on the basis that if a wheel touched it, it would not short, nor would it show if the paint wore off. Of course it is not as strong as your way, but this is not a major consideration, unless you go throwing your locos on the floor (see my PD thread a couple of years back).

 

http://www.rmweb.co.uk/community/index.php?/topic/79052-porth-dinllaen-in-0/?p=1930298

 

Bon voyage

Simon

Edited March 26, 2017 by Simond

[Focalplane]

Simon, what a nightmare.  I have to admit I do think about such disasters from time to time but so far, so good.  Mrs A. did knock a 4mm scale Hornby Rebuilt Patriot (Private Wood VC, she is a Wood also) from about 5ft onto a tiled floor while dusting.  Fortunately it landed on a pot plant and pretty much survived.  As it is a static exhibit reminding me of my 4mm days, I just turned the better side to the front.

 

This is one reason why Legge Lane has a frame around it, to prevent such accidents from happening.  But they can still happen, as we all know only too well.

 

My track rules set the minimum radius at 6 ft (the "one day I'll have a garden railway when I get a garden" plan) so I am hoping the bogie arch will be OK.  I suppose carefully applied electrical tape might be an answer, if not?

 

The car is loaded, the coupling rods, files and emery are close to hand for the inevitable waiting at Ouistreham-Caen.  Merci pour le "bon voyage".

 

Paul

[Simond]

Hi Paul, yes, was one of those moments. Loco now repainted by Warren Haywood, so happy ending.

 

My "test track ruling radius" is 1750mm to the inner rail gauge face, so all my stock should be ok on 6', and Peco pointwork. I think I'd epoxy a bit of black 10 thou inside the arch, I suspect the insulating tape will go manky rather quickly.

 

Not sure how the weather is at Cotentin, it's breezy in Folkestone, but the white horses of this morning have cantered off elsewhere.

 

Enjoy the crossing

Simon

[Focalplane]

Made it to Caen Ouistreham in good time. Managed to be frugal and made 1037 kim on one tank of diesel. Warning light came on as I entered an Esso station near the ferry terminal to fill up before hitting expensive prices you know where!

 

The coupling rods got some fettling treatment at a picnic table near Montluçon after lunch. Sunny but cool and windy. The rods need a bit more solder between the etches before they pass inspection.

 

But for now I am enjoying a pression before retiring to my cabin and leaving the "music" to the teenagers and their teachers on school trips who no doubt will not be sleeping much tonight. I seem to remember doing much the same 50 plus years ago.

[Focalplane]

The next few days may or may not see some more work on the Castle.  It all depends on the weather in NW Wales!  If you want to see progress, pray for rain, but this will only delay the outdoor work I have promised to take on.

 

Today I opened some boxes!  The first was the surprise early delivery of 4 coaches from Tower Models - the Lionheart (Dapol) Birmingham B Set.  They are very nice models but they don't compare with home-built Sidelines when it comes to pride of ownership.  They await the Heljan Large Prairie.  The nostalgia component to this RTR purchase is the commuter trains on the North Warwickshire Line.

 

The second box contained a lovely Ivatt 2MT mogul, made by San Cheng and painted by a Professional.  46512 was an Oswestry engine but is now at Speyside, a long way from its ancestral homes of Swindon and Oswestry.  More on this later.  Unlike the coaches this locomotive really does it for me because of its provenance of both nostalgia and the application of present day skills.

[Focalplane]

I don't have my good camera with me so I am using an existing photo you may have seen somewhere else on RMWeb.

 

My new pride and joy will not be spending much time on my workbench as it has already been modified and painted by Larry Goddard.  The Ivatt 2MT is a lovely model and the more so for the painting and lining.  It will pair nicely with two or more of the GWR B set coaches I also recently bought.

 

 

46512 was an Oswestry loco (89A) for several years and would have been employed on the old Cambrian lines east and west of Oswestry.  The loco men must have really enjoyed the tender cab when traveling backwards through a Berwyn blizzard from Llanfyllin.  (I was caught in such a blizzard this past winter while crossing over from Bala).

 

46512 was also on shed with 1459 for a while, the latter later going into storage in the adjacent Works.

 

Larry tells me he still has several 7mm scale locos left to sell and they too have received the attention of his skills with the spray gun, etc.  I already have the 14XX and pannier tanks don't really turn me on.  Besides I have a Castle and a Compound on the go with other kits lined up for later this year.  So do contact Coachmann if you are in search of a loco or two.

[Focalplane]

I have made some progress on the Castle's chassis this weekend, though much of the time today I have been asleep, having woken up feeling decidedly "run down".  I also forgot to bring a cable for downloading photos from my "big" camera, so these two are taken with an iPhone SE.

 

They show the basic sprung chassis for the loco which was assembled using the Poppy's jig and at the moment is only tack soldered.  It is square and the axles are true to each other.  I will add a photo taken with the frame in the jig when I can download it.

 

 

[coachmann]

That chassis is looking very tidy. Fair-do's that you continue to have the patience to build large 0 gauge locos. 

[Focalplane]

That chassis is looking very tidy. Fair-do's that you continue to have the patience to build large 0 gauge locos. 

 

Larry

 

One thing about 7mm scale is that the basic cost needs to be amortized over greater time!  I know you move fast so I fully understand your comment!  Which is why I have started to buy some RTR.  Gosh, the amount of Gauge O RTR seems to increase daily!

[Focalplane]

The chassis has now been fully soldered and is as tight as a drum.

 

Edit to add:  I should add that two years ago I could not have imagined doing what is shown in the two photos above.  It has not been difficult even though it takes time to achieve.  Gauge O is quite forgiving compared to 4mm loco kits, at least that is my opinion.  Others may disagree!

Edited April 2, 2017 by Focalplane

[Simond]

There's a beauty in solder... if it ain't right, you can always take it apart and try again!

 

Your Castle chassis looks superb. I had no idea you'd only been doing it a couple of years, cracking job!

 

Best

Simon

[Focalplane]

Simon, you are so right. Several of those frame spacers were unsoldered at least once!

[Jintyman]

Beautiful work on that chassis Paul, I totally agree with Simon, cracking job!!!!

 

Jinty

[Focalplane]

I continued to work on the chassis this afternoon and evening, adding various etches to the frames, ending up with trying the Castle (6' 8", not King) drivers for size.  They fit and don't touch each other which means I will continue to build the kit using them and not the slightly smaller (6' 6" wheels).

 

 

 

 

I then fitted the 0.9mm wire for the brake shoes and herein lies a potential problem, the wire will probably rub against the front drivers under normal running conditions.  This may be a result of using hornblocks but I am not going back now!  One solution could be to use black plastic rodding for the front shoe, letting the strength of the other brass wires carry the load.

 

The next test will be to mount the drivers again and see what happens.

[Simond]

Paul,

 

Can you ease the holes a little & solder the wires in off-centre?

 

Might get you a fraction of a millimetre.

 

Best

Simon

[Focalplane]

Paul,

Can you ease the holes a little & solder the wires in off-centre?

Might get you a fraction of a millimetre.

Best

Simon

Simon

 

Yes, this is an option which I didn't mention, but like your comment about the front bogie arch it may be better to insulate with hard nylon rod and Roket CA Max. I would certainly prefer to use brass rod if possible.

 

Since I am aiming for minimum 6ft radius curves, I plan to use a packing washer on each side of the chassis and this may tighten things up so that shorts won't occur. I just need to try out the alternatives knowing I have a fall back position.

 

Paul

[ROSSPOP]

Just  take a wee nip off the wheel flange circumference by setting up on an axle in a cordless drill and using a file........ simples.

 

nobody will ever know...........  then file a slight flat on the brake rod as extra insurance.

 

John

[Focalplane]

John

 

That was another plan which I failed to mention. In fact I am sure someone has already told me that is what needs to be done. Was it you?

 

Paul

[ROSSPOP]

no Paul.....

 

someone told me on the Western Thunder forum.....

 

You will need to watch that the connecting rod does`nt touch the very ends of the slide bars where they are fixed to their support brackets.......... you may need to file a slight chamfer on the ends of the bars, if your ride height is`nt central to the slide bars.

 

 

 

John

[Focalplane]

Thanks, John.

I had the same problem on the LMS Compound with the connecting rods rubbing against the slide bars. Lots of fettling required there as well.

Although David Andrews doesn't suggest it, it seems that continued trial assembly with the wheels and motion is essential with his kits as the tolerances are very tight.

Your chassis looks very good!

 

Edit to add that my 4 am waking allowed me to read the details of your Castle build so far.  Lots of useful notes, photos and ideas.  This is what RMWeb is all about!

Paul

Edited April 4, 2017 by Focalplane

[Deano747]

Hi Paul/ All

 

Excellent work so far!!

I'm following this very carefully for when I (eventually) get round to building mine. I plan to use the correct wheels also! 

IIRC it was David LO Smith mentioned trimming the flanges slightly and maybe someone else?! A small job in the lathe.

 

Regards, Deano.

[N15class]

Thanks, John.

I had the same problem on the LMS Compound with the connecting rods rubbing against the slide bars. Lots of fettling required there as well.

Although David Andrews doesn't suggest it, it seems that continued trial assembly with the wheels and motion is essential with his kits as the tolerances are very tight.

Your chassis looks very good!

 

Edit to add that my 4 am waking allowed me to read the details of your Castle build so far.  Lots of useful notes, photos and ideas.  This is what RMWeb is all about!

Paul

Its always best to keep trying the running of the frames as each item or groups of parts are added. It helps avoid any nasty surprises after painting while re assembling. Nice work.

[Focalplane]

A break from modelling after a visit to the NEC on Thursday - what a great venue!  But tonight I have been working on the brake problem and I think I have it solved simply by bending the 0.9mm rod away from the front driving axle.  So no need for a plastic rod and no need (I hope) to shave some of the drivers' rim off.  But these solutions still remain on the table, to be used as necessary.

 

So some advance tonight - soldering the connecting rod etches, the brake shoes and other parts on the instructions list.  I will also be fitting the crankpins soon.