Stanier 8F in S7

[DavidinAus]

An update: in the end I took the advice from those of you who said that I really needed to check that all the compensation mechanism was moving freely (thanks Peter, and others), and then as I took the inner chassis out of the outer tender farm I realised that I could use a variation on Steph's and Martyn's (3-link) advice. If I introduced a spacer/washer between the outer and inner frames where they are screwed together I could introduce a reversible (but potentially permanent) twist in the chassis.
It seems to have worked!
The compensation mechanism was not entirely free to move, and I unsoldered the pickups and freed the centre left wheel some more. They now all appear to move up and down freely.
I introducing a spacer at one corner between the outer frame and the chassis, thus effectively applying a permanent twist to the latter. Now on my granite, the wheel was only about 0.1mm in the air at worst. Is the correction enough, I wondered?

So with every finder and toe crossed, I reassembled as much as was needed to allow the tender to run, and .... it now runs, as shown below! A horribly crude test, and of course it isn't crossing pointwork, but at least this is progress:

I realised that as it is the front wheels lifting off the track that creates the problem, testing the tender on the S-shaped curve but with a dip in the track might not be good enough: the concavity of the track might keep the front wheels in contact when flat track or even a hump in the track might have the opposite effect and cause a derailment.

So instead I had to raise the centre of the test track and make the tender run over this. The only realistic way to do this is to pull it behind the locomotive! So this became the first trial runs of the locomotive and completed tender:

It doesn't run smoothly - this is because there are electrical short-circuits created between the pony truck wheels and the front locomotive steps, and also between the guard irons on the tender (they are realistically close to the rails, too realistic, and will need to be shortened a fraction). However the assembly never derails, which for me is a triumph!




My thanks to everyone for their suggestions. I am wary of declaring "Mission Accomplished" a la George W Bush, especially as I haven't either tested it over points or even fully assembled the tender as yet, but it is looking much more hopeful than ten days ago.

David

 

[Steph Dale]

David,
I am very pleased to hear you've got a solution and chuffed to bits that I helped to get there. It's always difficult to diagnose a fault from a few thousand miles away!
Steph

 

[OzzyO]

David,

if you have to lift your track to that hight to get the tender to run (if it has pick-ups on it, you may need it) but it looks to slow down very quickly.
If you still have a wheel that is still 0.1mm above the rail head you have something wrong. Using this type of compensation all of the wheels should be down on the rails and stay on the the rails. Are you only reaming the bearings out to 3/16"? If so open them out to approx. 4.8mm.

Have you checked that the body is square? You can do this by using a pair of parallels with short parallels that will fit between the outer frames and see if it (the body) will rock. If it does then you should know where to use any packing on the corners.

OzzyO.

PS. I've just looked at some of the earlier photos and noticed the the pivot point on the compensation beam is not in the centre and is a lot closer to the middle axle, when you have that you get more weight on the middle axle, that can cause the front or rear axle to ride up or not sit down on the rails. You also don't have a lot of clearance between the beams and the spacer near the centre axle.

 

[DavidinAus]

I too was concerned about how poorly the tender ran in terms of the general resistance, but I was so relieved to see it not de-rail that I was happy to ignore this for the time being!
I accept that even 0.1mm is a problem, and perhaps I need to address this also.
Note there are no friction-producing pickups - the brass bearings pick up from the split axles and there are electric leads from the brass bearings.
There is no lubrication at all in the system at present.
I need to confess something here, but in my defence I am a hospital doctor, not an engineer, so please bear this in mind as you read on ....
I have tried to ream out the bearings, but my idea of reaming them out was to use a rusty old Slaters 3/16" axle mounted in my cordless electric drill ! Rusty to give grinding capability.
I was hesitant to use a 3/16" drill, as this might cut too much, and have no idea how you obtain a 4.8mm parallel reamer, let alone how to use it - please could you help me here? I think I would struggle to find a 4.8mm drill, let alone a parallel reamer - and surely a taper reamer will ruin everything? I have bought a brand new 3/16' drill.

David

 

[Overseer]

David

I suggest you go to McJing Tools in Yagoona and buy a 3/16" parallel reamer for $11, or order online from them (mcjing.com.au), and see if that works to ease the bearings before ordering a 4.8mm reamer. If you find you still need to get a 4.8mm parallel reamer Chronos Engineering Tools (www.chronos.ltd.uk) have them in stock for £44.55 excluding VAT which would end up around $100 delivered, so maybe difficult to justify purchasing for occasional use. The other, cheap, option which will work fine for a tender is to put the axles in a drill and use some fine emery paper to reduce their diameter slightly.

Hope that helps.

 

[mickoo]

Reamers are not cheap so shop around, can't recal where I got mine from, will check the box when I get home but it was on the advice of another member here, don't recall it being that expensive, but if you use it for every bearing the cost soon evapourates.

To use a reamer you use it just like a drill, think of a reamer as a very very accurate drill, mine is slightly tapered 4.75 to 4.85 I think and I use it by hand, simply turn the reamer in the bearing hole and thin swarfs will come out, check regularily on your axle until it spins freely.

Having said that, I've alsways had trouble getting the Slaters nylon encased bearings to run smoothly, my Peppercorn A1 tender rolls like it is mud and all bearings have been opened out, however the current Battle of Britain build rolls really well, so not sure where the problem lies. The A1 tender is due a strip down to see what an earth is wrong at some point in the future.

One thing you will find with the nylon bearings is that the bronze insert is very thin and when you ream it tends to ovalate, especially on the sides where the nylon is very thin, so take nice slow thin cuts and you'll be just fine. Because reamers are tapered they tend to act like a screw so can pull into the work and you can over do the hole, also, cut from both sides which moves the smallest diameter to the middle of the bearing and not at one end.

Example and gross exaggeration, we have a taper of 0.1 mm across the bearing, if you taper ream from one end then the smallest hole will be the right diameter, but the hole you entered from will be 0.1 mm over size. If you ream from each side then the middle will be the right diameter and each side will only be 0.05 mm over size. The middle V will have a very narrow point and will wear quite quickly as the bearing opens out, however it'll not get bigger than 0.05 mm oversize. If you reamed from one side only then over time you whole bearing would become 0.1 mm over size = sloppy.

A drawing might explain easier if you need one

Also as Overseer suggests, polishing the axles is a good trick as well.

Mick D

 

[Ian@StEnochs]

No reamer, try this trick.

Take a piece of dowel or metal rod 4mm dia or slightly smaller and make a saw cut along its centre line for about 10-12 mm. Cut a piece of fine wet and dry paper same width and about 20mm long. Slip into the saw cut and fold round the rod. Rotate in the hole by hand or power drill moving in and out of the bearing. Check frequently with your axle until you have a nice running fit. Finally clean out with a piece of paper towel and lightly oil.

Ian.

 

[oldravendale]

Ian's suggestion is by far the least expensive and is a method I used until I got hold of a 4.8mm reamer. As Mickoo suggests, once used on a number of models the cost of a reamer evaporates and it is so quick to use.

Cost is obviously a concern though - at $100 I'd blanche a bit! I bought mine on the old bay of E - it was part of an unspecified mix of pre used hand reamers and cost abut £8 for the lot. As these are previously used there's a significant element of risk in doing this but I was prepared to have a go and it's paid off handsomely as the reamers I received included not only a 4.8mm but two 3/16" and a 5/32". Some of them are a bit manky, but equally some of them are like brand new.

Brian

 

[JimG]

Because reamers are tapered they tend to act like a screw so can pull into the work and you can over do the hole, also, cut from both sides which moves the smallest diameter to the middle of the bearing and not at one end.

Mick,

Machine reamers are not tapered - it's the hand tapers which have the tapered section on the end. Just in case someone gets a machine reamer by mistake.

Jim.

 

[mickoo]

Jim,

Your quite right, I'm home now so can check things.

I got mine from here, quick service and much cheaper than the usual places, probably because they are an industrial supplier and not a hobbyist.

Metal Cutting Tools - Reamers, Small Hole Drilling, Drill Bits - Drill Service UK

There's dozens to choose from but my 4.80 is by IZAR and the spec sheet for that is here.

2010 : 04,80 mm-ESCARIADOR HSS DIN206B MANO

I need a 5/32nd for the Battle of Britain project so will get from here as well, just a satisfied customer and I think it was Adrian who tipped me off about this site a few years back.

Looking at the prices it might pay to go with the 3/16" and then trim out with abrasive paper as others have suggested above, but for £26 + plus postage and maybe VAT, it isn't too bad a price to stomach.

 

[Steph Dale]

Mick,

Your comment about "Because reamers are tapered they tend to act like a screw so can pull into the work and you can over do the hole" doesn't bear out with the hand reamers I've got here. They all have the spirals going against the direction of rotation (i.e. the helix is in the opposite direction to a drill) so tend to just skid rather than jam in a hole. Admittedly that's not true for taper reamers or cutting broaches, but hand reamers are a synch to use...

Oh and, rather than a 5/32" reamer, I'd get 4mm; it'll give you a couple of 1/1000" running clearance on a 5/32" axle...

Steph

 

[mickoo]

Steph,

Hmm your right, the flutes oppose the twist, so why does mine pull in then? Or seem to?

4.00 mm will do me fine then

Mick D

 

[Steph Dale]

Aah - I suspect the same problem as you've been having with the nylon bearings: The penny has just dropped; you're 'corkscrewing' the reamer into the bearing and throwing up a burr on the inside of the bore.

How do you hold the reamer and workpiece? There might be a very simple solution...

Steph

 

[JimG]

Mick,

Looking at the prices it might pay to go with the 3/16" and then trim out with abrasive paper as others have suggested above, but for £26 + plus postage and maybe VAT, it isn't too bad a price to stomach.

I also use Drill Service and I noted that a lot of their imperial sizes cost a lot less than the metric sizes. I wonder if it is old stock they are trying to get rid of.

Jim.

 

[Ian_C]

Just note on the availability of the MOK 8F kit. I contacted MOK recently to order a kit and Mr MOK tells me that he's planning to produce 6 more and that's the lot. Not enough sales on this kit now to make further batches economically viable. My name's on one of them, so there are 5 left. If you are thinking of buying the MOK 8F kit, now's the time!

 

[DavidinAus]

Mechanical lubricators.

I'm beginning to wonder just how obsessive/nerdy I can get.

On my visit to England in June I travelled behind one of my beloved Stanier 8Fs on the Scarborough Spa Express. I took pictures of the engine, and noticed many details that would be useful for my model.



Among these were the mechanical lubricators and their pipes. They were all cleaned and nicely polished, and so were a quite prominent feature on the footplate of the locomotive. In working life they would probably have been grimy and not noticeable, I suppose, but now I had seen them, I felt I had to model them accurately.

The MOK kit comes with the two lubricators, but not with the pipes which go from them. So I had somehow to make the pipes from scratch. Stripping some mains cable I found multi-strand copper wire with which to make the pipes. Each strand was about 0.2mm thick, so approx. scale for a pipe 8-9mm across, which seemed about right. However, how to make them into the beautiful fan of pipework was not obvious, to say the least. I tried soldering the wires to the lubricator castings, but apart from clogging everything with solder, well you can imagine how successful that was. I then tried soldering the wire strands into ribbons six wires across, intending to use lower-melt solder to attach them to the lubricators. However I couldn't solder the wires together over a short enough length then to make the elegant curved sections onto the castings. Lots of burnt fingers and strained eyes.

This entry is to show how I eventually did get something approximating to the desired appearance.


Click to enlarge.

First I found some thicker copper mains cable, and flattened a section out with a hammer, evening its edges up with a file.

Click to enlarge.

Next I cut a small section of this copper strip and folded it over the necessary number of strands of 0.2mm wire and hammered the folded copper strip together to hold the wire, applying a tiny amount of solder to keep it all fixed. Then I could bend the curves into the ends of 0.2mm wire and separate them to go up to the lubricators.

Click to enlarge.

The one in between the two lubricators had to take ten wires/pipes, divided to go different directions, of course! The fixing strips were then used to attach the pipes to the footplate, in a position so that the curved pipes are coming from the sides of the lubricators.



The other end of the multiple-wire constructions help to hold the curved ends in place when soldering, and can then be bent into shape to represent the lubricator lines as they go down or across the chassis - a few travel across to the other side over a chassis cross-member, and are visible from above.



As I write this, I have a horrible premonition that someone will reply to say something like "Well, if you do this ..... it's actually quite straightforward, and only takes five minutes."

Was it worth all the trouble? I don't really know, but it is satisfying to have succeeded, and if the painting eventually makes it invisible, I may just have to be content with that.

David

 

[Isambarduk]

"So I had somehow to make the pipes from scratch. Stripping some mains cable I found multi-strand copper wire with which to make the pipes."

And how did you make the holes so that they became pipes

I have not laid multiple 'pipes' that often but I have just taken the strands of wire and gently stretched each one to make it dead straighten (pliers < wire > vice) and laid each one in turn, forming a suitable curve (against the previous pipe). I make strapping to secure the pipes as you did. I find it simple enough.

I would say well worth your doing it if for no other reason than it was satisfying ... wasn't it?

David

 

[Scale7JB]

Looks great and makes all the difference.

There is another way, and it's no less time consuming, so I'll leave it at that..

JB.

 

[DavidinAus]

I am getting to the final stages of construction now, and am a little sad if the rumour is correct and that this kit is being discontinued by MOK. Sad for several reasons: it is a very good kit and makes up to a great model (judged by the ones seen elsewhere on the 'net!); David Sharp has gone to some trouble to make it Scale-Seven-friendly; it will mean that my attempts to rewrite the instructions for him will be wasted; and finally some of the point of this 'blog will be lost - I wanted to encourage others - if I can do it, anyone can!

I have added much of the detail, provided by the kit manufacturer, to the body itself. This entry is about adding the sanding gear. There are three sandboxes provided by MOK, despite the fact that two of them are inside the frames! They should have tubes going out of them down to just in front of the leading driving wheel, and both in front of and behind the third driving wheel.

The outside one goes to behind the third driving wheel and has an additional mechanism (I don't know what function it has) beneath the sandbox itself. The sand-delivery tubes are going to be represented by 0.8mm nickel-silver wire bent to shape (I'm not making tubes again, Isambarduk, because making them look even with the sub-millimetre rolling bars was just too difficult !?!). I made support brackets from thin strips of scrap n/s with 0.8mm holes bored in the ends, twisted and bent to shape.



Here is the one for the outside sandbox, with a folded-up section of wire to represent the additional mechanism.



Once bent up and soldered onto the frames, this is the (unpainted) appearance.



The central sandbox, supplying sand to the front of the third driving wheel, was even more of a challenge, and in the end I made wire with multiple bends in it, allowing one end to be anchored to the sandbox, with the other supported by a bracket in position near the driving wheel.



This shows the course inside the frames of the central sandbox “tubing”. The wire can been seen attached to the internal sandbox behind the second driving wheel (the cylinder end is bottom left), then going past the leaf spring and over/under (if it was the correct way up!) the brake stretcher before curving towards the third driving wheel. I'll try to put arrows on the picture when I get home this evening (Aus.-time).



This side-on view shows all the three sanding jets in place. Of the sandboxes, only the rear one is outside the frames and visible.

David

 

[Dikitriki]

The outside one goes to behind the third driving wheel and has an additional mechanism (I don't know what function it has) beneath the sandbox itself.

Sand Valves. There is a casting available from Peter Roles.

PR38

Richard