Flying Scotsman - Valve Gear to Rod connection

[Cathurga]

Hey All,

Really sorry if this is in the wrong place, or whether it warrants it's own topic, but I have done a few searches to try and find the answers.

I am trying to repair my son's Flying Scotsman (dont know model numbers, but its the tender driven version). There is a connection from the valve gear that connects on the middle wheel, along with the main rods. I have no screws for it, and need to get some, but I don't know which ones to buy. They have options for large, medium, small shouldered screws, as well as one with no shoulder. It seems to me that it would be the no shoulder option, as the screw seems to 'trap' the tiny arm thsat rotates on its own axis. The arm seems to have an elliptical hole and where it connects to is not round, so it stands to reason that a no shoulder screw is required.

I have a pic that I copied of newmoddeller site, but am reluctant to use it without permission.

Anyone have any idea?

Any responses will be greatly appreciated.

Andy

[Topcat2018]

Not much information to go on, as there are several different versions of tender-drive Flying Scotsman. I guess that you are talking about the screw that secures the return crank to the centre wheel.

The return crank has an elongated hole with straight sides and round ends (not elliptical). The spindle that it fits over also has flat sides so that the crank doesn't simply sit on the spindle without going round but follows the rotation of the wheel.

A good starting point would be to tell the forum if it is a British-made or Chinese-made loco, which it says on the bottom of the loco.

Secondly, a clear photo of the valve gear would be a big help.

[P-Henny]

I have a pic that I copied of newmoddeller site, but am reluctant to use it without permission.

 

 

In principle, there are usually no issues with posting images lifted from other web sites if they genuinely aid the question being asked and the source website in question doesn't plaster the image with 'copyright' warnings.

Apart from which, ALL posted images are sent to a moderation queue to wait approval. So if the image should be deemed inappropriate, then it will get rejected then by a mod. So you can safely post your image and see what happens.

[Topcat2018]

@Cathurga

I'm not sure why you would need a shouldered screw. On all the tender drive A1s/A3s/A4s that I have the screw that secures the return crank just has a hex head and a plain thread less than 1 mm diameter. Its sole purpose is to secure the return crank to the crankpin of the middle driving wheel. If the screw had a cylindrical shoulder then depending on the diameter of the shoulder it would either:

a) not go through the elongated hole in the return crank or

b) go through the hole in the return crank but not prevent it from slipping on the crank pin because the shoulder wouldn't (and couldn't possibly) have flat sides.

[ColinB]

I am assuming that it is a very early tender driven loco. You can tell the difference between the screws, if it just has one slotted head screw on the centre wheel but none on the front and back driven wheels then it is the early type. If if has hex headed screws on all wheels it is the later type. The centre wheel has a plain screw, no shoulder on all the Flying Scotsmen I have. So if it is the old type you want a valve gear screw with a slotted head but no shoulder. If it is the newer type just before they went back to loco driven locos, then it is a hex head screw again with no shoulder.

[Cathurga]

Thank you all so much for the input. I managed to determine that it is a Chinese made unit, and from the posts made by yourselves, it seems that the no-shoulder 1mm threaded screw is what I need. Now to find someone who has stock!

Thanks also for the info about the pics, I try not to splash other people's pics around, but at least a moderator would keep me in check!

Once again, many thanks all!

Andy

[Cathurga]

Hey all,

It seems that the model I have is the R1072 version, and the service sheet indicates that the parts I need are:

X9822 Coupling Rods/Screws...or Screws pack X8427 either of which are unavailble since being discontinued in 2018...

I have trawled the net and not found any of this sort. Do you think if I had to ask Hornby direct that someone would have a few of these lying around as spares, they would respond?

I might get on to some other forums in the hope that I can find oneof these little screws, or is it possible that there might be a suitable replication SOMEWHERE? It seems a shame that apart from this, the model is in good order and would need to be scrapped.

Thanks again all...

[ntpntpntp]

So really you just need to know the specs of the screws, ie. are they metric or BA and what thread size?

I can't help, but someone will know and then you can find something suitable on ebay etc. If the screws you buy are too long then just cut shorter :)

Can you take the equivalent screw from the other side, and try it in a metric or BA tap & die set to determine what it will fit? That's what I do when I need to identify and source a screw for something. I keep packs of various small size nuts and bolts for general modelling use.

[threelink]

@CA

It might be worth taking the loco to your local model shop to see if they have any spare screws. You might find a scrap chassis at a car boot or toy and train fair or on ebay that would yield the right screw. If you are unable to source a replacement from anywhere, try a computer repair shop - I have saved all sorts of small screws from dismantled IT and dictation equipment and they might have done the same. Best of luck in getting this sorted.

[Topcat2018]

You can buy 1 mm screws from China on Ebay. Search for M1 screws and to avoid the search coming up with all the other sizes containing "1". I would add the exclusion terms -1.2 -1.4 -1.6 etc.

midlandhelicopters in the UK also have them and they are £5.49 for 8.

One seller is called meilianlu0 and they are £3.22 for 5 including postage. These are Philips head screws and silver in colour so you would have to paint them if the running gear on your loco is black.

I don't know for certain if the screws on your loco are 1 mm so I would recommend removing the one from the opposite side and measuring it with a micrometer or digital caliper. Screws are generally slightly smaller than the nominal diameter.

[Going Spare]

If you wish to stay with 'original equipment', speak with one of the spares suppliers such as Lendons, New Modellers Shop or Peters Spares. Describe the loco you have and tell them the screw you need.

Hornby specify different X-numbers for spares packs dependant upon the combination of the specific parts that are needed for any given loco. But as you need just one screw, which is almost certainly used in a multitude of other applications on similar 6-coupled locos with Walschaerts valvegear and etched rodding, they should be able to offer you another coupling rods (or valvegear) pack which includes your screw. (i.e. it is by no means only pack X9822 that will give you your screw). The alternative pack will give you some components that are not immediately useful but it should get your loco back on the track.

[Simmo009]

It is likely to be S1005 if it is a screw rather than a hex head bolt. Search that number on eBay and you can get them easily.

[Going Spare]

The OP has established the loco to be China-made so S1005 will not be the screw as that was used only on UK-made models and will not be suitable because it has a BA thread.