4472 Flying Scotsman 5"

[greenglade]

Evening all

I've been a bit occupied over the weekend so not much done but today I have made and assembled the gravity sander lever. I had to make an executive decision on this one. Don shows the lever much closer to the cab side than with the draincock lever but this means that the lever will foul the window frame. His handle looks correct for length when compared to the prototype, certainly much closer than the drain cock side with the top being about halfway across the width of the window frame. I had two options, space the handle out further from the cab side or leave as drawn and shorten the handle so the top is just below said frame? Scale looking wise it should be the former but the thing is, the reverser also fits into this corner and I need to be sure that the two don't get in each other's way, particularly the reverser handle fouling the sander handle. If once I have built and positioned the reverser my worry is wrong, I can always change the lever later. For now, I've played safe, the design is the same, just that the lever handle is below the window frame rather than midway up it.
Just the one picture to show the setup...

 

I've made a start on the two connecting rods, I hope to have them finished over the next day or two. I am following photos rather than Don's drawing, or at least I am for the rod that enters the cab as it has a noticeable shape that's in clear view from the cab to the control arm, the other rod runs behind the splashers so I'll go more with Don for that one...

Pete

 

[greenglade]

evening guys...

I've been a very busy bee since Tuesday, mainly as I wasn't happy with the sander lever and so we can scrub Tuesday's update as a waste of time... I shall explain.

I wasn't happy with the lever, although it was close to the prototype the forced shorter length and the distance off the cab side was really bugging me, it had to go or be made to look better. I first searched through my reference (there's a good picture in Yeadon's A1/3 page 74 that clearly shows the lever much further away from the cab side) and took a good look at Don's drawing for the reverser ( should have done this first). I'm not sure what Don was thinking but he has a few odd dimensions which I'll need to look closer at later, one is that he has the distance of the reverser arm's end 3/32 away from the cab side, which is fine, but also having the sander lever at the same distance doesn't work it needs to be further out to be in its correct position and also to put it closer to the control arm that's fitted to the running board. It's a bit difficult to explain as there's a lot going on, basically, the sander rod runs above the reach rod. Also Don's distance between centre's of the reverser and the reach rod, perhaps I'm not reading it right but it looks to me to be 2 inches too big? Anyway, no time to get involved with the reverser just now, let's just say, that the more I looked in detail the more I realised that my concern of Don putting the sander lever so close to the cab side was unfounded.

So I decided to remove the gear as assembled and modify the brackets and make a new lever, this wasn't that easy as the 8BA CSK screws that hold the parts on had been bonded in place with Loctite, this being done as you may recall me mentioning that 4472 for my era had very smooth cab sides, no rivets etc.. the only parts showing were the mounting bolts/rivets for the window frames and the vertical row of bolts at the front edge that hold the spectacle plate window, everything else is flush. I eventually got the bolts out, made up some spacers and reassembled using the original parts which are fine. The handle I did again, this time to a height that matches the prototype and in fact, the height that Don gives, I have no idea what he was thinking when drawing the draincock lever?

Anyway, the end result is much more like it should be and lines up with the control rod which would have been impossible before, well at least without a 'kink'. Here's the end result, I hope you agree with me that it's much more how it should be. BTW, if anyone has a picture of 4472's cab when she still had the gravity sanders I'd love to see it. I can see in the 'Yeadon's' picture that there's a lot more going on on this side of the cab, I'd like to find out what and reproduce it in miniature. the first picture to show the revised sanding lever...

 

Moving down the running board we come to the arm that changes the rod from the outside of the splashers to behind them, just as full-size. I should have taken this photo at a different angle as you can't see all the effort that I went to to get the first rod to look like the prototype. You can probably just make out the hump, this is where the rod goes up a little and then disappears behind the cleading. I had to modify this and add some more metal between the two humps as I hadn't appreciated that when the rod goes into the cleading opening it needs to be horizontal, I had the hump to far back which would have fouled the cleading. I'm sure you'll be able to see this better in future pictures.

 

Here we have the front end, what's not very obvious is just how much work was involved in making this rod, in fact, both rod's took some hours. First off, its actually two lengths of steel lapped together where they join and held by 3 8BA bolts, you can just see one of them in this picture. The steel included the eyes for bolting to the arms and thus needed a lot of material removed along the entire length. I have also added a small kink at each end, again you can see it in this picture, this is just to give a little more clearance behind the splashers. Also at this end, the underside of the rod where it crosses over the arm to the other side has also had some metal removed to give better clearance between the rod and arm. Everything is very close but works perfectly and well worth the effort it took.

 

At the end of the day, all of this is a waste of time if it doesn't work, I hope this video shows that it works very well...

 

https://i.imgur.com/xlJ4Eyn.mp4




Next up?? Hopefully, in the not too distant future, I'll be able to do the mounts for the lubricators which are currently on route from Mike in NZ thanks to Adam (CRO fittings). I probably won't do the lubricator internals yet but do need to do their linkage which sits behind the motion on the right-hand side being driven off the back of the expansion link shaft. This will be a pain to get at if I start doing the motion first, so best to get it out of the way asap. I may also tick off the 3/16 vacuum pipe that runs the length of the train to the forward standpipe, just another of those many things which are better to do now while I have good access. after that, perhaps back to the cylinders, crossheads, outside connecting rods, etc etc.. I think you get the jist...lots still to do...

More soon folk, thanks for watching...

Pete


 

[greenglade]

should have included this picture yesterday, it would have made things much clearer... here's a side view of the control rod which connects to the cab lever. You can now see the hump that I was trying to explain. Note the joins where I have added some more metal between hump and lever to get the hump in its correct position. The width of the forward section including the hump is a little overscale, I wasn't sure how much effort would be required to operate the sandboxes and whether it would cause this part to flex too much and affect its operation. As it turns out, there is no flex here, there is a little on the rod behind the splashers, even though it's twice as thick, but then again, it is 17 inches long. It has no effect on the operation so I may just leave it, as is. I could fit a clip to the back of one the forward splasher if I so choose, I will look at this another time, same goes for if I reduce the width of the hump etc...thinking about it, once the cleading is fitted which covers most of this particular rod the front bare section is very unlikely to flex, something to add to that very long list of 'to do's'...

 

Today I'm making a start on the train vacuum pipe, a friend kindly supplied me with a works drawing for pipe and rod layout a while back for another pacific locomotive which I'll use as it's very similar. The train vacuum pipe, steam brake pipe, carriage heating pipe and both water feeds seem to be in the same position as they mirror the tender so I'm more than happy to use it for 4472. I should have paid this drawing more attention before as there it is in clear view, the gravity sander lever...it's ok, I have it right...

I should have the pipe completed early next week, I need to make the IIRC condensation valve below the standpipe first, should be identical to that which i made for the tender some ten years ago... I should have made both together, or did I?... now there's an interesting thought.. wishful thinking more like..

Pete

 

[greenglade]

Evening guys...

As planned I have made a start on the main vacuum pipe which runs the length of the loco and tender, in fact, the whole train but you guys knew that anyway.. I started with the connection below the front standpipe, at first I had thought that there would be another condensate valve here as there is on the tender but after a little research and talking to others (thanks Pault) I observed that there isn't one on the front. I looked through many images of A1/3's, I would say that the majority (perhaps 98%) had no sign of a condensate valve on the front, certainly, there isn't one seen on 4472. I guess this makes sense as just how often would an express loco need to use the front standpipe? very little, perhaps only for turning on such an equipped turntable. So I didn't need to make another valve which saves me some time.

Having decided that there was no such valve fitted to 4472 I took a closer look at the reference that I had to hand to work out what there was, it looks like a simple cast elbow which is immediately below the buffer beam, there is a very small lip around its top edge which I have copied. For this 3/16 pipe which btw is very close to scale, I have chosen to use 5/16 unions for the connections. Full-size they are flanges but that's not very practical if needing to get one part undone and since they are all out of sight I'm happy to use them. When it comes to the pipework which is visible that will be a very different scenario, lubricator pipes come to mind. The first picture shows the elbow that I settled with, it's long so that it clears the buffer beam and also gives room for the nut to be easily tightened/untightened. The elbow itself I have shaped to look like a 'cast' item, ie, not perfectly smooth.

 

Moving to the rear of the train just before the pipe exits to the tender I made up a 'double T' for the connections to the brake valve and vacuum gauge. Looking at the picture, the upward pipe will be to the valve and the smaller 1/8 sideways pipe will go to the gauge. These are assembled with thread sealant rather than silver soldered together, just in case I need to change anything later, plus they don't need silver soldering for their job.

 

Starting at the rear, we first have the 'T' which is sitting just below where the backhead will be and behind the ashpan, the pipe itself runs under the ashpan, here it's resting on the trailing axle as I haven't made up any clips for this end yet.

 

Going forward, here we have the pipe coming up from under the ash pan and heading towards the star stay, I will probably make a clip that utilises the mounting bolt for the Bowden cable above to secure the vac pipe to the frame which will then bring it up to run parallel. The next union connection can also be seen, here I have deviated from the prototype and taken the pipe under to the opening in the stay, I think that full-size it would have gone through an opening in the stay. I could (and may still do) drill a hole through the stay and fit a double union to it so that the pipe bolts up to either side of it, it would be neater and more prototypical but involves drilling that fairly large hole at such a late stage, I'll ponder over this one for a while...

 

On looking at this picture I really think that perhaps I should take a look at drilling that hole? If feasible, perhaps a job for tomorrow...we shall see. As can be seen, the pipe is still running down the fireman's side and through the slot in the inside motion stay.

 

After going through the motion stay the pipe changes sides and runs along the driver's side, now somewhere in this area I need the feed to the vacuum cylinders and to make life easier I have chosen to make an unequal 'T' that sits in the middle of the stay. From here, I can run the two 1/8th pipes, one to each of the vacuum cylinders, which are sitting below and just forward of this point. You can also see the next connection before the pipe drops down again between the vacuum cylinder stay and middle cylinder. All of the connections are placed so that each of the pipe sections can be removed independently if necessary.

 

The last section of pipe runs over the bogie bolster and connects to the elbow seen in the first picture, here I have made a clip to hold the pipe in position. I will straighten the pipe out a little later.

 

Now a couple of pictures to show where we are, the standpipe needs to be shortened a little to bring it back down to its proper height, just a matter of threading the pipe a little more. I'm pleased with how this looks, it matches the photo's that I have of 4472. The pipe itself runs very close to the bogie shield on that side, it doesn't touch although I do wonder about when the bogie hits a dip in the track while in service. Interestingly, later pictures of this shield show that the offending corners have been cut off rather than just rounded as 4472 was for my era.

 

The last picture for tonight to show how things are beginning to fill up between the frames and I've barely started... I had planned to do the 1/8th vacuum piping next but alas find that I have none in stock. I'm also thinking of rerouting the sander steam pipe as I'm not happy with its position, I'll look at this later.. all those 'later jobs'.....

 

Thanks for looking in guys...

Pete

 

[greenglade]

So, today I spent redoing the pipework around the star stay as I wasn't happy with it, let's just say that it would have 'bugged me'.
I took the bull by the horns and drilled two holes into the boiler intermediate stay, one for the 3/8 pipe and another for the 1/8. Interestingly, this stay isn't on FS today, I know that it's had a new 'star stay' so I wonder if this stay was made larger to incorporate the boiler stay? it's a possibility, I'm sure that someone will know.
Anyway, it's on the original drawing so good enough for me. I shortened the middle pipe and reshaped it to fit the tank coupler union which I made to bolt to the stay, two were made for both sizes. The rear pipe has been put aside as it was too short and a new pipe made to replace it.
I have brought the pipes out from the side of the frames, two reasons, one it makes them much easier to work on but more importantly, I could use an electric hand drill to drill the holes without clashing with the frames. The first picture shows how the pipe is now routed, you can see the two couplers, I've put the 1/8 in the middle and will route the pipe on the other side, the pipe that exits the tender is close to the middle but favours the same side as I'm going to run the pipe on the loco. You may note that the sander steam pipe has been undone, I did this so that it was clear when drilling the holes, as mentioned yesterday, I'm going to redo these anyway. The cab and running boards were also removed for the same reason.

 

A closer view of the coupling units, I thought that I had taken a picture of these before mounting but it seems not. I have designed them to allow clearance of the stay overhang with the HEX sections being just clear for a spanner to fit.

 

I had thought that I'd need to leave this for now until I had some 1/8 pipe but remembered that somewhere I had a tube of 3' lengths of both 1/8 and 5/32 pipe which I bought years ago, a quick search paid dividends.. I have made the pipe from the stay to the front in one piece, it involved a few heating sessions to anneal it and shape to follow the desired path, extra care taken during heating as it's thin-walled pipe.
Two pictures to show this first is the front end, I have routed it through the inside motion stay like the 3/8 but this time on the opposite side, it then curves down to where it stops with a connection, a 'T' will be added here to split the pipe and connect to the two vacuum cylinders, same as with the 3/8 but of course to the other chambers on the cylinders.
In the picture, you can see where the pipe terminates and also just see the cylinders.

 

In the last picture for tonight, you can see the general layout of the vacuum pipes, I'm much happier with this setup.

 

All being well, tomorrow I'll make the last section of the 1/8 pipe to terminate under the cab floor like the 3/8. I need to make two more 'T's', one for either end. If time allows I'll take a look at the final pipe lengths that go to the cylinders, I would say that after that I'll do a quick test to see if the cylinders work but doubt that I'll be that lucky to have no leaks.. you never know though...

Cheers

Pete

 

[greenglade]

 

The last update for the week and alas I didn't get all done that I wanted to, the reason being is that while I was planning the route down to the vacuum cylinders and working out the best way of connecting the top chamber with the oneway valve underneath, I noted that I hadn't finished work on the valves. I did remember that I still needed to make the release/push pins but was happy to do those later as I can easily unscrew the valves and fit said pins from below. What I had totally forgotten about, was that I still needed to cross drill the valves and fit the 1/8 pipe for the connection. No problem I hear you say, unscrew the valves and do the work... well that's all very well except once the pipe was fitted there's no way to screw the valve back in as it would foul the main lower chamber body and the piston rod/gland and I wasn't going to take the wheels off to get at the screws to remove the vacuum cylinder stay to remove the cylinder and dismantle it... I think you get my drift. This isn't a problem on the tender as I designed the cylinder bracket to be independent of both body and chassis, it just lifts out as a unit with both cylinders attached once the body is removed.
So, a little lateral thinking was required, the obvious solution is to have the 1/8 pipe as a screw-in part, thus screw in the valve body and then screw in the pipe after, using the same thread sealant for both to seal.
That was what I went with, first noting the face of the valve that the pipe needed to be sticking out off, get that wrong and it either points into the chamber or fouls the bogie which is but millimetre's away. The valves are fairly small, they have the end screw cap, spring and ball within and so I needed to be sure that where I placed the fitting it didn't impede with the valve operation, in fact, I had very little margin to play with. I first made up the parts to hold the 1/8 pipe, just small brass HEX which was drilled through with a drill that matched the bore of the copper tube and then recessed larger by approx 5mm for the tube to fit into. Each 'connector' was then reversed in the chuck and machined/threaded 3/16 x 40 TPI.
The parts were then silver soldered together. Next up was to cross-drill the existing valve body's, the wall is very thin here and so I machined a small flat across the high point of the HEX using a 5mm end mill. This was then drilled/tapped to match the connectors.
I hope that lot makes sense, it's a hell of a mouth full to be sure...Once all machining was completed, I fitted the parts together, blocked of two ends, used soapy water around the valve/connector join and blew compressed air into then, no bubbles seen and I haven't even used sealant yet?, I think they will work fine.
The first picture shows one valve assembled and the other in component parts to show 'what's what'. They both need a little fettling to remove burr but basically they are finished.

 

two further pictures just to show that I did manage to get some of what I had planned to do done. This picture is a close up of the front where the vac pipes meet the cylinders. I still have some work to do here, those who remember the tender build may recall that I made up a 5-way connector to plug in the two top chambers and valves into using silicone tube as it needs to be flexible. As we look at the picture, this will be connected to the pipe on the right, ie the 1/8th pipe, the 3/16 pipe connects to the bottom cylinder chambers which the valves screw into. Looking at this now, I am very glad that I decided to do this before fitting the middle cylinder slide-bars and connecting rod, it would have been a complete nightmare to try and do it after, btw, the pipes curve around either side of said slidebar which of course will have it's own copper pipe feeds for lubrication, best do these after fitting...

 

lastly, a top-down view to show that yes, I did also find time to make and fit the rear 1/8 pipe section. Looks busy, doesn't it? just wait until all the lubricating pipework is fitted, god help me...

 

I have also decided what to do next, it must be the brakes, again, trying to do the parts which will be the hardest to get at as more and more parts are fitted to the chassis. i think/hope that once the brakes are done and tested I can get back to the motion and cylinders... fingers crossed...

Pete

NB: valves finished except for the pins, must remember to make those...

 

[dajt]

That's all looking very impressive Pete.

[greenglade]

Most of the vacuum braking system has now been made and tested, a few bits left, ie the short pipes at the rear to connect to the tender and the real biggy, the brake valve itself and it's piping, that will have to wait for a while as I need to research this fitting in more detail, drawings would be good if anyone can help.

Ok, so on to what I've been up to over the last few days, I decided to tackle those damn pins first before I forget them. They are basically plain turning although being stainless and long/thin a little care is required. This picture shows the first one having been turned from 1/8 down to 1/16. There's no length given for this pin, a case of trim to size once made and fitted. I took a rough guess at its length from looking at the drawing and the vacuum cylinder itself to visualise where the pin needed to reach without being too long and thus forcing the valve open.

 

Here are the two valves, as before I have left one in parts to show (this time) the pin. I have refitted the valves with the pins set at this length, I did mark the spring and eyeball it through the 'T' piece hole as I screwed in the valve to see if it moved. Not a very scientific method and to be honest I have no idea if the length is right, it's certainly not over-long as that would force the valve open this breaking the vacuum and there would be little to no movement when applying the brakes. Could it be too short, now there's a question that will have to wait?

 

I then made up the two connections from pipes to cylinders, I made these much more substantial than those fitted on the tender, I may revisit those later. As you can see, these are basic 3 and 5-way connectors.

 

It was then a case of assembling everything made so far, I have to say that things are getting very tight in this area and there's so much more still to fit... I need scale sized hands/fingers..lol
This picture shows the cylinders now fully connected, for the valves I used a small 'O' ring between the valve and cylinder body, for the 'T' piece out of the valve I used thread sealant to seal the join. I have used silicone hose for the flexible joins as the cylinders will pivot in operation.

 

A view from above, as I said, it's getting a little crowded in here and I still need to fit the middle cylinder slide bars and lubrication piping..

 

And of course, I have the video from the test, the gauge was reading approx 11 in/Hg of vacuum being produced from my 'Heath Robinson' tube in a hose method to produce a vacuum. Not having a brake valve fitted yet I had to resort to pulling the brake arm back in place for each application of the brake. At the end of the video, I left it filming while I switched over the pipes to show that it does work both ways. There's a little less movement on return, this could be for one of two reasons, I do have a very slight leak from the standpipe hose but also I don't think that the piston rod has anything in the gland to seal it, I had forgotten to check... I'll look at this tomorrow, there is one other factor and that's that the return is on the much larger 3/16 train pipe which may or may not have a bearing, the important thing is that it works in both directions. I won't be able to test if the vacuum is balanced for 'brakes off' until the valve is made and fitted, I'm thinking that all is going to plan though.

Mind you, thinking about it, I'm probably physically able to pull the arm down further than it would be in normal operation?

 

https://i.imgur.com/3VZoaXr.mp4



I guess that I'll now tie up any loose ends and then make a start on the brakes themselves, the bench needs a good sorting out first... more soon...

Pete
 

[greenglade]

Hi all

Not much to show for the end of this week but I have made a start with the brake pins which are now completed. Two lengths although there's only 1/32 in it. The smaller pins are 7/16 long from the head and the others are 15/32...22 of the former and 6 of the latter, the later also have slightly larger heads at 0.250 compared to the others at 0.218. They are made the same as those on the tender, ie, two parts which are them silver soldered together. Here are the finished pins, they have also been cross-drilled No. 57 for 3/64 split pins.

 

And I have fitted the first two to connect the brake shaft to the vacuum cylinders, replacing the temporary bolts used before. You may have noticed the play in this joint when viewing the video showing the brake cylinders working, with the pins fitted there is now no play, which, of course, means more movement on the brakes as they should be.

 

Next up will be the hanger brackets, the rear two are easy turning although I have to admit that they confused me for a while, not helped by Don's GA which shows the same type of bracket for all 6 wheels? I can now see, or should I say, I think that I can see that they are just inserted from the outside and secured with a nut/washer on the inside. The frames in this part of the chassis are triple thick so perhaps why a bracket like the other wheels isn't needed as this should be strong enough.

I'll let you guys know how I get on next week...

cheers

Pete

[polybear]

On 18/02/2020 at 14:18, greenglade said:

Ok, so on to what I've been up to over the last few days, I decided to tackle those damn pins first before I forget them. They are basically plain turning although being stainless and long/thin a little care is required. This picture shows the first one having been turned from 1/8 down to 1/16.
 

 

Hi,

 

I'm intrigued - can you tell me what the secret is for turning those pins without bending please, especially in stainless?

Thanks

polybear

[greenglade]

Hi

 

In this instance as the pins are very thin and reducing 1/8 to 1/16 which isn't a lot.

I held the 1/8 bar in the chuck with only a small amount protruding from it, faced off and then machined a spigot at 1/16 dia, locked the crossslide at that setting, pulled back along 'X', loosened the chuck jaws to pull the bar out a little more, tightened and then moved along 'X' as far as I could towards the chuck and then repeat this a number of times until the 1/16 length had been achieved. Part off the 1/8 slightly oversize, reverse in the chuck and machine to size. I was thus doing most of the cutting on the side face of the insert, this works fine if it's not too deep.

Hope my words make sense. 

 

Cheers

 

Pete

[greenglade]

Hi guys

 

Just a post to wish the old girl 'Happy Birthday' as today she reaches the dizzy heights of 97 years of age, I'd like to get my own smaller representation finished for her 100th but think that may be a tall order, I'll get her close though.

 

This print was a present from my Daughter, it's the closest that I've seen to a true representation of how 4472 looked during her career under LNER. This picture would be perfect for her first non-stop run on 1st May 1928 up until 1935 if not among other parts, for the wheel lining. She only had lined wheels for her first year of service and never again during LNER days. For my chosen era, the loco again is great bar the wheels as mentioned and a few very small details, the tender, however, is wrong for 1938 as she lost this corridor tender in 1936. As stated on the picture, she's seen here as she was in 1933, certainly before 1935 as she has the lower rear cab side sheets which were raised when the bucket seats were fitted circa 1935, seats which she still has today.

 

 

 

Anyway, 'Happy Birthday' old girl...

 

Pete

 

[greenglade]

hey guys

some pictures to share thanks to Adam...these have just arrived on our hallow shores...

first up, these lovely little gems, the Wakefield no.7 lubricators as fitted to 4472 for my era, today she has a bit of a mismatch of parts in this department.

 

close up of the lubricators.

 

And now the best bit, yes it does get better... this is the manifold, right now this is a one-off, a true scale Gresley manifold to fit the scale bush that Paul (Southern Boiler Works)produced from Adam's drawing to fit his exceptionally built boiler. I can't wait to get my hands on it....

 

 

Some exciting times ahead...

[greenglade]

good evening chaps, chapesses


I wasn't going to do this update till the end of the week when I hope to have all of the brake brackets completed but think it might be more helpful to show how I'm going to tackled the front and middle brackets which are a little more involved. Also to show an error, whether on my part or on the laser spotting I simply can't recall, anyway, there is a slight error from somewhere which I need to workaround.

Ok, so first up is the rear brackets, these are simple turning with 6BA threads either end and for the outside end, there is a small spigot which is cross-drilled for a 3/64 split pin. The shaft is 5/32 dia and has a thin 1/8th wide collar that sets its position against the side of the frames. The shaft length is important, as is the placing of the collar, the outside dimension being 5/16 for the hanger to sit on, then the 1/8 collar (silver soldered ) and finally the inside being 11/32 to allow for the thickness of the triple section of frames in this location. Here are the finished brackets...

 

Here's the drawing for the leading and main wheel brake bracket, the top section (body) will be machined from solid.

 

The brackets begin life as a length of 3/4 x 3/8 BMS flat, so far I have only made the basic blocks, mind you this was hard work for me, hack-sawed into separate blocks and then machined square. The depth is to drawing, the width and length are currently a few thou oversize as these have a radius to be profiled. The next job to do is to plot and drill the 4 holes, before doing this I decided it to be prudent to test out the spacing of these holes on a 1/4 wide test piece first before committing to the blocks themselves and this is where I discovered the error on the leading wheel. Blocks first.

 

Now the spacing of the holes is perfect but the error is that they are perhaps 1/32 too far to the rear of the loco (right as seen in the picture), not an insurmountable problem but annoying all the same. The way I see it is that I have two options, I could make as per drawing and just machine a small amount of the back section to clear the wheel flange, or I could just move the holes over slightly so that the bracket is central, just the holes are offset, oh and I'll need to remember to make an opposite pair. I'll probably offset the holes as that would place the bracket back in the correct position, I'll sleep on it and do this first thing tomorrow.

 

I clamped one of the laser cut hangers just to check that it wasn't going to foul the wheel, it looks fine so that's good. I will, of course, allow for any of this when fitting the brake blocks.

 

moving along to the next wheel and this is exactly as it should be, again the holes are spaced correctly.

 

The last picture for tonight to show the rear bracket in situ...

 

Hopefully, I'll be able to show the other completed brackets before the weekend.

Thanks for looking in guys.

Pete

[greenglade]

good evening all

Well, I haven't managed to actually finish the brackets but they aren't a million miles away, a little amount of fettling required, make the pins and some paint should see them complete. I have collected a number of photos to describe though so best get on with it now.
The first job was to drill the 4 holes, 3 for the mounting bolts into the frames and 1 for the brake pin. After taking a closer look at the error that presented itself in the last update, I decided for the front wheel brakes to drill the holes 'off-centre' to keep the bracket central between the wheels rather than to machine away from the edge that was closest to the flange for clearance. The picture shows the 4 blanks so drilled ready for machining, I could have drilled all of the holes down the centre and worked from there as the blanks at this stage are oversize. I thought that this might present me with some problems when it came to machining, that is, doing it this way, I could then machine all 4 blanks identically and thus no need for extra work in 'setups' The figures seen ringed in the picture are the plot for the DRO, the two blanks on the right, are as drawn and the two on the left are modified with their holes off-set by 30 thou. When drilling these I just flipped one of them the other way around to get them mirrored equally. I took extra care when drilling these as they are nearly 3/4" thick. Sizes are No. 22 and No.44, the lower hole on the front wheel brake brackets were later opened up to No. 41. If you look at the drawing posted in the last update you should just be able to see that Don specified No.41 and 44, most are 44 except for the lower bolt on the front brake bracket which shares its mount with the 7BA mounting bolts for the frame stay below the expansion bracket.

 

The next job was to hold all 4 brackets in the machine vice and begin to machine the shape, btw, I have not followed Don in any of this. IIRC Don starts by using a mandrel to shape the front rad, I always do all of the work that can be done while the blanks are still square, IE, I can set then up for each operation without needing to worry about register. Get all those jobs done first before tackling any rads etc. Here the tops are being machined.

 

The bottoms were done the same but at a different depth, no need to show that. This then left the 5/16 slot that the hanger sits in, with the job still set from doing the bottom, I changed the 1/2" carbide cutter to a slot drill and with it set 1/4 " off the rear face began to cut the slot, the depth is 7/32 from the No.22 centre. Note the piece of brass shim, I hadn't noticed when machining the top and bottom that one blank was a fraction undersize, well not really as they are all oversize but I think you get my drift. This only showed itself when machining the slot, you can just see a mark when the part moved... no harm done as that part needs rounding off ... lucky escape... The thinnest shim that I had soon sorted this out.

 

I then moved on to reducing the rear body, the drawing has the width at 1/4", so I needed to remove 1/16 either side, I removed a little less leaving a few thou, the reason is to not risk damage to No'22 hole for the pin, if you look at the bracket on the right you can see how close the hole is after being offset by 30 thou. At this stage I still wasn't sure if this would work but kept going, jiggling dimensions to hopefully solve the error.

 

After machining the other side to match this left the final machining operation and that was to remove the small amounts from the front face, this was up to the middle No.44 hole. Suitable packing was used as can be seen in the picture.

 

 

All of this got me to this stage, don't worry I didn't make it too small, the drawing isn't printed to scale.

 

After a good few hours and hand shaping, I could trial fit the first bracket, as you can see, these things are pretty close, more so as I'm a few thou oversize...The important thing though is that the flanges are clear, no contact when rolling the chassis and as there never should be any longitudinal movement here I think it's ok. I may take a little off at the flanges widest arc, this won't then interfere with the pin hole. This may be a prudent thing to do as I haven't painted the things yet which will only make the gap closer, I'll look at this next week.

 

Lastly, how did things work out for the 'offset' brackets, if I say so myself, pretty good?  A little closer but still clear when rolling the chassis, Once they are painted and fitted with smaller head bolts you'd be hard pushed to spot the error, even more so when the pin is fitted with its mounting-plate which will be central to the hole.

 

Next week I'll make the pin plates, take a look at whether i want to remove any metal near the wheel flanges and then give them a coat of paint, they can be mounted after that. I'll then make the hangers and perhaps the brake blocks, just leaving all the rig for underneath... 'just' he says...

thanks for looking all...

Pete

[greenglade]

Good day all


moving on with the brake brackets, as mentioned elsewhere I did decide to remove some metal from the side of the brackets to give more clearance. Now that I have bolted them properly home this was probably not required, you see, the bracket itself when up tight against the frame sits behind the wheel flange. Anyway, I removed 20 thou from either side but only down to aprox the second bolt hole, so nowhere near the larger pin hole. I did check even when the wheel is at full tilt and there was no contact, all's good then and the error hasn't caused any ill effect.
Only 3 pictures for tonight, first shows the first bracket now bolted fully to the frames and Loctite used to stop the bolts from coming loose. You can also see the pin holders, one of which is fitted to its bracket so that I can mark off how long the stainless 8BA studding needs to be. I am following the prototype here and using studding instead of a normal bolt, when I have made the hangers and fit them I'll also use a small washer here. There should be a split pin but 8BA may be a bit too small, I'll take another look at this before fitting the studs for good. In regards to the pin construction, I drilled both holes the same size spaced at 0.3438 in the securing plate and then for the pins, machined a matching spigot to fit into one of the holes and silver soldered to complete. all 4 were bolted together for profiling, this was done by hand.

 

You will recall that one of the bracket lower bolts shares a frame stay, well the first side was no issue, came undone just with a bit of effort, the other side though it was locked solid, clearly the Loctite used worked much better on this side, or I forgot to use it on the other side for that particular bolt when erecting the frames all those years ago? As it wasn't going to move and the head had come apart while trying I only had one option and that was to drill it out, not my favourite pastime at this stage of the build. I approached the problem thus, I fitted the bracket using the top two bolts and a length of 5/32 rod in the pin hole, once happy that all was square, I used the same sized drill that the holes where done with just to give me a centre point to start drilling, basically I used the bracket as a jig. I then removed the bracket, replaced the drill with one much smaller (1.6mm) and drilled right through the CSK screw that was stuck. I then opened this up to 1.8mm and tapped the hole 8BA, this allowed me to get some bite onto the screw and remove it, a picture just to show that I got lucky and hit the centre spot on. All that I needed to do then was to clean up the 7BA hole and all was ready to fit the bracket. This could have been a real pig but someone must have been smiling on me today...

 

The last picture shows that the pins have now been painted and are awaiting the hangers before being fitted, I have cut the 4 pieces of studding to length ready to do this.

 

The next job will be to fabricate the hangers and then perhaps the brake blocks themselves. These shouldn't take as long as the blocks for the tender as these are set in a 'ring', whereas the tender blocks were all made individually, we shall see.

Cheers

Pete

[greenglade]

Brake hangers

These start life as one of the few remaining laser cut items left in my arsenal and thus saved some valuable time. They still required some fabrication as they have bosses of various sizes to turn/drill and silver solder in place. I think the first picture shows the parts involved fairly well, the laser cut parts are a little thinner than drawn and I have taken this into account when turning up the bosses to arrive at the overall figures of 5/16 width for the top and 7/16 for the bottom. As can be seen, the top hole has one boss, this is the side that goes innermost to give the correct spacing for the brake shoes to meet the wheel tread. I took a quick measurement of the shoe width (IIRC 11/32) and it's spot-on in the middle of the wheel tread, so all's good in that respect...

 

here's the hangers after being silver soldered together, remembering to make 3 opposite pairs. As with previous such assemblies, the parts are held together with suitably sized bolts, these, in turn, have their threads coated with a bar of soap and careful application of the flux to avoid any foul up's during the brazing process.

 

Finally, for today, the hangers are tested in situ to make sure all is as it should be. One thing that does stick out is the steam sander pipes need moving a little, IIRC I did mention when making these that this may be the case. They should be a lot closer to the wheels anyway but I left them as was until I could sit the chassis on rails and judge correctly where they go. It's only the steam pipe which is in the way which as mentioned previously I was going to change, I can see now why on the prototype the sanders are nearly touching the wheel rims, it's very tight in this area...

 

So that's it for this week, I need the rest of today to get prepared for the club's 'Work in Progress' meeting later tonight. I'll make the shoes next, can't do the stretchers yet as I have no 3/16 stainless steel bar in stock, it's on order though.

More soon guys

Pete

[tigerburnie]

They say the devils in the detail and that looks devilishly difficult, you must have a lot more patience than I seem to have these days.

[greenglade]

Evening all...

Over the last few days, my son has been helping me set up a blog for my build, this will be held on a private server for now, if demand gets too high we'll move it but the current performance tests suggest it should be able to handle a fair bit of traffic.

Although there will be a fair bit of copy/paste involved in the beginning, there will also be a fair amount of 'rewrites' to make it read better and in a more formal way. More like a book so to speak.
I have also set up a Youtube channel and the links will be given in the blog./


This will all take a little time to catch up with where I am today but I'll try to get there asap, currently, there's not much content but then I am only on page 2 of the build thread on the MECH forum so far, although I have given some extra details of the loco and an introduction which will be enhanced as/when I get time.

There are a number of reasons for creating my own blog, one, it gives me much more control, my images are forever safe and my written articles will be easily accessible for when/if I get around to publishing that book. My son knows this stuff inside out so he will be helping me maintain and get the most from the tools available. His plans for the site far outweigh my own, I can't keep up...

anyway, here's the link... enjoy..    http://4472flyingscotsman.co.uk/introduction/


Pete

Edited March 8, 2020 by greenglade

[greenglade]

Brake Shoes

The shoes come as a ring of steel which is just under 0.400 thick, finished size required being 0.343 there are 10 in the ring so I get a few spares, here's a picture to show.

 

although the steel was pretty flat I still faced off one side before clamping it to the faceplate, I used the 3 jaw with reversed jaws to hold the ring, it was a little precarious but it was clocked and then tightened fully. With that done i then fixed the ring to the faceplate, this is pushing my machine's limits, not the workload but the capacity, I barely managed to hold it on the faceplate with the clamps being very much on the 'edge'. with the top slide set at 3 degrees i carefully machined the taper to match the wheel treads. As the part is much thicker than required, this allowed me to do away with any protective packing and just machine close to the face. The lip which is clearly seen in this next picture was machined off when later reducing the thickness on the mill.

 

Here we are machining the shoes to their correct thickness, remembering to remove the metal from the face that was up tight against the faceplate to remove the resulting lip. I removed most from this side just leaving a few thou to come off the other face.

 

A picture to show all 6 shoes now ready for final profiling (i'll make a button for around the hole) and to have the slot machined down the middle, width to match the hangers. The shoes also need reducing in length, they are a little oversize here. I have placed one shoe to show the machined face to match the wheel tread.

 

The last picture shows me checking that the rad of the shoes matches the wheels. There's still a fair bit of work to do before these shoes are finished, perhaps a day or two. The other 4 shoes I left un-machined as spares.

 

Now, back to more work on the blog.. I'm going to be kept very busy for a while it seems.... all good fun..

Pete

[greenglade]

Hi guys

Not an update as such, just me sharing my goodies which arrived from Adam (Cro fittings) yesterday. These consist of the Wakefield No.7 mechanical lubricators and the Gresley manifold, both to scale.

Lubricators first, here's a close up showing the level of detail which 3D printing can achieve, very impressive. A little of the step processing seen but I'll remove most of this and once painted I'd expect that most, if not all will no longer be visible. The quality of the detail is superb, you can read every word, my hand should give you an idea of the scale. These come with the hinge blocks already tapped 1mm for the pins which are also supplied. Since my smallest tap currently is 1.4 or is it 1.2mm? this was a welcome surprise.

 

The underside to show the 6 oil-way outlets, these are quite small but I'm hopeful of getting these to supply oil, I have already considered a possible mech to feed them, just need to draw it up and have a few R&D sessions. I know that Bob  (mech forum) has successfully fitted pipe to 8BA sized flanges which is probably pretty close to these, perhaps even a little smaller.

 

 

Here I have held one of the lubricators in it's proper location to take this picture.  Alas I can't hold the operating arm at the same time, when it's all built the arm will drop through the slot which you can just see and connect to the operating arm below. This arm is attached to the back of the expansion link and also to a rod which connects the the other lubricators arm near the smokebox, all as per prototype. Some may think that these boxes are too small to be practical, well in fact they are about the same size as Don's drawing for his own design, perhaps even a fraction bigger. The trick is going to be to design a system which pumps oil to the 6 outlets......  did i mention how much I love a challenge?...

 

this is something that I have really been looking forward to getting. Here we have  the scale manifold, drawn up by Adam specifically for my loco, although I do believe that Adam may have another in stock for any other true scale guys who may be considering the same...
First observations show that it's going to be tight although perhaps not as much as it looks. The prototype's manifold handles sit behind the water gauge fitting and it's top valves, although the manifold in general is higher up. I will look at this later once the boiler is back on the frames and the cab attached. I could raise the manifold on a spacer if there is room below the cab roof, if not I may need to get a little creative on the pipes running from the manifold otherwise it's perfect.  Yes the handles won't be easy to operate when the loco is running, but then they shouldn't need to be, these are after all just isolators.

 

More soon guys...
Pete

[greenglade]

Hi guys

sorry for no content during the last two weeks, lot's been going on here both with writing the blog and being isolated for you know what. the good news is that this gave me more time to write the blog as some may have seen. I was also finding machining the brake shoe slots very monotonous which also slowed things up a little.
Anyway, yesterday I finished the slots and today got the shoes for the leading driver near ready to fit, just need a little filing and polishing to complete. All being well, I'll get the other four to the same stage tomorrow.

So, a few photos to share, the first shows a start being made on one of the brake shoe blocks, they were simply centred in the machine vice, chocked up on parallels and machined with a 3 mm slot drill.

 

Now when testing the fit of the shoes I wasn't that happy with the look of them, they looked a little too chunky when compared to full-size photos and also didn't hang right in my mind's eye. Of course, those fitted on FS today may have some wear but even so, they still looked too deep in regards to the brake pad section, from want of a better word. A bit of a pain to remove more metal from the braking surface but even so I decided to do so. With the ring no longer in one piece, I'd have to do them separately and for this, I brought out of retirement the jig that had been used all those years ago when machining the tender brake shoes. Wanting to keep the 3 degree taper (IIRC the tender shoes were done on the rotary table with no taper which was then done by hand later) I decided to fit the old jig to the faceplate. Setting the rad to match the wheels and held securely with a screw into the faceplate near the centre and also two clamps either side of the jig plate after checking for squareness to the centre of the faceplate, each shoe, in turn, was then bolted to the jig and trapped between the two roll pins, that's probably not a very good description but hopefully, the picture will show what I mean.

 

The last two pictures to show the shoes both off and on, I still have work to do on these but will get the others to this stage first and then finish all of them at the same time.

 

lastly a picture with the brake on

 

Tomorrow, depending on how long it takes me to edit tomorrows first blog, I'll finish the shoes and fit them to their respective hangers, I have to make the pins first. I thought that I had done these, well I had but not to the right size... what I mean is, those odd 6 pins I made which were very slightly longer than the rest are the pins but I hadn't noticed that they should be 3/16 pins and not 1/8...lol I must be getting old... still, I now have 6 spare 1/8 pins...

Pete

[pgcroc]

Nice to hear from you again Pete.

I have been following your posts for a good while.

I do not have the skills to do what you are doing but I am fascinated with what you are doing.

Keep up the excellent work.

Peter  

[greenglade]

I have now completed the brake shoes and hangers along with their pins. I say 'completed' there will be a little more fettling later just to tidy things up before painting. Only two pictures to share but it is progress and I'm looking forward to getting on with the rest of the brake gear next week.

the first picture is just to give an idea of how much material I removed to get them closer to the prototype, the shoe on the left is the modified item. I have a few machine marks to remove and a little work around the pin-hole to get the shape symmetrical.

 

And a view to show all components ready for the stretchers to be fabricated. When linked up the hangers will hang more or less vertical with the brakes in the off position.

 

As stated. next week I'll make the stretchers depending on whether my propane bottle runs out, it's been getting low for a while. I have ordered a refill for next week but no delivery date given, should be by the middle of the week though. I'm hoping that in two weeks time I'll have finished all of the brake components and be able to test on vacuum... fingers crossed.

Pete

[greenglade]

Hi guys

Apologies for no updates of late, what with SWMBO working from home all day due to the lockdown, which it seems may now become her normal routine, the new norm so to speak, I've found it difficult to go out and leave her to it... I have been busy writing up the new blog though, this is now fully up to date which was no small achievement believe me.

Today I am actually making bits in the workshop, this is the first time cutting metal in a month, hope to have details soon although not sure in what format yet, might be easier just to post a link to the blog with a subtitle or such, we shall see.
For those who haven't visited the blog yet, here's the link, it's also in my signature for later reference.  http://4472flyingscotsman.co.uk/


More on 4472 soon...

Pete