Help with 'Speedy' valve gear and other issues...

[Roger]

I'm winging the cladding a bit, the throatplate piece needs to mate with the firebox cladding, but there wasn't anything to make that easy.

My afterthought solution is to add a thin flange on the inside for the cladding to be gently held against with the bands. That will need a rebait, so here it's been set up to do that. It's not going to be perfect because it's been beaten over a former.

20181014_175736 by Roger Froud, on Flickr

It's close enough.

20181014_195558 by Roger Froud, on Flickr

The thin strip is guillotined from the end of a sheet of 0.5mm Brass

20181014_203552 by Roger Froud, on Flickr

Then it's bent as close to the shape as possible and then held locally on part of the profile, it's not feasible to clamp it all the way round.

20181014_211542 by Roger Froud, on Flickr

The inside also has a thin strip, so I only want to get this as hot as absolutely necessary. With that in mind, I've formed a thin piece of Silver Solder wire which is held in place by folding it over the top.

20181014_213240 by Roger Froud, on Flickr

Those look like this on the inside...

20181014_213255 by Roger Froud, on Flickr

... and it looks like this after the first heating.

20181014_213953 by Roger Froud, on Flickr



20181014_214002 by Roger Froud, on Flickr

[Roger]

The Silver Soldering of the thin strip was remarkably easy, hooking the Silver Solder over the edge proved to be a good move.

I think I was pushing my luck with the Brass spacers though, so for the next section I thought I'd use some short lengths of Titanium welding wire for the clamps to bite on. The idea is that they won't end up Silver Soldered to the job!

20181015_093026 by Roger Froud, on Flickr

I only finished making these Toolmakers clamps a few months ago for use on the Bunker, and again they're come in really handy. I starter them over ten years ago.

So here's the first of the sides being set up. I thought it would be difficult to get it hot close to the clamps without melting the thin Brass, but that's proved not to be the case. I've rested the piece on a Steel plate to take the heat away from that bottom piece which is also Silver Soldered on...

20181015_093036 by Roger Froud, on Flickr

... and then heated it from the bottom, pointing upwards on the outside. The little pieces of Silver Solder just vanish when it's hot enough, and a quick look on the inside confirms that it's melted there too.

20181015_093413 by Roger Froud, on Flickr

You don't have to get the work anywhere near as hot as you need to do when applying the Silver Solder to the joint when it's hot. As soon as it's hot enough to melt, the job is done.

20181015_093739 by Roger Froud, on Flickr

Looking at how easy it was to Silver Solder this, I'm thinking that Silver Soldering the ends on the Side Tanks might be a good idea. Those could be jigged and Silver Soldered rather than messing about with rivets and angles for strength then caulking with Solder to make it water tight. I'm not suggesting that all of it be Silver Soldered, but the ends could be, and perhaps even the backs.

[Roger]

This has been a little bit fiddly to get it Silver Soldered all of the way along. Here, I've fashioned some 'hair clips' from Titanium Welding rod to apply the pressure from the Toolmakers Clamps without them getting stuck.

20181015_165556 by Roger Froud, on Flickr

I used the hooked over Silver Solder wire pieces throughout, and that worked pretty well. I used another piece of Welding rod to push the Silver Solder into place if it tried to move.

20181015_170327 by Roger Froud, on Flickr



20181015_185006 by Roger Froud, on Flickr



20181015_194837 by Roger Froud, on Flickr



20181015_215337 by Roger Froud, on Flickr

This is how it looks cleaned and offered up to the side piece.

20181015_220146 by Roger Froud, on Flickr

[Roger]

It seems pretty clear to me now that the key to making this easy is to provide decent locations at both ends of the wrapper. With that in mind, I've ordered some 3mm thick Brass sheet from which to cut a couple of pieces that will be Silver Soldered to the Brass backhead cladding. That will be thick enough to take a small tapped hole.

I made the side pieces deliberately too long because it's hard to get the right length to where it reaches the frames.

The shape was made by marking out the start of the gentle bend with a pencil mark and then pushing it by hand over the boiler barrel former which is about the right radius.

20181016_191149 by Roger Froud, on Flickr

The side will need to be trimmed to suit the infill piece which needs to me adjusted or re-made to suite the slightly wider backhead base I've ended up with.

20181016_191157 by Roger Froud, on Flickr

These are the shoulder pieces that will be Silver Soldered to the inside of the Backhead cladding

Inside of backhead cladding by Roger Froud, on Flickr

[92220]

Hi Roger.

That's a superb bit of forming on those corners!! What thickness material did you use? How many annealings did you have to do on each corner?

Bob.

[Roger]

Oct 17, 2018 7:46:35 GMT 92220 said:

Hi Roger.

That's a superb bit of forming on those corners!! What thickness material did you use? How many annealings did you have to do on each corner?

Bob.

Hi Bob,
I've just searched back and it's on page 361 of the thread. If you click on the ... ellipses ... where the numbers are displayed then you can enter that page number.

It's 2mm CZ108 Brass sheet and I think it took six annealings to get it round. I didn't push my luck with each stage and I used rubber and a dead-blow mallet as much as possible to avoid putting any more marks in the metal than absolutely necessary. I did use an Aluminium mallet for the last bit, but that was a mistake, it marks the work too much.

I was surprised at how easily it formed. It's not quite as easy as Copper, but it's much softer than I expected when annealed. I'd certainly do it like that again.

[92220]

Hi Roger.

Thanks for that. I'd totally forgotten that we'd seen it previously in your thread. I should have remembered you would have described such an
important process. I will have a go when I do my boiler cladding.

Bob.

[Roger]

Oct 18, 2018 7:38:02 GMT 92220 said:

Hi Roger.

Thanks for that. I'd totally forgotten that we'd seen it previously in your thread. I should have remembered you would have described such an
important process. I will have a go when I do my boiler cladding.

Bob.

Hi Bob,
It would be interesting to try forming that in Steel over a sturdy former like that. I don't see any reason why it couldn't be done, especially if it was done Red hot. Maybe I'll try it when I've finished the build and I've got time on my hands. My argument is that if you can move it a little you can move it as much as you like.
If it was made from Steel, TIG welding the other bits onto it would be easy.

[Roger]

The 1.5mm Brass sheet for the side tanks arrived today, so I thought I'd make a start and cut them to length.

This is almost certainly above the limit for the Formit, I wouldn't have risked it if I hadn't added that support under the middle of the bottom blade.
It was a real struggle to make the cut.

20181018_201417 by Roger Froud, on Flickr

I calculated the distance from the back of the folder to the start of the radius and wanted to make a trial bend on the piece of sheet I cut to true up the end.

I'd already made the forming roller under size, but it's clearly got a long way to go.

20181018_211034 by Roger Froud, on Flickr

This is the diameter I'm aiming for on the inside, so it looks like I need about 1mm more off the radius.

20181018_214931 by Roger Froud, on Flickr

So tonight I've drilled and tapped the bottom of the hole on the roller and made the attachment that can be bolted on so it can be machined from end to end without setting it up twice.

20181018_215248 by Roger Froud, on Flickr

[92220]

Hi Roger.

I shall follow this with great interest! Have we seen any pics of your small-radius bender? I have approx. the same radii to form on the bottoms of my tender sides. I'm going to have to make some sort of bender to get those radii correct....0.532"...a bit tight.

Bob.

[Roger]

Oct 19, 2018 7:44:11 GMT 92220 said:

Hi Roger.

I shall follow this with great interest! Have we seen any pics of your small-radius bender? I have approx. the same radii to form on the bottoms of my tender sides. I'm going to have to make some sort of bender to get those radii correct....0.532"...a bit tight.

Bob.

Hi Bob,
Here's a link to the album showing all of the photos I have of the folder. The design evolved a little as is always the way, but you can see the photos of how it ended up.
The key difference between this an traditional folders is that the height of the pivot point is adjustable from 0-22mm so you can bend radii up to 20mm
The bends I'm creating have an internal radius of 12mm, so slightly tighter than yours, but probably close enough to do with whatever radius roller I end up with. You're more than welcome to borrow it if you don't wan't to make your own.

[Roger]

Just returned from a most pleasant day out with my dear friend Bill to visit the Midlands Model Engineering Exhibition.
It was good to catch up with David Scott & Lilly (dscott) and Don (don9F), and very good to meet Malcolm (mbrown), Paul (juliet) and Baldric for the first time.

I was impressed with both the exhibits and the many trade stands, a sign that the hobby is still going strong.

[Roger]

Here's 2mm coming off the diameter of the former...

20181019_212421 by Roger Froud, on Flickr

... and that worked out close enough....


20181019_222314 by Roger Froud, on Flickr

... so the next bend was set from the same distance to the edge of the sheet and the bend measures close enough to the right distance between them.


20181019_222732 by Roger Froud, on Flickr

So this is what the folder was conceived to be able to do, no putting it off any longer....


20181019_224609 by Roger Froud, on Flickr




20181019_224618 by Roger Froud, on Flickr

...it worked out just fine.


20181019_224921 by Roger Froud, on Flickr

... except, I can't fold the next bend from the opposite edge because the clamping arrangement is too tall! Doh!

That's what happens when you change the design without thinking it all through. So I've designed a stronger, low profile clamping arrangement and ordered the material.


20181019_225803 by Roger Froud, on Flickr

Still, that's the first two bends done, and it worked like a charm.


20181019_232707 by Roger Froud, on Flickr

[Roger]

This might look a little over the top, but it seemed like a good way to hold the parts firmly at the awkward angles necessary to drill and tap the M1.4 bolt holes that hold the pieces together.

I already had the round Steel adaptor for the chuck which has a pattern of M8 holes on a standard pitch which match the holes in the former. It was a simple matter of just bolting that on the end.

I've made sure that the bolts are going to be hidden by the side tanks.


20181020_193420 by Roger Froud, on Flickr

Here it is on the boiler, and also my first attempt at the boiler cladding in card. I marked up the errors in pencil and then modelled it as a flat piece in CAD. The idea is to make it exactly to the model in case I need to make another one.

20181020_210943 by Roger Froud, on Flickr

The cladding on 1501 is in two halves, bolted together at the overlap on the top. I'm doing the same, not only because it ought to look more authentic, but also because it's easier to make.

I'm machining it in two operations, flipping it over front to back on the two dowels that are in a base plate I use for other jobs. There isn't enough travel front to back to do it in one.

The main thing is to get the curves at the ends right and to leave an additional 30mm either side so it can be rolled right to the edge of the final piece.

Here I'm drilling the 1mm bolt holes that will hold the two parts together. I've only machined 10mm of the side at the far end, I'm going to guillotine the straight sides which will be cut off later.

20181021_174146 by Roger Froud, on Flickr

Here it's flipped over and the other end curve is added. I've included the clearance for the safety valve and feed pipe.

20181021_205515 by Roger Froud, on Flickr

This is with the sides guillotined and the edges tidied up.

20181021_214743 by Roger Froud, on Flickr

It rolls quite close to the end on the front, but the back leaves about 25mm pretty straight. I used calipers to check that the diameter at the ends of the taper were right.

20181021_221925 by Roger Froud, on Flickr

It looked like this when that was done. It's 30mm too long on the top and bottom, so that was carefully marked with a scriber and guillotined to length. On the next one, I'll probably machine those short guide lines to save marking it out.

20181021_222431 by Roger Froud, on Flickr

Anyway, I'm pretty happy with that, it seems to fit pretty well.

20181021_225251 by Roger Froud, on Flickr

I bought some really thin 0.2mm Brass strip for the bands, but they're easily bent and damaged. I think I might be able to get some Steel strip that isn't Stainless, but it looks pretty expensive. I might just give this a try first.

Here I've scribed a line on each end and I'm holding it down with a piece of Gauge Plate that happened to be a suitable size of the purpose.

20181021_134449 by Roger Froud, on Flickr

I'm curious to know how bands are attached to the firebox section. I'll probably put a couple of holes in them and bolt them to the side of the firebox behind the side tanks. Does anyone know how is it done on full sized locomotives?

20181021_135935 by Roger Froud, on Flickr

[92220]

Oct 19, 2018 17:31:55 GMT Roger said:

Oct 19, 2018 7:44:11 GMT 92220 said:

Hi Roger.

I shall follow this with great interest! Have we seen any pics of your small-radius bender? I have approx. the same radii to form on the bottoms of my tender sides. I'm going to have to make some sort of bender to get those radii correct....0.532"...a bit tight.

Bob.

Hi Bob,
Here's a link to the album showing all of the photos I have of the folder. The design evolved a little as is always the way, but you can see the photos of how it ended up.
The key difference between this an traditional folders is that the height of the pivot point is adjustable from 0-22mm so you can bend radii up to 20mm
The bends I'm creating have an internal radius of 12mm, so slightly tighter than yours, but probably close enough to do with whatever radius roller I end up with. You're more than welcome to borrow it if you don't wan't to make your own.

Hi Roger.

Thank you for the link. Very interesting, and informative, series of photos. And thank you for the kind offer of the loan of the bender. I may take you up on it as it is a tool I would probably only ever use the once if I did make one. I wouldn't need it for the cladding as my normal rolls will do that.

Bob.

[92220]

Hi Roger.

That cladding is looking brilliant!! What thickness steel sheet are you using?

Bob.

[Roger]

Oct 22, 2018 8:29:13 GMT 92220 said:

Hi Roger.

That cladding is looking brilliant!! What thickness steel sheet are you using?

Bob.

Hi Bob,
The cladding is 0.6mm Mild Steel sheet which forms really easily. Seeing how easily Brass was dented, I'm pleased I've gone down this route. Of course, putting a curve in the cladding makes any material stiffer, but I'm impressed by how sturdy this feels.

[Roger]

The 3mm Brass Sheet arrived today so here are the blanks being machined for the corners of the backhead to support the firebox cladding.

20181022_202339 by Roger Froud, on Flickr

They will be Silver Soldered onto the backhead where there's a rebait on the corners.

20181022_220329 by Roger Froud, on Flickr

Dad had five of these large storage boxes, so I've re-used them for all of the incidental parts I've made so far and the special tools and servicing parts. It's reminded me of just how much is finished even though the locomotive looks very bare at the moment.

20181022_201552 by Roger Froud, on Flickr

[92220]

Thanks Roger. I think I might go down that same route.

Bob.

[Roger]

I decided to bite the bullet and blow £17 on a roll of 0.2mm thick Hard Steel Shim. I'd asked the seller to verify that this wasn't Stainless Steel because I knew it would be harder to paint and it needs to be black.

It's strongly magnetic and pretty hard so I think it's some sort of High Carbon Steel not dissimilar to Gauge plate.


20181024_160016 by Roger Froud, on Flickr

Anyway, it guillotined really easily, so I'm much happier about these now. They're chalk and cheese compared to the Brass ones that feel like they're not much stronger than thick kitchen foil.

20181024_165917 by Roger Froud, on Flickr

The new sheet of 0.6mm thick Mild Steel arrived today, so here's the second side being machined at the smokebox end.

20181024_153149 by Roger Froud, on Flickr

... then flipped over front to back and the firebox end done. You'll notice that this time I've completely cut out the pieces where the clearance for the 'I' beam and Safety Valve go. The first one was too tricky to clean up with a file with that in place.

20181024_174834 by Roger Froud, on Flickr

I've also scribed where the final guillotine line is to be on the inside. I cocked up the first one and cut it in the wrong place. Doh!


20181024_212559 by Roger Froud, on Flickr

I can set this square on the rollers so long as the back roller is out of the way. Then it's rolled to the half way position and then all adjustments are made at the centre else when it's tapered it would end up skewed.


20181024_213345 by Roger Froud, on Flickr


They fit nicely so that's another job done.

20181024_220531 by Roger Froud, on Flickr