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

[Roger]

Thanks Daz.

Here are the three Displacement Lubricators. I opted to Silver Solder the union fittings onto the big one so that the body would be more compact. There was room in the smaller one for more of the M3.5 threaded swaged type of fittings for the Pilot Steam lubricators.

The cross holes into the reservoir are 0.3mm, so this won't deliver very much oil. Hopefully it will be just enough to make the valve reliable and I won't have to keep filling them up.

You can just see the head of the M2 x 2 Stainless grub screws that plug the access hole for the cross hole. I've used a smear of 475 Loctite on those.

I'll have a look at where to mount these, and design a plate for them to attach to.

PXL_20240926_210557508 by David Buckland, on Flickr

It occured to me that the main Steam supply is from the centre valve on the turret, so I can turn that off and then hold the Whistle Valves on for a while to preheat the Lubricators and Servo Valve. Obviously they will cool down a bit between uses, but there's a fair bit of mass there, so it should remain pretty hot. The firebox isn't far away, so hopefully there won't be too many issues with condensate. We'll see. I think there's a good chance that this will be satisfactory. 

[Cro]

Roger,

Out of interest have you tried a whistle with a thin film of oil passing through it? Considering how they operate with condensate in them and can sometimes take a small amount of time to exhaust that water, will a thin film of oil passing through the steam supply effect the performance of the whistle?

Adam

[JonL]

It's a good point. Is the oil only on the operating side? Is the controlled steam oil free?

[Cro]

Sept 27, 2024 10:19:52 GMT JonL said:

It's a good point. Is the oil only on the operating side? Is the controlled steam oil free?

I assume that it’s only both operating side and supply based on the fact Roger has made 3, one larger and 2 small?

Adam

[Roger]

Sept 27, 2024 10:05:21 GMT Cro said:

Roger,

Out of interest have you tried a whistle with a thin film of oil passing through it? Considering how they operate with condensate in them and can sometimes take a small amount of time to exhaust that water, will a thin film of oil passing through the steam supply effect the performance of the whistle?

Adam

Hi Adam,
Well, I've lubricated the valve when it was assembled, so that will have got carried through to some extent.
I think the amount of oil is going to be tiny, so it's hard to imagine it making any difference.

[Cro]

Sept 28, 2024 6:15:20 GMT Roger said:

Sept 27, 2024 10:05:21 GMT Cro said:

Roger,

Out of interest have you tried a whistle with a thin film of oil passing through it? Considering how they operate with condensate in them and can sometimes take a small amount of time to exhaust that water, will a thin film of oil passing through the steam supply effect the performance of the whistle?

Adam

Hi Adam,
Well, I've lubricated the valve when it was assembled, so that will have got carried through to some extent.
I think the amount of oil is going to be tiny, so it's hard to imagine it making any difference.

Just be interesting to know, look forward to seeing the whole assembly setup working on steam and see if there is any impact,

Adam

[Roger]

I've decided to mount the individual Displacement Lubricators directly onto the underside of the Cab Stretcher, using spacer feet.

This is one of the feet for one of the small ones. It's made from a 25mm diameter Brass bar.

PXL_20240927_204245904 by David Buckland, on Flickr

I've transferred the positions onto the Stretcher using the 3D model, then drilled and tapped them M2.5

PXL_20240928_204946601 by David Buckland, on Flickr

The feet are held on using M2x6 Stainless Cap Screws from underneath, which I've ordered. The positions of the lubricators have been carefully chosen so that the reservoirs can be accessed without dismantling anything. It's also possible to remove the Whistles, detaching them from the Servo Valve so that there's room to then remove the unions on the pipes that allow the valve to be removed.

PXL_20240928_205115981 by David Buckland, on Flickr

[Roger]

I decided that I didn't like the idea of the Whistle Servo Valve being supported just by the pipes, mainly because disconnecting the Union Nuts means putting a force on them, and having to hold the body with my hand.

So here's a chunky bracket being made from a piece of 2.4mm Brass sheet. There isn't much room for a fold, and it would have needed much thinner material.

PXL_20240929_144324360 by David Buckland, on Flickr

So this was made in two parts...

PXL_20240929_154113000 by David Buckland, on Flickr

... which were Silver Soldered together.

PXL_20240929_154542129 by David Buckland, on Flickr

I managed to fill one of the mounting holes with Silver Solder in the process.

PXL_20240929_154743933 by David Buckland, on Flickr

Anyway, this is the layout...

PXL_20240929_203616981 by David Buckland, on Flickr

... which makes more sense when you can see all of the obstacles in the way.

Whistle layout by David Buckland, on Flickr

[JonL]

That is without doubt the most complicated locomotive whistle I've ever seen. It's either going to be a triumph or a wet fart, either way its going to be interesting!

[ianholder]

Love it! Sledgehammers and nuts come to mind.

[simon6200]

Roger put the “experimental” in M&EE.
I find it frustrating that most locos familiar to me, and on YouTube, have whistles which give an asthmatic wet gurgle. Even superb models with every detail too often fail in the whistle department. I made the whistle for my Springbok to the “Wheezeless Whistle” article in ME some years ago. It is fairly long to give a not too shrill note, and is tucked under the running board against the firebox side. The pipe is 5/32 thin wall, as short as possible. It sounds cleanly. It is angled slightly down to the aperture which is pointing downward, to drain condensation. If it is not angled down like this it doesn’t work. The first whistle valve I tried did not admit enough steam so was replaced with one that did.

[Roger]

Oct 1, 2024 2:05:01 GMT simon6200 said:

Roger put the “experimental” in M&EE.
I find it frustrating that most locos familiar to me, and on YouTube, have whistles which give an asthmatic wet gurgle. Even superb models with every detail too often fail in the whistle department. I made the whistle for my Springbok to the “Wheezeless Whistle” article in ME some years ago. It is fairly long to give a not too shrill note, and is tucked under the running board against the firebox side. The pipe is 5/32 thin wall, as short as possible. It sounds cleanly. It is angled slightly down to the aperture which is pointing downward, to drain condensation. If it is not angled down like this it doesn’t work. The first whistle valve I tried did not admit enough steam so was replaced with one that did.

Agreed, most of the club locomotives have a disappointing whistle, and I'd like to make mine less asthmatic.

I'm hoping that the 3mm thin wall pipe will be sufficient for the Whistles, but if necessary, I'll have to go up to 4mm like yours. All of the rest of the piping is 4mm through the Lubricator and Servo Valve, so that's the only change it will need. It won't look as authentic, because the pipe from the centre valve on the turret is quite small on the full sized locomotive, but that's what it might have to be. We'll see.

[Roger]

I'm just checking the dampers after the chassis had a run being pulled around a friend's track, and the first one has leaked much of the Silicone Oil and isn't working properly.

On examination, I think the problem was the hexagonal filling screw, which was just done up tightly and didn't have a seal.

Here's the modification to remedy that oversight. I've found some thin section O-rings, I think they're about 0.65mm with a 2.6mm ID
I remember buying some weird sizes a while back, but they haven't got anything written on the bag. Anyway, they're ideal for this job, so I've added a 0.45mm deep pocket 4.2mm diameter in the face of the Floating Piston so that the filler now compresses the O-ring against the face.

Hopefully that will resolve the problem. Accessing the front ones is dead easy, they can be done with the Locomotive on its side. The middle ones are more of a challenge because they're amongst pipes and the Anti-Roll bar. I can easily access it from the top if the Boiler is off, but that's not likely to be the case when it needs servicing next time.

With that in mind, I'll do all of the work from the bottom and add the procedure to the Owner's Manual I'm gradually creating as I do these jobs.


Sectioned damper with filler seal by David Buckland, on Flickr

[Roger]

Ok, this is what you're faced with if you want to remove the middle axle Hydraulic Dampers. You can get to the two bolt caps on the bearing halves, but it's impossible to remove the assembly because the Anti-Roll bar connects to the top cap too.

As for the top, I thought I might be able to reach the two cap screws that hold the top mount to the frame, but that's too difficult too.


PXL_20241005_084748641 by David Buckland, on Flickr

Here's another shot from a slightly different angle. Also not the Blowdown Valve Pipes coming down on the left. They're straight, and have to be slanted at an angle to come out anywhere near the middle where they aren't as much in the way of the Hydraulic Dampers.

PXL_20241005_084752008 by David Buckland, on Flickr

Anyway, something's got to give, because this is completely impractical from a maintenance point of view.

First, the Boiler had to come off so I could access everything.

PXL_20241005_150334515 by David Buckland, on Flickr

Then the Blowdown Pipes were modified to have a bend. I hadn't got any bending formers for 6mm, so I had to make those first.

PXL_20241005_194354638 by David Buckland, on Flickr

I had to strip down the Anti-Roll bar arrangement to get everything apart, and here it's back together again, but this time without the Hydraulic Dampers.

Currently, there's an E-clip that goes down behind the top mount to hold the top pivot pin in place. I've designed a sliding clip instead of that, it goes in the slot between the top mount and the frame in that slot.

The idea is that the clip can be reached from under the Pannier Tank, being lifted up to a stop whereby it clears the circlip groove and allows the pin to be withdrawn. I don't know why I didn't think of this in the first place, it seems so obvious now.

PXL_20241006_203142528 by David Buckland, on Flickr

This is the retaining clip for the removable bottom pivot pin...


PXL_20241006_141054791 by David Buckland, on Flickr

... which looks like this. The knurled handle allows the pin to be gripped firmly so it can be inserted in the hole. The pin is obscured by the Axle, and it's necessary to reach around it. Making it large and easy to grip ought to make it easier to insert. Previously, the pin was short, with an E-clip on both ends.

PXL_20241006_203219226 by David Buckland, on Flickr

This is how that goes together. The sliding clip is a snug fit on the Damper Body, so it stays where you put it. Gravity is trying to keep it in the locked position.
I've used an E-clip and then a spacer which is held on with Loctite.

The knurled handle is fitted to a shoulder and also held on with Loctite.

PXL_20241006_203247373 by David Buckland, on Flickr

And this is how that all goes together. I'm still detailing the top clip, but hopefully I'll get that done in a day or two. It's so much better than removing the top mount that I'll probably modify the front ones too. It's easy to get to the bearing caps on the front ones, so that can stay as it is.

PXL_20241006_203423917 by David Buckland, on Flickr


It's still not that easy to get your fingers in there to remove the Damper even though it's going to be easy to release them. However, at least it's now going to be possible.

[Roger]

Ok, here's the detail design of the top mount for the Hydraulic Dampers. This view is looking at the back face that would be bolted to the Frame.

The Red plate is a piece of 0.5mm thick Stainless Steel shim. The top 2mm will be folded over towards the Frame so a screwdriver can be hooked under it. It will stand 1mm above the top of the frame so there's room to get it in.

Here it's shown in the released position. There is a 2mm pin with a 5mm flange in the narrow slot at the bottom. The O-ring pushes the pin back against the locking piece so that it doesn't drop down when it's been released. The pin and slot controls the unlocked position.

Clip unlocked by David Buckland, on Flickr

This is how that looks in the locked position.

Clip locked by David Buckland, on Flickr

It's a really simple idea.

[Roger]

I decided to make the quick release arrangement for all four Dampers since it seemed to work so well.


PXL_20241007_190025614 by David Buckland, on Flickr

However, what I hadn't realised, is that the Balance pipe between the Pannier Tanks is only about 2-3mm above the mount, and that's not quite enough to release the pin.

So, if you look closely, you can see that I've made another style of retaining clip with a wide flange which can be moved with a bent hook from below.

PXL_20241008_175540907 by David Buckland, on Flickr

The oil hole in the hornblock isn't used for anything, so I've tapped that and used it to hold a stop which prevents the retainer from getting pushed down accidentally when the Damper is removed. If that happened, I'd have to remove the top mount to get it back in, and that wouldn't be easy.

PXL_20241008_181841756 by David Buckland, on Flickr


Obviously I can easily access this with the Boiler removed, but it's not so easy when it's in place. So I'm machining a special tool which hopefully will engage with the top of the Damper, allowing it to be pulled down and aligned with the bottom mount more easily. That's going to be a suck it and see job.

[Roger]

This is the Middle Damper again, with a special tool slipped over the top of the body. It's really hard to access this to pull the Damper down so that the bottom lug engages with the slot in the lower mount. This view is with the Boiler removed, but it's actually impossible to have the tool on this side when it is. The Blowdown Valves and pipes completely block access.


PXL_20241009_091711610 by David Buckland, on Flickr

This is the tool, which has a slot to miss the Piston Rod. It's a pretty snug fit on the Damper, so it can be used to wiggle it around and even turn it slightly to get the bottom lug to engage. This can only be put on and off when the Damper is in the extended position. However, you don't need to get it on or off when it's compressed.

PXL_20241009_091724077 by David Buckland, on Flickr

So here we are finally with the Boiler back on, and you can see that it's possible to fit this tool on the front side of the Axle, even though the anti-roll bar is on this side.

Thankfully, it's now possible to get the Damper out without removing or unscrewing anything.

PXL_20241009_134202844 by David Buckland, on Flickr

While I was putting the Snifting Valve back on, I thought I'd dropped the Copper Washer down the Blast Pipe hole. I thought it was in place, but now I'm not so sure since I've found a washer that just happens to fit.

Anyway, I thought I'd better run it on Compressed Air again to give it a chance to blow out in case that had indeed happened.

So here's a wobbly video of the Chassis running on 10 PSI...

(Click on the Photo)

PXL_20241009_113001787.TS by David Buckland, on Flickr

... and another at 20psi with the compressor turned off and the pressure dropping. It keeps running right down to 10psi.

This is running much more freely, just from pulling it around behind another locomotive in the Summer.

PXL_20241009_113221955.TS by David Buckland, on Flickr

[ettingtonliam]

So smooth, so quiet at 10psi!

[Roger]

Oct 10, 2024 7:50:11 GMT ettingtonliam said:

So smooth, so quiet at 10psi!

I think that's thanks for Don Ashton's valve gear that has 80% cut off. That gives more overlap which is going to make a big difference.
Presumably this also means that I'll have to notch back as soon as I've started off, else it's not going to be very efficient. I'll have to take a look and see what cut off it is at one notch back. It might be that it will happily start like that. It will be fun experimenting.

[JonL]

I suspect you won't really notice much difference in efficiency until you start looking at things like water and coal consumption over a full day. At this scale it does make a difference, but not enough to notice lap by lap, if you see what I mean. You have the patience of a saint; I'm desperate to see this in action!