Rob & Tash Showmans

Crystal would not run on air at all.
Valve setting is simple. The only adjustment you have is on the spindle length and notches on the quadrant.
Also make sure the valve pucks are loose on the spindle shafts. Just enough to allow the valve to flop off the face. The spring and eventually steam pressure will keep it on the face. But slight looseness is needed when cut back going down hill.

As said before do with LP cover off to start with. Before you do anything. Palm the flywheel over with full forward and full reverse. Check the spindle rods do not collide with the valve chest end. I had to remove 2mm off the HP rod once the length was set at the expansion link end.

I set cold and both covers off. This allows you to see all the events and get the rods basically the correct lengths. You can not do anything with the eccentrics as this is set by Steve at the factory. In steam I did a slight (1/ of a turn on the HP otherwise Crystal is as set at the factory.

Thanks Nick, and for the link. I'll give it another go at the weekend, as you say the running it is the rest of the novel and after all this work it's going to run.

Thanks Lynn, found the notes and as you say the timing is factory set by the key position so that makes it a bit easier. I've not yet cut the quadrants yet wanted to check my marks before I did.  

I'll be taking all the covers off again on Saturday, it turns over lovely by hand in both forward and reverse and seems ok, but I'll turn it over with them off and see all is as it should be.

Had a frustrating weekend again, have been chasing leaks and still have a couple to sort out. None of them major but all frustrating. I do however have a problem which I can't fathom out, partly because I don't fully understand how the passages in the cylinder link.

When I go to start the engine I loose all the pressure straight out the exhaust with not a sign of it running, has anyone else had this problem, or got any idea what the cause would be?

Hi Rob,

Your build is an award winner, first class job there!

Are the slide valves free to move on the spindle. Kind of sounds like they are not seating on the valve face.

What happens if you roll it over by hand when trying to start it.

Mark

Robfishman wrote:

When I go to start the engine I loose all the pressure straight out the exhaust with not a sign of it running, has anyone else had this problem, or got any idea what the cause would be?

Is this on air or steam ? if air what sort of pressure are you trying to run her at, sounds like what others have said, its valve pucks not seating.

What vintage is your cylinder block? some of the early ones had a problem with wall thickness internally. There are three main passageways in the block, in the centre is the vertical steam up to the regulator. At the back of the block is a passageway horizontally from the high pressure exhaust to the low pressure inlet. The third passageway is the low pressure exhaust which runs horizontally to the chimney. The problem was that the wall thickness where all these passageways go past each other. My first block would immediately run on air at 40 - 50 psi and when I opened the regulator it stopped. What was happening was there was a leak between the steam in and the high pressure exhaust so it was running like a single cylinder on the low pressure piston only. As soon as I opened the regulator it balanced itself out & stopped.

Another block I fitted to the Deans Showmans had your problem in that it wouldn't run and and all the air went straight up the chimney, this was a break in the wall thickness between the steam in and the low pressure exhaust.

There isn't really a cure other than a new block, I got it down to 2 hours to remove the old block and 2 days to fit the new one!

Like I said on the title, I hope I'm wrong but it does sound a bit like the problem Dean has with his Showmans.

Thanks everyone for your comments, gives me a few things to double check next week.

I've tried both compressed air and steam.  I'll double check the valve pucks, but I would have thought if they weren't seating correctly they would be letting by all the time when I tried on air.  

If at the same time I turn by hand still nothing, and it feels just like it does with no pressure in the boiler.

I'm from the first batch Steve and also hope it's not that, but your description of what happens to  Dean's matches mine.

I'll give it another go next weekend and hope it's 3rd time lucky.

Rob,
From what you have described I would say at this stage you have a bad block.

My block was a first gen and had the fault and I suspect yours has too.
The design has since been modified. Its a very complex casting and its not uncommon to have issues when casting them even more so in a smaller scale.

i found my fault by filling the engine with the safety valve off.
Fill completely to the top with the side covers off.
if water starts poring out the exhaust you know you have a problem. The only other way water should pore out the exhaust is from the low pressure valve port but with the side cover off this will be minimal

mine would fill completely to the top then empty through the exhaust. when it stopped I determined where the water level was and looked for the hole.
If you look on blackbeard's thread you will see the same issue and photos of where the fault is.

My heart sank when I discovered but it's just the nature of what it is, a rather complex casting.

The fault has been found in 3 blocks I know off and is located in the first internal bend back from the exhaust at the front of the block. This is where it is closest to the steam inlet up to the regulator.
Mine was porous at this point.

I now have a new generation block on mine.

Nick

Thanks Nick, I'll give that a go and see what happens.

Thanks all for your comments and advice.  

Well after a week of tinkering and adjustment we have finally been able to get pressure in the boiler.  Still loosing pressure through the exhaust but not anywhere near as much.  My compressor can get it to about 55psi, although it can't maintain it when running. As Lynn said they don't much like running on air, at least not without a much bigger compressor.



Once the lubricator comes back from STW towers I'll fire up and see how it behaves running on steam, then get the boiler inspector round for the boiler certs.

Hi Rob,

Looking good. If its something you are interested in, my 2" needs testing too. My club are not interested in testing it so I was thinking about 'going commercial' I'd be happy to share costs etc. Only across the way in Eastleigh, would be good to see your engine in the metal in any case.

Cheers

Will

Did you discover what the problem was with loosing pressure through the exhaust?

made-in-england wrote:Hi Rob,

Looking good. If its something you are interested in, my 2" needs testing too. My club are not interested in testing it so I was thinking about 'going commercial' I'd be happy to share costs etc. Only across the way in Eastleigh, would be good to see your engine in the metal in any case.

Cheers

Will

Certainly, once I'm at the point I'll give you a shout and if your not tested by then make sense to do both at the same time. I'll PM you my number, your welcome round for a coffee and a look anytime.

sonick45 wrote:Did you discover what the problem was with loosing pressure through the exhaust?

Hi Nick,

I'm not exactly sure as it's still happening, I've adjusted all sorts of things and each has helped. The biggest difference though happened when I fitted stronger springs to the valve pucks.  I'm hoping that's the cause and when running on steam it will help to form a tight seal. If not a bit more head scratching will be needed.

Dont worry about the springs Rob. The ones supplied are fine. Once expansive steam gets behind the valves they will seat and get run in.

Spoke to STW towers today and the lubricator body should be back with me over the next few days so should be in steam for the first time at the weekend. Both excited and apprehensive at the same time.

In the meantime I've started on the canopy at the weekend. 7th May is fast approaching and still a fair bit to both to the engine, trailer, and the small demolition job to get it out the garden.

A couple more of polished parts before and after.

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Generate by IceMaster's Flickr BBCode and HTML Generator

Robfishman wrote:

made-in-england wrote:Hi Rob,

Looking good. If its something you are interested in, my 2" needs testing too. My club are not interested in testing it so I was thinking about 'going commercial' I'd be happy to share costs etc. Only across the way in Eastleigh, would be good to see your engine in the metal in any case.

Cheers

Will

Certainly, once I'm at the point I'll give you a shout and if your not tested by then make sense to do both at the same time.   I'll PM you my number, your welcome round for a coffee and a look anytime.  

Thanks Rob, that's very kind. Would like to come and see your engine!

Love the pictures of the barley twist brass. Looking forward to being at that stage.

John

At the speed you're going John you'll be finished before me, lol.  Seriously though it is quite rewarding, while frustrating, to be on the finished game straight.

Spoke to STW yesterday and the modified lubricator is on its way to me.  I'll fit this at the weekend and then it will be time to think about lighting a fire.

That is a major step to get to and when you have it under steam I am sure that will give you a level of achievement justifying all your hard work. We will all await the video 😀

I have had some time to push on with mine but I don't think that I will be able to maintain the current rate so expect some gaps as I progress.

John

Having had a problem with the lubricator the tank was thought to be wrongly manufactured. Was sent back and picked up the replacement today.  Guess what it looked identical, put together and the same problem. Has anyone else got the same guts and had the same problem, and found a solution.  have emailed Steve again for advice, it's very unusual for something not to be right the first time, but hard to believe the tank is wrong twice?  

1. Lubricator problem.


2. Lubricator problem.


3. Lubricator problem.

Most people I know go & buy an LSM (or similar) ratchet one and put the STW one in a drawer. The ratchet ones are bullet proof and like the full size. Same with the steam valves for the injector & water lifter, R A Barker does them with PTFE seats which don't tighten up when hot.

Thumbs up for the LSM ratchet type ,fitted one to mine looks much better, the STW one didnt even see daylight just as Steve says went straight into a drawer.
Kev

Thanks Steve / Kev

Lynn had said the same, but they and the other suggested were both out of stock at the time. LSM have got some again and I've ordered one. Have also ordered from them and agree they are very efficient.

Turns out the the kit I have has the wrong cam hence the problem with rotation. Steve arranged for one to be posted out and I'm now putting it back together.