Just William (3.5 gauge 2-6-2)

[RGR 60130]

Have you got the 'notches' above the balls to allow the water to flow past them when the balls lift? Are they big enough?

Reg

[JonL]

Sept 19, 2020 8:28:13 GMT stevep said:

I still don't quite understand your problem, as when the bypass valve is closed, there should be no water coming out of the bypass outlet. As I have said before, I think there is an issue with your plumbing.

I'll sketch out the plumbing tonight and upload so people can inspect. As you say I'm probably missing something. I've misworded things there, the bypass was open. I just like to cloud this issue! Because the closing the bypass actually fills the boiler I think I'd swapped the terms round.

[JonL]

Sept 19, 2020 9:33:13 GMT RGR 60130 said:

Have you got the 'notches' above the balls to allow the water to flow past them when the balls lift? Are they big enough?

Reg

Yes but I guess it's possible they are not quite big enough. However the fact it now works some of the time suggests it might be ok on that count.

[JonL]

More fun today, the pistons have been "letting-by" quite a bit in the last few runs, with the exhaust noise getting noticeably louder. I will be whipping out the pistons and remachining them for a proper O-ring. On the up-side my son got to drive it properly for the first time, putting in a couple of laps of our circuit. I thought that the booking system for our club would make it hard to find track time but in fact the opposite has been the case.

[JonL]

Taking the pistons out today gave me a suprise; the graphite string on one piston was completely missing, I mean, clean and dishwasher fresh, no sign of the old sealing material. The other side there was a cresent moon of seal remaining but again no sign of where the old material has gone! I've gone back through old threads on this forum and found a lot of good advice on O-Rings (mainly this thread) and have now remachined the grooves to take a silicone o-ring. They seemed very well priced as well, especially as (hopefully) its a fit and forget solution.

I can't understand where the old packing has gone. It surely cannot have vaporised and just rushed up the chimney? Very strange indeed. If the cresent of old packing hadn't been there I was missing when I bought them, were it not for the fact it used to work fine!

I have now discovered (after modifying an oil can to get to the top of the axle boxes) that my locomotive actually has drillings in the centre of the axles that feeds the oil directly to the bearings. Doh. All this time I'd been fighting to get my oil can to the top of the axle boxes. In modifying the oil can I've made it unsuitable for that method of lubrication. Double doh.

I've got quite a while until my next planned steam test so lots of modifications and improvements planned. 

[stevep]

When I gave my Rob Roy a major 'shopping' many years ago, I had exactly the same experience. I surmised that little bits had broken off over time, and had gone up the chimney.

I replaced my soft packing with PTFE rings, and it all seems to be good after many years of running.

[JonL]

I've fitted the rings onto the piston but wasn't in a position to go any further today. Even with the calculated compression at 5% I'm still wondering whether I should make a tapered installation tool to get the pistons into the cylinders without damage. I'll probably be ok if I just take my time.

[Kevan]

You could try a bit of drinks can around the piston compressed with a jubilee clip or even a tywrap to compress the ring like the ring compressor thing that is used to put pistons into car engines. Probably a lot quicker than a proper taper thing!

[d304]

Hi Nobby. Just fitted my piston and rings using a large plastic cable tie. Cut the little notch off, pull tight and push up to the next ring and do again.

David

[JonL]

Great ideas, thanks. I think with care this should be fine. Thank you for your help.

[JonL]

Piston rings went in beautifully. They seem to fit really well, giving a really good feeling of compression without lots of drag. Very pleased.

I refaced the pony truck wheels today. They were not quite flush with the ends of the axles and its been bugging me. I also discovered that although one pony truck has the central lubrication system (apply oil to the centre of the axle and it gets supplied to the bearing) the other doesn't, so I have had to sort that. I made one too many assumptions about how much work had been completed on this locomotive. In some cases jobs had been completed on one side of the locomotive but not the other, so assuming both sides were done because you had seen one was a bit of a tripping point!

In other news, this is the clack valve balls I had supplied by a reputable company, after around 5 steamings. I won't be going back to them again any time soon. It does explain why my issues with the axle pump changed over time. It's hard to chase faults when new ones are creeping in.

[smallbrother]

Something odd going on with that ball to look like that after just 5 steamings.

I haven't seen that after years of running on any of mine.

Pete.

[JonL]

I think its just a very low grade stainless or even chrome plated steel. It's degraded to the extent that its physically shrunk.

[ettingtonliam]

Go back to your reputable supplier and tell them! Don't accept ' Well, nobody else has complained'. They don't look like stainless steel to me, however poor the grade. Are they magnetic? Have they all corroded like that, or just the one?

[JonL]

Yes they were magnetic. I used those balls in a couple of places, some have rusted and some haven't. They have all been replaced now with Silicon Nitride.

My previous experiences of this company were that they were not very good at customer aftercare. I bought a casting from them that took many weeks to arrive despite being told it was in stock. When it turned up it had hard spots, I didn't really have the facilities back then to sort chilled castings so I requested another, which to their credit they supplied. However that was only after a few emails following up if the replacement was ever going to arrive. It again took almost a couple of months to turn up despite being told, again, they were in stock. It's not the only issue I've had but like a mug I've kept going back. I won't repeat that mistake unless I genuinely can't get the things I need anywhere else. I should have known better!

[JonL]

Last night my friend dropped in the Cleading which he has rolled for me. To my amazement I got the holes in the right place on the sheet before he rolled it.

Getting it on was a bit of a faff as I don't want to disturb anything which means I'd have to get re-steam tested, so the dome was a bit of a faff. Luckily the dome isn't that tall on this engine.

[JonL]

I really hesitated before posting that picture but I guess I have a different goal to the professional engineers on this forum, pretty and passable paintwork that I can touch up if it gets chipped on a locomotive that will get heavy use. Perfection was never going to happen on a locomotive of mine. My utmost respect goes to those with the patience and skills to make the exhibition standard locomotives you are all making.



This is UPOL primer which I am hoping will give me a combination of a good priming coat and a good idea of any areas that need rework before going any further. 

[simplyloco]

Oct 3, 2020 14:52:59 GMT JonL said:

I really hesitated before posting that picture but I guess I have a different goal to the professional engineers on this forum, pretty and passable paintwork that I can touch up if it gets chipped on a locomotive that will get heavy use. Perfection was never going to happen on a locomotive of mine. My utmost respect goes to those with the patience and skills to make the exhibition standard locomotives you are all making.



This is UPOL primer which I am hoping will give me a combination of a good priming coat and a good idea of any areas that need rework before going any further. 

Looks fine to me Jon!
Keep up the good work.
John

[JonL]

Thank you John

[andyhigham]

This is our club sec's loco all paint, no real rust or grime.

Not rusty by Sigma Projects, on Flickr