The Home Straight?

[ericcee]

I've opened a new thread for the final stages - I hope I'm not counting my chickens too early!

I called MW on Monday to check on the availability of the next kit and Debbie told me that Kit 12 was ready (cab sides and roof, safety valves, whistle, pressure gauge and few other bits - a strange mixture), so arranged for it to be delivered today. She also told me that Kits 9 (dome & regulator) and 11 (saddle tank) had been delayed, but either or both should be ready next month, together with the valve gear mods (hooray!).
Still no signs of the chimney (!) or the injector. The drive mechanism for the lubricator (or its absence) also has me on tenterhooks - the rather nice lubricator is fitted snugly between the frames in front of the smokebox without any obvious means of driving it, unless there's going to be a rather long linkage back to the axle pump eccentric. I'm waiting with baited breath!!

Anyway, I got stuck in to the assembly of the rather rudimentary cab and after about four hours work it is now beginning to look like a Bagnall. No problems were encountered - in fact, I was quite impressed with the general accuracy of the various components. Only a couple of holes in the platework had to be relieved slightly to line up with the tapped holes behind.

Looking back over my notes on the Bagnall, I seem to have been very critical of MW's efforts, so perhaps I should take the opportunity to make a couple of more positive observations.
Firstly, I should say that everything is very robustly made. None of your fine scale replica rivet counting here - it is very obviously intended to be a chunky work-horse with no fragile bits to knock off. I hope it lives up to its promise in this respect.
Secondly, there are a number of design details that I applaud, particularly the fact that all the boiler fittings so far are supplied with lock nuts (where relevant) so that they can be correctly aligned without resorting to permutations of copper washers (a challenge I faced on the Maxitrak engine). And I particularly like the fact that the correct length bolts are supplied - a small detail you may think, but I got so fed up shortening the bolts supplied by Maxitrak that I bought packets of the correct lengths.

I shall endeavour to get some photos taken and posted here in the next few days.

Eric Cee

[ericcee]

Perhaps I was counting chickens ...!

For various reasons, I've not been able to take any photos, so, my apologies for that.
I have painted the boiler lagging sheet (satin black out of an aerosol) and the firebox end of the boiler (Hammerite "High Heat" matt black, again out of an aerosol) and, to my surprise, both look quite good after a modicum of polishing.

Kit 9 - the regulator assembly - arrived on Friday which brings me to the point of this post - a serious question. The assembly, as you would expect, runs the length of the boiler from the regulator handle on the backhead, via the regulator itself, under the dome, and then a steam pipe to a fitting on the front tube plate which is a sort of "banjo" to feed the steam down to the cylinders. My problem is that the large "bolts/bushes" at each end are proving to be a very tight fit in the bushes in the boiler shell - and I am terrified of stripping threads! I suspect that the threads on these boiler bushes have been contaminated or distorted during the making of the boiler but, since they are "internal", I can't get at them to check or clean them. I've no idea what the threads are, but the overall diameter is 16mm.

So - has anyone any suggestions on how I should tackle this challenge?

The steam turret on top of the boiler was similarly difficult, but not so bad. In this case, I repeatedly screwed the fitting in and then backed it off (as if I was tapping the thread), removing it completely evey now and again, to check and clean the threads. Eventually, I got it down to the correct level. Should I adopt the same approach?

I have emailed MW with this question, but no response so far.

Thanks in anticipation of any help.

Eric C.

[baggo]

Hi Eric,

The best bet would be to find out from ModelWorks what the threads are and then buy/beg/borrow/steal a suitable tap to recut the threads in the bushes. It may be worth getting the die as well in case the threads on the regulator are slightly oversize. If you try and force the threads in, you'll possibly finish up getting them jammed or damaged.

It's normal practice to only partially thread the bushes before they are soldered into the boiler and then cut them all the way through afterwards, thus avoiding 'burning' the threads during the soldering process. Possibly they were not cleaned up afterwards ?

John

[Deleted]

Hi Eric,

I had the same experience with the Modelworks Britannia boiler that I received recently - I bought a set of blanking plugs and some of them were tight, but they did ease up after screwing in and out by hand a few times. I suspect that there was flux on the threads. The screw thread will be 5/8" x 26 - see www.steamfittings.co.uk/asp/d-no.asp?ProductID=194&Process=1

Debbie is on holiday this week, which may explain the lack of response. She will probably lend you a suitable tap.

Regards, John

[Julia]

Eric
The threads will almost certainly be imperial from the Model Engineer sequence. Since the boiler is such a pricy item I would recommend checking with a thread gauge before doing anyting. The small fittings will be 40 tpi eg 1/4 x 40 the intermediate will be 32 tpi eg 3/8 x 32 and the larger will be 26 tpi eg 5/8 x 26. On my POP boiler I seem to remember having to "clean" all to boiler bushes with a tap. While a set of taps/dies is an expensive investment I prefer this route over using the fitting to chase out the thread. It is a shame this is not done in the factory.

Julia

[Phil Sutton]

With my Winson 1400,most tapped holes seemed to only have had a taper tap through hem,I ended up with a full set of taps and dies and going through the lot!

Phil

[ericcee]

Once again I am almost lost for words of gratitude for such a rapid and helpful response.

I had, of course, thought about acquiring an appropriate tap, but I hadn't thought of borrowing one from MW as John (JJ) suggests. And I agree that it looks like 5/8 x 26, as both he and Julia suggest.
Thanks to the other John (Baggo) for an explanation of the correct method of threading bushes in boilers - armed with this knowledge, I'll be able to plead my case with MW so much better.
Unlike Phil, I've not had any problems with the tapped holes other than those I've mentioned in relation to the boiler.

I shall wait another few days to see If I get a response from MW (I sent the email to three addresses!) and then either call Debbie or attempt to cadge a suitable tap from one or other of my fellow ME club members.

Thanks again for your help.

Eric

[ericcee]

I really ought to get the shed sorted out and make it a proper workshop!
Anyone who has been following this little saga may recall an exchange on the valve gear and references to Martin Evans' book on the subject (thanks again, Baggo) - and how I found a copy among a number of books I'd inherited. Well - that box of books was just the tip of the inheritance iceberg. Also included was the entire contents of the poor guy's workshop - ML7, Chinese milling machine, tools, materials - the lot. It took me weeks to get the stuff transferred into a brand new shed in the garden and I still haven't sorted all the bits.
Anyway, after a night's sleep with the 5/8 x 26 detail rattling round in my head, I went into the shed this morning to see what I could find. And - lo and behold - nestling in a box of other taps of sizes that I thought I would never need - there it was, nice and clean, apparently sharp and with a protective sleeve round it. A few minutes later I had the boiler bushes sorted to the point where I can now run the regulator fittings in by hand. I reckon that's my luck for this week, so I'll not bother with a lottery ticket!

By the way - does anybody need a 5/8 x 14 BSP left-handed tap?!

[ericcee]

Just in case somebody thought I had given up ...
I've had quite a palaver with our friends at MW with the supply of the last kit - the bits arrived without any paperwork and when that caught up, over a week later, it was evident that quite a few bits were still missing (and I'm still waiting for them). And then Christmas, the family and all intervened. One way and another, I've had very little opportunity to get into the workshop of late and I'm now about to be away from home for the next ten days.
Anyway, I'm still full of hope and itching to get on with it. The (sort of) good news is that I now have bundle of bits (from the rear cylinder covers onwards) with the ominous "R" suffix on the part numbers to rebuild the valve gear.
My target is to be steaming by Easter - watch this space!

PS -- And I've just spent the last hour and a half catching up with the posts on this board - I don't want to miss anything!!

[ericcee]

At last, I've been able to get into the workshop (aka the garage and the shed) to do some useful work.
I started by taking stock of all the bits that have arrived (in theory, I should have everything by now). As far as I can tell at the moment, a few things are still missing - the dreaded die-block replacements, the axle-pump bypass valve and the replacement axle springs (front and rear). Debbie knows about these, so I'm waiting with reducing patience!
The saddle tank arrived fully assembled, but the instructions were written on the basis that the various bits (outer, inner, front and rear) should be assembled with Araldite (!!) - I'm glad they thought better of that, as they obviously decided to assemble it at the factory by brazing. However, as the photo below shows, it was not cleaned up very well after this operation. I have carefully taken a file and flap-wheel to the right hand side, while the left hand side shows it as supplied.



There should be no more than 3 hours work to complete this.

The valve gear modifications consist of replacements for the cylinder rear covers, slide bars, crossheads, slide bar brackets, vibrating levers (or eccentric rods), reach rod, reverser pole, hornblock stops and springs (for both axles). As Standardsteam suggested some time ago, I'll open a new section to record the continuing saga of the valve gear.
Some time ago I said that I was curious to see how the lubricator drive would be resolved: as expected, there's a long rod to take the drive from the rear of the axle pump. I checked this out and discovered that the rod is a bit too short and the bends in it are not quite right, but I reckon I can fix this. I also checked the linkage for the cylinder drain cocks: again I reckon the long rod reaching from the cab to the front-end is too short and I think it will foul the axle keeps. I shall reserve judgement until I finally fit the drain cocks.

As I've said before - nil desperandum!