Member postings for nick feast

This is the third time I've typed this reply, forgotten how un-user friendly this web page is. Anyway it's a standard machine tool coolant pump made in their thousands by companies world wide over the years. Below is a pic of the similar thing in the guts of an original Bulleid pacific. Part of a double pump, two sets of gears on the same shaft. Not for forward and backward but one to pump to each side of the oil bath via a filter each side. Both feeds join in the middle and feed a spray bar going the length of the oil bath. Pumps in forward or reverse by a clever arrangement of non return poppet valves cast in to the pump body. Made by Hamworthy Engineering of Poole and originally designed for reversible marine diesel engines IMHO, although I have never seen this written anywhere.

OK, here is an update on a very old thread! 2 Q1 tender engines completed and a tank engine that never existing now running as well. It's an 0-6-4, successor to the SECR j class and feasible alternative to the Leader. See photo. More info to follow, perhaps something in the magazine if the editor agrees.

Just noticed this thread, the steam chest casting used on the first build was from the Derby 4F/ Clayton wagon. I have since made a couple of fabricated ones using 1/2" square brass bar and round, silver soldered and milled to size. The two 5BA holes were indeed intended as jacking screw holes as they don't match any threaded holes on the block.

I intend showing the loco built during the series at the Bristol show in August. It has a few differences from the original drawings such as hydrostatic oiler and multiple jet blast pipe. The tender was glued together using polyurethane compound as used in automotive bodies. Only a few small leaks so far, the joint technique needs perfecting!

Nick Feast

The flux was purchased a few years ago at the same time as the Comsol from a well known ME supplier and is labelled '86/140 flux for Comsol solder' . However their latest online catalogue doesn't show it, so perhaps it isn't that good.

I will be sourcing some different flux shortly but this doesn't actually help with removal of the black deposits on the boiler! I might give caustic soda a go as I suppose it's basically carbon and caustic shifted the black goo in my BSA bantam exhaust back in the last century.

Thanks to those who answered, perhaps a little more detail is needed.

I have a silver soldered copper boiler for a 5" gauge standard class 2. not huge but big enough to require quite a lot of heat to get it up to 300 degrees. There are several stays in the top of the firebox that weep under pressure. So with the boiler inverted and Bridgit flux liberally applied(suitable for up to 427 deg C) I put small pieces of comsol solder by the relevant stay heads. Applying indirect heat i.e. around the outside of the boiler and through the regulator hole in the back head, the flux smokes and blackens before the solder melts. This is the 'black lunge'.

I had supposed that it was better not to apply direct heat as this just sets the flux alight immediately.

So really two questions, is there a better flux and how to best get rid if the black deposit? It has to be removed chemically because there may well be joints that still leak and need to be cleaned internally to have any hope of taking solder next time.

Thanks

Nick

Does anyone have an efficient method of removing the black gunge left behind by Bridgit flux after doing a bit of Comsol soldering on a copper boiler? Strong detergent works after a fashion, meths seems to work a little, but the usual picking method is no good at all.

Any suggestions?

Over the past five years I've taken a 3 1/2" gauge Q1 to show on the Polly stand at Bristol, Ally Pally, Midlands and Sandown shows. I've also organised, set up and manned dozens of trade stands in another industry over the last 40 years or so. in the UK the pattern seems to be that once an exhibition is established the organisers will milk it for all it's worth, with high charges for space and minimal investment. Many industrial trade shows have disappeared in the UK for the reasons already mentioned in this thread.

However the factor that can't be replaced by an online shop is the sociable side of meeting many like minded people, and talking about the hobby. The royalties I receive from selling Q1 parts via Polly are certainly eaten into by the expense of two visits to each show, to deliver and collect the model. I take my model as a private entry so that I can at least get away before all the trade stands are dismantled, but last year in the snow at Ally Pally the buses to the car park stopped at 5.00 on the last day so I had to slither my way down the hill to the car park with the loco and tender on a sack truck! London bus drivers don't receive much snow training.

However I have met many interesting and useful people at these shows, even getting access to a set of SR drawings for the Q1 as a result of one discussion. A pity the loco was already completed by then!

Expensive food is obligatory along with the queues to buy it, but model engineers should be ashamed of themselves if they cannot avoid this cost with a little ingenuity. The Bristol show is conveniently located close to a well known supermarket built on the site of Thornbury Station, so a cheap sandwich, a bit of exercise and some railway archaeology can be combined.

I sincerely hope the present shows can find a way to survive, the organisers do need to get the traders(and clubs) participating in bigger numbers somehow.

Did anyone join yet? No more info on the website so far.

Series ran from ME4353 to 4405. I've built a Clayton and 2 Q1's and made a solid circular centre for the crank axle each time. Apart from giving a better chance of alignment of the throws and axles, it makes for a much smoother running loco. Totally un-prototypical, but if you want something to run hard, it works.

Straight slides work fine but cranking the top end of the vibrating levers improves valve timing. Robin Dyer didn't have access to the software available on the net today. Dockstader and others.

The most accurate way to position the slideshaft pivot point on the frames is to do it when all the parts have been made. If the reversing lever can be moved from full forward to full reverse with the crank fully forward and fully back, relative to the cylinder (it's inclined at 8 or so degrees), without imparting any movement to the valve, then it's in right position. Suspension shoud be in the normal laden position, which may not be mid point on its travel. Fiddly but perhaps easier than setting eccentrics.

Tender mounted axle pump is essential if you make the crank as above, a 1/4" ram will keep the boiler fed.

Make it as heavy as you can and it will pull three or four adults. 3 1/2" gauge locos are great if you can get the train moving, there will be more power than you can use.

Nick

And of course my forum pic shows plenty of steam from the exhaust!

A sure sign that boiler pressure was well down,

Or posed for effect!

Forget all the theorizing, have any of the people who contributed to this thread actually driven an unsuperheated model steam loco? At all times of the year?

I can't believe anyone would actually choose to drive around in their own mobile fog bank, getting showered with oily water as the lubrication is washed off their cylinders.

Even in winter my 3 1/2"Q1 which has 2 full radiant return bend superheaters produces very little visible exhaust, and it is definitely possible to feel the superheater 'turbo' effect when the engine is working hard. On the other hand driving the club's unsuperheated 'Maid of Kent' in damp weather is a pain, but it's too much hassle to convert it.

The only real drawback is keeping the superheater flue clean as it's hard to get a brush in there, making and fitting them during construction is not difficult. They have to be stainless, copper eventually disintegrates at the firebox end.

Nick

Hello Alan,

Just read this post, not been looking at the site lately.

As JohnS points out it is not unsurmountable but I am surprised. Measured 3 sets of machined wheels in the workshop and they are all close to 101.5 mm. However they were pre Polly doing the castings.

For the record the loco wheels on a Q1 were a nominal 5ft 1inch diameter. divide by 16 and metricate and you get about 97mm. I added a bit of diameter in the design, can't remember why now. Hopefully the detail of the wheel looks right.

Regards

Nick

I'll be interested in this too as I have a part built model which came with all the valve gear made up except the eccentric rods. I made them 'to the job' to give an equal swing of the expansion links to and fro relative to the valve operating (radius) rod. This worked out at 4.785" instead of the 4.8125 called for on the drawing. Not sure this will make much difference, what problems are you having?

If it ever gets finished it will be an Ivatt 2-6-2 tank, it should feel at home with all the Q1's in the workshop!

Nick

The latest ME has an interesting letter from Geoffrey Johnson, who has found out the hard way that just because a design is in print doesn't mean it can be built to work!

As a professional engineer he knows how to design and draw having spent a long time learning how to do it properly. Most model designers are amateurs who want to make their favourites in miniature. I am one of these, and a few mistakes were evident when modellers started to build from the Q1 series in ME.

By building two locos to prove the drawings I also found a few mistakes myself, so was able to update the drawings. Anyone purchasing drawings from Polly models will get the latest revision, and this will be shown with the revision date on the drawing number. This really should be standard practice.

But for future series in ME it really would help to know if at least one working model had been built to the author's drawings.

There must be loads of people like me who wanted a lathe for hobby use and bought a 180 style chinese lathe from one of the importers. I have been pleased with mine over almost nine years, built several locos and had no trouble with it. A few marks showing on the bed but I paid £750 and got 3 and four jaw chucks and a faceplate, fixed and travelling steadies. It is very heavy for a small lathe, but this is a good thing I reckon.

I would have paid much more for a 'quality' product, but for a couple of hours use per week I couldn't justify the extra cost. I would buy the same or similiar again.

Nick

I will be there on Sunday on the Polly stand to talk to anyone building a Q1. If I don't go my loco will end up in Nottingham, much too far north for a Southern engine!

Nick

Edited By David Clark 1 on 18/01/2013 15:42:54

Also didn't spot the announcement till now so all the best to David in his new ventures and thanks for letting me go into print in ME.

Nick

Just to confirm the dimensions quoted above are correct to rev 5 of the frame drawing corrected in Dec 09. All drawings sold by Polly after that date should be rev 5. I will check with them to be sure.

I hope to be showing the loco built for the ME series at the London show at the Alexandra Palace on the Polly stand. This loco has been used for passenger hauling over the last year so will not be in 'exhibition' condition. It has the hydrostatic oiler option, no added handrails or guards and is in Southern Railway livery.

Nick

I'm not surprised that 3 1/2" is seen as a more convenient gauge than the trolley demanding bigger gauges. I do admit to using a wheelbarrow to carry the Q1 from the shed to the car as it's about 50 metres. Very apt some might say. Last Sunday only three locos turned out at at BDSME, a 5"Peckett being'sorted,' the club battery Hymek and my Q1, getting a steam test having had the 4 yearly hydraulic before Christmas. Went on the track and did an afternoon of passenger hauling. All the big engines stayed at home. Moving a 25kg loco and 7 kg tender around involves a lot less planning and fuss, but the real appeal is the challenge of running the engine pretty close to its limits with a load on, not something you will often do with a 5" gauger on a typical running day.

Nick

**LINK**

To reply to the editior's question of 16th November, this post still obscured, and quite a few others.

The position of the right side banner seems to vary.

Thanks

Nick