Lancaster Green Ayre - The Barn Owls have returned.

[lezz01]

Can you not thin the cranks down a bit Jamie? If you only need another 2 mill that's only 0.5mm off each side of the two cranks. Not a huge amount in 7mm. What do they measure?

On another note both wifey and I are through the worst of the plague. See returned to work today and I should be doing my usual Friday evening shift in the pharmacy. Kimmy's only remaining symptom is a dull headache and I'm still a little short of breath but it's much improved and my sats are back up to 97. After the carnage we've seen around us, 15 from one nursing home alone, we consider ourselves very VERY lucky indeed. So it's back to the battlefield for us and none too soon either as our colleagues are struggling as the workload is intense and there are quite a few of us on the sick list.

Regards Lez.   

[jamie92208]

First of all Lezz, I'm very glad that you both have seen off the dreaded lurgi.  I hope thst your recovery continues. It sounds like youvsre having a bad time around you. Yes thinning cranks.  I'm certainly going to do sone work with that.  However I need to replace 2 of the 4 frame stretchers anyway so doing the other two shouldn't be difficult.  The front one needs to change anyway to get the dummy cylinder block in.  The next one is also right where the motion plate needs to go. The tricky one will be the rear one.  I'll probably mark out and cut one piece of brass fold it up and get it the right width then cut it into two pieces.  Some fun is coming up.

 

Jamie

[Dave Hunt]

Jamie,

 

My recent mutterings on another thread about Midland engines not being maroon but crimson lake has prompted me to dig out some details of the specifications issued to outside firms around 1880 - 1900 and I thought that the following may be of interest: 

 

Without going into minute detail of the number of coats applied etc., the undercoat was described as 'Oxide of Iron, called "Purple Brown" '. This was not the reddish/orange/brown that we usually think of as red oxide but a darker colour and was sometimes called 'chocolate brown' (It was the late David Tee's opinion that the brown painted goods engines of circa 1906 were simply painted this colour then varnished without the 'red' top coats being applied). The next stage was application of what was described as 'Oxide of Iron and Lake', to be obtained from Messrs. Leach & Neal of Derby or the Strathclyde Paint Co. of Glasgow. This was the colour that David White discovered was later supplied by Joseph Masons of Derby and that they still (in the 1980s) had in their range of vehicle enamels as 'Mercedes Red' and which he obtained from them. I got some from him, which I have used on all my Midland locos, and I believe that David gave some to one of the modelling paint companies (Precision Paints? - I'm not sure to be honest) for reference. In the 1980s David Jenkinson and Bob Essery ascertained from some old Derby paintshop foremen that the colour used in LMS days was the same as before the grouping. David Tee was of the opinion that suggestions it was a different colour were possibly due to a change in the undercoat to a lighter shade or that the composition and number of the final varnish coats differed. But even if that were true the difference would have been minimal and after a short while in service without the strict cleaning regime of the Midland the colour may have been perceived differently anyway. As I said before, the first use of maroon on the LMS was for the lining on the 1946 black livery and when some LMR Pacifics were painted 'red' in the late 1950s it was stated at Derby that the colour was the same as that which had been used on LMS engines up to the 1940s - this information came to me from Dennis Monk.

 

I hope that these ramblings are of some use.

 

Davej 

[lezz01]

I have always used British Leyland Damask Red. It's very close to the colour patch in Midland Style. The only problem is that car rattle cans tend to put down more paint than you need for modeling but you can either hold the can father away from the work or change the nozzle for one from a can of model paint.

Regards Lez.  

[Regularity]

Re the inside motion...

A shot of Trevor Nunn’s T26 GER 2-4-0 (LNER E4 to heathens) under construction.

The motion is a removable unit, soldered to thin single-sided pcb either side to insulate it from the frames (split frames on this) and held in place with a screw from each side hidden in the sand box.

This is all less than ¾” wide!

[lezz01]

You've gotta love a kettle. I know some of them are aesthetically beautiful especially from the late Victorian/Edwardian eras. However the motion is where the true art is. Both inside and outside motion is a true thing of beauty especially when it's moving.  Even stationary engines have a hypnotic quality, they can draw you in and you can watch them for hours. In fact stationary engines are much better to watch than steam locos are, more so if it's one with inside motion as they are very difficult to observe in motion unless it's moving slowly down a platform and you can walk alongside it or stand on the running plate. I'm afraid that we threw away steam far to soon.  Yes yes I know all of the arguments against them. Dirty, inefficient etc but what if we made them more efficient, what if we could have got them upto 50 or 60 % efficient and less labour intensive with better condensing gear. Oh well too late now.

Regards Lez.        

[jamie92208]

At the moment I've got two with inside motion. A single with tender drive built by my late friend Tony Bond, and a 2-4-0 that's painted but not yet lined that I've done. There's a video on You tube not brilliant but it's here.

I had a go at filing cranknwebs last night and got the first down  by over 1mm.  I ?may even be able to get away without widening the frames.

 

Jamie

 

 

 

Edited April 25, 2020 by jamie92208

[lezz01]

I knew you would Jamie. 7mm gives you so much more wiggle room than 4mm. If only I had more room....and more money. Oh well it is what it is.

Regards Lez. 

[jamie92208]

1 hour ago, lezz01 said:

I knew you would Jamie. 7mm gives you so much more wiggle room than 4mm. If only I had more room....and more money. Oh well it is what it is.

Regards Lez. 

I saw the light and went into a proper scale after buying one 7mm coach kit in the early 90's.  Once bitten there was no turning back.

 

Jamie

[lezz01]

Oh I can quite clearly see the light Jamie. It's just that I can't attain the light. I've had to punch a hole through the bedroom wall and go out of the room over the stairwell and back through the doorway just to get a moderate 00 layout in. I just don't have the room. I couldn't even manage P4 or EM as it's only 7'6" wide. Oh I could do Tewksbury shed in O gauge, but then it's a shed layout and will be way out of budget on loco's at what? £500 a pop for a tender and £375 for a 0-4-4. The cheap RTR one's are a nice little pull but how many 3f tanks do I need? Then there's the motion kits for the ones that it's visible on. I'd never get it past the boss either. I'm trying to get Tewksbury shed and quay branch past her in 4mm as a stand alone exhibition layout, most parts of which I have in stock, and that's a struggle. I have 3 very expensive hobbies and we've just sprung for a new filtration system for the koi pond. No I can only look wistfully on at O gauge mate.

Regards Lez.     

[jamie92208]

I understand Lezz.  We are very lucky having bought a house with a rather large shed in the garden that's big enough to put Green Ayre in.  I wish you luck with Tewksbury and look forward to seeing some pictures. Modelling a real location is very satisfying.

 

Jamie

Edited April 26, 2020 by jamie92208

[jamie92208]

After a couple of weeks dominated by negative scanning and other things, I got back to work on the 4F.  I started to file down the crank webs and having reduced each crank set by over 1mm got the assembly of 2 cranks plus 4 eccentrics down to 17.5mm which will fit between the frames.  I also filed 4mm of the motion plate to make that fit.  Now I need to do some measuring to make up the dummy cylinder block.   I also found that I needed a reamer to make the cranks fit on the axle.   Fortunately a friend about 20 miles away has one of the right size and if lockdown is eased I will be heading that way next week.  In the meantime I will be filing the various cranks and con rods to start to assemble the valve gear.

 

Jamie

[jamie92208]

More shed time achieved this afternoon.  I decided to have a go at drilling a 1mm hole through a con rod big end to take a 14BA bolt.   I managed it without breaking any drills   The bottom of the strap was left at 0.8mm so that I can tap that in due course as I also ordered a 14BA tap set this afternoon.  I Also managed to drill the piston gland and got the piston trial fitted.  I haven't yet measured up to cut the slidebars to length. 

The said big end is on the right with the bolt in place. The eccentrics have been fitted to the axle and below them is the first piston/slidebar set up.  My next task is to got the eccentric traps to fit on the eccentrics.  That will be fun.  However it's coming on.  The offending narrow frames are at the top of the picture, The front two spacers will come off and the centre brake hanger will be cut out in between the frames. 

 

 

Jamie

[Dave Hunt]

Looking good Jamie. Be very careful with the 14BA tap though - they are too easy to break. About a quarter of a turn at a time and then withdraw and clear the swarf. Takes a long time but it avoids nasty pinging noises.

 

Dave 

[lezz01]

Hi Jamie. It's looking very good.

I will just agree with Dave here mate. You do indeed need to be very careful with the 14BA tap they can break if you just look at them funny. It's very much a case of letting the tap cut and not making the tap cut. Use a good quality cutting oil and as soon as you feel it tightening up back it off a few turns and clear the swarf and wind it back in slowly if you have air to clear the swarf I would use it.

Any threading with a tap is not an easy job and the smaller the tap the harder it is.

The problem is that brass isn't a clean metal. It fractures as you cut it and it don't like being cut by steel. To turn it you have to grind a special shaped bit because it will just break the bit if you don't. You can get quick change bits but they are very expensive compared to HSS cutting bit's that you use for steel. You are going to be using a tap of high carbon steel to cut a thread in something that will resist being cut and the way brass resists being tapped is by binding the tap. So a little at a time and keep it as free of swarf as you can as swarf helps it misbehave.

If you've never done this before I would practice with an 8 or 10 BA first or at least buy multiple taper taps.

You also have to make sure the tap is cutting straight right from the start, it won't stand any sideways pressure at all. You can help it to start by putting a chamfer on the hole by twisting a larger drill in the top with your fingers just take the edge off the hole, this will also get rid of any burrs around the edge of the hole and everything you can do to make it easier will help. Good luck!   

Regards Lez.  

    

[jamie92208]

Thanks very much to both of you for the advice. I await delivery of thectap with fearcand trepidation.  One thing in my favour is that i can use thec1mm hole in the upper jaw to line the tap up with the 0.8mm holevin the lower jaw.  I don't have any cutting grease so will have to make do with normal grease till I can get some.  At thevmomentbI only plan to do 2 holes. Most of the pin joints I plan to use lacemakers pins and tissue paper between the faces when I solder.  I plane to make the cylinder block/slidebars/motion plate as one removable block with the eccentric straps, and die block area as another removable block. I just need to work out which joints need to be seperable so will need a few more 14BA nuts and bolts.  If all else fails with the tapping I'll just drill the 0.8mm hole out and use a nut.  All good fun.

 

 

Jamie

[Dave Hunt]

The type of brass is also a factor. The softer it is the worse it is for machining or tapping as it tends to 'grab' the tool. I have just been drilling and tapping some 12BA holes in brass bar and to my dismay found that it was quite soft but since I didn't want to wait until I could get some better stuff I persevered with the result that I broke both a tapping drill and a tap - the first time in ages that the latter has happened. The added complication was that both, of course, broke inside the workpiece meaning that I had to start again. Altogether just machining four pieces of bar to length then drilling and tapping eight holes (the pieces concerned were frame spacers for the bogies of the crane I'm building as I've had to alter the design of the kit so that I can fit suspension) took me the best part of a day's work. I wouldn't even have contemplated trying to drill and tap the stuff 14BA! In retrospect I should have used thicker but harder metal and put up with having to turn it down to size but hey, ho, we all make cockups from time to time don't we? Well, I certainly do.

 

Dave

[jamie92208]

Fortunately the piece that needs tapping is nickel silver. Can anyone enlighten me as to if it will be easier to tap..

 

Ignorant amateur in France.

[MrWolf]

Nickel silver, depending on the compound, is a little more forgiving to work with. However, the advice given above still applies. On brittle materials, plenty of patience and cutting fluid are important. I was taught to make no more than a quarter turn in the cutting direction, then half a turn back to clear the tap. On blind holes especially, a heavy compound or grease, helps to bring the swarf back out of the hole and prevents jamming. In this case you may have to make your cut and wind the tap all the way out. A tedious process, but necessary. Cast iron is about the only metal where you are better off cutting it with a dry drill and tap.

[dibateg]

Yes - 14BA taps very delicate...

 

When I assembled my crank axles, I drilled and pinned them with nickel silver wire - 0.8mm I think. Drilling through the axle is easy, the Slaters axle is very mild. I chemically blackened the outside of the eccentrics and the eccentric straps after making sure they all rotated freely as they have to be on when the cranks are soldered.  To assemble I used solder paste, a hefty flux ( No Nonsense plumbers flux ) and a miniature blow torch. If solder doesn't flow in to all the joints, a little more flux and solder wire should fix it. Once it's cooled down a jolly time is to be had cleaning it up. Then the redundant axle sections can be cut out with a piercing saw. I found the big ends had to be thinned down a little to pass through.

 

 

Hope that helps

Tony

[jamie92208]

Thanks very much for that Tony, much food for thought.

 

Jamie

[lezz01]

Hi Jamie.

You will be fine with nickel silver it's much more compliant than brass. You still have to use caution because of the size of the tap but in metallurgy terms it's a clean metal so it's easier to cut. It produces a swarf tail when turned not chippings a la brass. This means you can use a normal quick change bit, so it won't grab and foul the cutting teeth on the tap. You can also get away with using a lighter oil instead of cutting oil or grease.

All in all it's a huge win that it's not brass. It's at this point that people give up finescale thinking they don't have the skills for it. If you had broken 4 or 5 taps on your first attempt it may have put you off completely.

Regards Lez.     

[jamie92208]

Thanks Lezz. I have got some experience  with taps and fies but in 12" to the foot scale when a group of us restored a horse tram. However that was mainly steel with a bit of xast uron onde sizes from M6 up to 1" BSW.  My main problem will be bei g delicate enough.  I've managed to ream out the eccentric strapscthis afternoon using a chain saw sharpening file. A bit Heath Robinson but it did the job.  

 

Thanks againf for the advice.

 

Jamie

[lezz01]

Yes mate as I thought, you would have the sort of experience that most car and motorbike enthusiasts would have, but that was big boys toys and the big stuff. This, however, is starting into watchmakers territory where things are all a little more fragile and need a more gentle approach and touch. It's much more delicate than the stuff I used to do in the toolroom at Buckingham Electronics. I made and re engineered press tools and injection moulds. My only claim to fame is that I made the last mould used for the old round style blue flashing lights for the emergency services, They went to long light bars after that. It was the second mould I made after I had finished my apprenticeship.  I thought you might like that being an ex copper.

Regards Lez.  

[jamie92208]

You're a proper engineer then Lezz. Havi g been brought up with Meccano,I set off in life to be a chemical engineer but enjoyed myself too much and only did 1 year at Uni. Then one drunken night I ended up joining the Police but always kept an interest in engineering. I did some model engineering  at night school for a couple of years and always had this absorbing hobby.  3 years after retiring I got involved in the horse tram project and after the death of our engineering guru ended up designing and building the running gear from scratch, aleit with much gelp and advice. I then realised why I had wanted to be an engineer. We turned a garden shed back into a working oassenger carrying tram that's now at Crich. It was fun. Now my engineering is back to the small stuff and it's certainly helped me to survive the last 8 weeks with what passes for a form of sanity.  Your help and advice is much appreciated.

 

Jamie