Brassmasters Blk5 45284

Dave Holt
Posts: 101
Joined: Thu May 28, 2009 9:44 pm

Brassmasters Blk5 45284

Postby Dave Holt » Fri Aug 30, 2019 7:35 pm

I've put the Ivatt Class 2 tank to one side whilst I figure out how best to deal with the Bachmann body - the question being whether to do major surgery to replace the boiler with a spare DJH cast white metal unit or stick with the moulded plastic version. Suggestions on a post card......

Instead, I've decided to progress a Brassmasters Black 5 which I started some years ago and got as far as having the frames assembled (and painted in way of the driving and coupled wheels) with the axleboxes in, ready to be wheeled. The loco selected is one of the Armstrong Whitworth long firebox type. The running number chosen has been changed recently to one allocated to Newton Heath in the mid 1950's. Unfortunately, I haven't managed to find any published photos of this particular loco at that time so I'm making some guesses and assumptions about some of the details and changes that might have occurred since its original construction. I've assumed that the wheel sets would have been exchanged to provide a solid centre axle in place of the original hollow version which appears to have been the case on most locos from this batch for which I have photos. The axle holes don't go right through, just 5 or 6 mm in from each end. The friend who drilled them feared snapping a drill (1.1 mm dia) if he tried go go right through.

Recent activity has been to fettle the Gibson wheels (previously drilled for the crank pins), fit the crank pins and, today, to fit the wheel sets to the frames, as shown below. The wheels are clearly from two different batches, as indicated by the colour of the centre moulding. As I recall, I discovered a poorly machined flange on one wheel which was replaced without any quibble.

I note there has been some discussion about crank pin fitting and retention on my 9F thread. This loco follows my normal practice of modified Ultrascale bushes mounted on 14 BA cheese head screws. The heads are recessed into the back of the wheel and the centre ones are both treated to application of locking fluid and fitting brass wire staples set into the screw driver slot and holes either side of the screw head. To obtain adequate side play, the rear bosses on the centre wheels were filed almost flush with the rear of the spokes.

BM_Blk5_45284_001.JPG


The kit instructions suggest completion of the brake gear next, together with sand pipes to front and centre axles, then pick-ups. Sounds like a plan.

There won't be any progress tomorrow as I've decided to go to the O Gauge show at Telford. No, I'm not contemplating a change of scale, but I really like some of the stuff that appears on RMweb and Western Thunder, so I thought I'd go to see some of it in the flesh, so to speak.

Dave.

davebradwell
Posts: 69
Joined: Fri Jan 18, 2019 3:48 pm

Re: Brassmasters Blk5 45284

Postby davebradwell » Fri Aug 30, 2019 8:26 pm

Dave, have you compared the diameters of the original and replacement wheels? The prototype had a tight spec. on this as any significant difference meant the loco was trying to tear itself apart with one bit attempting to go faster than another. I'm not sure what the limit should be as just dividing down the full size tolerance would give a terrifying answer but knowing what the difference is would at least lead to consideration of the matter.

It's going to be another winner, anyway and I'll watch the build with interest.

DaveB

Dave Holt
Posts: 101
Joined: Thu May 28, 2009 9:44 pm

Re: Brassmasters Blk5 45284

Postby Dave Holt » Sat Aug 31, 2019 8:46 pm

Dave,
I hadn't really given any thought at all to the question of diameters of different batches, just assumed all the tyres are machined to the same tolerance, whatever the batch. I'm not familiar with the production process, but can one assume that tyres and moulded centres are made in batches together and then assembled or are the two parts made as required and randomly assembled from different batches?
In any case, the tread diameter isn't that easy to measure accurately, due to the coning and the flange to tread radius.
Prompted by your comment, I've tried to measure the wheel diameters and find a difference of 0.02 mm between the odd pair and one of the originals. The two black centred wheels are 0.01 mm different in diameter.
It remains to be seen if the loco tears itself apart whilst running.
Dave.

davebradwell
Posts: 69
Joined: Fri Jan 18, 2019 3:48 pm

Re: Brassmasters Blk5 45284

Postby davebradwell » Sun Sep 01, 2019 8:54 am

That seems very good - I was just raising the point as I once had significant differences in days gone by and they were very easy to measure. Just something to be aware of, really. Perhaps this is one less issue to worry about in future, although worth bearing in mind when digging out some old stock that's been lurking in a dark corner waiting for its day to come. I've heard of unco-operative wagons later found to have different size wheels each end of the axle but that's an entirely different matter.

DaveB

Dave Holt
Posts: 101
Joined: Thu May 28, 2009 9:44 pm

Re: Brassmasters Blk5 45284

Postby Dave Holt » Mon Sep 02, 2019 9:04 pm

Phew! Very near to a complete disaster today but I think I've just about got away with it.
Spent some time finishing off the brake gear by fitting the cross beams, pull rods and crank and securing the brake hangers, which had been left loose in their mountings to the frames. All appeared to have gone well so I moved on to the balance weight plates on the wheels. I then noticed that, somehow, I had partly melted the front face of a couple of the spokes on the RHS centre driving wheels. I must have caught them with the soldering iron whilst concentrating on the brake hanger fixing.
After an initial surge of despair, I found that the worst of the damage would be covered by the balance weight and there doesn't appear to be any detrimental effect on the wheel itself. There is some slight visible deformation of the spokes inboard of the balance weight but I have tried to build up the surface with layers of super glue (a technique used by aircraft modellers, I believe) and once this is fully cured, I will dress the spokes as best I can to hide the damage.
Note to self; be more aware where the hot iron beyond the tip is relative to the model!
Slightly out of focus view of the damaged wheel, after fitting the balance weight. The melted spokes are third and fourth down from the top edge of the balance weight.
BM_Blk5_45284_003.JPG

Overall view of the chassis showing the brake gear and balance weights fitted.
BM_Blk5_45284_002.JPG

Dave.

Knuckles
Posts: 1189
Joined: Fri Nov 18, 2011 9:15 pm

Re: Brassmasters Blk5 45284

Postby Knuckles » Tue Sep 03, 2019 9:18 am

Just read the whole thread. One to watch as I'll need a black 5 sorting out, either a Hornby conversion or a fresh build.

Needs to go round horrable curves though so can see it needing some abuse!
“He who dares not offend cannot be honest.” Thomas Paine

http://www.shapeways.com/shops/sparksho ... eationsscc
Mostly offering Loco kits & bits in 4mm.
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Dave Holt
Posts: 101
Joined: Thu May 28, 2009 9:44 pm

Re: Brassmasters Blk5 45284

Postby Dave Holt » Sun Sep 08, 2019 9:10 pm

Generally speaking, I do a lot of planning and scheming to work out when and how to fit various components during loco construction. For parts provided in the kit, I find the instructions are usually a pretty good guide although some deviations might seem appropriate here and there. For additional details, not included in the kit, a bit more thought is needed. This approach has stood me in good stead, overall, but I have come a bit of a cropper on this chassis.
For my own satisfaction, I decided to fit the whole length of the supply pipe to the exhaust steam injector, including a representation of the grease separator, even though a lot of it will not be visible from normal viewing angles. As it is chunky and stiff (1.6 mm diameter), I thought it best to fit it before trying to route pick-ups, which can be bent as necessary to avoid it. The Pipe & Rod drawings in the Wild Swan Profile books were studied and the pipe run set out, model size, on paper against which the pipe could be assembled. The line sketches are shown in one of the photos.
The pipe is formed from various diameters of brass wire and tube and arranged to plug into the inlet end of the cast white metal injector body provided in the kit.
The resultant pipe looked a rather good representation of the real thing and matched the sketches well in shape and dimensions. I must admit to feeling rather pleased with myself.
Oh, but pride comes before the fall! No matter how I wiggled and twisted the pipe, I could not get it to fit past various existing parts of the chassis. I contemplated splitting the pie into sections and then re-joining them in situ, but eventually, it dawned that if I removed the rear brake stretcher bar, it could be slide in from the rear, located through the hole on a front frame spacer and then eased into position. Luckily, the brake stretcher came off without too much trouble and was easily re-fitted after the pipe was in position.
The injector and a couple of wires representing the live steam feed and part of the water feed have been added, to give a bit more strength to the rather exposed injector casting.
View showing the line sketch used to make the pipe.
BM_Blk5_45284_009.JPG

Various views of the chassis with the pipe and injector in place.
BM_Blk5_45284_004.JPG

BM_Blk5_45284_005.JPG

BM_Blk5_45284_006.JPG

BM_Blk5_45284_007.JPG

BM_Blk5_45284_008.JPG

And one (slightly blurred) showing the feed pipes added.
BM_Blk5_45284_010.JPG


Dave.


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