Steve Beattie kit NBL Class 21 build

It is quite risky to bring heat close to the "thinner" white metal casts ... I suspect they are a lower melt quality than the casts that came with the Scorpio BR Standard 4, so I'm not risking that. I think I will Araldite the casting in place and then filler any gaps with two pack Cuprinol Woodfil and then stopper with Green Putty. Right now the blunt nose is only loosely located on the cab front for show.

 

Well thank you chaps... I didn't even know I'd made POTW until I saw this thread had been bumped up again.

 

Hi Bob,

I'm always happy to oblige and will certainly chip in on your workshop thread as invited, now my 24 build is waiting etch parts because I'm doing the early version with the side fairing fitted... these were removed under a modification when they went into Rail Blue and had their boilers isolated, so my advice is choose which era you are doing... also the 24 buffer beam is on the fairings etch, the other buffer beam is a 25 one which can be altered to suit. I've very interested to see how you do the 24/1 cab indicator box as I'd like to do the same as you and LED it. I've got a 25/1 kit in the que and will also be buying a 24/1 soon, so this mod would be very helpful too.

Paul

 

Thanks Ian for that and so glad you are liking the 21 thread too... it makes a nice loco.

 

The gear kit from Roxey Mouldings arrived this morning, I went for the 20:1 ratio and will fit the floating motor mount which the 21 kit requires, so once installed it will go like a train... oh sorry of course it is a train.

 

Very very nice Bob, I completely understand.

 

Thanks Pete, my thoughts too about sharing experiences and info and the such.

 

This last few days I switched attention to the bogie assembly principally because I'm reaching a stage with the body build where I need some wheels underneath so as to plan how everything at the drawbar end will fit nicely. Whilst on the topic of drawbars four pairs of lost wax drawbar kits arrived from Laurie Lynch at MM1 Models, these are a reissued ex JLTRT product line which to me are very much better than other makes I've used before. Anyway I had wanted to wait until I'd completed this bogie and then do the write up of "how I did it" on the second one which I'll still do, because it can be a bit tricky in places as there is a component pecking order in the construction stages which follows a logical course. So now having said that I'll jump forward a bit after constructing the main bogie etches and explain a modification or more like an addition I made. I wanted to fit a Delrin drive system and the kit that Roxey Mouldings supplied me didn't allow for the chain to pass over the bolster stretcher, a solution of cutting a slot into what is an integral part of the bogie fabrication would seriously weaken the assembly, so I decided to make a tiny carrier frame with working roller to lift the Delrin chain up over the stretcher instead, this worked clearing the stretcher nicely with a couple of millimeters to spare and also allowing for chain sag when changing direction.

And with the chain loosely places over the cogs for alignment.

At this stage the gear drive hasn't been located in the gearbox because I'm only interested in making everything line up and run smoothly, which it did because I proved the level and bogie balance by using my marble flat stone to correct slight wobble. So with Delrin attached now I finger pushed the bogie around Elton Crossing to ensure it would pass over then points ... and here we are standing on the level crossing.

 

So now I was happy and in went the gear cog, now at this point I'd made another little modification in how the floating motor mount and gearbox is positioned, because this bogie relies on axle extensions there is a slight risk the gear drive could become temporarily disconnected due to the lateral travel of the wheelsets. On other frame builds this would not happen because any "slop" could be taken up with packing washers between the axle bush and inner face of the wheel, as the Class 21 bogie doesn't have an inner frame it was necessary to allow the motor mount to slide laterally with the wheel.

Using the inside channel profile of the bogie stretcher I added a small extension "shoe" to the motor mount which could slide along the stretcher as if in a guide.

Finally I soldered the inner end etches to complete the base part of the bogie, yes the North British build diesels had spoke wheels and the Class 21 had 11 spoke 3' 7" diameter wheels.

And here we can see that little roller carrying the Delrin up over the stretcher clearing the edges nicely.