Great Central Railway Class 5A - LNER J63

[Hatfield Shed]

... my concern is that with the wheels being quite small and the gearbox quite substantial that much of the gearbox will be visible when viewed from the side if fitted to the rear axle.

When fitted to the rear axle the gear box/motor is sat like an 'L' if fitted to the middle axle it's sat like this ¬ so the gearbox is less visible when viewed from the side.

Having looked at the photographs I can see the benefit of less visual intrusion of the mechanism, from your choice of gearbox orientation onto the centre axle.

Provided the motor and gearbox assembly can move freely within whatever range the track imposes on the compensation I doubt there will be any problem, since this model is likely going to do its running at low speed. Dynamically, you may see a hint of torque reaction when starting, especially if the motor and gearbox assembly - which does look pretty meaty - comprises about a third of the all up weight of the model. A little more mass in the model would mask that, and more elegant solutions are available, but that's for the small mechanism specialist!

[Robpulham]

I agree,

When I built mine, I used the motor and gears provided in the kit. The motor screws directly to one of the frame spacers designed specifically to take it and isn't visible from the side.
The gent that I am building this one for has provided quite a few upgrades including the ABC motor gearbox which I am now accommodating.

To be fair, his kit may not have contained the motor/gears when he bought it (I don't know if he bought it directly from Garth Patrick or via the second hand market). Many older kits were designed around motor/gearboxes that are no longer available/or desirable so accommodating something different becomes the norm. It's just working out what is the best fit for each kit as you come to it.

[Robpulham]

This is a bit of an addendum to the last post with photos showing where I am at.







A weak area of the kit which to be fair is admitted to in the instructions is the cab roof. It’s half etched and as a result besides being very thin it also has a tendency to curl in the wrong direction for the curve of the cab. I wanted the roof to be removable so I did exactly the same on this one as I did on mine.

After fitting the curved ribs that are supplied, I cut a smaller piece of 10 thou nickel to fit inside between the ribs to add strength and I also added a couple of rain strips from 1mmx1mm brass angle which conveniently hides the holes left by etched slots.



.

There are not many more bits of etch to add before I get to adding the castings and final details.

[Robpulham]

Today I rechecked the motor and gearbox on the centre axle with all the other axles in place. Sadly, it was as I feared, the tight fit of the motor in the boiler area pushed the compensation beam down and left the chassis rocking on the centre axle. So back to plan A fitting it on the rear axle and cutting into/the brake cross beam.

Before doing anything drastic I took time out to knock up some ashpan sides and they have cured the gearbox visibility issue.









That still left the gear touching the brake cross beam so I bit the bullet and cut a section out of it.

[Robpulham]

Over on RMweb Mike Edge (of Judith Edge Kits) kindly pointed out that I had the ashpan sides correct but fitted the wrong way around – slope to the rear instead of the front.

I am very grateful for this because it’s an easy fix (already done) and was a detail that I was struggling to find. The GA I have only show’s an outline for the ashpan and all the photos I have the detail is lost in the gloom.
I had forgotten to take photos of them before fitting so taking them off to swap them around gave me the opportunity to do so.

I measured the space where they were to fit and cut a strip of a sheet of 10thou nickel 30.5mm wide. From this strip I cut two pieces each 17mm long. This left a piece approx. 30mm long and I measured 5mm up from each opposite end and then cut the piece diagonally across.

I wasn't sure that I have described that clearly so I knocked up a sketch in paint.



Once I had all the parts cut out, I placed each bottom edge in my hold and fold approx. 1.5 mm in and gave it as slight bend and then solder them together in handed pairs to give each ashpan side as below.

[Robpulham]

I haven’t had much workbench time in the last couple of weeks or so but when I have I have been slowly working on the chassis of the Class 5A fitting the pickups and getting it to run. The latter being a bit of a trial.

In order to make it so that the motor and pick ups can be removed without having to unsolder anything I made a frame spacer from a spare out of another kit and screwed a piece of Vero board to it







This is where the fun began, despite it running lovely when the motor was connected directly as soon as I added pickups in to the equation the rods started jamming at every turn which in turn forces the compensation beams up and down to one extreme or the other. This caused more than a few mutterings. One thing that I noticed was that in retaining the Dereck Mundy Crankpins at the rear albeit in a modifified form on the centre axle the thick boss was still causing issues by pushing the coupling rods in to an open-ended wedge shape. I had dismantled one side with the plan to carefully extract the crank pins and turn the bossed down on my Unimat SL. Life intervened and I bought a Unimat 3 early last week, so having collected it from Driffield on Tuesday, I did them on that instead.


It now runs much better on the rolling road but I am sure that once I get some weight in it and on a test track it will be fine. The rollers on my rolling road are set a lit far apart and sometimes that introduces a bit of a waddle which doesn’t help when trying to resolve running problems. – Prompted by typing this, I found and added some small washers which have taken out some of the side play on the rollers and running has improved already.

[Robpulham]

While awaiting more building materials I had some time in the workshop over the last couple of days and this has allowed the Class 5A to move much nearer to completion. All the etch parts are now on the body with just the balance weights to fit to complete all the etched parts.
From there I moved onto the castings, at the beginning Brian and I discussed the castings and since they were pretty poor (certainly when compared to the castings that came with my kit a few years earlier) and we replaced as much as we could but retained the Chimney, dome and Smokebox door. The dome and the smokebox door did clean up and don’t look too bad now but the Chimney when I examined it closely had some holes in the flare at the base. I filled them with lowmelt and reshaped the flare. This means that I will have to use epoxy to stick it on as I don’t want to risk any heat undoing the work on the flare.





The castings after clean up



Cab interior details









The Safety valves are from Laurie Griffin and they too had a prominent mould line across the top which required a bit of works to remove but still infinitely better than the reject whitemetal offering. I understand that this kit is now with Iain Young of Sans Pariel/CSP and that he intends to remaster all the castings. The kit will benefit greatly from that, I think.

[Robpulham]

Amongst the castings in the kit were what I originally thought were a couple of Ross Pop safety valves but it turns out that they were in fact the lids for the sand boxes either way they were not great.

What a great opportunity to make something meaningful with the new lathe, thinks I.

So, I turned up a pair of sandbox lids





Finally, one with the obligatory 5p piece for scale



I have to confess that these were my second attempt. The first pair were okay but I hadn’t quite worked out how to make the two identical so there were some slight discrepancies in size – probably not really noticeable at this small size but I knew I could do better so I did.

After making the first two sandbox fillers I turned (if you will pardon the pun) my attentions to the oilers. While buying other castings I had bought some oilers for the side of the smoke box and a set for the footplate. Having examined the ones on the footplate more closely in the photos I realised that the castings would be correct so I turned up a pair of those too. They were very similar to make, aside from I drilled these 0.8mm to take a piece of nickel rod to mount them.

I could have left a turned stem on the oilers but I need to be able to bend it so I reasoned that rod would be better for bending as I thought a turned stem would be likely to break off.



And again, with the 5p piece


The collets and chuck were invaluable and this type of thing really satisfies my urge to make things…

[Robpulham]

A couple of sessions this weekend, have seen most of the brass castings and the backhead finished and secured in place.
Prior to doing that I had to make a cab floor or rather the front section of the cab floor because my replacement backhead fell through the section that’s not provided in the kit when I tried it in place.



I added a couple of 2mm wide strips to the edges of the cab splashers and then soldered the additional cab floor to that which brought it to the same height as the rest of the cab floor.

After making the floor it gave me another option to secure the backhead so I made the back head and the cab gauges removable to ease the job of painting.





I folded a small piece of 10thou nickel into a U shape with a short leg to the front and drilled a hole for a 10ba nut. The idea of the U shape is to add a bit more strength to what is relatively thin sheet.







I added a short length of tube in the corner of the cab front and splasher and the tail of the pipe from the gauge locates into it with the back of the dial fitting over the peg where the vacuum ejector pipe enters the cab. Not strictly prototypical I am sure but it means that after painting a small dab of glue will secure it in place.

A few general shots of the smokebox details which is where most of it seems to be on this loco.



The clack valve is one of Jim McGeown’s from his most useful sprue of Clack and elbow castings as is the vacuum ejector elbow on the other side.
The lubricators on the smokebox are Laurie griffin and the small pipe and fitting is scratch built from tube, rod and scrap etch.





The rather nice turned whistle came with the kit and is without doubt the best fitting supplied.

Still to fit are vacuum pipes and the whitemetal fittings – buffers, dome and chimney, then balance weights and some lead in the side tanks before track testing.
The end is most definitely in sight.

[Robpulham]

I had some milliput out for making some modifications to some axlebox ready to make some castings of them. I needed a miniscule amount so it seemed a shame to waste the reast of what I mixed so I filled the back of the balance weights for the Class 5a.

They still need a little tidying up but they do look a bit better than just an etched skin.



When I did my J63 I had some etched washers that were just the right size to make the front windows into opening ones by sticking them either side of soe glazing material and wrapping a strip of brass around them.
I wondered if I was able to turn a couple with a proper recess rather than a wrap-around overlay, now that I have a little more confidence with the lathe. I ordered a 3.5mm boring tool and when it arrived, I thought I would have a go.
I cut a length of brass rod and turned a section of it down to the required width and then drilled progressively bigger holes in the end until I reached 5mm in diameter. Then I tried the boring tool ad had a gotcha moment. The tool might be 3.5mm wide but it’s also 3.5mm deep and it wouldn’t fit when trying to centre it in the hole for cutting…. In order to get the tool in I would need a bigger hole than I wanted.
,I scratched my head for a bit and then had a rummage thought the box of tools that came with the lathe. One of them had been ground with boring holes in mind but the corner of the cutting edge was chipped so while it would cut, I didn’t get a square edge to the bottom of the hole.
It was at this point that I remembered that I had bought a mini bench grinder from Lidl about 3 years ago and it was sat on a shelf under my bench.
Out it came and I had my first go at grinding a cutting tool for the lathe. Light touches soon restored the missing bit of tip and I now see what Ian meant when he said a sharp tool makes a lot of difference to how it cuts.
While I had it on the bench, I reground a couple more tools that had dings out of the edges too.



And one with the obligatory 5p for scale.

[Robpulham]

The build slowed down a little when I realised that the chimney casting had the flare cast lopsided. This meant that when you had the chimney sat on vertically on the smokebox there was more flare at one side than the other. I tried to reshape it with bars rolling it over a former the same size as the smokebox but I couldn’t improve it much.
After some discussion with Brian, I emailed Laurie Griffin and Andy Beaton to ask them if they had anything suitable in their ranges that might do (as long as it looked right it wouldn’t matter which loco it was originally designed to fit). Sadly the nearest we got to was an LNER standard chimney from Laurie.
The next step was to ask fellow Guild member Mike Hopkins who has been posting some excellent stuff on the Guild forum where he has been designing in 3D then printing waxes and having them cast in brass.
I supplied Mike with a drawing a couple of days ago and he went away to draw it up.

Below are some photos of the wax prints prior to removing the supports and sending them away for castings. Photo’s copyright of Mike and posted with his kind permission.

[Robpulham]

The final part of the build while awaiting the chimney casting was how to fit the cab windows.
I drilled each one top and bottom and added a pivot pin.





After thinking about bits of tube etc. I realised that I could add some bottom ‘hinges’ in the form of pipe type bracket and do the same at the top but only solder one tab so that the bracket could be eased back to make the window unit removable for painting.




A few shots as she stands awaiting her chimney. I also added lead to the side tanks and as I suspected she now runs quite smoothly on the rolling road. I will continue to run in while awaiting the chimney and when the weather improves, I will dig my test track out of the shed and test run around curves.

[Dave]

As usual Rob a great model, I do like the opening cab windows................4mm, I wonder, but mabe a window too far .

[Robpulham]

As usual Rob a great model, I do like the opening cab windows................4mm, I wonder, but mabe a window too far .

Go on, you know you want to....

You would have a better chance of getting some washers that would suit the window frame rather than having to turn fittings.

I had some etched ones in stock that were just the right size when I built my J63. I now wish that I had made them move but since I may be changing the chimney I may well do that at the same time.

[Robpulham]

I had a long morning finishing of some fencing at the back of the house yesterday so modelling took a back seat. I did however manage to do some test running of the Class 5A on my rather rough and ready test track which it passed with flying colours.

I took a video of the slow running. It's only just over a minute don't fall asleep.

https://youtu.be/5qOrTJtpFdo