Nile's Mostly Freelance Bodging Bench - Pre-Grouping Locos

[Nile]

That makes sense Pete. My next cunning plan is to do away with the UJ completely. As to why it is there is a bit of a mystery. One possible reason is to simplify assembly, as the motor can be just pushed into place in its holder. It does seem a bit over engineered.

[Nile]

And now for plan B, to eliminate the universal joint altogether and connect the motor directly to the gears.

At the top of the gear tower is a worm gear mounted on a short drive shaft.

All I needed to do was remove the shaft and mount the worm onto the shaft of a motor. Problem is that shaft is 2mm, all my motors have 1.5mm shafts. The answer is to use more of the brass tube I used before. But measuring with callipers I found that the worm shaft was 1.98mm and the outside of the brass tube was 2.08mm.  I 'turned down' the tube to the correct diameter using a mini-drill and files. This is a test fit of the worm.

 

The motor could now be mounted much closer to the gears, so close that I had to put some black insulation tape on the chassis block to prevent the lower terminal of the motor making contact. I modified the bracket to work the other way round and added a flywheel in the extra space.

This arrangement runs well, maybe a bit noisier than the original. It still needs to be run in.

This is the view from the outside now.

Plenty of daylight under the boiler. The flywheel is just visible, black paint will fix that.

 

Coming next, I'll add the underside of the boiler.

[NHY 581]

As usual, great modelling. However totally unnecessary had the design been better in the first place.

 

Expect a call from Oxford designers wanting to modify the future batches.

 

Rob.

[PenrithBeacon]

As usual, great modelling. However totally unnecessary had the design been better in the first place.

 

Expect a call from Oxford designers wanting to modify the future batches.

 

Rob.

I agree about the modelling but I would doubt if any future batches will be modified, it'll just be too expensive. You might just find that any future models won't have this feature though, and I don't understand at all why it wasn't designed out on the 'drawing board' on this model. The universal joint is a surplus item and engineers don't usually like this because surplus items increase costs.

 

Regards

[Pete Harvey]

I think the reason for the UJ is so that the Chinese designers could fit a cheaper basic inferior motor making the manufacturing cost less so that Oxford Rail can make more profit per model there is no other reason for the UJ to of been fitted.

[PenrithBeacon]

I think the reason for the UJ is so that the Chinese designers could fit a cheaper basic inferior motor making the manufacturing cost less so that Oxford Rail can make more profit per model there is no other reason for the UJ to of been fitted.

Thanks for that. The problem of course is that British modellers expect the space under the boiler to be free and Oxford must surely know this. Why did they therefore sign-off on this feature? Inexperience perhaps, or the bottom line? The way the new SLW Class 24 is selling I suspect anxieties about the retail price will matter less in future.

 

Regards

[Dr Gerbil-Fritters]

Come along Nile, there's a good chap....

 

 

you know you want to!

[Nile]

Is that meant to be a 380 class? A few survived until the grouping. I'm wondering if the Hornby model would be a better candidate as there is a potential problem with this one. I'll post details tomorrow as I need to take another photo of it.

[Dr Gerbil-Fritters]

It's similar to the 380, although I hadn't realised.  It was intended as a fairly do-able pastiche of the M&GNJR A class rebuild.

 

 

from the LNER Encyclopedia.

 

It doesn't accurately portray either, but looks quite nice and in the spirit of your freelance pre-grouping locomotives.

[Nile]

I've recently bought a book on MGN locos, I must around to looking at it over christmas.

The potential problem with this model is the way its boiler is fixed to the footplate. This photo should explain it.

The column into which the screw goes is neatly hidden on the model by the side tank.

But any conversion that involves shortening or removing that tank will expose the column. Does this mean Oxford won't be doing any of the locos with short tanks? There is also that square hole that doesn't seem to be doing anything.

[Nile]

With the motor out of the way there is now a hole in the bottom of the boiler that needs to be filled.

First I made a base and support from some 30thou plastic card.

 

I wrapped some 10thou plastic card around a bit of brass tube (slightly smaller than the boiler) and put it in some boiling water. After it had cooled I made the boiler bottom using two layers of the 10thou plastic and glued it all together (with MEK).

 

The view when re-assembled.

 

And after painting the new bits and flywheel black.

 

The top of the chassis block is now clearly visible.

Room for some valve gear maybe?

There is now room in the front of the boiler for more weight, or something else.

[ExPatBrit]

That makes sense Pete. My next cunning plan is to do away with the UJ completely. As to why it is there is a bit of a mystery. One possible reason is to simplify assembly, as the motor can be just pushed into place in its holder. It does seem a bit over engineered.

I think it's there to allow for any misalignment of the motor "tower" with the rear "tower". The alignment of both is dependant on the straightness, or otherwise of the chassis block. You couldn't just hang the flywheel and gear on the unsupported motor shaft, that would give you pot luck gear engagement and mucho vibration, that brass worm would be toast in no time flat. Alternatively if you aimed for a 1.5-2.0 mm motor shaft fitting in a bearing, any deviation from other than a perfect chassis and perfect "towers" would lock everything solid, assuming it would even go together.

Edited to add: The square hole is likely a location key for one or more parts of the production process, eg: locates the boiler square and parallel for drilling and tapping the screw holes, or ensures registration between one lining out op with another, etc., etc.

Edited December 14, 2015 by ExPatBrit

[Nile]

The observant among you will have noticed that I didn't continue the boiler band lining onto the new underside. As I have no use for a BR liveried Radial, this loco will be getting a repaint. After the Great War most of these locos were surplus to the LSWR. Some were acquired by the LMWR to fill shortage.

I stripped the loco down again, this time removing as much from the boiler as I could. This allowed me to file down the mould lines from the sides, as well as the unwanted bits from the smokebox door.

 

Being in bits also make repainting easier.

[WD0-6-0]

I was hoping you'd do this, it will look superb

[LNWR lives on]

The only thing I can think of as to the use of the UJ is that they wanted the small amount of movement it offers, or they decided they wanted to mount the motor and to drive off of that wheel required a long shaft, so they did it with a UJ than a rigid shaft

 

The rebuild is looking superb

[xveitch]

Would this rebuild be possible with the original motor/flywheel setup and just removing the UJ? 

The new space under the boiler really makes a visual difference to the model. It looks like Oxford Rail have missed a trick, especially as it looks like the Hornby version has been carefully designed to not intrude into that space. 

Can't wait to see what you do next 

[Nile]

Maybe. This is the business end of the motor.

There is only 2mm of shaft projecting, not a lot to work with. Alignment will have to be very good to avoid vibrations. I have another model to play with (later), so I'll see if it's possible.

 

Meanwhile the repaint of this one is finished.

[DLT]

Fabulous Job!

Dave.

[Izzy]

Hi Nile,

 

Great modelling as usual, you make it appear so simple too.......

 

Like others I am also puzzled with the drive arrangement. Given that a single U/J joint like this can't offset shaft mis-alignment as the double joint arrangement usually found in diesels can, (probably why you got vibration when you adapted it with the new motor if the tube/sleeve was even very slightly out of true), the idea that it's for easy production/allows for manufacturing tolerances/gives good performance doesn't really seem to add up. Weird. As it happens you seem to have found a much better arrangement and it will be interesting to see what the Hornby version finally arrives with and it's boiler design and performance. Perhaps some production experience in these areas does matter at times.

 

Wouldn't like to say that the good reception that the SLW 24 has received means prices overall can rise even further than they have already. From what I have heard the current ones are already causing many to re-evaluate what they can afford, irrespective of the quality of the models, and good design isn't always dependent on production costs anyway.

 

cheers,

 

Izzy

[DCB]

It looks to me like Oxford have gone for long term reliability with a high quality open frame motor which appears to have replaceable brushes and an almost indefinite life span rather than a cheap and very nasty can with no serviceable parts which I have a pile of from dead computers and a pile of dead ones from a certain manufacturer of 00 scale locos.

 

Can't the Oxford motor mount be slimmed down to improve the appearance while keeping the same motor.  The flywheel / UJ set up takes all the end loadings off the motor bearings rather like the old Airfic14XX chassis and those motors ran for ever ( sadly far longer than the chassis and pickups did)  All in all it looks like Oxford have done a superb job in making a loco which will stay on the track and still be working in 40 years time, long after the Hornby versions have been consigned to the scrap box or back of the loco shed.   Maybe Kernow should have a careful look to see how it osdone.

Edited February 26, 2016 by DavidCBroad

[Nile]

You're right about the motor, you can change the brushes if you can find replacements. I have another Radilal to look at, but that will have to wait until there is more space on my bench.

Something that didn't take up much space was this porter loco from Minitrains.

I wasn't keen on this model when it first appeared about a year ago, I thought it looked a bit too cute and toy like. But someone else had improved its looks by replacing the cab and adding a tender. I thought I would try something similar.

The small bunker at the back had to go. I simply cut it off from the cab floor.

 

I had a small tender left over from a previous Minitrains conversion, so I tried it for size.

I thought that will do.

Before I went any further I wanted fix a potential problem. The motor was leaning over at an angle. Although it was running just fine it looked odd, so I added a washer under one side around the mounting screw.

 

It now sits nice and straight.

 

The tender needed a little work. Its chassis is actually a bogie with a central pivot. This results in the body not sitting level, you can see that in the photo above. To fix that I added some strips of plastic to the underside and filed down the pivot slightly.

 

The chassis sits on these strips and stays level.

 

The result.

 

A bit of Nickel Silver rod was super-glued to the underside. This locates into the existing hole in the loco chassis.

 

The finished model, for now.

It needs a repaint, that can wait until after some test running.

[Nile]

This bench has been a bit quiet recently, my limited modelling time has been concentrated on kit building. But with Narrow Gauge South West rapidly approaching (20th Feb @ Shepton Mallet) I thought I'd do something to take there.

I have a few of the new Minitrains Baldwin 2-6-2T locos that I intend to use on an American line, they will represent the Davenport built locos that never made it to France for WW1. Here are the two types, with original semi-open cab and a later enclosed cab.

 

My cunning plan is to convert one to a tender loco using 3D printed parts from my range. Here is a rough mock up.

 

The tender is the one for the 2-8-0 conversion that I happen to have spare. I added some weight in the form of lead strips that fitted into spaces in the sides.

 

The lack of a chassis was solved with this sophisticated piece of engineering, two pieces of wood that when glued inside put the tender at the right ride height.

 

After thinking about making a drawbar to link the loco and tender I opted for the much simpler method of using the existing coupling on the rear pony truck. I just needed to fill the gap at the front of the tender with some black plastic card.

Another strip of plastic behind this gives the coupling something to push against when reversing.

Here the chassis has been glued in place.

 

[Nile]

Adding a tender makes the side tanks rather redundant. However those tanks added useful adhesive weight to the loco and removing them would reduce the pulling power of the loco, as the Sumpter Valley found with its ex-Uintah Railway Mallets. I've added lead to the tanks of one of mine, which improved traction slightly and moved the centre of gravity nearer to the middle of the loco. On this loco I'm going to retain the lower part of the tanks and fill them with lead, the crew should still be able to walk over the top of it.

Here it is with the top part of the tank removed. The pillars will be cut off.

 

There is just enough room for two strips of lead.

 

The tops and sides were made up from plastic card. At the rear I've added supports for the cab, they raise its height so it clears the front of the tender allowing close coupling. This also incorporates walkways between the cab and ex-tanks.

 

The cut down tanks would need extra supports to stop them falling off the loco. For these I've used plastic L beams glued to the undersides of the tanks across the loco. They are difficult to see one fitted, so here is a photo of them before.

 

Finally for now I've added some handrails using Gibson medium knobs.

[Nile]

To make it compatible with my American ng stock I'm fitting it with Microtrains 1015 couplers. A small amount needs to be cut from the front for this.

 

The coupler was stuck in place with superglue gel. Because its plastic tends to be a bit slippery I've glued a bit of plastic behind it to take the force when pushing, rather than rely on the superglue.

 

The gaps either side were filled with more plastic card and a footboard added along the bottom.

 

The 'thick' running boards along the boiler means there is no room for air tanks there, so I've put one on the tender. It's made from some plastic tube with plastic card ends.

 

To feed this tank I'm using one of my printed air-pumps, with the pipes made up from 0.5mm brass rod.

 

Here is a test fit before it's painted.

[Nile]

Here it is now painted and glued in place.

I'd also painted the smokebox and chimney silver, then rubbed a bit of graphite on. It probably needs toning down a bit more.

That hole I've drilled into the boiler is for another addition, a bell, also printed.

It's offset to one side because there isn't enough room between the domes.The whistle has been refitted, having been painted with brass paint.

 

This rear view of the whole model shows some additions to the tender.

There is a line of decal rivets near the top, and some pipes for the air tank.

 

This is the almost finished model.

There are some finer details I'd rather leave till later, and I wont add glazing until after the transfers and varnish. The cab isn't glued in place, it's front is sort of wedged in place between the boiler and motor.

Edited February 19, 2016 by Nile