7mm scale Manning Wardle Old Class i: a self-designed 'kit'

[jdb82]

4 minutes ago, Timber said:

Lovely work.   I will be interested to see where the leaf springs attach.  On the original etch it looked like they were to be folded up.  Are you going to do something different now in construction.

 

The model looks lovely - enjoying the read,

 

When I originally designed the etches, I wasn't sure how well the castings would turn out. So to cover both bases I did fold ups on the etch and did castings too so I could choose whichever looked best. I provided 'fill-in' pieces for the gaps left behind from the fold up section, which could be soldered in place and filed/sanded smooth. The bigger pieces were no problem, but as you'll have seen from the photos, the smaller pieces proved very difficult to solder in place and file back so you can't see them. Somebody else probably could! I'm the perfect test builder..... if I can make something look half-decent, anyone can!! Anyway the castings win hands down. On the next iteration of the etches, the fold ups will be removed, meaning it will be easy to solder the castings on. For this version though, I think I'll have to epoxy them on, as I'll unsolder all the filling in pieces, which were done with low melt solder so the splasher and trims didn't fall off.

 

[jdb82]

Alright, my brain has stopped working. I'm currently working on the flared top to the bunker. The flared piece obviously starts off flat on the etch, then is bend around a suitable drill bit to form the curve. The corners are sharp 90 degree corners, and I can't picture in my head the geometry the shape needs to be in the flat, or how to work out how long the top edge needs to be. On my etch, I simpley made a 45 degree angle with a straight diagonal edge. Having come to put it together, it became obvious this isn't right. This is how I did it (wrongly, I think). Flip part 68 upside down - just laid this way on the etch to save space.....

 

Is it just a case of curving the diagonal ends of the pieces with a radius that matches that of the curve? And how can I calculate the length of the longer top edge? Apologies if these are daft questions - I've never done anything with flares before. 

N.B. Parts 66 & 67 need the shape altering a little so they taper down towards the curved end...

 

Below is what I'm aiming for. Photo's below are of Izzy's (Bob's) model, as you can see what I'm talking about better than any other prototype photos I have - Bob, if you have any problem with me posting them here, just give me a shout and I'll take them down :-)  

 

 

 

Any suggestions greatly appreciated. I'm sure it's simple - I think I'm just having a brain fade....

[doilum]

I don't think there is a way to make this a foolproof first time fit component. This is due to the fact that the item has to be curved thus stretching the material.  The way forward, it isn't a solution, is perhaps to be generous in the size of the component and accept that a fair bit of work with the Dremel and some lead loading will be required . It may be possible to etch some grooves into the parts to aid the formation of the curve.

[Izzy]

No prob about the pics, glad they are of use. This blending of the corners is a common challenge with some tenders, early designs mainly, e.g. Johnson exMR, with exGE ones with rounded corners being more so......J15/E4 and so forth.  I've done the odd few ......     An aspect to watch here is the side flares are not symmetrical

 

 

 

 

so IIRC I made the rear bunker flare section to the correct width, measuring the maximum width off the drawing and just starting off with a 45degree slant, then blended the sides into what resulted after bending, bend them down more and 'raise' them into the rear corner joint.

 

You'll appreciate I made the bunker sides & back in single sections rather than as separate items, sides and then flares. As one unit it is easier to form the bend at the top. Personally leave the metal a single thickness, etched grooves introduce distortions that can't normally be hidden rather than a smooth curvature.

 

Hopes this helps, and I'm not teaching egg sucking....what you are doing is first rate... indeed you have prompted me to finish off a second MW that I started with the first one, so just about 30 years later, and ended up being an L class to boot.....

 

Bob

Edited April 3, 2022 by Izzy

[jdb82]

Thank you gents, I was worried that might be an answer...... what I might do, is follow Bob's method initially, shape/fettle it to fit, then take it off, flatten it all out and see what shape I need for the fret. I know it won't be perfect from the etch, but it will at least give a closer starting point. Fingers crossed!

 

Bob, would love to see the MW when it's done :-)

[Izzy]

 

2 hours ago, jdb82 said:

 

Bob, would love to see the MW when it's done :-)

It’s been finished a while now, apart from a crew and toning/weathering, but it’s just to a basic standard. Don’t want to dilute your thread here with it, I’ll see about putting a few shots somewhere. 

[jdb82]

Several strips of brass later, I have something for the bunker flares that I am reasonably happy with and can reproduce on the etch with what should be minimal work after fitting. Looking at the photos, there's a bit more filling of joins with solder and then filing back needed. I thought it looked ok when I did it, albeit in the dodgy light of my spare room, but apparently not so! 

Still, for my first bash at flaring, I'm reasonably pleased. I'm afraid it all needs a good clean up - the poor thing has been sat around for a while.....

 

 

 

 

Edited November 13, 2021 by jdb82

[Dave John]

I'd agree flares are awkward.

 

I think that the ends should be a curve on the flat, but the precise curve depends on how the flare is rounded. As a scratchbuilder I make them oversize and fettle to fit. ( Sometimes several times ! )  My preference when kit building would be that the etch designer makes them a bit on the long side and states in the instructions that they should be adjusted to fit. 

 

Some kit designers have a set of etched fingers to go over the gap. My solution there is to use some very thin copper foil. I have some that is about 3 thou thick which I put over the joint and then solder up. The foil supports the solder and gives it a surface to flow to and seems to reduce the tendency to crack when filing back. 

 

Very nice build so far. 

 

 

[jdb82]

10 hours ago, Dave John said:

I'd agree flares are awkward.

 

I think that the ends should be a curve on the flat, but the precise curve depends on how the flare is rounded.

 

 

 

Agreed - the curve on the end of each of the three parts in the flat, has to match that of the curve once the curve has been formed. On the etch I shall be putting a curve on the ends, but I'll not try to exactly match the curve I ended up with, as I suspect everyone will form them slightly differently, even if only by a fraction. As you rightly point out, most people would want enough metal left to fettle, rather than have big gaps  to fill. 

[jdb82]

And now with beading attached.

Also made a start on a custom gearbox, although I suspect this one will be a bit too rough and ready to work very smoothly. Another learning curve in the process of being ticked…

 

[Izzy]

Are you re-jigging with 1/8” axles and then using the gears out of the HL box? In the past quite a few people used replacement etched side plates with the Portescaps to get different configurations for particular situations. Being mainly plastic and properly designed and made HL’s run nicely and mostly completely silent. 

[Timber]

A while ago I successfully 3D printed a gearbox.  Using top hat bearings.   I found meshing the gears a bit of a challenge but by using 3D I developed something that worked in an agile way.   To be honest I started without bearings.  I simply had the axles running in plastic - it was fine to get something running.  I have seen a couple of examples on line where people have 3D printed gears.....not sure what plastic you would need but once again just to get something running it could be a quick answser.

[jdb82]

4 hours ago, Izzy said:

Are you re-jigging with 1/8” axles and then using the gears out of the HL box? In the past quite a few people used replacement etched side plates with the Portescaps to get different configurations for particular situations. Being mainly plastic and properly designed and made HL’s run nicely and mostly completely silent. 

 

I wasn't going to for this version, as all the cranks & eccentrics for the inside motion etc are all cast for 3/16".  I want to get it running as it is for now, as I have everything ready to go. I can't really justify the extra spend right now to re-do the chassis, castings and wheels. On the next version I'll do a 1/8" axel version and then I'll be able to use the HL box. 

 

29 minutes ago, Timber said:

A while ago I successfully 3D printed a gearbox.  Using top hat bearings.   I found meshing the gears a bit of a challenge but by using 3D I developed something that worked in an agile way.   To be honest I started without bearings.  I simply had the axles running in plastic - it was fine to get something running.  I have seen a couple of examples on line where people have 3D printed gears.....not sure what plastic you would need but once again just to get something running it could be a quick answser.

 

I did think about 3D printing them, and still might try that. I have some metal gears that I ordered from China for next to nothing so I'll see how I get on with them, but a 3D printed box does sound quite appealing, especially if I use some mini roller bearings in there.

[TurboSnail]

I have had a go at 3D printing gears and gearboxes before, but I tend to stick with HL or other ones these days, the issues I had were mainly around printing tolerances and warp. Firstly, the printed parts can drift/warp a little bit, fine for bodywork but even 0.1mm of movement can badly affect a gear mesh. Also, the gears themselves have to be fairly coarse (mod 0.5 or higher) to deal with over/under size printing, which means you don't get a great mesh and the noise and wear aren't great either - and of course you're more limited on the gear ratios you can achieve. It can be made to work, I'm sure, metal gears certainly might help, but needs plenty of experimentation and fettling to run nicely.

[jdb82]

I've boarded out the cab floor now, using 0.5mm oak veneer. Still need to glue it down, probably with superglue. I'm sure it shouldn't have taken anywhere near as long as it did!!

Must get round to cleaning it all up sometime soon - it's all rather grubby....

 

 

[Izzy]

I’d advise against cryno to fix the floor. Given the area covered and the different materials my experiences have lead me to using a flexible type glue like evostick that can absorb differing expansion/contraction rates between them.

[Timber]

this looks great - i am interested in how you fitted the second crew handrail.  Did you use a handrail knob?  Hard to see in the picture. 

[jdb82]

28 minutes ago, Timber said:

this looks great - i am interested in how you fitted the second crew handrail.  Did you use a handrail knob?  Hard to see in the picture. 

 

Yes it's a handrail knob filed to a suitable angle. To be honest, I've taken an educated guess here, as any photos of prototypes I have aren't very clear. The drawing is inconclusive, other than vaguely looking like there's something round-ish on top of this rear handrail, but seemingly flat on the front handrail next to it..... One of the (many) Manning Wardle quirks? Or maybe I've just got it wrong. Wouldn't be the first time 

[doilum]

Looking good. How that the direction of planking is prototypically correct.

[jdb82]

On 21/11/2021 at 13:19, doilum said:

Looking good. How that the direction of planking is prototypically correct.

 

I've never been able to find any photos of the cab interior for this class of loco. When I started the flooring, I was convinced that the last Manning Wardle kit I built (an L class) had the boards running in this direction, but having just looked back though the photo's from my build thread, they actually run in the opposite direction. Poo. I'll get round to cutting some new ones at some point, but after spending 3 evenings cutting them carefully to fit, I think I'll move on to another bit of the loco first! If anyone knows the direction specifically for an Old Class i, then me know before the end of next week 

[doilum]

Sorry to dampen the bonfire! My guess was based on the practicalities of supporting wooden planks on the longitudinal main frames. If the new ones are half as good " they'll do".

[jdb82]

6 hours ago, doilum said:

Sorry to dampen the bonfire! 

 

All good! I'd rather it was spotted now than after I'd stuck'ed down......

[jdb82]

Been a while since my last post - a combination of work, illness, Christmas and a side project have slowed things down. I have added the springs, tank brackets, lubricator warming valve, boiler bands, clack valves and sandboxes, as well as remodelled the tank filler, which I printed. I realised I forgot to cast the sandbox filler caps, so printed these as well. Lots of little bits that weren't really worth a post individually. I'm currently (re)cutting the boards for the cab. Here's the current, rather grubby state of play - I suspect there might not be much further progress over the next few days! 

 

 

 

Have a peaceful, hopefully model-filled Christmas!

John

[jdb82]

Time has been short recently, but I have now finished reboarding the cab floor so the planks now run in the correct direction. These will be numbered and kept aside until after painting, after which they will be stained and weathered.

 

 

[jdb82]

I keep telling myself I should give everything a good scrub and polish before posting photos...one day I will....before painting!

Since my last post, I have added the sandbox levers, draincock reach rods and the reverser reach rod. 

Then, attention was turned towards the cab roof. The straps locate in a half etched recess, inside and out, and the spectacle frames were all soldered on. Having consulted the CAD drawing to work out where to form the bends, I nearly messed things up. Not only do I need a certain distance of roof from back to front, the front and back panels are at different heights. Needless to say, I put the bends in the wrong place. A bit of finger and thumb persuasion later, I managed to persuade it almost into the right place, although the front panel sits a bit too far towards the back of the firebox really, but nobody will know if you don't tell them. The whistle, brackets and stays were then added. 

I'm not going to attach the roof to anything yet - I'll paint it first and worry about that later!