jdb82

Yeah, I realised about the O gauge axels.....once I'd bought one! I'd got a Hump Shunter, as I am mounting the motor vertically in the firebox. It's about the right size, so I'm looking into if it's possible to modify the HighLevel box, or whether I just make my own from scratch.

Lovely running! Out of interest, what gearbox did you use?

Over the last couple of weeks, I've been constructing the buffer beams - the front plate of which is described in my previous post - a 2mm hardwood strip has since been sandwiched in between the buffer beam plates and the buffer beam supports and soldered on to the running plate, along with the valances (I'm sure I shouldn't have found this as fiddly as I did!!). I have removed the parts for the inside motion from the sprues (apart from the balance weights which I have just noticed I've forgotten about and left on the sprue) and given them a good polish up with various grades of grit paper. I still need to drill out a a couple of holes, and polish a couple of parts further, but otherwise they are ready for fitting the the chassis. Don't expect that to be a quick process!! I'm likely to get side-tracked by the 'easier' bodywork...... When you put the chassis next to all the parts, it looks like it might be a bit of a squeeze. I have faith in my trusty CAD work though - it should all fit!

Not had too much time to spend on this recently, but whilst I pluck up the courage to start on the inside motion, I made a start on a couple of bits of body work. I finished the splashers off, filled in the gaps left behind by the fold up springs (not using these, and will eventually remove them from the CAD work) although looking at the photos a couple of areas need some further attention...... The eagled-eyed amongst you will also notice I had to move the holes for the fixing nuts at the rear of the running plate out a bit, as I'd got these a little too narrow on the original CAD drawing. Add it to the growing snagging list! Next up was the front buffer beam. Looking at photos, most i-class prototypes seem to have a thick-ish layer of hardwood sandwiched between a front and rear layer of steel. I plan on doing the same, but here's the front layer with the coupling chain bracket and the buffer bodies attached. The buffers themselves are a self-contained sprung buffer - the hole in the side of the body is for a retaining wire that will hold the shank of the buffer head in place that will be soldered in and filed smooth at a later date.

I used Jewellery Casting Scotland. Excellent service - almost always turned around in a week, and good quality each time I've used them :-)

Looks great! Really love how you are going about this :-)

That's a novelty......according to my wife I'm not right very often.

Must admit that on the drawing I worked from it looked as though it sat just above the chassis, but it was close - difficult to tell accurately. It should look OK I think.

In between an unexpected week in the Lake District, and various bits of DIY directed by Mrs B, I have managed to get a free-rolling chassis without incident. There were a few other small details that I’d have liked to have added to the frames before putting them together (like the guard irons, frame supports and spring balance arms), but the jig I use means I need a flat surface to butt the frame up to. So next, I prepared the frame spacers, cut out the space for the horn guides, and opened out the bearing holes before using the jig the align everything. Having set up the jig using the coupling rods to establish the wheel bases, the spacers, motion bracket, ash pan and cylinder chest were soldered between the frames. I then added the front and rear guard irons, spring balance rocker arms, frame supports, blowdown valves and bearings for the fixed axels and horn guides for the centre axel. Really, I wanted to build the chassis rigid with no springing or compensation, purely to see if it would run well, but my (over?) ambition to fit inside motion necessitated the centre axel to be removable, so I thought I may as well pop a spring in there too. I'm sure someone will tell me this is a bad idea! However on first inspection, all seems to run well and freely. I also had a play about with the splashers, simply shaped around a drill bit, and soldered onto the vertical sections which fold up from the running plate. The etch needs changing as the the splasher tops are slightly too short, but nothing that can't be hidden on a test build! Only had time to do the rear two so far. When I designed the etches, I didn't know whether to use a laminated approach for the springs that fold up from the running plate, or cast them. In the end, I've decided to go with the cast option, but either way, I needed to fill the hole left by the top layer of the spring. On the etch, I put a spring-shaped 'void filler' so I could fill that hole, solder in place and sand back smooth. You can also just about see this next to the rear splashers. Finally, just because I wanted to check the fit, I cleaned up a slide bar and cross head. The fit between the two is too loose and I'll need to change the print next time a send some castings off. I'll shim the cross head for now though.

Next job was to make the coupling rods – a simple 3 layer lamination and a knuckle joint to provide articulation if required. This could be soldered solid if you weren’t using any form of springing. I'm going to spring the centre axel - I need to be able to drop the axel out so I can remove the cranks and eccentrics for the inside motion, so I might as well spring it whilst I'm at it. I lined each layer of the coupling rods up by using drill bits in the holes to ensure the holes were perpendicular to the faces. The holes were then opened up using a broach and cutting oil to accept the crank pin bush. I perhaps ought to point out, that whilst opening out the holes, and for the second loco build in a row, I bent the coupling rod whilst doing this……that’s when I broke out the cutting oil, which worked much better. I remember thinking the first time I bent one that I need to use oil next time. And still forgot. Just as well I had a spare fret! All good now though.

Feel free, but don't expect it to be quick! I am aiming to get as much done this summer as I can before September comes and I'm back to work....

Brilliant as always!

The first snips into the fret... I made up some of the parts to fit between the frames. Eventually the spacers will position the frames accurately, and the following parts will drop in and soldered to provide extra strength and support. First, I made up the fire box and ash pan representation. This is a series of switchback folds that just need soldering together, after the numerous rivets had been punched out. I really must invest in a proper rivet punch rather than the gravity punches I use – there was a lot of bending in the material to sort out afterwards – a proper punch with an anvil would have eliminated some of that bend. Next, was the cylinder chest and head. The cylinder head is made from 2 laminates (both for the front and back of the chest, sweated together, with a 3rd on top for the end of the cylinder itself. The inner layer is 0.4mm smaller, which provides a nice little recess for the cylinder chest wrapper to be formed around and soldered to. The motion bracket was a simple 2 layer lamination, which also doubles as a spacer, adding much needed rigidity to the frames. To be honest, I didn't have a drawing of the this, and so the result is an amalgam of knowledge of a different MW class, and what was needed as regards support for the cross slides, space for the eccentric rods to pass through, and clearance at the sides for spring balance arms. It won't be too far off. So far, so good.

Agreed all the wheels look good. It’s fine for that level of detail. Good shout on the ethanol. Hadn’t thought of that.

Agreed! I hate the stuff for cleaning. It doesn't seem to matter how many times I clean the tank/built plate/parts with 99.9% IPA, I always seem to get a blue tint to my cleaning cloth. It doesn't seem to affect any resins used after it on subsequent prints though. Other limitations I have found with it are it doesn't print fine detail very well (although that's not what it's designed for), and I've not found settings yet that allow for good dimensional accuracy - anything that needs precision needs a fair amount trial and error experimentation which can be a quite time consuming! I reckon I'm about 1/3 of the way down the bottle, and the Yorkshireman in me won't buy anything different 'till I've run out of the eSun....

It was Jewellery Casting Scotland Ltd. Only used them this once, but really nice people to deal with.

I recently have - it's a great resin in terms if tensile strength, and it drills and taps for the crankpins really well. What I'm not sure about yet is the durability around the axel area after removing and installing the wheels multiple times. I have a feeling they might become a looser fit over time, but I only finished a set of 6 wheels for my Manning Wardle Old Class i build last week, so I guess time will tell. Mine were designed for Slaters axels.

I used AutoCAD for the etch artwork. There are many free alternatives that would do just as good a job, but AutoCAD I can use free through work, and it also has the benefit of loads of tutorial videos on YouTube being available to help out the newbie enthusiast! With regard to the material thickness, as DGO says, the brass parts are thinner (0.3mm) than the N/S (0.4mm) purely for ease of forming bends and curves on the bodywork. I admit that when you handle the fret as a whole, it feels pretty thin, but once everything is soldered up together, I hope it will be fine. If not, then I would imagine that having it etched as 0.4mm next time would be achievable without major redesign work. I guess I'm still feeling my way around a bit..... Basically, yes. After doing a lot of development test prints in a standard ABS-like resin, I bought a castable resin (PowerResin Zero), where you print the pieces, and then had them investment cast. Have a look here from about halfway down the 1st page onwards and you can see what I did.

I've started a new thread to follow the build of the Manning Wardle Old Class i - you can follow it here if you like :-)

If you followed my last build thread (https://cutt.ly/zQeImru), you’ll know I love a good Manning Wardle. For the last year or so, on and off, I have been designing etches and castings for an Old Class I in 7mm scale, a lovely little loco that was used by contractors up and down the land. This project has been slowly burning for about a year now whilst I have taught myself the finer points of CAD design and 3D printing, which I have thoroughly enjoyed, as well as being something I can pick up and put down as time permits. And yes, I know Slaters do a 7mm scale kit of a K class, which is very similar, if not the same, but that was part of the reason for choosing this prototype – can I do as well (or better?) than something that is commercially available? I like a challenge! Having sent the artwork off to the etchers, I received them back all shiny and pristine. If only they stayed like that! A week or so later the castings arrived – more about them and the process over on my 3D printing threads, but I’m fairly pleased with how they have turned out. The plan is to try and squeeze working inside motion into it – just to see if I can more than anything. That might be a step too far. Anything commercially available was too big, so I designed and had cast the necessary parts. It works, and fits, according to the 3D animation in Fusion360 that I did. But in the real world, with my less than experienced bodgings? We’ll have to wait and see. I’ve also had a go at some wheels – I had some 3/16” axels, and wanted to try printing some wheel centres for them. I used a high tensile resin, but whether it will be durable enough for repeatably pushing the axels in and out remains to be seen. A local retired engineer turned up the tyres. Below you can see my initial attempts. You may have seen my dabblings with learning the 3D modelling process on my 3D printing workbench thread, where there are a few more details about the castings and wheels and how I went about creating them. Find it here: https://cutt.ly/zQeImru Here’s everything as it arrived to me. Now to hack the frets up and see if I can remember where it all goes!

And here are the castings literally fresh from the postie this morning. No cleaning up, and pips left on the prints from the supports still very much there. Generally very good quality and happy with them, although not without blemish - I'd set myself up thinking that they would come out as perfect as the prints, which was probably a bit unrealistic to say the least. The detail on the smaller parts is excellent, and all of the castings are better than some I've come across before - it’s the bigger parts where the most noticeable imperfections are. All being well, they will put the finishing touches to the model quite nicely. Now they are all here (apart from the one sprue I seem to have forgotten to print and therefore not cast - it had the expansion links and the top ends of the connecting rod to fix them to the crank shaft), I can start work on construction the model itself. I have designed the frets which are back from the etchers, so I'm all good to go! I'll start a separate thread for this though Apologies for the number of photos that follow - but we all love photos! Also bear in mind they are VERY cruel close-ups!

I have also been playing with making my own wheels. I'm currently experimenting with a high tensile resin to see if it will be durable enough. I have printed a wheel centre to be a tight push fit into a steel tyre that I've had machined up by a helpful & local retired engineer. I then either file or drill a 'key' into the resin and the tyre, and fill with 2 ton epoxy. So far this method seems to keep the wheel concentric to the axel, but time will tell if the union between the wheel and the axel will be strong enough with the resin alone. My next hurdle was the crankpin - even when tapping slaters wheels for a 10BA screw, I've never had much success tapping them perfectly perpendicular to the face. So to perhaps the most over-engineered solution ever. I used the .stl from the wheel centre to create an inverted 'imprint' of the wheel into a lower 'base', and corresponding top half with a correctly sized hole to hold the tap vertical. The wheel is put in upside down in the base, and the lid put on top, preventing it from moving. This allows the hole to be tapped nice and straight. You'll all be laughing at me now as you'll use one of many ways to ensure your holes are straight, but this one seems to work for me!! The resin was a translucent water washable job, which needs using up as I don't really use it for anything. You can just about see the key at the bottom of the wheel here: And as per my previous post, the colour makes it hard to see the detail:

A couple of updates..... Having fiddled and fettled the 3D CAD work on Fusion for the Old Class i, I have got them to a point where I was happy with them. I then printed them in a castable resin. I used PowerResin Zero (mainly because it was on sale!) which has produced my best quality prints yet. Incredibly sharp and detailed, just by using the recommended settings - almost unheard of! Just a few examples.... difficult to see the level of detail because it's black, but you get the idea. As the eagle-eyed will spot, I haven't sanded down the pips from the supports, and I did snap a couple of parts by not being careful enough. These have now been sent to the casters, so I should find out in a few days how well they will turn out.

These models are superb! I'll be happy if mine turn out anywhere near as nice as these. I'll be interested how my castings turn out. Hopefully I'll get time to print and send them off in a couple of weeks, and then I'll post them on here. Blender was easy to learn - I only used it for putting the sprews together though, and Fusion to create the parts themselves.

I'm working off a scale drawing that I've had for some time, but I'm not too sure of it's origin. It's not hugely detailed, but seems to have done the job. I've started building some of the etches and everything seems to fit quite nicely. I can send it your way if you'd like, just let me know. The Colonel Stephens Society also do scale drawings of Morus & Siddlesham which have been very useful. The bits not covered by the drawing I have used a variety of photographs for, and then scaled dimensions from known measurements. Not a perfect way of producing a model, but I've not had any luck with Statfold Barn replying to emails/messages, as I believe they are in possession of the Manning Wardle GA drawings now. If you find any more, do let me know! I'm going to print my detail parts in a castable resin, and then cast them in brass. I've refined some of the CAD work in Fusion, and reorganised all the sprews - they are now ready to be printed and sent to the casters. Pic below are just test prints in grey ABS - I haven't bothered cleaning them up after snipping the supports off. All this as soon as I get some time to do it! Work always gets in the way.......holidays soon though, then I'll have a blitz. Would love to see some of your work :-)