ScottW

@Lacathedrale The height of your pivot will depend on the material you are using. For a simple beam compensated system with fixed axle the compensating beam is commonly made from 1/16" rod and the pivot beam from 1/16" ID tube. To determine the centre point of your pivot you need to measure up from the wheel centre line the distance equal to half the axle diameter+the diameter of the compensating beam+half the diameter of the tube used for the pivot beam.

Positioning the pivot equidistant between two axles is probably the most common and simplist way to build a compensated chassis. Although you can, depending on which two axles you are positioning the beam over, position the pivot closer to either the leading or trailing axle which then puts more weight on the axle. It is believed that this gives better running but I must admit I haven't tried it. I have built a locomotive that incorportated beam compensation, the rear axle is fixed with the pivot postioned equidistant between the leading and centre axle and it runs perfectly well.

3 hours ago, Lacathedrale said:

- there are many options. I have so much choice that I don't know what is simplest - I assumed CSB but I see Simon is using torsion bars instead.

 

Until you actually start on a chassis you are unlikly to ever find the simplest solution. There is no 'one size fits all'. What works for one person may not necessary work for another. Just because Simon prefers to use compensation (torsion bars) doesn't mean that it will work for you. I know a number of  modellers that swear by CSB's, on the other hand I know others who don't get on with CSB's and prefer compensation.

My first S Scale locomotive incorporated simple beam compensation acting on the middle and leading axles with the rear axle fixed. I have subsequently built a locomotive incoporating CSB's but I'm now swaying towards full compensation as per Simon's locomotive.

If you feel a CSB chassis looks relatively simple to produce then do it. If it doesn't work out then try compensation. Only then will you find the simplist solution that suits you.

Stating the blindingly obvious but a scratchbuilt chassis doesn't come with 'a set of instructions'. The builder is required to design his own chassis which will more than likly be based on one of several design concepts eg compensation, individualy sprung, CSB's etc, etc. These variuos concepts have been written up in a number of books, articles and on-line threads as Simon previously stated.

I came to S Scale from 4mm and still use the same techniques and design concepts in S Scale as I did in 4mm. Sometimes I still use the same 4mm products. Bearing that in mind, one option may be to build a chassis based on a suitable 4mm chassis kit? Wizard Models produce a chassis kit for a 4mm scale Terrier, download the instruction sheet from Wizard's website then produce the same parts using a suitable Terrier drawing and follow the instructions to produce a running chassis.

On 11/07/2021 at 20:45, Timber said:

The 3D printed interior is designed to hold the body shape and allow space for glazing.

 

Once fitted and glazing in place the seat ends can be blended to the side of the coach with plastic filler.

I was wondering if the 3D printed interiors could be used, possibly with some modification by the builder, for other makes and types of coaches?

Scott

Three months have passed since my last post. Drawn away by the nicer weather progress on the mineral wagons has been slow going, but I have managed to finaly finish the bodies.

On 14/06/2021 at 22:00, AJCT said:

On the assumption that (as the thread title suggests) we're talking about South Eastern Finecast rather than Wills Finecast kits, my answer is... "built it".  "It" in this case is the ex-LNER J38 which was not one of the original Wills range, but may have been derived from the similar J39 when that was upgraded around 30 years ago.  As it happens, I did create a J38 from an original Wills J39 kit many years previously, but that was sold off when I migrated to P4 and felt that my earlier 00 handiwork wasn't worth trying to rebuild.  That turned out to be a good decision: the original version was essentially a bodyline kit intended for a Tri-ang chassis, whereas the more recent kit No. F171 has an etched nickel-silver chassis with provision for the wider 4mm-scale gauges... or so I thought !

 

As I've said elsewhere, my MO with P4 tender locos (kit or conversion) is to tackle the tender first - the theory being that achieving success here will encourage progress with the engine.  First issue though was to find that the top edges of the tender sides weren't exactly straight -

- and this even shows on the kit-box photo.  So I filed off the top-edge beading and replaced it with 0.3mm brass wire soldered on with lowmelt... another first for me.  Here's the finished version -

- which I'm much happier with, and I think I've also managed to get a better shape to the front and rear cut-outs.

Next up was the tender chassis: for suspension I used Kean-Maygib sprung units which I'd had squirrelled away for decades, and simply used them glued on to the outside of the 00 subframes to allow for the wider gauge.  Following the example of my friend Don Rowland, I fitted tender-only pickups, connected to the engine with a miniature plug-and-socket: this shot of the underside shows the socket over the front axle -

Following a discussion with a fellow modeller on the subject of over-heavy cast-whitemetal tenders, something else I did was to replace the tender internal floor and coal-space parts with 40-thou plasticard, the whole thing being assembled with cyano.  This reduced the overall tender weight by about 38grams, and partly shows here -

The basis of the coal load is from an Airfix mineral wagon kit....

 

And so to the engine.  Here's the soldered-up chassis frame, with Kean-Maygib horn-blocks and axleboxes, in my Poppy's jig -

I dutifully used the EM/P4 frame spacers provided in the kit, but... when it came to offering up the motor/gearbox assembly (Mashima 1426 with HighLevel 60:1 Roadrunner) I found the frames were too close together -

I considered using a narrower motor and a SlimLine gearbox, but the J38 is BR Power Class 6 and I really wanted the power of the planned 1426.  So the radical solution I came up with was to saw the whole chassis in half lengthways, and then re-assemble it in my Poppy's jig to keep everything square.  To hold the frames the right distance apart I used the tubular brass 00 spacers at each end, packed out with washers and one of those little brass knobbly bits you get on the ends of steel guitar strings (useful as they're 2mm ID) -

I then soldered the otherwise-redundant 00 frame spacers to the stubs of the EM/P4 ones, viz -

- and re-inforced the joints by drilling 1mm holes and soldering in wee "rivets" of 0.9mm brass wire.

 

After all this, assembly of the motor/gearbox on to the rear driving axle along with Gibson wheels and crankpins was relatively straightforward, and after plenty running-in round the Newton Duns circuit she runs beautifully - right down to an almost imperceptible crawl.

 

Construction of the loco body (cyano again) didn't cause any particular problems - apart from making sure that the running-boards were properly straight, so I built up the body on a small piece of plate glass and bits of packing to ensure that everything ended up square -

- well, nearly !

In some ways, it's the finishing touches that take the time - handrails (especially the curved one over the front of the smokebox), lamp-irons, brake-gear, sand-pipes etc.  Just a front vacuum-bag and some fine wire for the lubricator pipes to add, and then she'll be ready for the paint shop -

Overall, quite a satisfying build, and I was able to practise some techniques new to me - as well as learning critical things like whether the chosen motor/gearbox will actually fit...!

 

Alasdair

 

 

 

Superb account and a lovely build. I'll look forward to seeing the finished article.

Scott

On 04/04/2021 at 14:07, Timber said:

Not so many post recently......

Prompted by Timber's comment here are some shots of the progress made on my batch of mineral wagons. I did intend posting regular updates but kept getting sidetracked. Anyway, as you can see they are beginning to look more wagon like.

A number of years ago, when the new S Scale rail was first produced, I made up a small panel of straight track using code 87 rail and 4mm scale chairs. I made the panel to see if the 4mm chairs could be used with the code 87 rail as my chosen prototype used four bolt chairs, which is not available in S Scale. I didn’t experience any problem threading the chairs on the rail and the final outcome was more than acceptable. I am intending on using the 4mm scale chairs when I eventually get around to track building.

10 hours ago, Regularity said:

Trevor built an outside-framed 0-6-0ST for Scott, and made it as per the prototype arrangement (see mention below) and lining up the axle boxes is a bit of a fiddle when reassembling the loco.

 

On the prototype, the outer wheel sets tended to have outside axle boxes only, and the centre axle supported by inside and outside axle boxes, to reduce the stress on the cranked axle

Here are some pictures of the 0-6-0ST Trevor made. As pointed out, only the centre axle has both inner and outer axle boxes. The outer axle boxes were made from Tufnol and you can see from the pictures that the compensating beam acts on the outer axle boxes but secured to the outside of the inner frames.

Currently manufacturing some door hinges for my latest batch of wagons.

I'm finding it to be one of those laborious tasks that drag on a bit, confounded by the fact I have ten sides to do. Five down, five to go.

@Rosedale

13 hours ago, Rosedale said:

In building the chassis I will be closely following the techniques illustrated so well in Scot's articles. But I think I'm going to use internal rocking solebars for suspension. Because of the hopper it will be difficult to have a lateral rocking W-Iron. And I'm not sure I'll be able to get enough weight in (even with a large lump of ironstone!). But I can get an rocking solebar behind the actual solebar and this system works very well.

I will be interested to see how you tackle these rocking solebars. The North British and Caledonian Railway had both tank & hopper wagons which sat on open frames. In the past I have pondered how best to compensate such wagons whilst retaining the openess of the frames. I must admit I hadn't considered a rocking solebar.

I continue to be impressed with the latest resin 3D printers, the level of detail produced is superb. Are you doing the whole wagon or just the hopper?

Over the weekend I had a break from wagon building and did a bit of layout planning instead. The design has been bubbling away for a while now and I've got it far enough to allow me to start thinking about the best way to build and support the baseboards. Here is the picture of the Templot plan printed out at a scale of 2"/ft.

The design is based on Bonnybridge Central which saw running powers by both the North British and Caledonian railway. It is designed as a 21' x 11' roundy-roundy, not being long enough to allow for a fan of sidings in the fiddle yard I've had to incorporate two sector tables instead, one to simulate the line to Kilsyth and the other, the line to Bonnywater Junction.

The wagon works are in full swing with a batch of five dumb buffered mineral wagons.

Going back to the very first post in this thread I put up a picture of two wagons currently being worked on at the time. Well, after a year and a half, here they are finally finished.

1 hour ago, Compound2632 said:

I hope you will continue with this thread, showing us more examples of your exquisite craftsmanship.

1 hour ago, airnimal said:

I totally agree with the above comments. There isn't anything better than to see quality of this standard. More please.

Thanks for the comments, guys.

This wagon was in fact one of four wagons going through the paintshop. I'll post pictures of the other three over the coming days, once I've finished tiddlying them up. I'll probably post the pictures over in the S Scale Workbench thread rather than here.

To bring some closure to this thread here are some final pictures of the completed wagon. Unfortunately due to the bad light today the pictures are not as clear as I would have liked.

I do hope these pictures highlight the advantages of building your own stock from scratch.

2 hours ago, Timber said:

Just finished my model of B&M WYE Locomotive. 

Looks superb, thank you for sharing. 

2 hours ago, Regularity said:

At the risk of being a pot calling the kettle black, how are those progressing?

They're not!!!

Over the years I have been getting distracted by other projects. That said, I am having thoughts on continuing again with the Caley 4-4-0T, I just wanted to get a few wagon projects out the way first. Also, I'm keeping my ear to the ground waiting to see what @flubrush does, he had made a few noises that he might produce some prototype wheels for the Caley 439 class.

Scott

2 hours ago, Lacathedrale said:

OK, so for the sake of argument if my bogie and my driving wheels are both using twin compensating beams - what's the simplest way to lay that out? Is there a standard implementation guide I can see? I do apologise for asking as I get the impression that this is very much 'salt to taste' but I just don't have a reference point from which to diverge.

As far as I am aware there is no 'one size fits all' method. Using the theory behind each of the various concepts I believe people tackle the practicalites based on their own ideas and abilities. After all, what works for one person might not necessary work for another. It might be worth posting the question in the Kitbuilding & Scratchbuilding section to gather ideas on how other people have tackled compensating/springing a 4-4-0/0-4-4 chassis?

Scott

8 hours ago, Lacathedrale said:

Absolutely beautiful. You'd recommend then that the bogie has individually sprung hornblocks rather than pivoting frames? As I said this is literally the first time I'm attempting this so success is more important than it being perfect!  At this stage, if someone can say 'do it this way, it'll work and be the most expedient way to achieve it' then I would very much appreciate that, and then once I have one under my belt, can experiment with alternate solutions

I'm not in a position to say if individually sprung hornblocks are any better than a pivoting frame or even equalising beams for that matter. The only experience I have of building a 4-4-0/0-4-4 chassis is what I posted above. I expect any of the methods mentioned will do the job and the decision to adopt one particular method will come down to the indivduals prefrence.

Before starting the NBR 4-4-0T I did consider the method described on the CLAG website but felt it was a bit over engineered. I opted for the Exactoscale sprung hormblocks as I felt it was fairly simple to set-up and I liked the idea of soldering the hornblocks to the outside of the frames to represent the external axleboxes.

Scott

I have two unfinished chassis' on my shelf waiting to be finished, both of which I am ashamed to say were started a long time ago. One is for an NBR 4-4-0T and the other a CR 0-4-4T.

With regards to the NBR 4-4-0T, it was my intention to have the loco fully sprung. The main driving wheels are sprung with CSB's whilst the bogie wheels are individually sprung using Exactoscale sprung hornblocks. The Exactoscale sprung hornblocks are soldered onto the outside of the bogie frames so that they represent the external axleboxes fitted to this type of locomotive. I wasn't intending on fitting a spring between the chassis and the bogie, instead I was planning on installing a metal spacer, made from brass rod, so that the weight at the front of the loco would act downwards on the bogie. I also wasn't going to cut any slot in the bogie pivot as the leading axle has about 0.5mm of play each side of the chassis which I'm hoping will be enough for it to traverse most reasonably sized curves. Fortunately the prototype does have quite a small wheels base.

The CR 4-4-0T is being built in a similar way except I am intending on using beam compensation on the driving wheels. As with the NBR chassis, the bogie is sprung using Exactoscale hornblocks. My intention will be to power the loco using a combination of Mashima motor and High Level gearbox driving off the trailing driving wheel.

I actually managed to finish the bogie before putting it away on the shelf and it has dummy springs and compensating beams fitted externally. 

As I said, these are work in progress so I can't comment how successful the designs are at this stage.

Scott

1 hour ago, Lacathedrale said:

Ah, lovely. I guess for me it is simply a case of getting started, so while a parallel conversation on the S-scale list on groups.io is ongoing about carriage construction, I wondered if this might be fertile ground to discuss a brass chassis scratchbuilding. I'm tracing an LCDR A-class 0-4-4T drawing from the SECR society which seems fairly dimensionally accurate. This is what has resulted:

 

As you can see, my plan is to use a 1420 motor with a Roadrunner+ gearbox, and high level hornblocks in the frames. Somewhat experimentally I'm also going with dead rail, RC-control. As it stands I can fit a fair sized set of batteries in the tanks - 50mm x 18mm x 8mm. In this case, I've hedged my bets for a single 300mAh battery in one tank, with a voltage booster in the other tank.  My thoughts are to use 3/8" x 1/16" brass strip for the frames.

 

I have some other questions if that's OK? Bear in mind this is unlikely to be without error and fault, so reliability and ease of construction much more important than elegance

 

• Should both driving wheels be sprung? Or one fixed, and one sprung? I am assuming yes, with a springy  wire to bear on the gearbox/motor to stop it moving around.
• What's the most straightforward arrangement for the trailing bogie? Thread/nuts and a spring? Should the wheels be sprung/pivot?
• I was thinking of using countersunk screws to hold solid frame stretchers at the front, and strip at the rear to help with weight balance. Other than holes for the wheels, gearbox and a support for the bogie, do I need to bear anything else in mind?
• While I get ready to sketch the extra components - generally speaking, how wide should the footplate be? and the distance between the outsides of the frames?

 

I figure if I get the chassis with the driving wheels and gearbox/motor built, I can at least prove the principles

 

35 minutes ago, Lacathedrale said:

Thank you Scott!  I've used a mandrel to turn down wooden wheel blanks on my unimat, so very similar to that, albeit much more 'serious'

 

Having done a bit more digging I think the A-class needs some further tweaking. The prototype uses 5'6" wheels. Assuming I'm using 10 thou brass for the splashers, the model would only have 40 thou between the outer flange diameter and the underside of the splasher.  The high-level hornblocks by default have 60 thou of upward deflection, so we have a shortfall of 20 thou. The society has 5'7" wheels and rims available off the shelf - which gives only 20 thou clearance and a shortfall of 40 thou.

 

The solution would appear to be, to use 5'7" wheels and fix the front (driven) axle, springing the other driving axle.

 

Thoughts?

Would these questions be better placed in

Sorry if I sound pedantic but it would then leave this thread for you to show us the fruits of your labour.

15 hours ago, flubrush said:

 

William,

 

When I checked the Alan Gibson Workshop wheels with our form tool,  the flange width was OK and the flange depth was 0.024".  or 0.006" too large.   So taking 0.006" off these wheels' flanges would pretty well get them to SSMRS standards.  If you do the adjustment with a form tool,   that would probably guarantee the standard.   You would have to be careful using the form tool so that you don't loosen the tyre on the plastic centre.   And don't let the form tool start cutting the tyre face since the forces will almost definitely mess up the wheel.

 

A few members actually prefer the AGW wheels since the deeper flange helps to keep things on the rails if you have tight curves on your layout.

 

Jim.

I can confirm everything Jim has said. When you profile a wheel you need to hold the wheel on a mandrel so that it is being secured solely by the steel tyre.

Here are pictures of the mandrel I made when re-profiling the Gibson wheels:

The wheel is secured by pressing the tyre between the front face of the mandrel and the brass washer. As Jim said, don't let the tool cut into the tyre face as the forces involved will over come those securing the wheel. This will more than likely result in the plastic spokes coming into contact with the brass screws and damaging them. Ask me how I know

I would also recommend using a cutting fluid other wise the finish will be rougher than a badgers a**e.

Scott