BenWeiner

Thanks! More Lancastrian than German, this body. A parallel project is to do a similar conversion on the tender drive of a Fleischmann BR 55 loco; that's about as German as they come.

Ben

I've been looking at the Lima power bogie with a micromotor today. It needs to fit in a much smaller space than was originally available. Instead of a 1:76 Deltic, it will go in a 1:87 D6700 or class 37. The smaller interior space is compounded by the loco's bonnet section which pushes the cab back; the biggest resulting issue is that the cab doors in the class 37, which are recessed significantly, are almost exactly above the bogie centre. This means they align with the motor itself, the widest point on the motor bogie!

There is also a headroom problem. and that is where I started to get cutting. The top of the motor frame had no role to play so it was removed. To reduce the risk of the remaining bogie distorting I put three screws through the frame into the acrylic 'plug' in the middle that holds the new motor.

All in all there is 24mm or so width available. As I had things, the back of the motor projected much further than that. I was a bit stuck for a while. It's a motor that is 15mm end to end, really very small, but was this the end of the experiment? Then I realised that I could push the motor right through the other face of the drive bogie.

This has meant finding a new, more fiddly but more satisfactory way to retain the first set of pinion gears. Later on Lima used screws for this but in the mid 1970s a springy metal piece was held in largely by compression against the motor frame and was located on two tiny moulded spigots on the gear shafts. I've drilled through these and fitted 12 BA nuts and bolts with 10 BA washers instead.

Finally I cut away the original rotor bearing and its bracket and made a hole big enough to shove the motor through. Now there is enough room for the motor to fit. A pity that the loctite is holding the motor pinion gear so well on its shaft, as it is several mm too far forward now. I can think of one or two solutions to that problem.

In passing: I have left out the reason for the big and untidy hole above the centre axle. This holds a 3/8 inch brass rod (the biggest practical dimension I could find). The rod replaces the pads on the cosmetic side frame that provide lateral support for the body. Like the motor, this is supported by the acrylic 'plug'. It would have been good to use the hole in the bogie too, but my experiment in drilling resulted in a hole that wandered off square so I was obliged to enlarge it. A little more learning.

14 hours ago, jamespetts said:

Aha, yes, possibly! What format and scaling do you need? That would be very helpful.

SVG is good. 100% scale -- it would be wise to make a paper or card template of the bulkhead to check the dimensions of the output against before committing to printing the decals.

I use Inkscape, along with other software including CAD and DTP, for this kind of work. LibreOffice Draw would also suit.

Intriguing. I could probably do you decals for the bulkhead stripes - do you think you could produce the artwork?

What will the platform canopies look like? A portmanteau of Oxford and Didcot could work, just about. The last riveted iron canopy was taken away from Oxford, on the bay platform, only in the last decade, though the south ends of the main platforms (then 1 and 2) were and still are covered by welded flat roof canopies dating from the 1970s. Didcot's canopies, where they still exist, are riveted and have decorative valences. As for the ticket hall, both stations have a 1980s building but they differ considerably. On the platforms there is plenty of Didcot's Great Western heritage evident in the buildings; nothing whatsoever at Oxford.

All interesting to read, thank you for this comprehensive overview.

Passengers definitely improve the look of the train. I think the people need to be cut at the waist to overcome the fact that the seats are broadly speaking at table height. It's a shame there will be nothing for their legs to do, as no known mode of transport exposes only the legs of its passengers to external scrutiny.

Ben

Can't resist adding this (same photostream) as a counterpoint. We have scans of similar photos (possibly from the same visit) taken by a club member. I'll have to check the dates again.

Plenty of diesels amongst the PLA photos on Flickr: there are more where this came from.

Along with all the other excitement during our outing to Ally Pally, your photographer did manage to capture some genuine fly shunting (non-coupled stock movement) taking place.

Thank you for showing your plans (in words and image!). It would be nice to see some trial trackwork. I've never been to Morden station but it looks as though the station throat is quite stark -- track, ballast, cable, concrete retaining walls and brick enclosing walls and that is all there is. No space for anything else. In which case the track will get quite closely examined by the layout's audience.

1 minute ago, jamespetts said:

Will this be making an appearance in West Hothley any time soon...?

That's the plan!

I bought a Klein Modellbahn open wagon with one end board demounted, intended by the manufacturer as a runner under the overhanging load of the next wagon. It came in a set with the other wagon and some overhanging steel beams as a load.

Peversely I actually saw this as a way to buy two wagons rather than as a way to get a runner wagon. So the existing end became a template

And a new end was made from 0.5 mm plastic card and 1.5 mm U channels with one side cut off to make L sections. The top bar was a 2 mm channel.

This fit nicely once the channels were trimmed

And is now mostly painted

I've been mucking about with a homebrew version of the Micromotor Lima pancake replacement kit. It worked! And the recipient Deltic now rolls freely on the track because the frictional resistance of the new motor is so low. Lima fans will love the fact that the original gearchain remains and thus the original Lima growl remains. By the way, it's also very speedy and very powerful despite the tiny size of the new motor. And it doesn't stall quite so badly either. The characteristic stalling of Lima's three-pole motor was one of my motives, so to speak, to try this out.

The new motor is 12mm diameter and I turned down a 40 mm acrylic rod to fit into the pancake motor housing and hold it. Here's the fit of the holder into the motor bogie being tested

And the motor fit in the holder

Friction holds the whole lot together, then loctite holds a sleeve onto the motor shaft that increases its diameter from 1.5 mm up to 2 mm, and more loctite holds the pinion gear onto the sleeve.

I learned from the info in Peter's Spares catalogue that Micromotor have videos on Youtube showing how to fit their kits together and I followed the advice to fit the pinion so that its outer face was 4 mm from the front of the motor case. This still left the motor (which is 15 mm long) sticking out quite far on the other side. This photo shows a trial fit where it's sticking out a lot less.

You can get the official kit from Peter's Spares. I came across it on an Austrian web site and started mucking around before I knew it was something I could buy in the UK. My motor, pinion gear and the sleeve for the motor shaft came from Modellbahn Union which meant rather expensive postage.

Incidentally the wheelsets are replacements (much, much better) and these also come from the aforementioned source of spares!

We got into Ally Pally this afternoon and have started putting the layout together.

Definitely a day to celebrate for the Orchard Wharf team. Allowing for many months when we were unable to work as we expected, this has taken a long time. It is now much clearer how long it takes to put together a system on this scale that uses an integrated control system. I hope the experience gained can be put to good use in future projects.

Too early to say this is finished work, but the next few months will give us the opportunity to test everything out and I think we are going to find we've created something that works well and fully meets our original ambitions.

Come and see us at Ally Pally next month where we expect to be up and running!

Ben

On 2/22/2024 at 11:10 AM, John Jesson said:

Text. I transferred the file with all the text in it, but found the text didn't appear, only the file. What I had to do was open the file, select all the text, then transfer that to the forum. I don't know why this should be. After all, the pictures are transferred as files, but show as pictures, so why should text be any different?

That's a very good question! The convention is that to put text into a forum post you type it in directly -- and I suspect because it is technically quite complex to support it well, the very rational alternative option of dragging a text file into the box and having the system take the text out of it for you is done only rarely (for example in Google Docs).

Thanks John!

Ben

We had a good work session on Saturday - the time draws near when trains will run (though whether they'll complete their journeys remains to be discovered).

Things still look a bit disordered; we're working underneath the boards, which we can conveniently stand on their sides, so this is a typical view:

And here's some very advanced and theoretical paperwork. In this case, to work out the frog polarisation of a diamond crossing and turnout that span a board joint and thus represented a bit of a challenge during the session. Looking at it now, I think it makes just as much sense whichever way around it's turned and probably more so with the pad face down:

See us at Ally Pally!

We're on show as a layout under construction at London Festival of Railway Modelling this year, 16-17 March. Come and see us and find out how we're getting along!

No absolute guarantee that there will be running trains, but if you are an MRC member and you want to help us run trains at the show, please contact Ben or John - orchardwharf@themrc.org.uk

Quick check shows a set of quint-arts do fit on the traverser, including the loco. These ones could do with a bit more above solebar level though. Must get that moving.

This evening the CAD from earlier in the week was exported from TurboCAD to QCAD as a DXF file, then exported from QCAD as an SVG (having first changed the drawing units from imperial to metric).

The SVG was opened in Inkscape and the 'polylines' (CAD term) selected as 'outlines' (computer illustration term). Incidentally the enclosing rectangles are a way to check all the characters were the right width and height and allow some of the 'snapping' features in CAD to be used; they're not part of the design of the characters.

The outlines were pasted into Fontforge.

The next step is to generate a font file and see how they look.

A note on sizing

As I mentioned, the originals are 1:1 (with a height of 125 mm). The notion of an output size is meaningless to a font editor, but there is a configurable 'ascent size' which is the height of the character including any empty space above and below it. This is only significant in that, ideally, the points defining the shape of the character are at whole-number coordinates, so the greater the value of the ascent size the more finely those points can be positioned. In other words, the resolution is configurable.

I chose an ascent of 473 (fairly low; 1000 or higher would be expected) for this first go. Why? because when I pasted the outline data straight in from Inkscape the character completely filled the space between the top and the bottom guidelines with no resizing, which is convenient. Once pasted, the characters can be resized but of course the resolution can never be better than it was when they were pasted in. I will have to test the output to see if they look coarse. Thing is, the curves in the CAD have already been converted to a sequence of short straights in the process of exporting the CAD data so the infinite smoothness of a vector curve has already been lost. As I plan to print these characters at a final size of roughly 2mm height it is not a problem for me, but it would almost certainly be noticeable if the characters were reproduced at original size. It's worth remembering that they were actually applied by stencilling.

Tonight I drew some numbers. Hopefully these become a font based on the specifications of the Österreichische Bundesbahnen. That is, not Deutsche Bundesbahn and not DIN. Yes, they are different and thanks to some posts on the Austrian kleinbahnsammler.at forum the dimensions are available (as former national standards they are I believe in the public domain). These are drawn in TurboCAD at 1:1 so each letter is 125 mm tall by 72 mm wide -- except the 1.

We couldn't resist a second session this weekend. Today James and I took stock of our CBus progress, as a prelude to answering my question: 'what would it take to allow us to use the control system to move the turnouts when we are fettling the high level track?' We were able to spend about three hours tracking down unfinished connections here and there with both the two centre boards connected and powered. A point of concern is that we have at least two servos that never happily settle in place. These make quite a lot of noise as they fails to settle and seem to cause the controlling CANMIO board's power regulator to get hot. So that will be our starting point next time.

Meanwhile John has been reworking the storage box for the Pepper Warehouse model, a large building that conceals part of the fiddle yard at the London end of the layout. Here is a photo of the partially complete model (in its first iteration) sitting in the box. A new Pepper Warehouse will be made because this one, a pioneer for us in lasercutting, was made from greyboard and, without having the benefit of a box, it's suffered quite a few knocks. It'll be better the second time! Note, this is the back of the model. The real structure stood at the eastern end of the East India Docks close to Bow Creek (the mouth of the River Lea). John added a second floor to the building, so that its roof could hide the high level fiddleyard traverser.

Today's session was fairly brief. A review showed that the servocross modules elsewhere on the layout had almost all been done, so we looked into providing power to the high level traverser on board 1. This is directly above another traverser serving the low level. There is limited headroom and wires on the underside would be problematic. We came up with a solution. More on this when we have something to show!

As all four main boards are set up I connected together some of the inter-board cables for the very first time.

Left to right: DCC main bus, accessory and control power buses, CBus (the smaller connectors).

On 1/7/2024 at 1:54 PM, jamespetts said:

Excellent - good to see progress! Next Saturday, presumably, is the YMRC?

In fact, it seems that we can meet on Saturday. Have a look here: https://www.themodelrailwayclub.org/events/

@jamespetts many thanks for the supplies!

Yesterday I tackled the short on board 2 high level DCC. This occupied roughly five hours! It was due to three places where copperclad sleepers were not isolated. In a couple of cases you would never have known there was a connection -- but there was!

After that I connected up all the servocross modules on board 2 high level - about 1.5 hours, which given there are four allows us to estimate how long it will take to do the rest.

Again a day with no visible progress but plenty of effort expended. I'm looking forward to having a larger team in the coming weeks so we can move a bit more quickly towards what I see as our next goal: running trains across the high level.

A very fine train! Perhaps we should put flanges on those wheels?