Wednesday, December 31, 2008

A conundrum

On the NZ120 list yesterday, a suggestion that someone overseas could step in and produce items for sale locally.
Honestly, its just not going to happen. There's no money in it. I'm doing casting for myself, making models that I want/need. now if other people are interested in them, then I can probably sell some, but I'm not in a position to go into full scale production (well, maybe not, watch this space).
I'll also have to work out what they are worth. I've looked at the UK market and its hard to tell. UK modelers are an amazing bunch. Buy a perfectly respectable model, then strip it down and hack it into some other variant (different head code boards, drivers arm in the wrong position etc), but mostly sticking with the horrible tension lock coupler ( though I think there's some movement towards kadee's). They will buy etched frets for a model without the correct dimensions ( often for quite substantial sums of money) and then merrily file it down to whats correct ( when the manufacturer should have got it right in the first place)
I think they are all mad. maybe we should be more like them.

Monday, December 29, 2008


Just to prove I have not been sipping Margarita's on the deck for the last few days (that's my wife's job), here's some of the models I've made this last weekend. First up are a collection of l wagons.

Back row L2, L4 and La6 (though there's no real difference between the series from 4 to 10 I think), front row L1 and M1. This should provide enough variation on a goods train, though there are still a couple of odd wagons that I need to make just as one offs ( steel L1, and a steel l4; well approximate sizes anyway).
I've also had a crack at a hutt as normally seen on E wagons.

Now I just have to get pouring the rubber.
(does anyone else have any requests?)

Things one shouldn't do while on holiday

When one gets the chance to sit round, drink beer in the sun and do not much, one's brain tends to wander off into all sorts of weird and wonderful places. At the moment its trying to convince me that this is a good idea for a layout. Maybe its because I have a copy of Noel Cameron's updated 'Rimutaka Railway' in front of me.

Yes, dear readers, I'm just as concerned as you.

Actually, thinking a bit further ( and maybe because I have not had a beer yet today), what are the real problems with this whole set up? Modeling cross creek is not a big problem, its actually a small yard ( having been to see the real thing I was struck by just how small it really was). The loco depot is quite big and until it closed was also the depot for south Wairarapa, so not just H's were stabled there.
There's a good selection of trains through. Every train needs to be re-arranged before it leaves. This can also be considered a drawback.
The layout would have to be a stand alone, as there is no way it could function as part of a modular set up. First off theres the center rail, which would preclude other locos running on it (not much space under your typical N gauge loco these days).
You would need a fiddle yard at one end, and you would probably have to handle the locos and wagons all the time ( sounds easy, but its how things get broke). You could possibly model summit as well, but I have not thought much about the type of operations at that end.
The number of operator required to run something like this, unless you are good at doing DCC consisting on the fly, or are a member of a large family (I suspect if you did carry it off, there would be no shortage of people wanting to operate though)
The main problem is the loco's and their collection of 'jiggly' bits.

While its not the best picture, it shows that a certain Mr Widmark decided back in 1875 to annoy future generations of modelers by hanging something that should be well hidden out for all to see (he was Swedish, maybe that explains it). That Stephenson's valve gear is a bugger. Now I know people have done it (even in 2mm scale of all things) but I think if they ever went to court charged with murder they could use the model in evidence for an insanity plea.

On the plus side, the H is a big loco, so there's no problem fitting an engine in there, and also possibly a sound decoder and a speaker as well (and that would be impressive if you could get the odd syncopated beat that they had, plus a wheelslip noise). They also have the same wheelbase (well the driven wheels) as an atlas GP38, so that's all the gearing done in one foul swoop. The wheels are split frame, approximately the correct diameter, and its possible to knock the steel axles out and replace them with something a bit more solder friendly.
See, I've done a lot of drinking ah thinking about this. The only question I have now, is will I be good at basket weaving at the funny farm.

Saturday, December 27, 2008

A touch of the sun

Its high summer, the temperature outside climbs above 20C and there's not a cloud in the sky. Given my Scottish ancestry (my natural skin colour is pale blue) there's only one place for me, and that's inside. And if I am inside, I may as well be at the modeling bench. In the last 2 days I've made masters for an L1, L2, L4 and an La6. Still progressing are the Xa, and I need to get started on an La3 and an M1. I'll post some pictures soon. the only thing I really have a problem with is that I have made the wagon sides from 1mm thick plastic. This looks far too thick for scale, but for casting the thicker sections make life far easier.
Also, if anyone has plans for a Vb it would be very useful.

Exhibition layouts

I've been thinking more about odd shaped layouts. The only New Zealand feature I can think of that would work like this would be the Raurimu spiral. I don't think anyone in this country has made a decent attempt at this in model form. Plus you would be looking at a layout that would be at least 8' square. OK for a home layout but not that great for an exhibition layout. On the RM web forum I've been looking at some of the layouts there. One thing that has struck me is the large number of layouts built for the exhibition circuit there. In NZ we build layouts for display, at maybe 3-4 shows a year ( and that's a high number only if you travel long distances). The UK circuit you could manage a show every weekend if you were so inclined.

Wednesday, December 24, 2008

Seasons greetngs

Well, its Christmas eve here, but still doesn't really feel like Christmas (well, I could be wrong, it is raining). Maybe its waking up this morning to 'let it Snow' playing on the radio, which lets face it is about the same odds as me winning lotto on the weekend. You would think a country thats been in existence for 150 years would have developed some more self identity than that.

Well, the latest Railfan is out. Some good articles and one that I found interesting on the Wanganui branch. It has got the little grey cells stirring with possibilities.
Finally, merry Christmas to all my regular readers. Here's hoping that next year is better than this one past.

Monday, December 22, 2008

I think I'll just give up now...

Found this on the Railway Modelers Web forum tonight. OK, so its OO9 and must be a pig to get to run well, but its just stunning.

Just as a teaser here's a picture of the layout to give you an idea.

I think I'll just not bother any more, as I'm never going to be able to match this. And the next thought is; 'How could we do something equally clever'.

Sunday, December 21, 2008

Fruitfull day

Heres the first products of my resin casting this decade.

I'm still working on the airbubble problem, and I might have to invest in a cheap set of digital scales judging by the 3rd pour I've just done. The scales I have a fine for brewing beer and making cakes (mmm, cake...) but don't cut it to measure out 5g of each component.

Rubber mould making update

Current update: machine oil is no good to separate different layers of rubber. I've just spent a nerve wracking 10 minutes carefully cutting the master out of the block in approximately the correct place around the top of the Lc. Vaseline is the way to go.
I'm using easycast resin for the first time here, and while I'm impressed with the viscosity, I do have a minor problem with it. Back in the old days when men with mullets roamed the earth, I used epifill as my favorite polyurethane. this was a mix A with B in a 1:1 ratio, but it was nice and thick, and you could do it with a screwdriver and then smear it into the mould. the amounts could be measured by eye. with this stuff, you measure it by mass, and I fear my cheap plastic scales might not be up to it. on the other hand, the 2 piece mould has dropped into place under its own weight, is nicely lined up along the sides, and all things being equal, should work a treat.

Update; second time around, got the mix right. Had a stack of moulds on hand, and only got 1/2 of them filled, as the resin went to a rubbery form inside 3 minutes. will have to learn to be much faster, or work somewhere thats much colder.
First casts had air bubbles all round the place in the 2 part mould that I've had a go at fixing second time around by forcing the resin into the courners and edges etc.

Rubber mould making pt 2

To make a 2 part mould requires a bit more thinking. For a basic case like my lc top, not allot more.

Here I've taken the plastic surround that I built, removed it from the base it was on and glued it back together. I then have tried to reattach it to the 1st part of the mould with F2 glue. This has not worked as silicone rubber sticks to almost everything else incredibly badly, which is why it works fro this. The one thing that it sticks very well to is other silicone rubbers. I nearly feel down here as I almost forgot to paint a thin layer of oil on the rubber surface and the master before I poured in the rubber for the plug mould. Readers would have been able to hear the swearing from a substantial distance.

All things being equal, I should have my first casting out tonight.

Public transport not good for everything

Here's something that caught my eye this morning on another blog I read.

Of course if it happened in this country they would have been caught at the stop waiting for anything to turn up.

Saturday, December 20, 2008

Back in action

Got a pleasant surprise this morning.

Silicone rubber and resin delivered from in Auckland. May as well knock out a tutorial about what to do with it then.

The rubber is a 2 part mix with a 10:1 ratio between parts A (the big white one) and B (the blue one). I could give you a detailed discussion on catalysis etc but I can't be stuffed, so just accept that its fine as long as you don't stuff up the ratio.

To prepare your masters for casting, you will have to attach them to a piece of plasticard.

On the left is the Lc top, and on the right is the casting for the headstocks, handbrake and brake cylinder. Build a plastic box around then to contain the rubber, (note that the Lc top will be a 2 part mould so there should be a 1cm gap arround the master so that the mould will be strong enough for casting). Finally, you will need to cover the masters with a thin coat of oil. This is to help release the master after the Silicone has cured. I've had problems extracting masters after forgetting this step. However take care as some oils may prevent the rubber from curing next to the master surface. I've used Vaseline before, and today's is using a lubricating oil. I'll report back if it goes wrong.

This is what the Rubber looks like during the mixing process. to work out how much you need you will have to calculate the volume of your mould box in cubic centimetres, which will give you the mass of rubber that you will have to mix up. mine came out at 50g. use a set of kitchen scales to weight everything out. Don't get the rubber components on anything as its a bastard to clean off. Stirr it until the colour is uniform. At this point you should degas the rubber to get rid of trapped air bubbles which can lead to imperfections in your mould. Unfortunately, I've got plenty of hot air but no vacuum. We'll just have to solve this another way in a later step.

The sharp end. I pour in a small amount of rubber into the mould, and then use an old paintbrush ( it will be useless for anything else after this) to give the master a good coat. The plan is to have a layer of rubber over the master and no air bubbles next to the surface. After you have done this then pour the rest of the rubber into the mould boxes.

The final step is to remove any trapped air bubbles. Do this by gently tapping the mould on a hard surface for 10 minutes. I have also used an electric razor to vibrate the mould as well.

Now just put aside to cure overnight somewhere warm.

Update: the moulds were cured after about 4 hrs, and the oil does not affect the curing of the rubber. the 10 minutes spent getting all the air out seems to have worked, there are no large visible flaws in the mould surface.

Tuesday, December 16, 2008

Book your trips early

Posted here for your information and early planning. The Chch convention in 2010 (wow, where did that decade go?).
(page 2 is of particular interest. I promise that I am working on it...)

Sunday, December 14, 2008

Of Underframes...

I've been letting my brain wander ( it like that while I'm on the bike or doing crap tasks at work) on wagon topics, and more precisely on how to model the underframes. As my brain sees it, there are 2 main alternatives.
1) An RP'd underframe cast in one piece. Pluses are the incredible amount of detail that can be incorporated. Minuses are that someone with the necessary know how and skills has to be chained to a computer till its sorted out (oh, and researching the incredible level of detail required). also, a new master has to made fro each different variation 0n the underframe.
2) Etching. This would use an inner frame with cosmetic outside bits. pluses are the level of flexibility possible with this approach. Minuses are having to build the damn things right.

My brain has come down in the 2nd camp. The position has been strengthened by the discovery of the following web site ( its in 4mm, but the ideas are pretty good).

What does seem like a good idea is for separate W irons for 4 wheeled wagons( While I don't think I'm going to have a go at the springing, the flexibility of this system shows a lot of promise. Cosmetic solebars and axle boxes can be added, and the wheelbase is simply sorted by gluing the W irons onto the chassis at the correct distance. This can also be extended to wagon bogies (again, for more details). From memory most of the variations can be modeled with 3 wheelbases; 5', 5'6" and 6'. What is even more handy for modern image modelers is that the wagon bogies are almost identical (to all intents and purposes) apart from the springing and so can be represented by 1 bogie.
Another plus is that I think I can probably handle the 2D thinking required.

All I want for Christmas

Just idly thinking tonight, while I should really be doing some writing for work.
2008 will go down as a not great year for Nz120. We end the year with a general lack of decent kits ( etch-cetera excepted), and a very low local profile. This is something that will have to be rectified before the scale can move forward again. I have not been overly prolific this year, mostly being reduced to pontificating from my digital soap-box. Hopefully next year i can get back into doing some modeling.
I will now also admit that maybe the height of summer is not the best month to organise a model making challenge. I have not picked anything up on the workbench for 2 weeks.
Tonight's question to you all is;what Nz120 bits would you all like to see in your Christmas stocking this time next year?

Thursday, December 11, 2008

More loco news

Just while we are on the locomotive topic, Kato USA have finally started selling spare parts for their GG1. This includes the complete powered bogies with the correct wheels for an Ed. This also includes the drive train which is worth its weight in extremely expensive things. Based on the current exchange rate with the south pacific peso the basic bits for 2 Ed;s will set me back $100 (sans motor). Just as well I don't have to buy stuff from the British.

More steam loco stuff

This evening I've got out the measuring stick to see whats out there in the way of steam loco drivers.
to recap, here is a list of standard NZR driver sizes, and translation to their scale size.
3' (early loco's F, D, L etc) - 7.5mm
3'6" (B series) - 8.25mm
4' ish ( Wf, wg, Ww, Q, Aa U series) 10.0mm
4'6" ( A, Ab, K series, ja series) 11.25mm

so how does the commercial stuff line up.

Bachmann 4-8-2 9.5mm (10.5mm)
Bachmann J 4-8-4 10.5mm, 11.5mm)
Fleishman 2-6-0 8mm, (10mm)
Farish 0-6-0 9mm, (10.5mm)
Minitrix 4-6-2 11.5mm (14mm)

(numbers in brackets are the diameters over the wheel flanges)

A cursory look would suggest that the Minitrix 4-6-2 is almost ideal for any pacific, and the 8 coupled locos are way too small. however, the devil is in the detail ( or in this case the wheel flanges).
for any NZR 6 coupled loco the wheelbase spacing is 12.5mm ( 5'), and so any wheel has to have a flange measurement under this value. Likewise the 8 coupled locos. Now if anyone can get me measurements on the various kato loco's out there, I'll add them to the list (this goes for other loco's I've missed).

Wednesday, December 10, 2008

But still hard at work.

'When engineers get to use their own crayons'

I did take a trip to the railway station to do some on site examinations. Found 2 of the EE red sets, one still with the original lights. What they were thinking with the yellow ends is beyond me.
also got some shots of the bogie brake gear.

its also interesting to note how little of the bogies is actually visible under normal lighting conditions.

What I've been up to

The reason for the lack of blog posts in the last week is...

'I'm the one at the front right'

....I got to wear a silly hat. The picture is as good as it got from where my wife was sitting. Its the final challenge to complete a doctorate. Walk across a stage, stand while someone summarised all those years of work in less than 100 words. Shake hands, move to the left of the stage, shake hands, take bit of paper and then move up to the rear of the stage to take your seat. Then stay awake for 2 hrs with no toilet breaks possible.

And the secret to my success here; not taking both feet off the ground at the same time.

Friday, December 05, 2008

Friday Night

Well, its been a long week at work. I've moved my companies laboratory this week, which has been a mission in itself. Carrying the can for $140K of instrument is a novel experience that leads to many sleepless nights. And to cap everything off, last night was the Christmas meeting for the local model railway support group. An excellent BBQ, some good discussions ( some even on model railways), and then someone brought out the single malt whiskey. The old body was not feeling particularly hot this morning. I'm blaming the salads.

Hopefully, this weekend I'll get some modeling in (as well as the sleep I've missed). I've sold some old 12mm gauge track I acquired a long time ago, which should cover the cost of buying some casting implements, and with that maybe "2' models" will be back in action again.

Wednesday, December 03, 2008

Important questions

Sorry that there's been no updates for the last couple of nights. Its into the silly season at work, with invites to various Christmas parties, followed by equally important questions like 'just what is the legal blood /alcohol limit for someone riding a bicycle'. I'm guessing it may well be substantially less than the 6 pints I drank last night while holding conversations with scientists.

And so far we have 4 competitors I believe. Anyone else is free to join in, especially those of you who have yet to de-lurk.

Monday, December 01, 2008

Off and Running

Well, tonight I start my signal box. the main problem with it is that it was assembled by a man who could not read a ruler.

Further problem is that the side thas wrong is the one that I've already done the work on. Still, whats 1mm between friends...