Re: Rolling Stock for Banavie Road

JimG

Western Thunderer
very interesting. I am using .013 spring wire. The prototype wagon, which spent an hour being run about on the layout this afternoon, weighs 155gm; so approx 39 gm per wheel. The length between pivots is 23.5mm so I am off the scale of the graphs. So time for rusty mathematics! The W-iron allows up to 1mm movement from the null position. As I could see some axle movement I suspect that I am getting at least .5mm of flex from the spring.

Simon,

As a matter of interest, I just weighed my "heavy" Slaters wagon. It's a Midland five plank open and it tips the scales at 118gms, or 29.5gms per wheel, which is getting close to your wagon's details. I've also just measured the weight of the other Midland five plank open I have which has had no additional weight added and it tips the scales at 62gms/15.5gms per wheel. I would have to go searching my archives but I think that the recommendation at the time for Scale7 modellers was to go even higher with the weight - above 200gms. Maybe someone else with Scale7 interests might remember better.

Jim.
 

JimG

Western Thunderer
I managed to move on a bit with the axleguards after being diverted to do a bit of layout construction and also some driving wheel construction for another modeller. I am trying to get a fair bit of weight into the underframe to get the weight of wagons up to what I might need. Using the tables I posted a short while ago, I reckoned on using 0.008" guitar wire with a 0.5mm deflection for the normal ride height. With a total deflection of 1mm designed into the system that would give a wagon axle end +/- 0.5mm movement. Using the tables, this meant a wagon with 14mm between spring pivots would need an all up weight of around 60grms to give an 0.5mm deflection with the 0.008" wire.

I machined the solebars and headstocks for the underframe out of 5mm x 2mm brass strip with rebates in the upper ,inner edges to take the 15thou nickel silver floor such that the floor and the top of the frame parts were flush.

axleguards-29.jpg

The completed underframe

axleguards-30.jpg

...the underside...

axleguards-31.jpg

...and a closer shot of the end. The weight of the this underframe is 31 grms.

The underframe is to go under a Caledonian 6 ton van Diagram 3 goods van. The early examples of this van had vertical, external panelling. Later versions had horizontal planking, but both versions had exactly the same dimensions and fittings, so I aim to build several of both types.

axleguards-28.jpg

All the parts for the body were milled, with the sides and ends in the centre and lower right, the floor and inner "ceiling" with partitions at the top, and the outer skin for the solebars with all the nut and washerplate detail to stick on the plain brass solebars at bottom left. I found it surprising that this small pile of styrene amounted to 21 grms.

The inner body frame was built up...

axleguards-32.jpg

...then the outer parts were stuck on and placed on the underframe...

axleguards-34.jpg

and the deflection appears to be just under 0.5mm, as predicted with Russ Elliot's formula.

And just to show that I am trying to keep up with Messrs Page and Cook...

axleguards-36.jpg

... you can just about make out the nuts and chamfering on the curb rail. :)

axleguards-37.jpg

I also persuaded one of the solebar detail strips to stay in place to show the effect. I intentionally left off the wagon number plate since you can read some of the details on the plates in S scale and I will opt to etch them separately.

The axleguards have worked quite well but I need to adjust some of the measurements since the bearing carriers show a tendency to drop out on occasions. The main reason is that I reduced the size of the lugs which hold the carriers in place with the intention of making it easier to fit the carriers, but went a bit too far - easy to fit, easy to drop out!!! ;) . So the next etch will have the lugs enlarged to avoid the problem. I also overcooked the undercut allowance for the bearing holes and slots and the fit is distinctly agricultural. :) But they will be adjusted for the next etch,

My next act will be to try adding some bits of lead sheet in the "U" channels of the "W" iron assemblies to get the weight up to around the 60 grm mark. I'm also aware that I am probably not going to get anywhere near 21 grams weight for the styrene body parts of an open wagon, so I will want to see if I can get the underframe heavier to compensate. I can always drop back to 7 thou wire, but I would rather stick with one gauge of wire for every wagon.

It will be a bit quiet on this front for a week or so until I get the February S Scale Gazette produced and get the Yate exhibition out of the way. :) But the next job will be finding a way of making the distinctive Caledonian three bolt buffers.

Jim.
 

Attachments

  • axleguards-33.jpg
    axleguards-33.jpg
    71.9 KB · Views: 11

Steve Cook

Flying Squad
And just to show that I am trying to keep up with Messrs Page and Cook...
Keep up...sorry Jim, I can't speak for anyone else, but you are so far in front I'm just catching your dust as it settles :thumbs:


Fantastic stuff, I love how you've machined location slots in the sides to create the basic carcass - I'm assuming the build is pretty rapid with all the up front work that goes into the parts...

Steve
 

JimG

Western Thunderer
A rather nice looking van Jim. Do I take it there was outside framing round the doors?

Scott,

The doors are also panelled and are flush with the sides with very long and heavy straps from the hinges.

axleguards-38.jpg

I've got the panelling strips milled on the doors and I'm now thinking on how to make the hinges. :)

I believe that the North British had a very similar van - probably designed by Drummond who took the design over to St.Rollox when he left for the Caledonian.

I'll pop one of the "W" iron etches in the post. As you can see from my previous post, I need to do a bit of adjusting to stop the bearing holders occasionally popping out and I'll do that for the full run. Do you have any of the Exactoscale 2mm OD bearings? If not, I'll pop some in with the etch.

It looks as though the 0.008" guitar wire requires a wagon weight of around 60 grams to work as intended. If this is a bit heavy for you, there is a D'Adarrio 0.007" string which would require a weight of around 36 grams.

http://www.stringsdirect.co.uk/p/912104/daddario-pl007-plain-steel-ball-end-single-string-007/

Strings Direct is probably the best source for single steel guitar strings - they seem to carry every range.

http://www.stringsdirect.co.uk/c/818/strings/single-guitar-bass-strings/electric-guitar/

Jim.
 

ScottW

Western Thunderer
Thanks Jim, I'll look forward to receiving the W irons. I'm in the process of putting together an NB brake van so the W irons will be destined to go on it. I'll let you know how things turn out. I don't have any of the 2mm OD bearings so if you don't mind popping some in I'd be very grateful.

After posing the question regarding the van I thought I'd take a look through the Caley wagon book and soon realised there was no outside framing. I suppose I should have had a look in there before posting. Yes, the NB did have similar vans, in fact there were many similarities between Caley wagons and NB wagons.

Scott
 

JimG

Western Thunderer
Keep up...sorry Jim, I can't speak for anyone else, but you are so far in front I'm just catching your dust as it settles :thumbs:

There's a bit of a loop going on here - I'm using yours and Jamie's brake van constructions as my yardstick at the moment. :)

Fantastic stuff, I love how you've machined location slots in the sides to create the basic carcass - I'm assuming the build is pretty rapid with all the up front work that goes into the parts.

There is a lot of work on the CAD and CAM work which might be difficult to justify if only one item was being built. But I'm intending building six or eight of these vans, so it means that I can get into sausage factory mode for them. :) It will still take about three hours of milling per wagon but at least the machine can be left to get on with it while I do other things.

Funnily enough, I cut the locating slots too accurately, with zero clearance, and I had to apply a small amount of filing to get them to fit easily . :) I will have to adjust them to give a couple of thou clearance. I'm hoping that the brass underframe design will suit most of the wagons I want to build with adjustments for length and wheelbase.

Jim.
 

JimG

Western Thunderer
Have you thought about resin casting?

Scott,

I have, having read Maurice Hopper's experiences with his LSWR van a year or two ago. As far as I can gather, you really need to be looking for up to forty or fifty castings from the moulds to make the cost per wagon reasonable and I know that Maurice managed to sell off quite a few of his run of castings to other members to keep the unit cost down. In my case I will be looking for four each of the both varieties of 6 ton van and I don't know if I could get shot of 40+ of each to other members. :)

I also reckon that I could knock out four of one type of a van in less time than it would take to go through the resin moulding process, especially since once I've programmed to do the bits for one on the CNC mill, the succeeding ones can be built much quicker. Where I might look at casting is for things like buffer stocks and there I might look at using lost wax casting.

The push on building freight stock at the moment is that the small dockside layout that I started last year as a possible exhibit at the Yate show this year has been re-started as a club project. I stopped work on it last year when I realised that I wouldn't get it into a reasonable condition for showing but other members in the club were looking for a project and the layout was brought out of mothballs. The last couple of weeks has been spent finishing off the baseboards and I hope to get the track down after the exhibition is over. I built all the track last year off the baseboards so it might be a case of just tacking it down. Another club member is starting on a Caledonian 0-4-0ST and I'm making the wheels for that, and I've got to get back on to working on my dock tank as well, since it was the intended loco for the small layout. TimC on this board is starting on some of the buildings required. So it will be heads down and go at it for a bit, especially since other club members won't let me off the hook. :)

Jim.
 

JimG

Western Thunderer
I'm in the process of putting together an NB brake van so the W irons will be destined to go on it.

Scott,

I just had a thought. Does your brake van have larger wheels - i.e. 3'8" or 3' 9"? The present "W" irons are designed for 3' 1" wheels and the vehicle would sit about 1.4mm too high if the larger wheels were fitted.

Jim.
 

ScottW

Western Thunderer
Jim,

Fortunately the wheels on the brake van were 3' 2". I have no intentions of quibbling over 1" and so I'm going to use normal 3' 1" wagon wheels. I would like to say that I new what size the wheels were all a long but after reading your post my heart quickly sank and I had to run off and check the GA. ;)

Scott
 

JimG

Western Thunderer
This is my bit of scattergun although it's still in the same scale and gauge and the same railway company and era. :) But I started building a small S scale layout as an attempt at a "quickie" to get an S scale layout to exhibit at the Yate exhibition this February, but had to give the idea up last summer when I realised I wouldn't get it into a sufficient state of completion fit for exhibitng. That's where the idea for the 0-6-0 dock tank came from - I should have been building something like a Class 1 4-4-0 tank for Banavie Road. :)

However, some other members of the model railway club were looking for a project and this layout was raised as a possibility. The track and baseboards had been built last year so it was a project that could get off to a fairly quick start. It is a dock layout - giving a subject which can cater for a wide range of goods traffic, and no passenger services. TimC of this parish, one of the club members, opted to construct some of the buildings for the layout and he has found an excellent prototype in Port Dundas in Central Glasgow - on the Forth and Clyde canal. So it is now a canal dock layout. :)

Another member of the club has shown interest in building a Caledonian 0-4-0ST to use on the layout and it has fallen on me to produce the wheels for it - the quite distinctive cast "T" section spokes much liked by mid-Victorian loco builders. So for the past month or so, I've been having a go at producing the wheels, with somewhat chequered results - i.e. increasing the pile of broken cutter shanks. :) However, I found some information on the web which looked as though it would give me accurate data for feeds and speeds of small carbide cutters. I applied the information and produced a wheel over the weekend with no broken cutters - result!! :)

Here's the prototype wheel on the original Drummond Class 264 tank of the mid 1880s

264Driver-02.jpg

...and here's my effort of the weekend

264Driver-01.jpg

The one compromise is the axle diameter which should be 7/64" or 2.78mm, and I've bored to 3mm to suit 3mm axles.

I think I will deepen the balance weight slightly, but I'll wait to see what the builder thinks. The tools behind are the parts to hold the spoke centre in the lathe for turning to finished sizes. I've modified my methods from making the wheels for the 0-6-0 dock tank last year and I have had much better results this time round. The only problem I see is that the depth of the lip between wheel and tyre is slightly too deep and I think this is because the centre didn't seat fully in the tyre. With the "production" wheels I'll pit a small chamfer on the edge of the centre to make sure it beds fully in the tyre.

Jim.
 

ScottW

Western Thunderer
Superb Jim. :thumbs:

I remember reading an old article written by Peter James, who happened to model the Caley in 4mm EM gauge. He made wheels of this type in two halves with a blank sandwiched between the two halves to form the 'T' section. But this was in the day before CNC!

Scott
 

JimG

Western Thunderer
A bit further on, I've almost completed the set of wheels for the pug.

264Driver-03.jpg

(I need to get myself a north light for interior shots in the workshop - as being discussed in another thread. :) ) The wheels still need a final clean up and tidy up - they still have a fair bit of steel swarf in the spokes, a knock-on from using cutting oil when machining the tyres.

In truth, the wheels are the second set I have made since I made a bit of a c*ck up when cutting the tyres on the first set. I machine the very basic shape of the tyre with a knife tool with the topslide set over by 3 degrees and leaving a crude flange. However with the first set, I didn't leave a wide enough chunk of flange for the form tool to shape and finished up with a poor root radius on the flanges of the tyres.

So I thought about using a tool I had got a short while ago for another purpose - a small USB microscope. I rigged this up on the lathe to check out the setup of the form tool. I haven't got a picture here, but I put a six inch rule in shot to do a rough measurement of the total flange width plus root radius so that I could machine the rough flange to a width that would allow a properly formed flange. The tyres were rough machined with the knife tool, then the microscope was used to set up the form tool.

264Driver-04.jpg

It was a very basic lash-up - clamping the microscope stand base to the topslide. :)

264Driver-05.jpg

...and a view looking at the chuck with the form tool on the left being presented to the holder for the wheel in the chuck. And the picture from the microscope was...

264Driver-07.jpg

The form tool is at the bottom, showing the tyre profile, with the wheel holder above, and I've lined up the back of the flange on the form tool with the front edge of the holder.

I've also got a good sized image on the PC screen

264Driver-09.jpg

Plain, vanilla WinXP. :) Mach3, which drives the CNC mill, works best on an XP machine with a parallel printer port, so the PC was especially sourced to do the job.

And once the tyres were profiled, I had a quick look to check out that the root radius was fine this time.

264Driver-08.jpg

...with the form tool close to the tyre of one of the wheels. The tyres on these wheels are narrower than normal since the prototype's wheels were 4 7/8" wide, hence the tyre being a bit short of the chamfer on the right. I'll rig up the knife tool to chamfer the tyres.

The USB microscope was originally purchased to let me inspect small milling cutters since my eyes plus Optivisor were not up to the job. :) This use was not envisaged, but I might build a better holder for any further use in the lathe. :)

Jim.
 

Dikitriki

Flying Squad
I knew S scale was too small for me if you have to use a microscope:)

Joking aside Jim, a great use of the technology. And the wheels are very impressive indeed.

Richard
 

Peter Bunce

Active Member
Hi,
I have only just joined so am late to the post, which is very informative, though I do not model in S scale. Thanks for putting it together.

With all the joining of plasticard could I suggest looking at 'Limonene' - I have no connection with them at all, but is sets slower than Mek Pak. and is not as strong, and it can be laid on with a large (watercolour style) paintbrush.

My supplier is Magnacol, who sell it by post in 250ml plastic bottles - their website is http://www.magnacol.co.uk/

Yours Peter Bunce
 

JimG

Western Thunderer
With all the joining of plasticard could I suggest looking at 'Limonene' - I have no connection with them at all, but is sets slower than Mek Pak. and is not as strong, and it can be laid on with a large (watercolour style) paintbrush.

Peter,

I bought a gallon of the original Mekpak about forty years ago, intending to share it around fellow modellers at the time, but only shared about half of it, so the half gallon remaining has lasted me till now with about half a whisky bottle full left. My brush of choice is the original Mekpak brush which was bought from the late George Slater himself even longer ago, when he used to tour the exhibitions demonstrating the use of Plastikard and chain smoking. :)

However, I've been reading about Limonene and I was going to get some to see how it worked. I have to admit that most of my joining with Mekpak is now between fairly substantial sections since I now tend to mill the finer details from solid so I don't tend to be working with ten and five thou sheet or strip where Mekpak can sometimes be a bit strong. But I have some fine beading to apply to some vehicles I am just about to build so it might be time to get some, although a 250ml bottle might be a bit too much. :)

I'm just about to start a batch build of six more Caledonian 6 ton vans following on from the first one I built a few months ago and documented a bit farther up this thread here. I started about a month ago but work came to a halt when the PC controlling the CNC mill stopped talking to the mill and it took about two weeks to get things going again. I got the brass frame parts and the outer sides done before the mill gave up on me, and I've got the inner support parts done since I got it going again. Here are all the bits laid out before I start putting them together.

CalWagon-01.jpg


...with the sides at the top, the inner body supports and the brass solebars in the middle and the ends with the buffer beams at the bottom. The prototype van is at the top. The four van sets to the left are the panelled variety as in the first van, but the two on the right have the flush planking used on later Caledonian versions of the van. I'm experimenting with engraving planks using an engraving cutter on these sides and these are the sides I might use Limonene on since I will be applying the fine beading round the planking with thin five thou strip. If the engraving works out, I will use it on some other stock with the same type of planking - like a brake van.

I've also been experimenting with reproducing the very substantial hinges for the van and here's some of the early experiments with milling them out of 60thou Plastikard

CalWagon-02.jpg

The door mounted hinge straps are on the left and the body mounted hinge fittings are on the right. Things are a bit delicate as indicated by one or two details missing, having been knocked off by swarf on the cutter as it passed. Experimentation will continue when I've got a new 0.6mm ball end cutter - finger trouble caused the previous two to bite the dust. :)

Jim.
 

JimG

Western Thunderer
Things have been going on since the beginning of the month, but I got diverted slightly onto a different venture - but still wagons for the Caledonian layout. The S Scale society is in the process of bringing out a wagon kit for a 1907 RCH open and we are just waiting the delivery of all the parts necessary for the kits before we start making them available to members. The kit has been designed by Dave Provan, Parts development Officer for the SSMRS and Parkside Dundas have made the moulds and produced the plastic sides. I've been sitting on 200 sets of the sides for the last month or two and I thought it might be worth trying to fit one of my brass underframes and sprung "W" irons to the superstructure, and try and get it ready for the society's Autumn meeting a week ago. However, lots of things got in the way and the wagon wasn't completed in time, but I've got a fair way down the road in the meantime.

The first job was to design a floor for the sides which would hold the brass underframe. This floor would have to have plank detail on it and my first efforts at making a floor combined with packing to accept the brass underframe didn't work out too well since marking out the planking was not successful. So I opted to make the floor separately from 10 thou sheet and cut the planking on it. Holding 10 thou sheet on the mill isn't all that easy and I dug out my Seklema Multmat got some years ago to do the job. The problem with the Multimat is that it is not a uniform thickness and is intended for use with engraving heads which adjust for material thickness while cutting. On a standard milling setup with a fixed height cutter, this becomes a big problem - as I found out three years ago, and the Multimat was shelved for other methods. But for thin sheet, the Multimat can't really be beat and I searched around on a bit of Multimat until I found a flat area large enough to take the part and went ahead.

CalWagon-03.jpg

Here's the planking detail being cut using a 0.1mm engraving cutter. In fact with this cut the "rags" left can be cleaned off but I've found that this means that the cutter isn't deep enough and if I dropped the cutter by another thou, the "rags" would disappear. The damp sponge on the right is used to clean the Multimat after cutting.

CalWagon-04.jpg

Here are all the bits with the original sprues from Parkside Dundas top left, a partly built body top right, the brass underframe middle right and the floor and underfloor packing centre left.

CalWagon-05.jpg

...and a closer shot of the floor and the packing, showing the planking cut by the engraving cutter.

CalWagon-06.jpg

The next job was to join the floor with the packing, with the floor just overlapping the packing level to provide the projection to slot into the sides.

CalWagon-07.jpg

The floor is inserted in the three side assembly with just a wee bit of trimming required on the right.

CalWagon-08.jpg

The finished body with the floor in place.

CalWagon-09.jpg

...and up-ended with the brass underframe in place. The next job is to add the "W" irons and wheels, after I've decided how to keep the brass underframe in place. I can either just glue it but I might get problems later if I have to solder anything to it. There's a fair bit of metal in the underframe and it takes a bit of heat to solder anything to it so the plastic around it would probably be adversely affected. So I'm debating to either use the buffers to hold it in place, or fit two countersunk screw through the floor and cover the heads with filler to allow the underframe to be fitted/removed.

CalWagon-10.jpg

..and just to show some other work had been done - the six van bodies put together from the work done at the start of the month. It's not quite clear in this picture, but two of the vans have flush planked sides typical of the later batches of the diagram.

CalWagon-11.jpg

Here's a close up of one of the flush planked sides, all done with the engraving cutter on the mill. They have to be finished off with thin beading round the edges of the planked areas and I'll apply that by hand. Note the chamfering on the bottom edge to keep up with Jamie and Steve. :)

CalWagon-12.jpg

...and a close up of the panelled side awaiting the hefty hinges on the doors. The gaps in the panelling is where the hinge straps go. :) Also spot the error in the body - no chamfering. I missed out the chamfering operation when I made this one. :)

My thoughts now are turning to making detail parts like springs and axleboxes and the possibility of using casting to do that. A chat with TomStaff at Scaleforum gave me a few ideas and that might be another area of exploration coming up. :)

Jim.
 
Top