Jump to content
 

No. 269


Guest Natalie Graham

Recommended Posts

Guest Natalie Graham

Here is my entry for the Scratchbuild Challenge. The idea has been turning over in my mind ever since my post on the thread about what two locos people would choose. I opted for a G&SWR Stirling 221 class 0-4-2 and a Manson 266 class 0-4-4T and build a model of the Cairn Valley line. The idea grew after I discovered I had drawings of both locos, a large size GA and a drawing in an old MRN for the 221 and a GSWRA 7mm drawing on card of the 266. I also don't want to start a big project as I have my house up for sale and hopefully might be moving in the near fuiture. A model of one of the smaller stations on the Cairn Valley would be a perfect small project. So, with the announcement of the challenge today it seemed an ideal time to make a start on the Manson loco. No. 269 worked the Cairn Valley line for some time so that one is the subject of the model.

 

Here is the result of today's efforts, a pair of frames complete with the obligatory small coin for size comparison. The second frame hasn't been assembled in the photo in order to show the method of construction. A near scale thickness outer frame with a thicker sub-frame, both from NS, which also provides the guides for the hornblocks made out of a piece of 0.5mm brass filed accurately to 3mm wide and two strips of 0.006" x 4mm brass. 2.5mm holes were drilled in this, working up from smaller size pilot holes as using the large drill right away can rip the strips apart. The fact that these holes aren't all in perfect allignment won't be an issue (she says optimistically) as will be seen as construction progresses. The outlines of the springs were bent away to allow the hornblocks to slide in place and then straightened to retain them in place. All needed a bit more work with the files when the photo was taken. Now I need to order some wheels for it from the 2mm SA

 

post-5551-0-62617700-1331844486_thumb.jpg

 

And just to show what I am up against working on this, here is a photo of my toolbox :rolleyes:

 

post-5551-0-84581600-1331845491_thumb.jpg

Link to post
Share on other sites

  • RMweb Gold

I have similar problems in my workshop with the dogs flopping down wherever they feel like it!

This looks like a fabulous project and a more than suitable contender for 'innapropriate on Highbury' when finished. Could you possibly put a picture of the prototype up as I'm not familiar with it.

 

Regards Jerry

Link to post
Share on other sites

Guest Natalie Graham

He's better off in the toolbox than when he 'sunbathes' under the daylight lamp on the bench. That really gets in the way.

 

I can't find a photo that won't be copyrighted. The best I can do is the 0-6-0T No. 105 on this page The 266 class was pretty much identical but with the rear pair of drving wheels replaced by a four-wheel, outside-framed bogie for working the tight curves of the harbour lines at Ayr and Ardrossan.

Link to post
Share on other sites

  • RMweb Gold

He's better off in the toolbox than when he 'sunbathes' under the daylight lamp on the bench. That really gets in the way.

 

I can't find a photo that won't be copyrighted. The best I can do is the 0-6-0T No. 105 on this page The 266 class was pretty much identical but with the rear pair of drving wheels replaced by a four-wheel, outside-framed bogie for working the tight curves of the harbour lines at Ayr and Ardossan.

 

Thanks for that. A pretty little engine - my favourite!

 

Jerry

Link to post
Share on other sites

Guest Natalie Graham

Without the headband magnifier I couldn't see to do it. Without it I have a job to see what I have built.

 

Anyway, a little bit of progress as the frames have now become a basic chassis. Here is a photo complete with its high-tech assembly and construction jig.

 

post-5551-0-77960600-1332280740_thumb.jpg

 

The 'jig' is simply two pieces of 1/8" ply glued together with two saw cuts across it to accomodate the two cross-shafts (0.55mm diameter brass lace pins) which will be the brake-hanger pivots. These pass through both frames and keep everything alligned while the spacers are soldered in place. Making the heavier sub-frames slightly smaller than the thinner mainframes leaves a ledge along the top and the ends to nicely fit the L-shaped spacers.

 

I thought I was onto a winner on ebay tonight when I spotted a photo of GSWR No. 269 listed. However it turned out to be the Great Southern and Western Railway in Ireland.

Link to post
Share on other sites

Hi Natalie,

 

That looks really good - I'm not familiar with this particular prototype, but Victorian/Edwardian 0-4-4t locos seem to have a certain style about them. I'm interested how you're going to arrange electrical insulation/pick-ups on this loco - I presume you're not using split frames as those spacers look like nickel silver?

 

Andy

Link to post
Share on other sites

Guest Natalie Graham

I'm interested how you're going to arrange electrical insulation/pick-ups on this loco - I presume you're not using split frames as those spacers look like nickel silver?

 

They are nickel silver, but that's the beauty of live steam, no need for electrical insulation. :)

 

Only joking. This is the clever bit, if it works, split axles but not split frames. That means I can have a good, solid, all soldered, metal chassis without messing about with pcb spacers which rarely seem to work for me. I have used a variation of this method in a 3mm chassis before but this is the first time I have tried it in 2mm scale.

Link to post
Share on other sites

Guest Natalie Graham

Live steam in 2FS - now that I would like to see! (although I think that ought to go into the innovation category... ;))

 

I have always fancied a go at a 2mm live steamer, hardly innovative though, Arthur Sherwood was doing them in Z gauge 40 years ago. http://www.zen98812....o.uk/steam.html

Link to post
Share on other sites

Guest Natalie Graham

Thanks for the compliment. The frames, like all the metalwork, is cut with a piercing saw. For 'holes', like the cut-outs for the hornblocks, a hole is drilled inside the outline of the area to be removed and big enough to thread the saw blade through, then the outline is cut with the saw and tidied up with needle files and riffler files as required. A pretty good 90 degree corner can be cut with a piercing saw.

Link to post
Share on other sites

Guest Natalie Graham

It is pretty much an essential tool if you are going to be building from sheet metal. Here's a couple of good basic instruction vieos on how to use it.

 

http://www.youtube.com/watch?v=m90PBUiR1dY&feature=related

 

http://www.youtube.com/watch?v=AqikSp-yeRA&feature=plcp&context=C4efc836VDvjVQa1PpcFOvQ-vccbT4Z9jApZuovUApyg5N23ACSOs%3D

 

One thing to watch is that sometimes you will get a blade which refuses to saw in a straight line and insists on wandering. When you get one like that chuck it away, it will only ruin the workpiece.

Link to post
Share on other sites

They are nickel silver, but that's the beauty of live steam, no need for electrical insulation. :)

 

Only joking. This is the clever bit, if it works, split axles but not split frames. That means I can have a good, solid, all soldered, metal chassis without messing about with pcb spacers which rarely seem to work for me. I have used a variation of this method in a 3mm chassis before but this is the first time I have tried it in 2mm scale.]

 

Am I right in thinking you are going to use an insulating bush in the hornblock?

Link to post
Share on other sites

Guest Natalie Graham

Am I right in thinking you are going to use an insulating bush in the hornblock?

 

Yes, they are in place now. Once the epoxy has cured I will take another photo and post an update.

Link to post
Share on other sites

Guest Natalie Graham

There's not going to be anyhing unusual about the brakes. As I had drilled the holes in the frames, putting the pins through them provided a convenient way to keep the chassis alligned while I soldered it together, given that there were no axle bearings to put shafts through at that point.

Link to post
Share on other sites

Using the pins is similar to how I align the frames. I use two 3mm/society ( in my case) spacers which I bolt in place. Then confirm the alignment with axles before solding scrap piece of metal in to the chassis as spacers and removing the 3mm ones for re-use.

Link to post
Share on other sites

Guest Natalie Graham

A little bit more progress: 269 now has a set of insulated bearings for the driving wheels. These are made from 2mm OD x 1.5mm ID brass tube. (Trying to find the right sizes on the Squires stand in a gloomy corner at the Glasgow show wasn't easy. :) ) A piece of .005" styrene sheet about an inch long was wrapped around the end of the tube using sewing thread to hold it in place. This was then dipped in the freshly boiled kettle and left for five or ten minutes. This produced a nice styrene 'tube' just the right size to fit around the brass tube. The stryrene was then araldited around the brass tube and left for a couple of days to cure.

 

While this was happening I drilled and cut the coupling rods from a strip of .018" nickel silver folded double at one end and soldered together at the other.

 

I now had a length of plastic covered brass tube. This was spun in the lathe and given a light smoothing with a file just to catch any bumps in the plastic. two lengths were cut about 11mm long. Another high-tech jig was made from plywood to make a nice snug fit for the chassis upside down. A piece of styrene was cut to pack the chassis to the right height. (Well, nearly right. I miscalculated and the chassis will probably cause the loco to sit about a third to a half a millimetre too high, but I think I can live with that. 9mm wheels will be marginally undersize anyway.) Two litle jigs were made from 1.5mm OD x 0.5mm ID brass tube cut to 12mm long and a length of 0.5mm straight brass wire soldered through the middle. The jigs were put inside the plastic covered tube and araldite applied to the outside of this tube. These were then put in place in the hornblocks and the coupling rods fitted over the ends of the little jigs to ensure the bearings were correctly spaced. Making sure everything was square and correctly alligned the chassis was again left for another couple of days to allow the araldite to cure.

 

Hopefully the first photo should show how this was done. The more observant among you might notice that the end of one of the axle jigs is missing. I managed to get it well and truly epoxied to the bearing tube and had to cut the end off to free it.

 

post-5551-0-06425800-1333046138_thumb.jpg

 

After it was all cured the protruding ends were cut off the bearing tubes and then the centre sections cut out. I threade a length of brass rod through the bearings to support the bearing tubes while I cut them with the piercing saw. Then the ends were filed nicely smooth. The results are shown in the second photo along with the surviving axle jig. I have left the bearings a little long on the inside for now until I see how much space I need for the gears, springs axle muffs etc.

 

post-5551-0-11630800-1333047252_thumb.jpg

 

Trying a set of 9mm dia 3mm scale wagon wheels as a temporary meaure the chassis runs smoothly when pushed along the workbench and testing the bearings shows them to be fully insulated from the rest of the chassis. Now I need to see about some proper wheels and a motor and gears.

Link to post
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...