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Londontram

Steve's Caledonian loco work bench

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Hi, great to see you back building a very nice looking CR loco.  I do not know if it is of help but if you follow this link  http://www.stationroadsteam.co.uk/stock%20pages/3052/index.htm you should find a few photos of your chosen loco built in 5 inch gauge by someone who knew what they were doing and I suspect had access to research materials not available on the web.  Probably  the St Rollox works photos in the Hunterian Library in Glasgow. 

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Hi, great to see you back building a very nice looking CR loco.  I do not know if it is of help but if you follow this link  http://www.stationroadsteam.co.uk/stock%20pages/3052/index.htm you should find a few photos of your chosen loco built in 5 inch gauge by someone who knew what they were doing and I suspect had access to research materials not available on the web.  Probably  the St Rollox works photos in the Hunterian Library in Glasgow. 

I'd love to have a look but I cant get that link to work is the address right?

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I'd love to have a look but I cant get that link to work is the address right?

Google 5 inch gauge connor and you're there.

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Got it thanks and wow what a beauty she is, I tell you what its a lot easier to work out whats happening at that front end with the model than it is from any of the plans or old photos so they'll come in very useful.

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Thank you Manna the wheel base between the drivers is 8ft 7in and from the front wheel to the first driving axle is 6ft 6in. I've ordered the gearbox and like yours I have a stock of mitsmi motors so I just need to order the wheels. Next job now I think I've got the chassis how I want it is to sweat together a couple of strips of brass (already in stock) and cut and file it to shape. I can then drill all the axle holes,

I've already got some axle bearings and frame spacers and axles so getting the chassis up and running will be the priority. I'm glad I'm building it in 00 as the slide bars sit over the top of the front wheel which I'd like to give a little side to side movement to and between that and the outside frame I'm thinking its all going to be a bit tight in there.

 

  Oh well that's part of the fun of it isn't it? What was it President Kennedy said when talking about going to the moon "We chose to do this thing not because they are easy but because they are hard" etc.etc.

G'Day Gents

 

An old Nellie chassis is very close.

 

manna

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G'Day Gents

 

An old Nellie chassis is very close.

 

manna

Damn it that's put the cat amongst the pidgins, He right there's about a 1.5mm difference and if one uses the M7 version Which I happen to have in stock) then even the wheels are pretty close. I would need to shrink the area on the outside frame section between the driving wheels by the same amount and extend the end of the chassis under the cab by about 1mm which I've done on Inkscape and to be honest its such a small amount that it doesn't affect the balance of the loco at all so what to do, make a new chassis cut shape and file then drill out all the holes. Then have to make the con rods etc or use this chassis and wheels connecting rods etc. and just add a section to the front to fix the valve gear and front wheels too.

Edited by Londontram
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To follow on from the last post here's a few views of the Hornby M7 chassis in the first one with the outer side frame in bout the correct position showing that even though the chassis wheel base is slightly shorter when tweaked the side frame wont look out of proportion, Note also the front wheel is also in its relative position. Another lucky find is that one of the Mitsumi motors is a perfect fit on the chassis even the worm gears are the same and mesh this means the motor will sit a lot lower allowing the lower Conner body to fit with room to spare as can be seen in the second picture.

post-17847-0-05528500-1501863290_thumb.jpg

post-17847-0-85077800-1501863310_thumb.jpg

Note that due to the chassis design the chassis is best turned around so is in effect running backwards with the motor driving the rear driving axle and the motor laying forward into the boiler. I just need to find a way to hold the motor in place now, I see a few people have used silicon to fix them in place can anyone tell me the exact type to use and how well it works.

 

As well as the front "pony" wheel I had a couple more giving me enough to do the tender as well so there's another saving.

post-17847-0-85535100-1501863337_thumb.jpg

I'm afraid to say to cut down work and having things like the wheels and con rods already there also how well the motor sits in place I'm fast coming round to the Nellie chassis (All you who think I'm compromising and taking the easy way out blame Manna he put the idea in my head)

 

PS After connecting a couple of wires to the motor and just holding it in place with finger and thump it quite happily run in both directions stopping and starting with ease interestingly running much quieter in what would be the forward direction if this chassis is used.

 

  What shall I do guys?

Edited by Londontram
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That chassis looks like a good fit! I would say go for it. I doubt the slight alteration to the outside frames will be noticeable when finished.

 

Gary

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Wow, I go away for a couple of weeks and you start building again....

 

Andy G

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Well you know me Andy did you really think I would stop where I was on the loco front?

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I recut the revised drawings on the Silhouette cutter yesterday the drawings of the side frame having been tweaked to take into account the fact that I'm now going to use the Hornby M7 chassis. I did these frame sides and other parts in 20 thou but am not happy with the quality of the cutting round some of the finer detail parts and cut outs in the side frames so after the success of the first cut and laminating the parts I might redo this cut on 10 thou like the first cut and build them up by lamination, it seems to make them feel stronger and the cutting is finer and crisper.

 

So learning lots but not progressing fast still have a look at the new altered side frame bottom along side the first cut one, the bottom one having had the area around where the axles will sit shortened by 1.5mm. As you can see although a compromise to fit the Hornby M7 chassis you can hardly see the difference and unless you know you won't be able to tell on the completed loco.

post-17847-0-48166800-1502385989.jpg

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Do you need to cut out the whole slot for the front pony? Looking at the pictures the axlebox fits in there leaving a small hole above it. I would just cut the hole out, which will make them stronger and less likely to twist out of shape.

 

As you say, not much in it, so I think you are right, no-one will notice...

 

Andy G

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Do you need to cut out the whole slot for the front pony? Looking at the pictures the axlebox fits in there leaving a small hole above it. I would just cut the hole out, which will make them stronger and less likely to twist out of shape.

 

Andy G

Probably not but its only cosmetic the wheels wont run in the bearing but in the chassis. luckily that's quite a strong area and when done the bearing assembly will glue across the gap but until its sat on the wheels I'm not 100% sure of the exact position

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Hmm, watching with interest. 

 

 

Are you going for radial on the front axle or a dummy bogie ? 

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Are you going for radial on the front axle or a dummy bogie ? 

Hello Dave, on the original this front axle is a fixed axle and although I originally thought of a bogie of some sort to help it through points or tight bends (though I wont be having anything less than second radius curves and medium points when I do build my railway) with the cylinders and slide rods there's just no room. So at this stage I'm looking to have a little bit of side to side "play" in the front axle maybe 1/2 mm either side to help with the track work. If this will work or not I'm not sure so its a voyage of discovery for me as well I'm afraid.

 

I need to extend the chassis forward to accommodate this axle but also to make the mount for the slide rods so the extension will be brass and when well tested will be held in place by a combination of glue and two tapped screws conveniently already placed on the top and bottom of the M7 chassis.

 

As pretty much every thing other than the cross head is hidden behind the outside frame even though the original has a top and bottom slide bar I'm going to take advantage of the out side frames hiding every thing and only have a top slide bar which will give just a little bit more room for the front wheels but hopefully from the outside you wont be able to see any of this.

 

Trial and error I'm afraid chaps trial and error..

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Hello Dave, on the original this front axle is a fixed axle and although I originally thought of a bogie of some sort to help it through points or tight bends (though I wont be having anything less than second radius curves and medium points when I do build my railway) with the cylinders and slide rods there's just no room. So at this stage I'm looking to have a little bit of side to side "play" in the front axle maybe 1/2 mm either side to help with the track work. If this will work or not I'm not sure so its a voyage of discovery for me as well I'm afraid.

 

I need to extend the chassis forward to accommodate this axle but also to make the mount for the slide rods so the extension will be brass and when well tested will be held in place by a combination of glue and two tapped screws conveniently already placed on the top and bottom of the M7 chassis.

 

As pretty much every thing other than the cross head is hidden behind the outside frame even though the original has a top and bottom slide bar I'm going to take advantage of the out side frames hiding every thing and only have a top slide bar which will give just a little bit more room for the front wheels but hopefully from the outside you wont be able to see any of this.

 

Trial and error I'm afraid chaps trial and error..

You could consider the Hornby idea of "Steamroller" wheels, ie flat, wide with no flanges.

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Hmm good thought but I'm not keen on flange less wheels if there not meant to be there and to be honest I cant see it working on a 2-4-0 any way

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Hi there, like Andy, I've been away for a while. It's great to come back to see you are taking on a really good looking loco!  On the frame slots being slightly out of whack, did you cut the slots first and then cut the outside afterwards. If you do, it helps stop the material from moving around. 

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Hello Jason nice to hear from you again.

 

No like the dumb ------- I am  I drew the frame first and then added the cut outs which meant I could move the cutouts out the way but had to redraw the frame section just to take the 1.5mm out of the axle spacing then re position the cutouts though to be fair it only took a few minutes .

 

I had to redraw the frame as any attempt to compress it meant the whole frame was shortened making the front end where the cut out for the valve gear and the area where the cylinder will go to short as well.

 

To compensate for the compression the area between the valve gear cut out has been increased by 0.5mm and the cab lower side sheet has been increased by 1mm as well.

 

Having done a re cut and found its spot on against the chassis I can go with it as it is now. The only down side is I'm not getting a very clean cut with 20 thou plasticard, oh I know it doesn't go all the way through 20 thou but I used to be able to see the impressions on the reverse side of the plasticard but now I cant this is even with a new blade. I do wonder if its the make of plasticard as the one I'm using now seems to have a higher - how can I say? "soapy" Polyurethane feel about it where as the stuff I was using before felt a lot stiffer and would "snap" more easily and cleanly around the cut lines.

 

So I'm wondering if this is why the cuts are not so defined and deep as they were, maybe the more elastic nature of this plasticard means the blade pushes it into the tacky mat slightly and it springs back after.

 

The trouble is as much as I try all I can get is this new type of plasticard so I've decided to cut in 10 thou and laminate three layers up to 30 thou so it has strength but is not over thick.

 

This has caused me some problems on a few other jobs like some carriage sides I'm working on as well.

 

No worries I'll get round it some how

Edited by Londontram

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Please excuse another armchair suggestion: if laminating the frames, why not make the inner layers a bit smaller than the outer layer so as to keep the impression of a thin metal edge?

 

I've just bought a second-hand copy of Vol.3 of Ahrons' Locomotive and Train Working in the Latter Part of the Nineteenth Century which has some interesting stuff on the history and allocations of these 2-4-0s.

Edited by Compound2632

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Please excuse another armchair suggestion: if laminating the frames, why not make the inner layers a bit smaller than the outer layer so as to keep the impression of a thin metal edge?

Now that's a bloody good idea and easy to do at the drawing stage thanks for that Compound I like that very much.

 

Any information is useful is there any chance you scan it for me if possible?

Edited by Londontram

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I thought you might like to look at the drawing process that goes into making the slots on the splasher. Once the line drawing has been down loaded and sized the general shapes can be drawn and for this stage the outline of the splasher come sand box is shown.

 

Again using the original drawing a copy was made of one of the slots basically by drawing two circles one 1mm and the other 0.8mm and these were placed on the drawing at either end of the slot next came an oblong shape to join the two this oblong being tapered from 1mm down to 0.8mm and when over laid the three parts were joined by using the union key on the drawing tools list to make one drawing.

 

This gave me the slot which could be repeated for all the other guaranteeing they would all be identical. The first slot was placed on the drawing of the splasher so as it lined up with the slot below on the original drawing.

 

Next a circle was drawn so as to just touch the bottom of this slot and sized to touch the bottom of all the other slots. Then a star was created and placed on the top and altered until all the points lined up with all the slots.

 

It was just a case of repeat printing the slots and turning them until they had the right orientation and placing them over the original plans slots using the circle and star as guides.

 

Its easier to see whats going on in this first picture showing half the slots in place and the next lined up ready to put in place with another spare off to the left

post-17847-0-94939200-1502668794.jpg

 

when finished the star and circle are deleted having done there job and the complete splasher with slots is moved aside and is now ready to cut shown here with a previously drawn cab side

post-17847-0-65383500-1502668866.jpg

 

This is the moment when Jason JCL pops up and tells me theres a much quicker easier way but hay this works for me. Let me know what you think. Steve

Edited by Londontram
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Steve,

 

That is a good little tutorial, and very helpful in understanding how you draw these complicated shapes for the cutter.

 

Gary

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No, I certainly won't tell you about the Object -> Add Splasher Slots  command :)

 

Certainly looks very pretty, have you thought about going into graphic design?

 

Two things about cutting, I think Andy will bear me out here:

  • there is a big difference in the properties of styrene sold by different manufacturers, and you aren't the first person to find this problem, so when you find a brand that works for you it's an idea to stick with it;
  • when creating cuts, start on the objects right in the middle of an object and work outwards. Apart from your work here, another example would be a coach side, set up the cut so that the windows are cut first, then the outside of the coach.

Looks brilliant though, and considering you were looking to throw the computer out of the window when we spoke last, you are doing some amazing work.

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