Building the SRC V Class

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AndrewCudgewa
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Re: Building the SRC V Class

Postby AndrewCudgewa » Thu Mar 15, 2012 12:14 pm

G'day SA-Pete (as opposed to US-Pete ;) )

sarail wrote:the use of two sections of fine evergreen styrene C channel carefully glued onto the top of the top slide bar, and bottom of the bottom slide bar to represent the "enclosed" look of the crosshead fitted to the V, however it seems this has already been suggested.


Yes, that's the solution I had arrived at though I hadn't considered C channel, a much better idea than my connecting two strips, which I will adopt if I go with this (still considering US-Pete's idea above). The only difference is I will only apply it at the outward face as the inner face is to all intents invisible under the running board, boiler, gubbins etc. I will smooth down the crosshead to try and get the outside faces as close as possible.

sarail wrote: The only other option I was considering (but will probably cause damage to the RTR mech should it not work), would be to remove the slide bars all together, then using two sections of brass C channel, mount them above and below the centre line of the cylinders. Then create a jig to create a new crosshead from brass square rod (that's the same inside diameter as the inside section of the C channel), drilled on one end to accept the piston and thru 90 degrees for the connecting rod pivot. This way, everythings kept nice and square, and you shouldn't have any problems.


Thanks for troubling to think this through and putting it forward Pete. This was the most advanced of the options I considered (and one also put forward by Buninyong in our discussions). My reason for not proceeding was as you have correctly ascertained, it being a one-way street. Further worrying me with this option was the difficulty of working a good enough attachment for the new slide bars to the Mazak (now I know what the 'orrible stuff is called, thanks RB), particularly given the attachment does need to have some muscle to handle the movement.

Thanks for your inputs Pete, appreciated. If it was less critical I would be trying the second option you and Buninyong put forward, my preference being to give it a crack to develop the skill.

Cheers, Andrew

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Re: Building the SRC V Class

Postby Merlin » Thu Mar 15, 2012 12:20 pm

For what it's worth, the V has the same style of crosshead and guides as the NA, and for the same reason; their history as Vauclain compounds. :geek: A Vauclain compound has two cylinders, one above the other with two piston rods connected to a common crosshead. To fit the connections to these two piston rods and keep everything balanced the crosshead was made in a cruciform shape and held between four slide bars. There are two in front of the crosshead (that you see) and two in similar locations behind. When converted from compound to single expansion, the single piston rod just gets placed on the centre and everything else pretty much stays the same. For that reason, and given that you don't want to go to the trouble of making all new crossheads and guides, I think the solution Andrew first mooted is probably the best. Viz, make up a pair of purely cosmetic slide bars that go in front of the existing crosshead and its guides. You could maybe ice the cake by gluing a slab of something or other onto the front of the existing crosshead that would fill up the gap between the new, cosmetic, slide bars and represent what you see of the crosshead on the real V. :idea: I'll look forward to seeing further progress. ;)

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forthbrdge
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Re: Building the SRC V Class

Postby forthbrdge » Thu Mar 15, 2012 1:30 pm

Andrew,

I am almost to the point of going out and buying one of these locos to see what things look like :roll: !

Going back to the extra guide strips, could the reverse work. Smoothe face of the interior head and place a secondary guide bar between the crosshead and the wheel. This interior non aesthetic guide bar would function truly as a guide, so then you could cut the top and bottom off the exterior crosshead and the build the guide out with some shaped strene to match the trapezoidal section of the prototype.

I don't have a Consolidation, but I do have ten-wheeler that I believe is built on the same basic frame. I will look at that too.

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AndrewCudgewa
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Re: Building the SRC V Class

Postby AndrewCudgewa » Thu Mar 15, 2012 9:30 pm

G'day Merlin,

Thanks for the background and endorsement of the approach, appreciated particularly given your experience of years in these matters. I had'nt thought of the revetment of the motion and need to build it out. If I can do it without blocking the sliding I will give it a go. Thanks for the suggestion!

forthbrdge wrote: I am almost to the point of going out and buying one of these locos to see what things look like :roll: !


G'day US-Pete, I can save you some dough! ;) I took a couple of pictures of the area and the parts diagram (which annoyingly isn't available on line) for you this evening:

Image
Image

Nb. Have just noticed this diagram omits the bottom slide bar for some reason, I think mistakenly as all the Roundhouse 2-8-0s I have seen have the same motion.

forthbrdge wrote: Going back to the extra guide strips, could the reverse work. Smoothe face of the interior head and place a secondary guide bar between the crosshead and the wheel. This interior non aesthetic guide bar would function truly as a guide, so then you could cut the top and bottom off the exterior crosshead and the build the guide out with some shaped strene to match the trapezoidal section of the prototype.


Another interesting variation on the solution again Pete, thank you for sharing it. Having re-looked at the motion I am firming up on my original idea again though likely taking from your first suggestion and at least possibly taking the top and bottom "wings" off the slide bar and using a strip of brass or like to keep it in.

Cheers, Andrew

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AndrewCudgewa
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Re: Building the SRC V Class

Postby AndrewCudgewa » Fri Mar 16, 2012 11:13 am

Chapter 7 – Other Heavy Work, Brake Cylinders & Frames

Looking across the chassis, the next obvious place for work is the footplate in front of the cylinders & boiler and the RTR cow catcher/pilot.

First, how does the “as built” footplate here compare with the prototype? Measuring the distance from the cylinder face/front to the back of the buffer beam - 12mm vs 12mm – great! Measuring the width shows it to be similarly as close to identical. I know I shouldn’t be surprised given the shared heritage of the prototype and the model, however this is a really pleasant surprise. :) The front footplate appears slightly thicker than the prototype, presumably for strength, not surprising as this RTR model has no pretensions of being a fine scale replica. However the top surface immediately in front of the boiler doesn’t seem right – there is chequer plate, presumably for adhesion for the poor fireman as he shovels out the cinders in all weathers, but it seems a bit too modern for a loco of this era. Now arises a very common problem with earlier era modelling – do you think I can find a picture showing what the surface of the footplate was just in front of the boiler? I can’t, and from enlarging the pictures I do have it doesn’t appear the V had the chequer plate there. So, I file it off with a jewellers file enough to flatten the corrugations down far enough that paint will do the rest. Then I call one of the magazines and order the next copy which will just happen to have a crystal clear photo of this section of the V and note how it’s one of their characteristic features seen on no other VR loco etc. etc...... :roll:

Here’s how it looks after this work:

Image

Next, the pilot/cow catcher needs to come off – it has too many strakes and is too thick. Note there’s no need to fully remove this, just reduce it to dimensions that will fit within the buffer beam that will be built up. Indeed any extra that we can leave to the buffer beam dimensions will help with the strength of the buffer beam (rather than it be taken by styrene). So, at the end it looks a bit raggedy as it will be hidden and does'nt need finishing, something like this.

Image

Given the RTR chassis isn’t being entirely dismantled during these modifications, these works with files/saw/Dremel are being undertaken with electric and mechanical elements still in situ. As such I take a couple of protective measures for the mechanism etc. – where filing/Dremelling I shield as much of the area not being worked on as possible with tissue and in this case a box to cover the motor, gears, wheels etc..(No rude comments on the box please, it was donated by my wife and just happens to be the right size..... ;) ) to insulate moving and possibly magnetic parts from small shards of filed metal and mess, as shown below:

Image

Secondly, I suspend the loco as shown in the picture below to ensure the heavy force I am putting on the file/saw/Dremel is not being taken by the wheels and running gear but rather by the solid block of the chassis. There’s no better way to stuff a RTR chassis than place unholy forces on it, particularly from above.

Image

Anything else here need doing? Yes, there’s the rear brake cylinders (just below and to the right of the flywheel in the picture above), larger than the prototype by approx. 1mm and mounted too high up the frames. I was considering leaving them as they seemed to be quite solidly attached and too close to the motor to mess with, however a little wobbling and they easily came off.

I think I mentioned in an earlier chapter the gap between loco and tender (and you can see you could drive a truck through it above!). Part of this may be to allow the 2-8-0 to traverse silly radius curves, though there’s a lot of space so the curve would likely be too silly for the wheelbase! In any case, they are shorter than the prototype V - prototype distance is 24mm from the rear driver centre, model is 20mm for same. Also, their shape is wrong, the V having an upward diagonal from just abaft the rear driver, whereas the RTR has an oblong shape.

So, my answer is to add faux frame extensions with an angle at the base closely aligned to the prototype at that point. I did consider extending these across the face of the existing frame to emphasize the diagonal however there’s no real benefit, the rectangle is still visible behind and I’m not going to cut this thick block of metal so close to my motor. Fortunately the V has quite a bit of detail gubbins there which will help conceal this when done. To form and add the frames, I needed to ascertain footplate height so they’re not too high. I also tested them to ensure there would still be adequate frame clearance with the tender. I formed them from thick styrene, then superglued them on with a reinforcing weld of superglue. This sets quickly and is strong enough given they will not be bearing any load of consequence. The result looks like this:

Image

Nb.
- They don’t go to the full height of the frames as the V has a lower footplate
- Those black holes on the chassis side are where the brake cylinders used to be.

This has been one Chapter where I can assure you the work undertaken was far less than the words to describe it!

Next: Chapter 9 – More smoke & more mirrors

Cheers, Andrew

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forthbrdge
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Re: Building the SRC V Class

Postby forthbrdge » Sat Mar 17, 2012 12:27 pm

Great series, Andrew. Keep things going! Looking at your photo of the crosshead I agree with you. One thing I didn't take into account is the model crosshead is configured in a fundamentally different way than the real thing. On the model the interior guide is part of the main rod, whereas on the real thing the main rod is pinned in the middle of the crosshead. The way the model is configured the interior guide rotates slightly as well as translates, anything placed tight to it may bind with the rotation.

As a of-topic side note I read a very nice article on the design of crosshead guide bars about a year ago. It was very interesting to an engineer nerd :geek: such as myself, even if I am not a mechanical. (I build targets as my ME brother likes to joke...) The guides actually resist a significant amount of bending up and down during operation and some locos from this era did not have strong enough guides, though judging from the photos the V was not one.

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AndrewCudgewa
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Re: Building the SRC V Class

Postby AndrewCudgewa » Sun Mar 18, 2012 10:06 pm

G'day Pete,

Yep, got it in one. This is a good example of my comment on manufacturers and their mechs, this build up allows just enough play to enable some movement, but not let the motion be sloppy. We mess at our peril! :lol: They don't always get it right, but for the price, this is a pretty good effort by Athearn/Roundhouse, slightly overscale but all metal and I think it would put in years and years of service.

Thanks for your continued support of the series, appreciated. :)

Cheers, Andrew

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Re: Building the SRC V Class

Postby AndrewCudgewa » Mon Mar 19, 2012 4:30 pm

Chapter 9 – More smoke & more mirrors

Ok, anything else need doing on the chassis? Yep, there’s that chunky & wrong shape motion plate/bracket (the vertical plate bit at the cab end of the slide bars). On the prototype, it looked like this:

Image

(Picture: Enlargement from Phil Dunn Collection picture)

I was to Dremel the plate down accordingly, until a “smoke and mirrors” alternative was :o suggested by Buninyong! (Yes, he of the hair shirt! :shock: ) Given the motion plate needs to be kept fairly strong (it is cast), Buninyong suggested that rather than thin the entire plate, just to thin the edge, thereby combining the finer appearance with the strength of the plate. Here’s a before and after shot (after right end, before left end) of the plate from above:

Image

On the loco, this small change is quite noticeable (again before on left, after on right) and for me sufficient to alter the appearance enough to represent the prototype plate:

Image

However, I left the “after” picture (right) as-is deliberately as it showed up an error I hadn’t picked up with my naked eye – note the plate is unevenly thinned – much finer at the top. I have since re-done this thinning. Now, I’m not going to suggest you photograph each part of your builds, I certainly won’t be, however the ability for the camera to pick up something wrong here is quite stark. I’ve had similar on my layout where a layout picture quickly reveals something I hadn’t noticed was wrong or missing before.

The other change is to introduce the graceful arc down the top edge of the plate. I arc’d it but not quite as gracefully as prototype, again for strength. Here’s the plate viewed from the smokebox end before (L) and after (R):

Image

I have been doing something also several times over the last few week that I took as a matter of course, however thought I should mention it as it is part of the build. Every now and again, particularly after any work on the motion or like, I periodically re-assemble what there is of the loco and give it a run. In this way any problems should show up and be more easily traced. So, here is “The Pistol” resting in The Yard after an earlier (note pilot, brake cylinder, no frame extensions) test running session on “Glenburn”.

Image

Commuters on Glenburn platform are reported saying they saw a UFO in the vicinity.

Next: Chapter 8 – Tender is the Night

Cheers, Andrew

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Re: Building the SRC V Class

Postby AndrewCudgewa » Mon Mar 26, 2012 8:43 am

Chapter 8 – Tender is the Night – The bogies

Ok, an embarrassing admission first – I found the plug! Remember back in Chapter 2 when I noted the cheap build of this loco probably resulted in there being no removable plug for the wiring between loco and tender and the only option was to cut the wires to seperate them? In poking around the tender for this stage I found there was indeed such a removeable plug, nicely tucked up beneath the DCC-ready card. That actually makes more sense than the mounting on the Bachmann 4-6-0 (below the footplate). So, I win a Darwin Award for not looking further :oops: .....and now of course the loco and tender can be separated to work on. :roll: Here's the plug:

Image

Ok, bogies first – the tender bogies supplied don’t resemble the V bogies in any way other than that they hold two axles and wheels......and these are discs rather than the spokes of the prototype.......And they have this excellent pick-up methodology which just yells “don’t even think of messing with me”. In the picture below (bogie removed from pinion) you can see the pickup strips quite ingeniously routed from the pinpoint axleboxes to a central point on the bogie brace bar wherein power is taken through to the loco via a small wire (just visible left of the pivot) on each side:

Image

A year or so ago I saw these on EBay and purchased them as fascias for just for this kind of moment...............

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...............obviously the wrong moment though as they are both too wide, far too solid and have bits that the V bogie didn't. I considered keeping and cosmetically altering the existing bogies but had a nagging feeling this compromise was a bridge too far. So, I looked further into the contacts and found an article about improving them that gave confidence I could do something. I also tested and found the loco could run Ok (but not brilliantly) without tender pick-ups, so in the worst case I had an out. I dared to think this was something I could do better. My thoughts turned to conversions. There are a couple of Steam Era bogies with close wheel spacing that perhaps could be (dramatically) cut down and added to, so I went to the SEM site and found to my great surprise that SEM had added J Class bogies to their bogie range!! At this point my enthusiasm ran ahead of my common sense and I called SEM to order immediately, then realised when David answered that it was 9:30pm!! Ever the gracious and understanding professional, David took the order and offered to place wheels with the correct diameter and spoke numbers, and I promised never to call so far beyond business hours again. :oops: Service is one of the constant rhubarbs of online groups, in my experience you would be hard pressed to find better service than SEM offer.

Now, the J bogie admittedly isn’t a V bogie but it has the right wheel spacing and in appearance very much closer to it than any other option I have found, though from pictures it looks like the Frateschi 2-8-0 tender bogie is an Ok likeness, certainly a better starting point than the Roundhouse bogie type. Small changes are required to bring the SEM J tender bogie to a better likeness, namely – Firstly removing the diagonal plate behind the axlebox on the outer ends (I would remove the inside also but they are hard to get to and acetate is hard enough to work!). I used a knife and files for this, hard work as the acetate is very hard! It’s easy to break off the remaining bogie frame arm, I did several times however these can be superglued back on – they won’t be load bearing so the weld should hold.

Next is removal of the central raised section at the top and centre of the bogie, a file should suffice for this. Then I filed the late design axleboxes down quite flat which isn’t a bad approximation of the earlier stile. Lastly I added styrene detailing (with superglue again) – two reinforcing bars on the top, slivers of tube on the axleboxes to represent the small round piece at the base of the axleboxes. These changes are seen in the comparative picture below:

Image

To fit the SEM bogies on the existing pivot they need to be filed out about 0.5-1mm and a small finger be filed off the bogie pivot. I found a bogie contact kit on Hollywood Foundry’s very helpful and useful site, and ordered. Next will be to add these contacts, connect these to the pick-up wires and do some testing to make sure this all works, for the next Chapter.

Nb. With this chapter, this account has now caught up with where I am currently at with the V build, so the pace may slow a bit!

Next Chapter 9 – More Tender is the Night – More chassis than I expected and then the body

Cheers, Andrew

Edit: I have corrected "pinion" to "pivot", a Buninyong correction I had missed!

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Re: Building the SRC V Class

Postby AndrewCudgewa » Tue Apr 03, 2012 10:37 am

Chapter 10 – Tender is the Night – A bit more chassis and then the body

Nb. I have just realised the last two Chapters as my ordering was Chapter 7,9,8....9 and 8 numbers should be reversed, but the build order is as posted.

Next is to add the contacts to make this bogie “live” (nb. I polish the SEM wheels to remove the chemical greying as this seemed to be the right thing to do to ensure best conductivity, not sure that it matters? Perhaps a reader can confirm?). I purchased a bogie contact kit from Hollywood Foundry and set to work modifying it to provide wipers on top of the bogie wheels as the use of spoked wheels precluded the wipers acting on the inner face of the wheel as recommended. This is a fairly simple process, however care is required to ensure the contacts touch the wheels well enough to pick up the current however not too hard. The Hollywood Foundry instructions are characteristically helpful and complete, so I don’t need to add to them. The picture below shows the final result prior to attaching the wires:

Image

To test that it was working I did two things, the first was a test of the first bogie with the second (original) bogie isolated, then a test with both old and new bogies live. All good. I added the second bogie, all stopped.....Hmmmmmm......Placing just the tender on the track with another loco, still all stopped, so it’s not just this loco and therefore in something I have done I must have introduced a short circuit. I found the tender base is metal and where the contacts centred on the bogie, the pick-up strip was touching this metal on both sides of the chassis hence the shorting. Once I located the issue it was easily fixed with a wrapping of thin electrical tape to isolate the live section from the chassis.

Image

As above, I also added decent weighting to the tender to ensure a good connection between wheel and rail at all times (and offset the very slight inertia introduced by the wipers), and now the tender both runs very smoothly and could conduct an orchestra. A little bit of weight off the possible maximum load is a small price for smooth operation. Time for some more test running per the earlier chapter – Interestingly, with bogies and changes to the loco, the V-in-build actually starts to look a bit like what we’re trying to make, sort of kind of.... ;)

Ok, bogies are all good, next task is the tender body, below shown with all pull-offable bits pulled off, but before alteration otherwise.

Image

Measuring it up, I was in for a pleasant surprise – the tender body is quite close to the V prototype :) :

- Length - The body is 1mm too short, the chassis is close to spot on

- Width - is close to spot on

- Height - Side body height is approx. 0.5mm too high. Side frame is 1mm too high, mostly due to the thin metal frame layer mention above. Rear platform is 1mm over height.

Probably the most obvious problem is the round embrasures on each side of the front of the tender are approx. 1.5mm too wide. As they are well formed, have nice surface detail, and replacement would be difficult to achieve invisibly, I won’t be changing them - Yes it’s a further compromise but this one of the lesser choices. I’ll let you know if anyone ever says to me “Nice V Andrew but what a pity about those tender front embrasures being 5” over scale, it’s just not right”.

..........So, not a bad match for a tender made on the other side of the world around a close cousin to the V, to a Phoenix tender (albeit based on a Baldwin prototype) on an Australian locomotive. And that’s just as well as the tender body is made from very hard plastic that would present issues modifying. Indeed, if I had had to, I would have likely just built a new body rather than tried to cut/shut this one.

Having made the decision not to alter the tender body itself, some changes need to be made to remove “non-V” elements, these are:

- Off-centre water filler
- Shunters steps
- Flare
- Rivets - Yes, rivets. I am no rivet counter however the pattern on the model is quite obviously different from the V.

Having done this, and filled in the hole where the fake coal was and the other holes with putty, the “reduced” tender looks like this:

Image

And so, finally, having worked on all the major bits of the tender we can get to the detail. For the detailing of any item of rolling stock my approach is this - Look across all diagrams and photos you have of the prototype and work your way from one end to another, or from one side to another, whatever method, however trying to ensure you pick up every single piece of detail you are going to incorporate, and write it in a list. This sounds simplistic, but I have found it the best way to ensure nothing is missed. Further, the list gives you a work plan (particularly helpful if you take a break during building the model) and enables you to “tick off” each item as it is completed. While writing it up, I start to think about a logical build sequence – to ensure the least risk to added detail from new detail going on. For example, I will build any under chassis detail last as it will be easiest to work on the tender while I can sit it flat on the modelling desk.

My detail/work list for the tender is:

Rebuild:
- Flare
- Rear buffer
- Steps
- Toolboxes
- Lamp holders
- Replacement inspection covers
- Front handrails (I have managed to retain the rear ones and they are very close)
- Coal board
- Couplings
- Buffers
- Safety chains
- Solebar/chassis side detail
- Rivets
- Below chassis detail – wheelguards, pipes, air hose

Deliberate exclusions are:
- The builders plates – as these will likely follow my usual method of card which has enough rise to appear separate from the body
- Tender bogie chains – this model will be used regularly in service and I’m not a masochist :geek:

My relationship with detail is funny, it’s a real love/hate. I love doing it and seeing the loco come fully to life, but sometimes I just wish it was done. You might later find yourself referring to this as the “Curse List” as you work your way through 10 items of detail to find another 20 still waiting, and still those goods trains are underpowered, however it is a really good feeling when you cross the last detail item of the list and it becomes the “Satisfaction List”.

Next: Chapter 11 - The last straw, and other detail

Cheers, Andrew


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