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Chas

 

I would imagine trying to tighten a bolt inside a tank will be quite difficult. (I can only imagine my language if I tried to do that:rolleyes:)

 

Could you extend the extension piece in your drawing and fold through 90degrees. Then the bolt could be threaded from below through the splasher. All depends on access of course.

 

Jon

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1 hour ago, Jon4470 said:

Chas

 

I would imagine trying to tighten a bolt inside a tank will be quite difficult. (I can only imagine my language if I tried to do that:rolleyes:)

 

Could you extend the extension piece in your drawing and fold through 90degrees. Then the bolt could be threaded from below through the splasher. All depends on access of course.

 

Jon

Hello Jon, it's not as bad as it sounds, because you can position a screwdriver or nut-spinner along the length of the tank (front to back) and lay it at a fairly shallow angle, enough so as to be able to engage either a slot (in a bolt head) or the hex head of a bolt, at any rate for half a turn or so. Or worst case, a pair of needle nosed pliers. I've dealt with undoing and doing up screws and bolts in eye-wateringly inaccessible places in the course of servicing audio electronics, where you're tightening up a 1.5" bolt a quarter turn at a time - a bit like the situations you sometimes have in full size car engines too.

 

Re. your idea of extending the extension piece, I couldn't extend it straight back along the splasher top, because the reversing screw casting will be going there, but the idea of extending it is an interesting one and I'll have a think about whether it could be extended or further modified in some other way.

 

I haven't any experience in designing these kinds of brackets, tab extensions and so forth, so David's and your advice - coming as it does from people who've dealt with these kinds of issues many times before - is very welcome!

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2 hours ago, Chas Levin said:

Ahh - got you! I had misunderstood slightly and gone down the path of extending the tabs on the roof front vertically downwards and messing about with bolts below stairs.

Thank you - that picture certainly says a thousand words, as they say!

Ok, so that would work on the LH side, where the tank top carries on rearwards, past the line of the cab front and where there is indeed access underneath - here's a photo of that side ('scuse the lack of cleaning up inside the cab):

1293533930_LRMC1220210212(3).jpg.3b352a2660005338eba2585680165031.jpg

 

But on the RH side, the tank top drops down to the level of the built-up inner cab splasher (actually it's where the reversing screw casting will go) at the point where the tank top meets the cab front:

1200636797_LRMC1220210212(4).jpg.95ea09ef6b4fdeeba0cf4aa3a518d9e6.jpg

 

(And that photo hopefully also illustrates how the lower cab front comes up immediately underneath the tank top slots). I do have access underneath however to that lower vertical cab front section, so... I wonder whether this might work:

 

1221629478_LRMC1220210212(6).jpg.f7d4093699de631b73c85169ff0c5dc2.jpg

 

Hope that's clear: instead of the bolt going vertically through the tank top, it would go horizontally, fron inside the tank, through the vertical lower section of the cab front, then through an extension piece joined to the cab roof tab, then through a captive nut on the lower cab front wall. There's access inside/underneath, though access to both areas inside/underneath will be a little awkward, especially to tighten up that RH side bolt inside the tank, but do-able I think :scratchhead:.

Inside the cab, the captive nut and the bolt end would be behind the reversing screw casting and I'm sure invisible...

Got you! That looks like it might work, yes. You can always superglue a screwdriver to the bolt head to get the bolt into position - the bond is easily broken once the bolt is in place. Drill the holes as accurately as you can (using the vernier as a scriber again!) but don't worry if you have to make them oval in order to make fine adjustments later - one often does.  

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4 hours ago, Daddyman said:

Got you! That looks like it might work, yes. You can always superglue a screwdriver to the bolt head to get the bolt into position - the bond is easily broken once the bolt is in place. Drill the holes as accurately as you can (using the vernier as a scriber again!) but don't worry if you have to make them oval in order to make fine adjustments later - one often does.  

Yes, the drilling of the holes is occupying my mind currently, because of the unfortunate Catch-22 that only with the cab roof (and its new extended feet) in place could I judge where to drill, but drilling would then be impossible because the cab roof would cover everything!

Well, a solution will emerge in due course. I find with things like this that getting on with other jobs and giving it some time to percolate works wonders; a bit like a computer working on calculations in 'background processing', something suddenly pops into my mind when I'm not conscious of considering the problem.

I daresay you're right though that I'll end up with oval holes to allow some manoeuvering!

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7 minutes ago, Chas Levin said:

Yes, the drilling of the holes is occupying my mind currently, because of the unfortunate Catch-22 that only with the cab roof (and its new extended feet) in place could I judge where to drill, but drilling would then be impossible because the cab roof would cover everything!

Well, a solution will emerge in due course. I find with things like this that getting on with other jobs and giving it some time to percolate works wonders; a bit like a computer working on calculations in 'background processing', something suddenly pops into my mind when I'm not conscious of considering the problem.

I daresay you're right though that I'll end up with oval holes to allow some manoeuvering!

A professional model builder once told me not to hope to get them in the right place. I still hope to get them right... but I expect to ovalise them. 

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Today was spent making and installing boltable feet for the cab roof - here's the first one, the right-hand vertical one:

1707377005_LRMC1220210213(1).jpg.78f037ff10b1edc55f071f1b7dacc637.jpg

95697534_LRMC1220210213(1).jpg.e62e9a79610e96e373488ebead439aa5.jpg

2116747472_LRMC1220210213(3).jpg.d350ada51bec97a420d582e8c326d69a.jpg

1013565543_LRMC1220210213(3).jpg.8a34a104042d3628b9d33e861e9f0441.jpg

 

You were quite right David about the inevitable ovalisation of the hole:

1971777586_LRMC1220210213(4).jpg.ee5ec960197f78a20f8222fd1ec6e984.jpg

345001555_LRMC1220210213(4).jpg.59e13df5cb03d6c5357b886e020ef136.jpg

 

I found I could reach in to the cab through the right hand door to mark through the bolt and on to the cab front wall, but the marking was a little too far left and a little too low because of the angle and the necessarily thin scribe, necessitating enlargement as you can see. It looks worse than it is, but I'll probably put a washer on the bolt inside the tank, just to make sure it has sufficient land to gripwell. The only 14BA bolts I had in stock were 1/2" countersunk - short cheeseheads are now on order - and here's one inserted a few turns, just to check clearance:

1385573925_LRMC1220210213(5).jpg.0701b438adda7179fcbc7198d17e69ff.jpg

562081267_LRMC1220210213(5).jpg.1c4aa255bac5d4fa1bbf079ed72e7265.jpg

 

(Apologies for the large amounts of messy soldering: I tend to want to make things as strong as possible internally and as it's never going to be seen I don't worry about cleaning up. Also, I'm taking these pictures on my phone and the second lot were done under an LED magnifier lamp with gives a somewhat unattractive hue to the solder, especially after a few de-fluxing washes :rolleyes:).

You were right Jon that doing up a bolt inside the tank like this is an absolute b^gger and much more awkward with a long bolt, as it wobbles around and the greater length means the screwdriver's at a worse angle. Your suggestion David of supergluing the screwdriver to the bolt is a good one for straight applications, but here, the screwdriver needs to change angle continuously as the bolt rotates, a bit like a universal joint. It'll be easier with the short bolts though.

 

Next was the left-hand foot, the horizontal one - I left this one deliberately and put in a second hole, in case I had trouble with the first one, but I'll trim it off in due course. You can also just see on the second picture that I've bent the rear roof wall's tabs backwards just a touch to hold the back of the roof in place too:

1005762419_LRMC1220210213(6).jpg.e8fe7fa239420e973164da98ce312c28.jpg

1170281195_LRMC1220210213(6).jpg.b6d79c902578932345f69a2be1e1fcc7.jpg

1076510233_LRMC1220210213(9).jpg.88adba11803f817408644c98dfa54d6d.jpg

831412920_LRMC1220210213(9).jpg.f5743beb178dfa44d43f5aa120067b62.jpg

 

The hole for this was a little more accurately positioned, done by measurement (and a bit of luck!):

1164595475_LRMC1220210213(10).jpg.2fbf824db421e9e693ef070e0565cfed.jpg

1974398334_LRMC1220210213(10).jpg.0b06c886c09f4e7e5d47f508fa0f2078.jpg

 

Here's a shot of the bolt going up through the inner cab side top and bracket:

2143663650_LRMC1220210213(7).jpg.15d640f2a1a685cbe518d6ea811f7f91.jpg

588397422_LRMC1220210213(7).jpg.90d295e949bacab49decb5bfc649c4ca.jpg

 

Overall it went very well - thank you again David for the suggestion. It's a great technique that I can see being useful in a wide variety of situations...

Edited by Chas Levin
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On 07/02/2021 at 20:16, Daddyman said:

Are these any good, Chas? https://www.caley.com/fitting.php They're listed as "cylinder lubricators" and there are two or three different types on the sprue. From what I can see of C12 photos on the internet, they just have standard ball lubricators, which the Caley Coaches sprue includes. 

 

Nice job on the tank-top gap! Pity about the boiler. Can you do anything? I can't quite work out from your post what has gone wrong - is it not parallel along the length of the loco, or is 12 o'clock not at 12 o'clock? 

 

And yesterday's post brought the Caley Coaches sprues you pointed out to me, which do indeed include suitable lubricators:

 

665937157_CaleyCoachesinclubricators.jpg.5a42519cb785fef98e254ddaf4f8b1c7.jpg

 

I couldn't actually find a photo of them on Caley's site though, so I bought them 'blind' but they look just right, which I'm glad about as I'm sure they'll look much better than any I might have made, which would have been a bit over-sized, for one thing.

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9 hours ago, Chas Levin said:

588397422_LRMC1220210213(7).jpg.90d295e949bacab49decb5bfc649c4ca.jpg

 

Overall it went very well - thank you again David for the suggestion. It's a great technique that I can see being useful in a wide variety of situations...

Yay! Well done! 

 

Glad the Caley Coaches lubricators are suitable too. 

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Some more details added today, while I wait for the thin tubing to arrive to use on the vac and steam piping; firstly, the front frame pieces (separate from the chassis etch, they go up under the front of the footplate, against the back of the buffer beam) and the front lifeguards, attached to those pieces:

1607493316_LRMC1220210215(1).jpg.55eb06971294d30b06b2b20d8158140e.jpg

1264560150_LRMC1220210215(1).jpg.f7894f3d8052e3e78e912e9e32e3bcce.jpg

 

They took some careful alignment: the frame extension pieces are easy to place, but the lifeguards are difficult to get accurately and symetrically aligned. The overlap area between their top sections and the half-etch pockets on the frame extension pieces is only about a mil, so holding them in place with an aluminium hairclip and fluxing and soldering them without causing any movement (even a fraction of a mil shows) is delicate!

 

Next, the rod - or pipe - that passes out of the right-hand tank front and enters the side of the smokebox wrapper, just above and just behind the hole for the cylinder lubricator. Can anyone tell me what this part actually is, please? It's been added in the photos below and can be seen, below the handrail and running parallel to it (well, as parallel as my phone camera this close to the subject allows it to appear - I really must try photographing from a little further away...:rolleyes:):

522543715_LRMC1220210215(2).jpg.125732333088db752353d0cd3b0edeee.jpg

1977224911_LRMC1220210215(2).jpg.9b4b5d501cc40680ee6c073bd9ce8a0e.jpg

400578651_LRMC1220210215(3).jpg.ce7c5ace1c4875c8fe405ceee034632a.jpg

1111209297_LRMC1220210215(3).jpg.707dd93432cd34f32b184624fcc66ef6.jpg

Edited by Chas Levin
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A quick early morning correction: further study of photos shows that the rod or pipe I was asking about doesn't go through a hole into the front wall of the side tank, it goes alongside the tank, in between it and the boiler - which also means it can run at a more natural looking angle, parallel to the boiler when viewed from above:

755932922_LRMC1220210216(1).jpg.f9e5523f664e7fcb6b2ee0f46e6a28dc.jpg

307183546_LRMC1220210216(1).jpg.f9954cd42995bb01145c648ebcd1db6d.jpg

 

Some more cleaning up to do where the hole it had gone through has been filled, and around the front end entry into the smokebox, but amongst my new cleaning-up Secret Weapons are these:

https://www.scalemodelshop.co.uk/6-pack-sanding-needles-2-of-each-150-240-320-albion-alloys-4444-p14776/s14776?utm_source=google&utm_medium=cpc&utm_term=albion-alloys-6-pack-sanding-needles-2-of-each-4444&utm_campaign=product%2Blisting%2Bads&cid=GBP&glCurrency=GBP&glCountry=GB&gclid=EAIaIQobChMIooSHhIPi9wIVge_tCh2pawBdEAQYBCABEgKDf_D_BwE

 

They're made of reasonably flexible plastic with a grit content that comes in various grades, and the shape and flexibility allows reaching things like that patched hole above, which is not only difficult to access because of where it is, but also because of the other fittings - steps and handrails - around it. Usual disclaimers: no connection, just a happy customer - and their Sanding Sticks are really excellent too, also the polishing pads, the flex-i-files - well, you get the picture: I'm a fan! :)

Edited by Chas Levin
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On 10/02/2021 at 14:03, Jol Wilkinson said:

I've never tried that with my 50W Antex but I suspect it wouldn't work very well. The knob will act as a heat flow restrictor and probably also lose quite a bit of heat (large surface/volume ratio), whereas will the RSU it doesn't do it so much for then current flow. I always had to apply the iron to the boiler/w.h.y. to get a good joint with a regular iron and also had to do a cleanup job afterwards.

 

If you haven't already seen it, this video by David Brandreth is excellent.

https://www.scaleforum.org/demonstrators/david-brandreth-resistance-soldering/

Jol, I finally sat down and watched this video last night, very interesting. I hadn't realised the high current involved - David mentions 35 to 40 amps. Is this standard across all RSU units?

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1 hour ago, Chas Levin said:

Jol, I finally sat down and watched this video last night, very interesting. I hadn't realised the high current involved - David mentions 35 to 40 amps. Is this standard across all RSU units?

Chas,

 

I don't know. The London Road Models RSU transformer is rated at 100VA, the USA  American Beauty units start at that and go up to over  1000 Watts (they quote watts rather than VA). As for others, I only know of one UK RSU built for modellers but don't know of the output current rating.

 

However, it appears that you need current of around the level that David Brandreth quoted to generate sufficient heat at the joint being soldered to raise the temperature locally and quickly to melt the solder without excessive heat "spread".

 

Jol

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44 minutes ago, Jol Wilkinson said:

Chas,

 

I don't know. The London Road Models RSU transformer is rated at 100VA, the USA  American Beauty units start at that and go up to over  1000 Watts (they quote watts rather than VA). As for others, I only know of one UK RSU built for modellers but don't know of the output current rating.

 

However, it appears that you need current of around the level that David Brandreth quoted to generate sufficient heat at the joint being soldered to raise the temperature locally and quickly to melt the solder without excessive heat "spread".

 

Jol

Thanks Jol, I'll investigate further; makes sense that you'd need some serious juice for the sort of heat required.

 

I was intrigued by the demonstration of the pattern of heat spread, as I'd been puzzling over how the current - and heat - move through the workpiece. As I understand it, by connecting a piece of metal to an electric circuit, the current moves through the whole piece of metal simultaneously, molecule to molecule (the analogy we were taught is that it's like a pipe that's already full of water, which is then connected to a pressured water supply - the water in the pipe all moves at the same time).

So to explain the success of the RSU, we must be looking at the combination of high current and a narrow path - the probe point. And, as the path broadens and the current 'fans out' from that point contact, across the wider workpiece, the heat reduces, hence the pattern shown in the molten solder demo at 12'30".

 

Hm... interesting :scratchhead:

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15 minutes ago, Paul Cram said:

The heat is generated at the point of maximum resistance which is the joint to be soldered. The hetr spreads from there is my understanding.

Yes, I think that's exactly it Paul.

 

I'm still interested though in how and why it differs from a 'normal' iron in the way that it heats - I'll have to go and read up some basic physics I think.

 

A normal iron heats by conduction, as it's in contact with the workpiece. So, I would have thought that the heat using that method should follow a similar pattern to heating by RSU, in that I would expect it to be at its greatest at the point of contact (the iron tip), fanning out (and reducing in temperature) from there; which is of course what we observe with a normal iron.

 

So, if that's the case, how and why is using an RSU better?

 

I have read that the heat is 'more localised', which I take to mean that it spreads out less. I wonder how or why that's the case...

 

Just to be clear, I'm not asking this from the point of view of a sceptic as I realise that modellers with way more experience than I have swear by them. Never having used one I don't have an opinion yet, but I'm interested in the physics of what's happening, partly because I can see myself getting one in due course....

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The RSU itself doesn't generate heat as such. It is the current flowing from the carbon rod through the workpiece that generated the heat at the point of resistance i.e. the joint to be soldered. If dering a chimney for example the carbon rod would be placed at the top but the heat would be generated around the base where it joins the smokebox. The benefit is that the base of the chimney can bu tinned or solder past/craem can be used and there is no solder outside the joint to clean up.

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5 hours ago, Paul Cram said:

The RSU itself doesn't generate heat as such. It is the current flowing from the carbon rod through the workpiece that generated the heat at the point of resistance i.e. the joint to be soldered. If dering a chimney for example the carbon rod would be placed at the top but the heat would be generated around the base where it joins the smokebox. The benefit is that the base of the chimney can bu tinned or solder past/craem can be used and there is no solder outside the joint to clean up.

Interesting, thank you Paul. I shall look at getting one I think...

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So, while waiting for the brass tubing from Eileens for the vac and steam valance piping runs, I took some time out for some other projects:

1793263083_Thorntons4-4-0.jpg.a93ce048726256f2c028ed6321476b34.jpg

1982913943_Thorntons4-4-0.jpg.8e207ed72a6fca799a6cca9d00ab4d73.jpg

 

This is Thornton's latest RTE (Ready To Eat) 4-4-0 and I'm pretty pleased with it. Nice rivet detail, but those molding lines will need some work. I'll run it in for a while, then look at adding some detail: I wonder what solder is best for joining dark and milk chocolate? :)

Edited by Chas Levin
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While work on the body is held up it seemed a good time to return to the chassis and tackle the brake rigging, which I'd had some difficulty in working out - no fault of the instructions, more to do with my lack of experience!

Arranging the pickups around the rigging is an interesting challenge - my previous build had little going on underneath so it wasn't a problem.

I am coming to the conclusion however that removable rigging might be called for: with it permanently fixed, neither the motor-plus-pickups assembly or the hornblocks can be removed and even if repair or maintenance is never needed, I'd intended removing them after final testing in order to clean and paint the chassis.

Is this something a lot of people do?

I've seen occasional mention of it in others' builds, but the general pattern seems to be permenent soldering...:scratchhead:

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12 hours ago, Chas Levin said:

While work on the body is held up it seemed a good time to return to the chassis and tackle the brake rigging, which I'd had some difficulty in working out - no fault of the instructions, more to do with my lack of experience!

Arranging the pickups around the rigging is an interesting challenge - my previous build had little going on underneath so it wasn't a problem.

I am coming to the conclusion however that removable rigging might be called for: with it permanently fixed, neither the motor-plus-pickups assembly or the hornblocks can be removed and even if repair or maintenance is never needed, I'd intended removing them after final testing in order to clean and paint the chassis.

Is this something a lot of people do?

I've seen occasional mention of it in others' builds, but the general pattern seems to be permenent soldering...:scratchhead:

Removable every time, Chas (Thorntons got that part right) . This is one way to do it (see Morgan Gilbert's post - "45609"): 

I've always done a version of that way myself, but I don't do the tube through the frames (I found opening out the holes in the frame for the tubes caused the hole to wander). Instead I put wire through as normal and then cut some small pieces of tube which go on the wire between the frames and the brake hanger. In 00 the overall width between the backs of your brake hangers should be 17.5mm though you'll need to check that this looks right with regard to the wheels - you don't want the brake blocks proud of the wheels. From there, knowing the width over your frames, you should be able to work out how long those bits of tube need to be - around 2mm each side. The wire through the frames and through the tubes can then be just long enough to hold the hangers - too long and you'll have to bend the hangers too much to get the rigging off. 

 

I have a piece of wood 17.5mm wide which I use as a jig when soldering the hangers to the cross pieces.

 

Having said all this, Dave Bradwell has recently alerted me to a problem with this method, which, it's true, can occur: the action of removing the rigging can bend the hangers along their length or weaken the joint at the bottom where they meet the cross piece. This can lead to a situation in which the hangers don't spring back to vertical, which can lead to shorting on rods and valve gear. His method, which I'm inclined to try, is to slot the hole at the top of the hanger so that the brake rigging can come off downwards rather than outwards. The method of fixing is then a piece of scrap etch soldered to the centre of the lower cross piece (that between the bottom holes of the hangers) which bolts to a captive nut on a existing frame spacer or a specially added one. Hopefully you can see the principle here: P1350370.JPG.893b2cb008b8c93ed75013a0f36ed9d4.JPG

Note that there are no slots in the tops of the hangers - I've just lopped them off, as they're hidden by the tender frames. You won't have that luxury...  

 

Don't worry about pickups: somehow you'll get there; there's always a way to bend them round obstructions. I certainly wouldn't compromise on any detail for their sake. Whatever you do, make sure your pickups are soldered to a PCB pad which can be bolted to the frames - something you should have planned for when putting frame spacers in, but not impossible to do now. Having the pads removable allows you much more freedom when bending the pickups - you can bend them off the loco, instead of trying to bend them against the wheels, and having them spring back to a position just off the wheel. 

  

Right, that's enough of me rambling! 

Edited by Daddyman
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On 21/02/2021 at 08:29, Daddyman said:

Removable every time, Chas (Thorntons got that part right) . This is one way to do it (see Morgan Gilbert's post - "45609"): 

I've always done a version of that way myself, but I don't do the tube through the frames (I found opening out the holes in the frame for the tubes caused the hole to wander). Instead I put wire through as normal and then cut some small pieces of tube which go on the wire between the frames and the brake hanger. In 00 the overall width between the backs of your brake hangers should be 17.5mm though you'll need to check that this looks right with regard to the wheels - you don't want the brake blocks proud of the wheels. From there, knowing the width over your frames, you should be able to work out how long those bits of tube need to be - around 2mm each side. The wire through the frames and through the tubes can then be just long enough to hold the hangers - too long and you'll have to bend the hangers too much to get the rigging off. 

 

I have a piece of wood 17.5mm wide which I use as a jig when soldering the hangers to the cross pieces.

 

Having said all this, Dave Bradwell has recently alerted me to a problem with this method, which, it's true, can occur: the action of removing the rigging can bend the hangers along their length or weaken the joint at the bottom where they meet the cross piece. This can lead to a situation in which the hangers don't spring back to vertical, which can lead to shorting on rods and valve gear. His method, which I'm inclined to try, is to slot the hole at the top of the hanger so that the brake rigging can come off downwards rather than outwards. The method of fixing is then a piece of scrap etch soldered to the centre of the lower cross piece (that between the bottom holes of the hangers) which bolts to a captive nut on a existing frame spacer or a specially added one. Hopefully you can see the principle here: P1350370.JPG.893b2cb008b8c93ed75013a0f36ed9d4.JPG

Note that there are no slots in the tops of the hangers - I've just lopped them off, as they're hidden by the tender frames. You won't have that luxury...  

 

Don't worry about pickups: somehow you'll get there; there's always a way to bend them round obstructions. I certainly wouldn't compromise on any detail for their sake. Whatever you do, make sure your pickups are soldered to a PCB pad which can be bolted to the frames - something you should have planned for when putting frame spacers in, but not impossible to do now. Having the pads removable allows you much more freedom when bending the pickups - you can bend them off the loco, instead of trying to bend them against the wheels, and having them spring back to a position just off the wheel. 

  

Right, that's enough of me rambling! 

Morning David, thank you, some interesting food for thought there (and no rambling IMHO:)). Too late to open up the holes in the frames to acommodate tubing as the wires (with flanges) are already in place but in any case I noted your point about wandering centres.

So tubing over the wires would seem to be a good option. I note your point that the wires then just need to be long enough to hold the tubes in place, so they can be a little shorter and thereby ease removal of the tubes.

 

Actually, I'd been looking at making the removable joint at the lower end of the brake hangers: soldering the top end where it hangs off those wires (which I thought would have the advantage of keeping the hanger positions reliably in place relative to the wheels) and leaving the ends of the cross-members long enough to go through the holes in the bottoms of the hangers...

1875004751_LRMC1220210221(1).jpg.7cae6a4c114bcf5f956dad8434c4b8e2.jpg

1638960739_LRMC1220210221(1).jpg.d62ae4b9e8b51f5778ea98e2666716fc.jpg

 

Hm: I was about to continue by asking whether there are any disadvantages in that idea but while typing it, I found myself thinking that leaving those cross-member ends long enough to give even a half-reasonable hold would not only look wrong but provide a possible point of snagging on other things: agreed? And that's probably why wiser and more experienced heads have come up with the tube method (whether through the frames or over wires) you suggest.

 

The other question is what to do about the attachment to the brake cross shaft levers under the cab end. One idea I had was to leave them unsoldered on the cross shaft, so that when the hangers are unhooked from the frame (using the tube method, as I think we've now established!) the whole assembly swings down, pivoting on the cross shaft...:unsure:. I'm sure I've seen somewhere something similar, a pivoting type of arrangement.

 

Dave Bradwell's method (which I can indeed see from your picture) sounds excellent and I would do that if I could as I like solidity / permanence / belt+braces but I don't think it's possible here, though I'll have another look later.

 

And yes, I did indeed include a pickup PCB that bolted rather than glued - you can see it in the above picture in fact. I did originally try bending pickups off-loco but found it easier in situ. I'm not entirely happy with the 0.33mm PB wire I'm using; I may well stick with it on this loco but I'm going to look at other options on the next build.

 

Edited by Chas Levin
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24 minutes ago, Chas Levin said:

Actually, I'd been looking at making the removable joint at the lower end of the brake hangers [...] which I thought would have the advantage of keeping the hanger positions reliably in place relative to the wheels [...] 

 

No, Chas - the whole idea of having them removable is so that you can get the wheels out. If the shoes and hangers are good and close to the wheels, then you have no chance of getting the wheels out if the brake rigging is fixed. 

 

26 minutes ago, Chas Levin said:

The other question is what to do about the attachment to the brake cross shaft levers under the cab end. One idea I had was to leave them unsoldered on the cross shaft, so that when the hangers are unhooked from the frame (using the tube method, as I think we've now established!) the whole assembly swings down, pivoting on the cross shaft...:unsure:. I'm sure I've seen somewhere something similar, a pivoting type of arrangement.

That's one option (and one of the better design features on the 52F C16), but you can also just position things "nearby", so that they look like they're all connected. 

 

I have no thoughts on pickup wire. I use 0.45 N/S wire, but am not particularly zealous about it. I've never got on with the PB wire. 

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2 hours ago, Daddyman said:

No, Chas - the whole idea of having them removable is so that you can get the wheels out. If the shoes and hangers are good and close to the wheels, then you have no chance of getting the wheels out if the brake rigging is fixed.

Yes, understood. Actually, the question of positioning of the brake hangers and shoes has been exercising me a little too. Because I need to be able to deal with sharp curves (necessitating some sideplay on the driving axles) and also allow for the movement of the compensated driving axle (which imparts some lateral movement of the wheel top and bottom when it tilts), I've been looking at positioning the brakes decently clear of the wheels, but with the wires through the pre-drilled holes and given the width of the brake shoes, this meant that the hangers sat at quite an angle, leaning away from the wheels. Looking at photos of the prototype and others' models and the Isinglass drawing however, the hangers seem generally to hang near vertical. Even allowing for the fact that the drawing and all the prototype photos - where the brakes are clearly visible - show the locos with the brakes on, it still looks wrong, so I'm going to thin down the shoes a little to allow the hangers to sit nearer vertical. The shoes are quite wide compared to the drawing so I think there's some room to play with on that dimension.

I think though that the tubing idea will result in the rigging being more stable when in place than my idea using the hangers' lower hole, so my lower hanger hole idea is best discarded...

2 hours ago, Daddyman said:

That's one option (and one of the better design features on the 52F C16), but you can also just position things "nearby", so that they look like they're all connected.

I'm delighted to hear that 52F also pivot their rigging - I never know with things like that whether it's a silly idea or not, so it's reassuring when someone else has tried and tested it!

I'm not so keen on having the cab-end ends of the brake pull rods (hope I'm using the right term there) just floating; I know it would look fine from normal viewing angles, but I'd prefer to have them attached as it seems safer (in case they catch on something) and might they not rattle a little if they're not anchored?

2 hours ago, Daddyman said:

I have no thoughts on pickup wire. I use 0.45 N/S wire, but am not particularly zealous about it. I've never got on with the PB wire. 

And yes, to reply to what you said in your last but one post, I know I'll get the pickups in place one way or another! The DJH J9/10 didn't include any brake at all in the kit, so I used some shoes and hangers from a Mainly Trains etch and ran a wire between the bottom holes of each hanger from side to side, but I didn't put anything else in place, which made pickup routing easier. But no, I won't compromise detail for pickup convenience.

Can I ask what it is that you didn't like about PB wire?

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1 hour ago, Chas Levin said:

Yes, understood. Actually, the question of positioning of the brake hangers and shoes has been exercising me a little too. Because I need to be able to deal with sharp curves (necessitating some sideplay on the driving axles) and also allow for the movement of the compensated driving axle (which imparts some lateral movement of the wheel top and bottom when it tilts), I've been looking at positioning the brakes decently clear of the wheels, but with the wires through the pre-drilled holes and given the width of the brake shoes, this meant that the hangers sat at quite an angle, leaning away from the wheels. Looking at photos of the prototype and others' models and the Isinglass drawing however, the hangers seem generally to hang near vertical. Even allowing for the fact that the drawing and all the prototype photos - where the brakes are clearly visible - show the locos with the brakes on, it still looks wrong, so I'm going to thin down the shoes a little to allow the hangers to sit nearer vertical. The shoes are quite wide compared to the drawing so I think there's some room to play with on that dimension.

I think though that the tubing idea will result in the rigging being more stable when in place than my idea using the hangers' lower hole, so my lower hanger hole idea is best discarded...

I'm delighted to hear that 52F also pivot their rigging - I never know with things like that whether it's a silly idea or not, so it's reassuring when someone else has tried and tested it!

I'm not so keen on having the cab-end ends of the brake pull rods (hope I'm using the right term there) just floating; I know it would look fine from normal viewing angles, but I'd prefer to have them attached as it seems safer (in case they catch on something) and might they not rattle a little if they're not anchored?

And yes, to reply to what you said in your last but one post, I know I'll get the pickups in place one way or another! The DJH J9/10 didn't include any brake at all in the kit, so I used some shoes and hangers from a Mainly Trains etch and ran a wire between the bottom holes of each hanger from side to side, but I didn't put anything else in place, which made pickup routing easier. But no, I won't compromise detail for pickup convenience.

Can I ask what it is that you didn't like about PB wire?

Hello again Chas. PB wire snapped quite easily when I tried to do the things with it that I happily do with N/S wire. I have sometimes wondered if there's a coating on N/S wire that needs to rub off, as the pickups work terribly at first, and then seem to bed in. 

 

Pivoted on the whatsit at the back is the right way to do it, so carry on!  

 

Re brake hangers/shoes, don't worry about compensation and play - they'll be OK. I think Morgan / Gilbert recommends a piece of thin card between wheel and shoe. Any more looks awful. You can chamfer the shoes on their rear edge. 

 

Many kits get the position of the holes for the top cross wire wrong, and hangers at the wrong angle can spoil the look of a loco. You can either fudge it by bending the wires fore-wards (as opposed to aft-wards), or make yourself a jig to drill the hole at the correct place. The jig would have two holes: one you insert a piece of wire though, and through the frames, and the second hole you drill through into the frames for the new cross wire hole; it's a bit of a job finding the right position for the second hole, but it's often 1mm away from the original! Filing the blocks can sometimes work, as long as you don't lose the character of the blocks.    

Edited by Daddyman
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