2mm Coal Tank test build

[John lewsey]

Very nice

[Branwell]

I made a start on mine when it arrived, but it is currently on pause awaiting the availability of the Chris Higgs chassis.

There are some photos below showing progress to date. I deviated substantially from the instructions and had to modify a few parts to get this far. I would call this kit "difficult" when compared to others I have half built(!) but I am pleased with the way it is coming together.

 

I haven't gone any further with the boiler and smokebox (which is the next step), as until I see how the motor fits, I don't know how much of the underside of the boiler tube to cut away.

 

When I do get round to the smokebox, I intend to form it in the same way I did the L&Y radial tank (Nigel Hunt kit) smoke box. There's a photo of this on my Gallery.

Basically, I rolled the wrapper to be a tight spring fit. I spread solder paint on the top half of the inside of the wrapper and soldered it in place with a gas flame.

The bottom edges of the wrapper (which remained unsoldered) could be peeled back and rolled the other way to match the profile of the smokebox front plate.

 

While there is no etched wrapper in the kit, a suitable one forms part of the previously available shot-down Brassmasters etch for a Bowen Cooke 3000 gal. LNWR tender.

(Perhaps that nice Mr Higgs could be persuaded to include one on the chassis etch?)

 

At the moment I am debating with myself as to whether a 5 thou. "inner wrapper" should be installed, level with the front of the boiler tube, then the outer wrapper placed on top, projecting forwards by 10 thou. to fit over the front plate. If only a single wrapper were used, the front plate wouldn't fit inside it, and would have to butt onto the front of it.

 

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You're making a very nice job of it, Nick - much neater than mine.

 

Thanks for the thoughts on the smokebox wrapper as well - food for thought.

 

I'd also be interested to know what other modifications/deviations you've made.

 

Regards,

 

David

Edited August 28, 2016 by Branwell

[Nick Mitchell]

I'd also be interested to know what other modifications/deviations you've made.

 

While useful background, I found that most of the 4mm instructions didn't apply at the "ground level" in 2mm, so I started writing up my own construction notes as a set of "alternative" instructions for the body.

 

They only go as far as I've got with my build, but I have attached a copy of my working draft, in case anyone wants to follow exactly what I've done.

 

I will update them once I've got the chassis built and know how to finish off the body.

 

Coal Tank 2mm construction notes NPM.pdf

[Branwell]

Thanks Nick - very useful.

 

Having had a quick read, the one thing in there that I'd echo is the fragility of the footplate before the valances have been added - my test build has a prototypical bend at the cab doorway!

 

David

[nigelb]

Nick thats really useful  i  have been  slowly working on  my  model  in between  a 7 mm   6 wheel coach   talk about little and large  LOL

 i   have been pondering the cab hand rail issue  and  like your idea  better than what i was thinking   which was t  use a pin to make a dimple on the underside of the overhang

 

[Hendreladis]

Finally started fiddling with the coal tank. Found some old (Mike Bryant era old) gears pre moulded on to muffs in the gloat box and opted to use them in the drive train. That meant the motor ended up in the cab after a bit of hacking.

 

The boiler in the pictures is over size. In the absence of a drawing I guesstimated from a photo. Not great and if anyone can give dimensions for said boiler I would appreciate it.

 

Definitely won't get around two foot radius curves without a pony truck. Time for more filing . . .

[Nig H]

Finally started fiddling with the coal tank. Found some old (Mike Bryant era old) gears pre moulded on to muffs in the gloat box and opted to use them in the drive train. That meant the motor ended up in the cab after a bit of hacking.

 

The boiler in the pictures is over size. In the absence of a drawing I guesstimated from a photo. Not great and if anyone can give dimensions for said boiler I would appreciate it.

 

Definitely won't get around two foot radius curves without a pony truck. Time for more filing . . .

Hello Andrew,

 

Nice work. The external diameter is 4' 6", so 9mm. There are drawings and an article in Model Railways November 1975.

 

(Did you get my email re the 0-8-0?)

 

Happy Xmas to all,

 

Nigel

[Branwell]

Nice to see somebody else having a go and looking good so far. Must have another go myself ...

 

What's the ratio of the gears you've used?

 

As Nigel's said, the diameter of the boiler is 4'6", so 9mm OD tube is spot on for size,

[John lewsey]

The coal tank looks very nice

[Hendreladis]

Thanks for the info on the boiler guys. Managed to unearth a drawing in the Roche collection which helped. There are still bits on the etch I don't understand and I seem to have lost the footsteps. Looks like I'll be going through the bin . . .

 

Checked the gearing. The plastic gears are a 20 and a 26 so not great coupled to the association 30:1 but it runs. The trailing truck is a bit of a bodge caused by having to make adjustments to the drive train as the build commenced. I have two more etches so we'll see if the planning is any better second time around. Chances are I'll wait for Chris Higgs to solve the problems.

 

This will go back on the gloat box for now. I a bit disappointed with aspects of the build. It is acceptably square and pretty much the right length but the proportions aren't quite right. Maybe a chimney etc. from Mr Tilson will help.

 

The chassis has developed a twist somewhere along the build. Everything goes around and it is possible to twist it back into alignment and get all wheels lying flat but overnight it relaxes back into a corkscrew. Irritating.

 

Wasn't happy with the motor so far back but it has allowed plenty of space for weight over the wheels and within the chassis between the drivers.

 

BTW the coupling rods are from the old association stainless steel generic fret. Pretty sure the stainless will grind throu h the brass crankpins at some point even with plenty of broaching and easing during assembly.

 

Overall verdict? Someone out there will certainly be able to make a decent job of this kit. It ain't gonna be me. On the plus side skills are increasing and so is the understanding of how much slop to include in the mechanisms. That was the most daunting knowledge gap. Time will tell if the lessons have been learned properly.

[Hendreladis]

That nice Mr Tilston came up trumps with the majority of the castings required to take the coal tank a bit further. Ultimately they all proved a bit generous in size but a bit of fettling and filing brought them up to my expectations. The toolboxes needed about 20 thou off the bottom, their tops reduced by another 10 thou then re profiled but they were only a gnat's smidgeon off for length. Safety valve needs the seat reduced and a bit of thinning of the lever on top but its okay. The dome is quite hefty and a bit 'wobbly' but some filing overcomes that. It may need a few more strokes having seen the pictures. In one picture it looks as though it leans a bit to one side. A compromise. It is okay in other planes and I can probably live with it.  

 

The smokebox door (which is very nice and a good fit for size) hasn't been attached yet. The chimney is out of stock for a while but will hopefully be available by the time other minor jobs have been addressed.

 

I had struggled to work out the purpose of some parts on the etch. Eventually it became clearer once I had paid more attention to drawings and photos. There is potentially an awful lot of fiddly detail to include. Given that I had never taken note of it previously I may well exclude the vast majority on the model. If you are close enough to spot the twiddly bits you are close enough to see a legion of other flaws. I opted to attach a front footstep using an extended length of wire through the footplate on one side. Too tight to other handrails to get in with cutters but Jim Watt has suggested grinding it off. What could go wrong?

 

Lots of scraping and araldite carving to do. The value of the pictures is that it pinpoints the worst bits. You'll also see that it has been dropped a few times but hopefully final prep before paint will allow the bumps and bruises to be ironed out.

 

Runs okay now too so encouraged to finish it eventually. In the meantime it goes back to the box.

 

Mobile phone pics attached.

 

 

[nigelb]

Damm I suppose I better got on with mine  now

[Caley Jim]

............There is potentially an awful lot of fiddly detail to include. Given that I had never taken note of it previously I may well exclude the vast majority on the model. If you are close enough to spot the twiddly bits you are close enough to see a legion of other flaws..........

Looking good, Andrew.

 

I wouldn't be too quick to condemn 'fiddly bits' to the bin, or the 'scrap box'.  Sometimes small details can add the essential 'character' to a model, even though their presence is not immediately obvious.  I work on the principle of what I call 'significant details', defined as those details which would be significant by their absence.  In general terms, if a detail breaks up a space or the profile of the model, then it needs to go on.  For example a row of rivets running diagonally across a tender needs to be there, but you can get away with omitting them if they run along the angle of the body and footplate.  Similarly a small pipe running under the angle of footplate and valance will never be missed, until it turns upwards and cuts across the edge of the footplate.

 

Jim

[Nick Mitchell]

Up until a couple of weeks ago, I was happily sitting back waiting for the Masterclass chassis to appear.

A conversation with that ever-so-persuasive Mr Hunt convinced me there was nothing to loose in having a go with the shot-down LRM bits in the mean-time.

So far, it is working out quite nicely...

 

The radial truck was always going to be the tricky bit, but I had a spare one from a test-etch of Nigel's L&Y 2-4-2T kit.

I used the "radial cheek setting tool" from that kit to help solder a pair of 1.5mm wide n/s strips to the inside of both frames while they were paired up back-to-back on the fret. On the 2-4-2 kit, the cheeks fold in from the frames and the slots in the tool hold them at the correct angle while you put a fillet of solder in the folds. Here, they held the cheeks at the correct angle and spacing, and I positioned the pair by eye to line up with the bottom of the frame extensions.

After cutting out and separating the frames, I cut back the cheeks to a sensible length, fitted some frame strengthening plates across the tops of them, and then filed out the horn gaps.

 

For the drive train, I turned again to the Radial tank for inspiration. I decided to use the same gearing (21t worm wheel and 20t / 14t spur gears) giving 30:1 overall reduction, driving onto the centre coupled axle. For the motor, I intend use a coreless 719 - superficially identical to the current Farish ones, but obtained from eBay at £5 for four! If they turn out to be rubbish, a genuine Farish will substitute. A Nigel Lawton 8mm coreless would also fit.

 

Fitting bearings for the intermediate gear axle caused some head scratching. I'd initially thought about using a section of the frames from the aborted 2-4-2 teat etch as an overlay to the inside of the main frames, but then thought better of it. In the end, I used them only as a template. I used an Association gear meshing/marking tool to measure the meshing distance in the 2-4-2 frames, and mark out an arc on the Coal Tank frames. The hole for the bearing was going to have to break out of the top of the frames, ending up as more of a slot in which to fit the bearing. I made the slot slightly too large (deliberately!) and then with the driving axle bearing soldered in place, used the meshing/marking tool as a jig to hold the intermediate gear axle at the correct meshing distance as I soldered it to the frame.

 

Nigel H sells a set of generic etched frame spacers, to be used with thin double-sided PCB. I had a set tucked away and they were ideal for this little project.

You can see where they ended up in the photos below. I used more spacers than one might normally expect, in an attempt to make the thin frames a rigid as possible. I think I have succeeded in that respect. I even went so far as to make one spacer into a representation of the motion plate, and added suggestions of the top slide-bars and valve spindles. These will be practically invisible under the boiler, but were fun to make.

 

After installing the spacers, the front and centre driving axles have been opened out to 1.6mm for Simpson springing. Springs and some cosmetic detail has been added.

The kit only has provision for a single tank support bracket each side. I understand there should be another pair near the front of the tanks. They may end up being hidden by the steps, but I will probably have a go at fabricating them from scrap etch anyway.

I haven't fitted rods for brake hangers yet, as I intend to use the Association wheel quartering jig, which they would foul. Besides, one of them ought to be positioned right on the flange of the intermediate gear axle bearing. Not sure how I'll surmount that problem yet - maybe a cranked hanger, or maybe even no hanger with the brake fixed only to the pull-rod at the bottom.

 

The photos below show:

1. My method of holding frames together with Association frame jigs in a vice to solder the spacers in place. The spacers were previously soldered to the RH frame - top in the photo - and checked for square-ness. You can make out a Fence Houses spacer wedged in to keep things square where the frames are particularly vulnerable.

2. Checking from every angle that the frames are parallel and square to each other.

3. A rough mock-up of where the gears and motor will end up - hopefully well hidden. The back end of the motor will protrude into the cab by a couple of mm, but shouldn't be visible from most angles. There should be plenty of space for a decoder in the bunker, and the side-tanks and front section of the builder will fill with lead. A good chunk of lead should fit in the ash-pan too.

4. Once the boiler is in place, the motion plate etc, won't be visible. This shot is to prove the bits really are there!

5. The chassis as far as I've got with it - springs fitted and details such as tank  supports and life-guards fitted. The springs at the rear will engage in eyelets on top od the radial truck to provide centre springing and some down-force. (It is necessary to have two springs, as experience has shown the trucks will tend to rotate around a single one.)

 

I'm posting this now, as it is the happy point before I put in the wheels, gears and motor, and find it wobbles or binds or won't go round corners...

 

Nick.

 

[John lewsey]

Hi Nick that really is very nice

[Nick Mitchell]

I thought I'd give an update on how things are coming along with my experimental Coal Tank chassis.

 

Although far from complete, I'm now happy that using the supplied chassis (radial truck aside) is a viable option.

I have had a few tense moments along the way, however!

The pictures below show where I'm up to, but I have a few comments too.

 

Despite my cunning plan to solder the radial cheeks for both frames as one piece while the frames were lined up and attached to the fret - guaranteeing alignment.... when it came to testing the truck in place, it was obvious that they were not anywhere near aligned! I don't understand how, but the radial axle leered at me from a jaunty angle. The beauty of soldered construction is that when things are wrong, you can take them to pieces and solder them again. Which I did, again with the aid of the "tool" from Nigel's 2-4-2 kit, and all is now well. The relative position of the cheeks was only a few thou. out, but the effect was that the chassis could never have run satisfactorily.

 

The 8 thou nickel silver does make it rather delicate - one can't be too ham-fisted - as I found out to my cost, but with the spacers in place the frame seems pretty rigid.

Once I had put the gears in, and the centre pair of driving wheels, I found that the gears were able to bind. I had allowed a bit of side-play on this axle, and with the Simpson springs taking up space, there wasn't quite enough room. You'll see from the "underneath" picture how I've since thinned the spur gear on the driven axle.

To do this, I had to remove the wheels from the muff, and in pulling them out, I managed to distort one of the frames slightly. I suppose I should have melted the muff off, but the temptation to try and re-use it overcame me.

I am normally to be found in the "tight muff" camp when it comes to fitting wheels, but after the ease with which I now know this material can be damaged, not wishing to court further disaster, for this loco I have adopted the "loose muff" approach. I will inject glue once the coupling rods are in place and everything is running smoothly.

The frame was straightened eventually, and touch wood, bears no lasting damage.

 

The motor (which I'm really pleased with) is simply epoxied to the long central spacer. The top of the spacer has been adjusted to be about 10 thou. below the top edge of the frames, and this gives an acceptable mesh for the worm.

 

I found some pieces on the etch which I couldn't identify, and which I pressed into service as the backing plate for the (absent from the kit) front tank supports. Rectangular with a half-etched line down the centre, they were too long, but were easily brought down to size. I hope I won't miss them at some future point in the assembly of the body!

Incidentally, the web of these supports is the wrong shape as supplied (for the two which are supplied) and needed filing to an inwards curve once soldered in place. An appropriate bit of the etch frame sufficed for the front support webs.

 

You can see in one of the pictures the support I made for the back end of the boiler. This was turned, and pegged into the hole in the cab front. The bottom part of the cab front and a section of the floor has since been removed (which would have been much easier to do in the flat) to accommodate the motor. As can be seen, this protrudes just over 2mm into the cab, but is fairly unobtrusive I think.

 

At the front end, all the mechanism is contained within the length of the tanks, and especially with the weighshaft and balance weights in place, should be well hidden.

Now I know exactly how far the worm extends, I can go back to the upper works and make the necessary cut-outs in the boiler tube.

 

I am planning to use the Association coupling rods (from the generic etch). The ones supplied have too many things I dislike about them. They are meant to be jointed, which is difficult to make work and look good in 2mm scale - especially with built-in slop in the axles. They are also far too chunky (which is not an insurmountable problem). But fatally, the holes are too big for the Association 0.5mm crank pins I have used. Fortunately, the Association etch has a pair of 14.5 + 16.5mm rods on it which are just right (fluted side hidden), but unfortunately they are temporarily out of stock. Still, I have plenty of other jobs to be getting on with.

Edited February 28, 2017 by Nick Mitchell

[Nick Mitchell]

Some stainless steel coupling rod etches arrived from Shop 2 yesterday. The word on the street is the artwork for these items has gone AWOL, so the nickel silver version won't be coming back into stock soon.

Coupling rods really need to be thicker than 10 thou. I had no joy soldering these together in pairs, so in the end superglued them, which seems OK so far.

 

I've installed one of the new "Long format" CTelektronik DCX77 decoders in the ash pan (picture below). I didn't know these existed until I was offered the choice when I went to buy one.

The original plan was to mount the decoder on a plate sticking up into the bunker, but with something happy to slip between the frames, the bunker area can be kept clear. It might be nice to model it fairly empty of coal.

 

On the track, things are looking very promising indeed. The link below is to a video showing it strutting its stuff. I had to blu-tack a b-t-b gauge over the centre drivers to calm it down. It really needs more weight than this, but there will be plenty of room in the tanks, smokebox, bunker and even a bit on top of the motor.

 

https://youtu.be/wjlvwOrW-XM

 

Just need to fit the brakes now to complete the chassis.

 

[nick_bastable]

that looks to be running very well congratulations  

 

Nick

[Caley Jim]

'Bare' chassis never run well without a bit of weight added to them to help pick-up.  Looking good Nick M.

 

Jim

[Nig H]

There are some good pics of the Bachmann 4mm version in the Bachmann topic under 'trade etc', post 380 dated 14 April. The pics may help with the detail.

 

I have been slowly building my 2mm version. The coupling rods fouled the brake pull rod so I had to bend down the wires at the top and bottom of each brake hanger to ease the pull rods down a bit. I also had trouble with the ejector(?) pipe passing over the tank support bracket near the front of the right side tank. I had to enlarge the hole in the cab spectacle plate so the rod for the pipe could be eased up a bit, file a flat on the underside of the rod where it passed over the bracket and file a slot along the bracket where the rod passed over it.

 

I'll post some pics if I get a chance.

 

Nig H

[Nig H]

Here are some pics of my Coal tank. Not much left to do build-wise.

 

 

 

 

I used 5 thou plasticard for insulation, but subsequent soldering made it curl up so the rear end of the body is slightly up in the air. I'm pleased with the performance of the motor - I got it from Farish but it looks almost identical to the Chinese ones, the latter being a lot cheaper!

 

Nig H

 

 

 

 

 

 

Edited March 16, 2022 by Nig H
duplicate pics

[Nig H]

Today I thought I'd add the remaining soldered bits. The steps were awkward to fit, especially the small footplate steps under the tank fronts. Eventually I was satisfied with their alignment under the footplate so I tried to fit the chassis to the body. No way! The coupling rods wouldn't pass the steps just mentioned by quite a way, not just a sliding fit needing a tweak to sort. I'd put washers on the crank pins between the driving wheel and coupling rod and it seemed that these washers would need removing to have any chance of the coupling rods fitting between the step supports. So, off with the rods, remove the washers and re-fit the rods. I'd decided that the step supports would need to have the 28swg wire replaced with 31swg wire, and that I could increase the distance across the footplate between the step supports by drilling holes in the middle of the underside of the footplate angle in line with the half etched location slot mentioned in the LMR instructions. After battling to re-assemble the steps and the wire, I managed to solder the two step assemblies in place, and it looks like the rods will now fit inside the step supports.

 

There was no reason not to form the bends in the front guard irons now, and after doing this I found the chassis front brakes would catch on the guard irons. I'm currently pondering what to do about this little setback. One option is no brake gear or steps......I'll probably find that the radial truck catches the rear steps when I can get the chassis front end sorted out.

 

Nig H

[Jol Wilkinson]

Nig,

 

the rear radial axle has little sideways movement on the real thing and with model curves, you may well get a problem with the wheels meeting the back of the cab steps. My two 4mm P4 versions will go through B6 points and around a 5' radius curve but I've not tried them on anything sharper. The Bachmann OO version seems happy with train set points, but has the benefit of an extra 1 mm clearance either side.

 

The front footsteps can also be a problem in 4mm too. Careless handling can squeeze the steps inwards, resulting in a clash between the rods and the step and head scratching while you work out why a loco that was running perfectly has either a limp or comes to a dead halt.

 

Jol

[Hendreladis]

Hi Nigel

 

Amazing level of finesse in your build as always.

 

I suffered the same problem with the front steps on mine and just bodged a solution by hanging the front steps off some .010" NS having drilled some holes a bit nearer the edge of the footplate. Ultimately I just bent the rod out at an angle to avoid the coupling rod but, in hindsight, I should have gone for a more scientific bit of joggling. As I recall I did think about that a the time but (a) am impatient, (b) I had already soldered it all together after countless attempts - those steps just kept falling off. Perhaps the ultimate benefit I had was the use of the Association stainless steel coupling rods. Pretty sure they are less than .010" thick which offered a bit more clearance. 

 

The rear steps worked out okay as I recall. I didn't go for the radial truck approach just whacked the wheels in the frames with a bit of slop. It goes around 2' curves pretty happily but I'll probably replace it with something cleverer in due course - i.e. once you have demonstrated a better way!

 

Do you find that the motor driving the axle directly gives you adequate control? Presumably you are on 30:1 or so??

 

Andrew

[Nig H]

Nig,

 

the rear radial axle has little sideways movement on the real thing and with model curves, you may well get a problem with the wheels meeting the back of the cab steps. My two 4mm P4 versions will go through B6 points and around a 5' radius curve but I've not tried them on anything sharper. The Bachmann OO version seems happy with train set points, but has the benefit of an extra 1 mm clearance either side.

 

The front footsteps can also be a problem in 4mm too. Careless handling can squeeze the steps inwards, resulting in a clash between the rods and the step and head scratching while you work out why a loco that was running perfectly has either a limp or comes to a dead halt.

 

Jol

Hi Jol,

 

Thanks for your comments - noted thanks. All four footsteps in 2mm seem to be very fragile, and I wonder how long they'll stay attached to the loco.

 

Hi Nigel

 

Amazing level of finesse in your build as always.

 

I suffered the same problem with the front steps on mine and just bodged a solution by hanging the front steps off some .010" NS having drilled some holes a bit nearer the edge of the footplate. Ultimately I just bent the rod out at an angle to avoid the coupling rod but, in hindsight, I should have gone for a more scientific bit of joggling. As I recall I did think about that a the time but (a) am impatient, (b) I had already soldered it all together after countless attempts - those steps just kept falling off. Perhaps the ultimate benefit I had was the use of the Association stainless steel coupling rods. Pretty sure they are less than .010" thick which offered a bit more clearance. 

 

The rear steps worked out okay as I recall. I didn't go for the radial truck approach just whacked the wheels in the frames with a bit of slop. It goes around 2' curves pretty happily but I'll probably replace it with something cleverer in due course - i.e. once you have demonstrated a better way!

 

Do you find that the motor driving the axle directly gives you adequate control? Presumably you are on 30:1 or so??

 

Andrew

Hello Andrew,

 

Thanks for your comments too. I hope to do a bit of test running tomorrow and see what's what. So far the motor, which does drive direct onto a 30:1 worm wheel, seems  to work OK. I can't tell for certain until I've weighted the body with lead etc. 

 

 

Nig H