7mm On Heather's Workbench - the only one left

[Heather Kay]

Back to this build again, and time to consider the loco frames.

I have, so far, been sitting and considering the loco frames all morning. Somethin' ain't right somewhere.

Let's assess where I am with this. The client's wishes are for a sprung loco, with the kit pseudo inside motion. I want to be able to let the wheelsets drop out for assembly and maintenance reasons, which will need a little engineering to fit the cast leaf springs with screws. Leaving aside the erroneous slidebars and so on, this ought to be a straightforward build. So why am I finding it difficult?

Well, for a start, the cast brass hornguides are not designed to be sprung. Secondly, they have a bar across the bottom, which would require cutting out to enable the wheelsets to be dropped out, meaning a keeper plate needs making or procuring. Thirdly, and probably most egregiously, they too small for the etched slots in the loco frames. Finally, they will need some carving about to allow for the inside waggly bits. The cast leaf springs are a little anaemic, but would pass.

If you're reading this before I've edited it, it won't make much sense!



I have a JLTRT 8750 kit on the shelf, and on a whim I dug it out to compare the hornguide and spring castings. The lighter castings are from the 2251, the yellower ones from the pannier. I checked the pannier hornguides against the 2251 frames, and they fit nicely. They are also designed for springing. The spring castings include a bracket which attaches to the cast keeper plate. My reasoning, obviously, is to dump the 2251 parts for the pannier parts.

I'm looking for some wisdom from Thunderers before I make a concrete decision. Is my proposed path of using alternative parts workable?



Incidentally, having a frame spacer right where a spring mounting is supposed to fit doesn't seem like a clever idea…

 

[Sandy Harper]

Hi Heather
I have come to this build a little late but, reading your previous posts, I can understand your frustrations!

In an earlier post you were concerned about fitting pickups in the loco but then went on to say that you were also going to fit them in the tender. My experience, especially in O gauge, is that one or the other is sufficient for reliable pickup as long as at least two axles are either sprung or compensated in some way. If the loco is also going to have inside motion then I would avoid even attempting to fit separate pickups to it and either use the 'American' system or use plungers/ wipers in the tender.
When I use split axles for pickup in the tender I 'fix' the rear axle and spring the front two. I find that this will give adequate and reliable pickup, even for DCC operation.

Keep at it!
Regards
Sandy

 

[SimonT]

Heather,
when I started my 57XX build I decided the horn guides, axleboxes et al weren't up to what I wanted. I did a couple of those cheeky drawings using a Swindon master and a short while later they were in Laurie's ranges as sprung GWR pannier tank hornblocks and axleboxes. The keep plate can be drilled and tapped to be removable; I soldered my keeps in place.
Simon

 

[Heather Kay]

Hi Sandy! Thank you for your thoughts.

The tender works much as you suggest, though not with split axles. The front pair of axles are sprung, the trailing axle fixed, as the kit is designed. I plan to fit it with wipers on all wheels. The loco is currently pending. With everything going on between the frames, I may well end up as I did on a WD 2-8-0: plungers on the trailing driven axle, the rest without pickups. If I can contrive wipers for the leading axle, it might be okay, but where to hide the wires down the frames! These solid cast boilers don't leave much wiggle room, sadly.

Battery power, or go back to clockwork, seems to be the answer!

I've decided to use the pannier castings, though I'll need to blag another pair of springs from JLTRT. The 2251 spring castings can be repurposed in the pannier kit, as that's planned to be a rigid frame.

 

[Yorkshire Dave]

Battery power, or go back to clockwork, seems to be the answer!

BlueRail Trains are making progress with their Dead Rails battery system in Horatio's thread. [URL=http://www.westernthunder.co.uk/index.php?threads/radio-control-by-bluerailtrains.5312/]Radio Control by BlueRail Trains.[/URL]

 

[Heather Kay]

I'm stuck with 2-rail current collection, plus electronics, for this build. Onwards!

When the mojo is feeling jaded, or would prefer to be somewhere entirely different, I find it's usually best to not try too hard. I started out this week pondering the loco frames, and decided to purloin the 5700 kit springs and hornguides. Still needing the stamina to actually try and assemble things there, I returned to the tender. I felt that by cleaning up and fettling castings, I might start to make some progress. I could see no reason why the white metal springs and axleboxes couldn't be tidied up and fitted.

A reason soon came. The castings were rubbish. Some bits were mildly miscast, and the whole ensemble didn't fill me with hope it would look better when fitted. Morosely, I went a-hunting for better castings, feeling that requesting replacements from the manufacturer would probably not end up with anything better than I already had. Happily, Hobbyhorse Developments lists a full set of what I need, under the Reynalds Range. There are also much neater toolboxes there. The lumps that came in the kit have been consigned to the scrap box. I don't think they're even worthy of the Bits Box, frankly.

So, what next, as I found myself stymied on the frame details? What about trying to work out how the hand brake weigh shaft and scoop lowering mechanism went together?



Without the aid of any instructions, but careful study of Mr Daniels' photos and Mr Hannah's build on t'other place, I have ended up with something I'm happy resembles the layout of the real thing. I can see some tweaking is required on alignments, but I'm pleased with my efforts.

To celebrate, I may well set about detailing the bodywork. Brian has added new photos to his Flickr album of 3205, which fortuitously show the tender from above. I think I shall have my work cut out replicating some of the features so revealed. For example, who knew there would be hooks on the bunker rear plate to stow the weather sheet? Or the inside top edge of the side raves was riveted? Some fun photo picking will be required to get things looking right, I reckon.

 

[Heather Kay]

You know when you get a part in a kit that doesn't quite ring true, but you press on with it because you think it'll be okay? In this build it was the tender front floor. The kit had a chequer-plate etch, which doesn't match what I can see on the preserved tender or in period photos of various Collett and Hawksworth tenders. I made a new one by the simple expedient of tracing round the etched part and cutting it out of some brass sheet.

Trying to find out the orientation of the water scoop column led me to the realisation the handbrake column should be set a slight rake leaning forward. No clue as to actual angles, so I've matched it to the pull rod under the floor.



I've also added one or two details to the scoop.

While studying Brian D's new uploads, with a view to adding some juicy details to this build, I noticed the tender attached to 3205 is a different one to the older photos. As the client requested the older tender, that's some juicy details I can miss out. The kit resin casting includes two bolted inspection hatches either side of the tank filler. Sadly, these are not correct for this build, but it would cause more harm than good to attempt a removal.

It's a slow old process, but I've moved a little forward this week. Once I get replacement castings sorted out, things will gather pace.

 

[Heather Kay]

Time to tackle the tender side raves. These are etched parts, complicated by the need to bend curves and fix rivet strips inside. Not being happy with gluing brass to brass, I thought I'd have a go with low melt solder and a low temperature setting on the iron.



Not too bad. Forming the strips is a pain. They're etched over long, and need to be bent in various ways to sit over the cast side details. Happily, the iron at 180 degrees was sufficient to let solder flow without causing irreparable damage to the resin. I need to go back and get some glue down into the side panel and body joints.

I also had to make a new coal plate. Whether it was just me doing something wrong, or what, the etched parts ended up too short. There is a cast one in the kit, but the least said about that the better!

Still to do: tool racks, handrails and lamp brackets, plus odd detail castings round the tank filler area. There are also weather sheet posts to make and fit, though I will leave them a while as they will be vulnerable to damage. I've been informed my order of castings from Hobbyhorse has been shipped - I only placed the order this morning (Saturday), so it seems the bits will be here early next week.

I think I'm happy with this week's progress. Next week, another build takes precedence. I've worked out that a week on a build makes much more progress than my previous "build-a-day" routine.

 

[Hobbyhorse]

Time to tackle the tender side raves. These are etched parts, complicated by the need to bend curves and fix rivet strips inside. Not being happy with gluing brass to brass, I thought I'd have a go with low melt solder and a low temperature setting on the iron.

View attachment 61024

Not too bad. Forming the strips is a pain. They're etched over long, and need to be bent in various ways to sit over the cast side details. Happily, the iron at 180 degrees was sufficient to let solder flow without causing irreparable damage to the resin. I need to go back and get some glue down into the side panel and body joints.

I also had to make a new coal plate. Whether it was just me doing something wrong, or what, the etched parts ended up too short. There is a cast one in the kit, but the least said about that the better!

View attachment 61025

Still to do: tool racks, handrails and lamp brackets, plus odd detail castings round the tank filler area. There are also weather sheet posts to make and fit, though I will leave them a while as they will be vulnerable to damage. I've been informed my order of castings from Hobbyhorse has been shipped - I only placed the order this morning (Saturday), so it seems the bits will be here early next week.

I think I'm happy with this week's progress. Next week, another build takes precedence. I've worked out that a week on a build makes much more progress than my previous "build-a-day" routine.

Happy to speed the build along with our express mail order service, easy as the post office is only 50 yards from the front door.
Simon

 

[Heather Kay]

It was a nice surprise, Simon. Thank you!

 

[Sandy Harper]

I am contemplating picking this build up again, after some extensive coach work finally clearing the bench. I've been thinking about the cab front spectacles.

View attachment 57017

The kit appears to be designed to be fitted with suitably shaped glazing material stuck straight into the front sheet.

The real thing has opening spectacles with nice brass frames and the latch. I asked Laurie of JLTRT if he could send me some measurements of the various castings in their stocks. I actually got a small selection in the post! Sadly, neither actually fit.

Now, I would like something that better represents the opening spectacles. Failing an off-the-shelf casting - and I've had a look at the usual ranges of castings without luck, unless you know better - how could I approach fabricating a facsimile of the frames? They don't need to actually work, though that might be fun.

Heather,
Cut some brass to slightly larger than the shape of the spectacle aperture. Lightly tack over aperture, drill some relieving holes in the centre and mark the brass from the outside, remove and file away the unwanted inner brass to shape and then finish off to the required outer dimension.

Does that make sense? Easier to do than write down!! Oh, forgot to say, solder two bits of brass together and drill and file both before separating.

Sandy

 

[Heather Kay]

Well, it's been a while since I picked this build up. I was thinking I might start to tackle the loco frames again, but I was distracted by the tender.



You will recall I opted to upgrade the whitemetal castings for Hobbyhorse ones. In this shot, the supplied kit parts are on the left, replacements on the right. I also acquired some replacement spring castings, but on reflection they aren't quite right for this style of tender. They are now safely stored in the Bits Box for when an older tender requires them. Now, I have fettled the Hobbyhorse castings already, but I hope it is possible to see they are a slightly finer finish and have significantly fewer mould lines. The axleboxes are actually deeper than the kit ones, and match the prototype far better.

Anyway, I was all up for sticking the bits in with the hotting stick, when I decided my time might be better spent finalising the underframe detailing and arranging for electrical pickup.



The brake rods and stretcher bars are all brass castings. They needed little cleaning up, aside from opening out holes. One of the rods needed a repair as it was miscast slightly. What you can't see here is the first time I put it all together. I was well pleased, pinning all the joints so they still moved about. I went to attach them to the tender, only to find I'd fitted the rods in the wrong order. Obviously, the wheelbase is asymmetric, but it's not immediately obvious. I am using low temp solder for pins, as it means I'm less likely to do harm by poking the iron in the wrong place, so it was a matter of moments to disassemble the ensemble - and then do it properly! To aid aligning the cast brake shoes, I've fitted 3mm lengths of tube over the hanger pin. The jury is still out as to whether I should insulate the shoe faces. I think it might be wise, as spaces are bit tight at times, and with suspension and sideplay it gets a bit close at times.



More detailing commence. I took the brake rigging back out while I fitted what I haven't quite identified. It's a drain point, or grease trap for some pipework, at least. There's a bracket visible on the real thing - and the trap is a different shape, but let's not worry about that - so a bit of scrap etch came in handy. It's not quite in the right place, but allowing for the different trap it'll do. Two further wires added at the front to represent feed pipes. I may decide to take them back out, as they're not really visible if I am honest, and the power wires to the loco will give the right impression.



The final step today was to fit some copperclad for wiper pickups. I've roughed out a wiring diagram, too. It rather looks like the only pickup available will be the tender. I may be able to squeeze in some plungers on the trailing (driven) axle in on the loco, but I'm not going to fret if I can't. Time to contemplate arrangements to fit electronics. It's may be some time!

 

[Heather Kay]

Today's shenanigans begin with cutting great big holes in the tender floor.



There is method in my madness … I think! With a solid cast boiler and not a lot of spare space under the loco, the only feasible location for the DCC decoder is in the tender. As designed, though, inside the cast body of the tender is inaccessible once the underframe and running plate are fitted. By cutting a big hole in the two floor parts, access will be available once the running gear is dropped out.



I think that'll give plenty of access wiggle room. I think the rest of the day will be spent adding more upperworks details. Did I mention I'm a gold medal prevaricator? Anything to avoid the elephant in the room, vis the loco frames and inside motion!

Onwards!

 

[Heather Kay]

Well, that's most of the fiddly stuff on top done. The little wooden block to protect the scoop dome from the filler lid is a confection of brass channel and a block of styrene. The fireman's tool tunnel needed some intense peering at photos. There's a pattern of bolts/rivets on the side rave that gave away the location of various brackets for this. On the backs of the toolboxes are some protective sheetwork, the purpose of which I haven't fathomed yet. I need to fit the handrails, steps and lamp brackets on the rear. I also need to repair the front handrail bracket, which is formed from the end of the side rave by twisting it ninety degrees. Something stronger will need to be made up, I think.

I reckon the axleboxes and springs can go on next. Then I can think about fixing the tender body to the upper floor level. I might get on to the loco this week!

 

[Heather Kay]

I've been trying out a "one build per week" regime, but I've decided to try extending things a bit. I need to increase my construction speed, so I'm considering four weeks per build to see if I can get anywhere near Tony G's throughput!

So, another week on this loco. Well, and the tender.



I hate fitting buffer housings. Perhaps it's because all the loco ones I've encountered have been barely adequate castings. Either way, I find it a chore to get them aligned and pointing in the same direction! What you can't see here is the bottom right hand bolt head on the left buffer has been ground off, and a hole drilled through to take the coupling storage hook. In real life, the hook is trapped under the bolt, but at this scale no-one will notice. I think a smear of filler is needed for the step slots, and I need to fit the vac pipe - but as the needs the body glued in place it'll be done later.



Similar work has been done on the front buffer beam. The various detail parts included the vac pipe parking bracket, which saved me some fiddling about. I had to make a scrap etch bracket for the steam heating pipe, though.



The rest of the morning has been spent fabricating the vac pipe along the fireman's side hanging bar. Not having anything suitable in the Bits Box to represent the pipe flanges, I did a little experiment with 12BA washers. Thinking I would be clever - this only works with the pressed brass kind, mind you - I actually pushed rivets in the washers to represent the bolts. Obviously, as soon as any solder arrived on the scene, that all went out the window, but it was a nice try at any rate. I bought some Finney7 etched brackets at Reading before Christmas, so they've been pressed, literally, into service holding the pipe in place. I chose 1mm brass wire, which is a tad under scale. I think it looks okay now it's fitted. The steam heat pipe, which runs the other side, will be a little thinner, and include the lagging of course.



You can't quite see it clearly, due to dodgy lighting, but I've added the small pipe that will clip into the vacuum pump isnide the frames in due course.

There's not much left to do so I can avoid the frames. I suppose I must tackle them now.

 

[simond]

Heather,

I think your brassy springs look rather nice, and, when fitted with 12BA csk screws into tapped holes in the spring mounts, will act as keepers. You'll have to attack the errant frame spacer, or the spring mounts on that axle. Quite odd.

I have had some success with Fourtrack cast hornguides, & hornblocks, used them in most of my locos, whether sprung or compensated. They are rather generic, and presumably there are more accurate models of GWR pattern parts available.

I know Steph has some in his / Finney7 range, not sure of any details however.

Hth
Simon

 

[SimonT]

If you want accuate cast GWR small loco horns go to the Laurie G range; they are designed for springs. I mastered them for my own use and they went into his range. The F7 GWR small hornblock is etched and works best with compensation. They were designed by Martin and must be in a large number of models by now.
Simon

 

[Heather Kay]

Simon, thank you for that idea - filed for future reference - and apologies for the delay in responding. Radio silence was mainly due to not having a lot to report that hasn't already been covered in depth on many another thread!

I tackled the loco frames. I admit I don't like steam loco frames. To be fair, I haven't many to my credit, but I always seem to approach the subject with some degree of trepidation. I think it's my generally pessimistic world view. If I think about something, and expect the worst, when it all works out fine it's a definite bonus. If it doesn't work out well, then I hadn't expected better!

Part of the issue with this build was the additional complication of wiggly bits inside the frames. I know they're designed to be pretty much idiot proof, but it was still a worry. Would it all fit in there, bearing in mind the issue recounted some pages back of the wrong sort of slide bars? So, figuring out the inside motion, checking clearances and making a rolling chassis was my goal this week.

First, I tackled my other bête noir, Araldite. My mistake in the past has been to use the wrong sort. Being impatient, I rather take offence at having to wait a day for something to set. I have the same feelings about Milliput, which is also a two-part epoxy. Having had generally poor experiences with the sort of Araldite that's dispensed from a double-barrelled syringe affair, I invested in some proper old-fashioned tubes of the stuff. It was also the lengthy setting variety. My target? Crankpins in the various wheels for builds on the go, and attaching this build's tender body to its floor.

Colour me surprised when it worked as it should! Things seemed to be looking up at last.

Back to the frames, now I had wheels to which I could fit coupling rods…

Having managed to attach the half-etched NS overlays to the already constructed carcass without turning it banana-shaped, it was time to fit the cast hornguides I had half-inched from the 8750 build (being constructed as rigid, you might recall). Obviously, they didn't fit the slots in the frames, so I spent most of Wednesday carefully filing them out. All kinds of things could have gone wrong at this point, but by some miracle I managed to keep things aligned so the cast bearings slid up and down with an axle in place. I forgot to mention that I was doing this stage because I needed at least the leading and centre guides temporarily fitted so I could begin to work out what, if any, clearances were to be had for the internal gubbins.

With hornguides tacked in place with low temp solder - each was marked with corresponding marks on the relevant frame slot, in case there were minor differences in my bodging - I could partially dry assemble an eccentric on the centre axle, and fit the connecting rod. With little fettling, the cast rod parts are a nice friction fit, so no solder was harmed at this stage. My aim is to have the centre axle fitted with all the internal motion including the crosshead so if needs be it can be dropped out of the frames as a single unit.



You may recall the included slide bars and crossheads in this kit are generic items really meant for outside cylinder locos. The slide bars, in particular, I deemed very wrong for this model, although to be fair others have built this loco using the provided parts without issue. Obviously, correcting the overly long slidebars might have a knock-on effect with the throw of the connecting rods, soo this was another thing I was on the lookout for. I haven't mentioned how I'm dealing with slide bars, yet. They're still in the prototype stage, but they do seem to be a working solution. More later.

The crosshead casting needed quite a bit of filing down. As supplied, it wasn't possible to pass the crosshead through the motion bracket, which would be needed if the assembly was to be demountable. Being inside the frames, I felt I could sacrifice a bit of the cast detail on what would be the outside face on an outside cylinder loco. So, I thinned down the main connecting rod bearing and bolt detail, and took a little off the cast oilbox. This made a nice just-about-fit through the motion bracket. Things were looking up. To cut a long, and somewhat rambling, story short, I found I didn't need to remove anything from the hornguides on the front axle. I might just file a small notch, just to be safe, but for now no further surgery is required.

How about getting this perisher on wheels? Right-ho!



There you go. Now, I am going to put it down to fluke, because the suspension scheme worked, the axles were true, the frames rolled sweetly at first attempt, and only needed two coupling rod bearing holes gently opened a snitch to give a reasonably sweet chassis. I needed a lie down after that, I was so surprised!

There's still a lot to do. There's a ton of detailing, motorising the thing, and working out the demountable underslung spring castings. I set myself a goal of having the frames on wheels by the end of the week, and I managed it.

While I'm here, have a chuckle at the following. As I am replacing the supplied slidebar castings, I needed something to plug holes in the back of the cylinder block. I also needed something to guide the piston rods. I decided I could repurpose the castings so they fitted inside the cylinder block. It needed quite a bit of butchery, and the soldering is not of the highest order, but it worked. Not quite right, I admit, but it works.



From above, what ought to be lost inside the outside cylinder casing on a larger loco is on full view. There are two pairs of slots for the slidebars. Originally these are etched items, but I've found some brass stock that's almost exactly the right width that will serve for new bars. I have a couple of alignment issues to deal with, but that's for another time.



From below, you can see the remains of the cast detailing, plus brass tube guides. I won't win any prizes for the way it looks, but I am considering a cosmetic representation of the cover plate and drain cocks to plug this area. You will note temporary bearing stays, which stop everything falling apart until I get the proper springs organised.

I think that will do on this build for a while. Another build beckons.

 

[Heather Kay]

Just for the heck of it, I posed loco and tender on the test plank.



Still a way to go, but it's getting there.

 

[Heather Kay]

Hoo-ha! Nearly two months! Anyway, some progress to report.

I set myself the target of getting the pickups wired up on the tender, and getting the loco chassis powered up. It didn't quite go according to plan.



First up, the tender. The stray plug on the right is for the DCC gubbins later on. Another plug disappears to the front for loco connection purposes. I aimed to be neat and tidy, and more or less achieved what I wanted. Happy with that, I turned to the loco.



I spent a while yesterday trying to work out how to wire up the motor. I know how to wire it up, obviously! What I mean is trying to work out where and how to run wires in the frames. At this stage, it's highly likely the loco won't have any current collection capability, mainly due to the inside wiggly bits making it awkward to hide wiring. I've worked out I could fit wipers to wheelsets two and three, and as I like to collect electricity from as many wheels as possible, I think that will be okay. While trying to work out the wiring runs, it became painfully obvious I should fit the cast springs and hornkeeps, and the firebox bottom. The latter would need quite a bit of surgery in order to fit around the springs. Anyway, after futzing about for ages, I settled on a scheme which, importantly, lets me detach the centre springs to let the axle with all the wiggly bits drop out. It's not quite Dikitriki standard, but I successfully drilled and tapped for 12BA countersunk bolts to hold the centre springs. Phew! The other springs are soldered on, since those wheelsets will be removable by the simple expedient of taking off a wheel.

So, two days in and I've failed to motorise the loco chassis, but done a ton of other bits and pieces instead. Perhaps motorising tomorrow, then.