My 7mm dabblings

mickoo

Western Thunderer
Steph, cheers I think your correct if they need it as the ones I have go all the way into the axle so suspect they will do as is for lenght. I had a niggle it was 6BA but could not the reference for looking last night lol
 

OzzyO

Western Thunderer
Hello mickoo,

I'm a bit late in replying to your build thread about the tender wheels, would it have been any better to have used the Mitchell / Finny wheels from Slater's as these don't use the Allen screw to fix them on to the axle. So may have a smaller (brass) boss, some of them don't have a brass insert so the only part that you would get any shorts from would be the axle ends. The wheels that I'm thing of (apart from the disc wheels) are 7849MF and 7851MF.

One way that I have found to get Slater's wheels running near true is to rub the back of the wheel on some wet'n'dry that is stuck down on a length of flat wood, or if you can get one a four sided diamond block, the one that I use came from Aldi for about £10. These are a set of tender wheels that I did for a G.W.R. tender using the above method and they ran nice and true.
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The other way that you could could get the wheels running true (no wobble) is to take a very light skim off the back face of the rim and then rub the brass boss down to the the same as the rear of the tire. Then fix the rim in place on the wheel centre (may be use some Loctite 290 on both parts).

I did a loco in S7 a bit back using "turned" Slater's driving wheels that had the quartering moved due to the turning of the wheel rims,
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To refit the wheel centres I did use Loctite 290, I think that you "may" just see the centre that is out of place.

If your going to turn any wheel treads I would say don't just use the axle to do all of the driving but use a "face plate behind the wheel and a driving plate on the front of the wheel"

One thing to remember is that a profile tool will add a lot more cutting force than a tool that follows a profile form.

OzzyO.

PS. 6BA X1/4" for the Slater's standard axle screws, Have a look at Items mail order for them.
 

mickoo

Western Thunderer
Ozzy, cheers, one of the steps to reduce wheels to S7 is to take 12 thou off the rear face, I opted for 10 thou in the end and then took 10 thou off the rim and simply used a file to round off the edges, not the S7 way, very Flintstones / tin plate I acknowledge.

I did just use the axle with the set screw for the majority of the work and skimmed right off to where the screw was holding the wheel to the axle, then I just took the screw out and relied on the tightness of the axle and trimmed off the last nibble of hub left by 10 thou....now remember children, don't do this at home!

With the tool that close to the centre and effectively holding the axle in place it worked, I wouldn't advise anyone to copy the method, but a full face visor helps if it decides to go wayward and it helps if you stand out of the line of fire;)

I accept that larger loco wheels will probably need a face plate behind to stop the rim flexing, even the tender wheels had a little flex but I just kept running the tool in and out a few times, each pass taking the slimmest slivers off until virtually all the flex had been worked out, then I'd wind the tool in another 2 thou and repeat.

As mentioned above, the acid test will be a run through Love Lane point work.

I do have a form tool and had intended to do most of the work above and then trim with the tool, I got the tool from Cynric at Reading just before he passed away and never got around to using it, sadly, although the bag is marked S7 it's certainly not and fits a Slaters finescale tread perfectly, leaving me to the conclusion that it is for finescale and of little use to me.

I can't remember what I paid for it, but it's free to a good home for the first person to PM:thumbs:......sorry chaps, gone to a worthy home already.
 

mickoo

Western Thunderer
Ever onward, brake shoes, well just two, it's a long and painful journey but I think the extra effort is worth it visually.

Granted not much of the tender brakes can be seen, but that which can is rather thin if the kit is followed.

Anyway the pictures
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An overall view of progress, the rear brake shoe is just hung there and it's immediately apparent there's something amiss with the pivot point :confused: Each pivot point has a small sliver of 1 mm cable insulation added to space the hanger the correct distance from the frames.

Bottom is one of the pull rods with 1 mm pins added for the brake hangers, above that a selection of etched brake components in various stages of construction, at left the raw etched parts with holes drilled for the associated pins. In the middle the next two shoes stuck to a scrap of 1 mm Plasticard, the two etches on the left will be bonded to the rear with the holes aligned and then the resultant Plasticard trimmed to leave something looking like that on the right.

On the right is a completed shoe and hanger, the shoe pivot is a small stub of 0.6mm wire and the etches come with some half etched detail on the shoe and bracket, not required on the real thing, nor any LNER 8 wheel tender I've yet to find a photo of? So it's filled with filler and sanded smooth before the pin was added. Above all that is the rear pull rod that runs behind the wheels. The final step is to insulate all the brake gear from the inner chassis, two small cuts are made in the hanger above the shoe, the front and rear are offset to allow a little more strength from the Plasticard laminate. This means that if the shoes or pull rods touch the tyres then the current will stop at the insulated gap in the hanger and not be transferred to the chassis.

IMG_4368b.JPG

Overhead view of the temporarily hung brake, the extra width allows the show to be chamfered to fit the wheel cone profile, quite important that as if left square there's a big gap between the face edge of the shoe and tyre. The pivot point is out by what appears a good 2 mm, but not is all what it seems;)

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Side view of the shoe in what should be it's final position, not good, however the wheel is CSB sprung and is in the fully relaxed position, when loaded on the track it'll rise up by about 1 mm which should make the shoe conform closer to the wheel radius, however tests have shown that it still won't be enough and the shoe will not follow the tyre profile. Softer CSB wire will allow the wheel to rise up further but then the tender will be sat too low, so it looks like the pivots will all need to be removed and new holes 1 mm further forward drilled.

As noted above, 60% of the brake gear is invisible and this rear one 100% is invisible from the outside, but 80% visible from the inside and the rear of the tender is very open so it needs something I feel, something more than the basic kit offered, besides the practise will be good for the main driving wheels which I'm guessing will need to go through the full fat coke method as well.
 

mickoo

Western Thunderer
So, one side done, just the other to do, should be easier as the concept has been proven.

I wasn't happy with the gaps between the full fat brakes and pull rods, so in best Dikitriki white suits tradition out came the obsessively insane modelling tools. Essentially I cut some spacers from 1 mm tubing and slid them over the lower hanger pins, 0.4 mm thick at the front and 0.6 mm at the rear, this spaces the brake hanger much better between the pull rods and fattens up the hinges nicely.
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There's about 0.5 mm play between the pull rods and tyres, maybe a little less; on reflection the thickness of the pull rods is a little too heavy, but they'll do and I'm happy with what we have. The front pin will affix to the brake cylinder linkage and the rear pin needs a turn buckle and then a cross rod between the two sides, the buckle will have to be plastic to insulate left and right sides, not sure how to replicate that as yet.

Some locos also appear to have an extra cross piece between the 2nd and 3rd wheel, a flat bar bent around the hanger and bolted to each side, needs more research to find which tenders have this but it's across most of the LNER 8 wheel fleet as far as I can tell, but which specific tenders I've not yet worked out.

As an aside I've noticed that some A4 tenders seem to have what looks like a water trough spray sheet inside of the inner pull rod on the LH side, maybe on both sides? I know the LNER investigated over spray after the death of an inspector; water from a passing engine either blew the cab screen in or flicked up some debris which fatally injured the inspector. I think it was the two Elizabethans which passed each other North of York at a set of troughs, if to time, both locos picked up at the same time as they passed each other.

An overall side view
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The shoes are not gapped correctly but should pull up better when there's some weight on the CSB, mind even at this stage it looks passable, below.

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Chassis fitted to tender shows the the current gaps are not too bad.

Close up of the full fat linkage
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This is exactly the chunky look I was aiming for which better represents the real thing, it's only a very small detail but I think the original skinny etched hangers and blocks would have spoilt the overall effect.

Finally some very cruel blow ups of the rear hanger and how visual it is at the back of the tender.
IMG_4385b.JPG

That insulating cut on the outer etch will have to be filled and the inner chassis cut back a little by the hornblock, there is an air tank to go in here which will help hide things a little.

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Final shot shows the extra width gained by adding the Plasticard laminate, the pull rods are a fixed spacing so just the original two etched hangers laminated together would of looked very '2D' In reality the brass bushes should be part of the hanger base, I might try and solder them onto the other side and flare the solder to give a more cast look, not sure what to do with this side as I still want it to all flex and swing as the tender moves through point work.
 

mickoo

Western Thunderer
Lovely work Mick really nice
John

Cheers,

I am trying to restrain from going over board, and just try and make it out of the box, but the brakes were something I couldn't live with;)

I'd kind of been putting this area off for a while and faffing around elsewhere before biting the bullet, but now one side is done and it's not too hard, just monotonous, then the rest should go together pretty quick.

I've yet to look at the castings in detail, but in passing, one axle box looks like it's going to take some fettling so I'm toying with replacements from LG at Telford if he does them. The air tank is straight in the bin so a new one from 10 mm tube will be made up with straps and the water scoop looks the part in passing, it could be more detailed with pull rods and lifting mechanism, but none is supplied and I've no decent photos anyway, they can be added later if information becomes available (next trip to NRM to photo under Mallard might help) so it's not going to hold me up or make me loose sleep over it.

Next step on the chassis are the brakes on the other side, and with the wheels hopefully arriving this week which will require lathe work and fitting it'll be onto the rest of the under works, specifically the tank and front end brake lay shaft and linkages that you can see through the gap between the loco and tender. I've also some upper works to finish off, streamlined fairing and other such oddments, might do those tonight to have a break from the brakes;)

All I need soon is a layout/photoplank/testing area to run it on, though I think that conundrum is going to take a little more hand wringing before I finally decide on what I'm going to do LOL
 

mickoo

Western Thunderer
Those pull rods are suitably meaty - I just hope those wheels run perfectly true!

Adrian,

In truth the longitudinal pull rods are too thick, they need to be half that thickness but I went with what I had in the kit rather than making new ones of those as well, next time, or next LNER 8 wheel tender will have thinner ones more to scale.

I did even contemplate separating the shoes and pinning them so they could conform to the wheel profile better, again like above, next time;)

One of the wheels does have a little wobble but clears both sides with ease, fortunately these are not the wheels I'll be using, these are from the LMS Jubilee where the slight wobble won't be as much an issue, though I will try and straighten said wobble when I get to that project;) In reality the real rods are much much closer to the wheel, bare fractions away from the tyre.

Because the brakes are loose fitting and swing and there's side play in the wheel sets, there is a high chance that the tyres will touch the pull rods at some point, hence the insulating cuts so that only the pull rod and lower brake lever will become live and not the chassis or body....I hope:thumbs:
 

mickoo

Western Thunderer
Moving onward, snatching time here and there were almost at the finish line.

Updated since last time.

;Other side brake rigging added.
;Correct wheels from Salters fitted, turned to S7, hubs reduced and axles modified to suit.
;Remaining sheet work on tender top, stream lined fairing and coal fence edging.
;White metal parts fitted, though springs still require the reworked hangers and fixings to complete, currently just held in place with double sided tape to see if I can live with them, may just opt for a set from Ragstone as replacements, also very tempted to whizz some up in 3DSM and get them printed, that way I have more control over the quality and costing, but requires more time....which could be utilised elsewhere.
;Replacement tank on under frame made and pseudo plate work to support it, supplied casting was too small.
;Weight added, now tops 600g, might push that to 1Kg depending on running tests tomorrow at Love Lane.
;Sound proofing added, drastically cuts down hollow effect and gives a better sense of mass when rolling.
;Dummy floor for coal space.
;Front end fittings added for water scoop, hand brake and valves etc.
;Buffers fitted, not happy with these as castings very poor so had to fill space around buffer and then drill to suit as buffer sloppy in housing, still some play and current sprung retention method is very 'Edwardian', two options remain, A: fix the buffers solid with glue once painted, B: rip off buffer beam, fit replacement castings and buffers and work forward from there.

Overall top view.
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Side view.
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Front end.
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Rear end showing replacement tank.
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Not happy with that brake on the right! Needs straightening, also requires insulated bar between left and right brake lower pins.

Under view showing pseudo plate work and new tank
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Still to do.

;Rear insulated cross brace on brakes.
;Front brake lay shaft (possible Ragstone casting) and linkages.
;Front draw bars and simulated interconnecting pipework.
;Front footplate from 1/64 ply wood strips to give wood grain effect and more 3D depth to that area.
;Some form of electrical pick up, having opted for insulated axle boxes one should really opt for split axles, however I'm tending toward not splitting the axles and having alternate left /right collection, I.E. short out only one wheel per axle, left, right, left, right etc. Or, wipers.
;Spring hangers and fixings...or replacement Ragstone castings.
;Hooks n Hoses, after paint I suspect.
;Decision on actual loco to model, affects electric lighting fitting or not.
;Prime and blacken required areas.
;Paint n decal.
;Coal.
 

mickoo

Western Thunderer
Really really lovely work mate..!

And the brake hanger insulating idea is inspired!

JB.

Cheers, but the next one will have to have a differing approach, it works but very fiddly and some of the Nickel Silver parts have come unglued with it being on and off a few times. I've had to re-glue but used a two part epoxy we have at work called 'double bubble', that seems to have more grip and retentive strength than super glue used previously.

Your idea of a thin Plasticard strip on the shoe face might work better generally, or even a thin smear of 'double bubble' would work for brakes where the pull rods are not in close proximity to the tyres, basically all other applications except LNER eight wheel tenders LOL.

For the next ones I'll probably go with all metal shoes and arms, then insert a small bore plastic tube for the pivot and hang that on a 1mm brass fulcrum.

Ideally I'd like to whizz up some correct brake gear in CAD and get etched, that way I can have the shoe pinned and move so as to lie in the correct orientation with the tyre. On the DA etches some of the inner and outer halves of the brake gear do not quite line up with each other; so pivots become twisted as the drill follows the pre etched holes rather than making a new straight one. The other option would be 3D printed brakes (with fixed shoe), of the two choices etch work is faster and easier to produce.

I'm also tempted to make up my own set of etch work in NS for LNER 8 wheel tenders, specifically the narrow streamlined variant, riveted and smooth, the DA one goes together respectfully well but there's a few areas where discreet tabs or half etched slots would have helped it progress better.

I've think I've worked out why the footplate side sheet slots were too big, the side sheets have half etch rivets, not punched, so the sheet is half thickness, the slots in the footplate seem to be from common artwork which would suit a smooth sided tender where the thickness would be correct and fill the slot. Two ways around this, full thickness sides with punched rivets (my preference) or two sets of artwork for the footplate with slots to suit respective side sheet material thickness if half etched rivets are employed.
 

alcazar

Guest
Can you still solder to the brake hangers with that Plastikard in place?

Did you think of Slaters Microstrip for the pull rods? No chance of shorting then, and suitably thin sections can be had.

Is this for an A1 or an A2?
 

mickoo

Western Thunderer
Can you still solder to the brake hangers with that Plastikard in place?

Did you think of Slaters Microstrip for the pull rods? No chance of shorting then, and suitably thin sections can be had.

Is this for an A1 or an A2?

Nope, can't solder to the hangers, not directly but I managed to solder the pull rods to the pins at the end to trap the brakes between the pull rods, hot iron, tinned pull rods first, big blob of flux and in and out with the iron, soldered just fine. Failing that, any decent epoxy adhesive would probably do just as well.

Microstrip is fine but in these small sizes tends to wave and flex and doesn't have the rigidity that metal has.

It's for an A1 ;)
 

SimonT

Western Thunderer
Mick,
I have printed shoes and hangers on my 52XX and I have also done some pivoting shoes and hangers for Len for a LMS loco. It might be worth a play to see if LNER shoes can be made to work.

Simon
 

mickoo

Western Thunderer
Little update, the tender ran through Love Lane flawlessly, the weight and CSB certainly made for a nice smooth passage with little discernible wobble or 'Hornby' body roll. I do think I need to reduce the CSB SWG a little to give it a more softer passage, but overall it went well.

Which means I can move on to current collection, as there are four axles I've opted to not run split axles, though it can still be added later if required, I think good track, pick up from tender and pony and leading trucks with stay alive on the chip will be sufficient for most operations. Thus I only shorted four wheels in an alternate pattern, two left and two right, the pictures explain better.

Top view showing left and right bus bars
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Bottom view showing bus bars and pig tails to respective axle boxes.
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Close up of Axle box, pig tail and shorted wheel.
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Basically skrawked a slot in the back of each wheel and then slit the hub and rim with a slitting disc, laid in some 28swg wire (cheers Adrian;)) and flash soldered to hub and rim, then sanded smooth and filled slot with two part epoxy and sanded smooth. The axle box was just slit with a slitting disc and some small thin wire soldered in and the joint reinforced with two part epoxy.

The power rails have 1.2mm holes drilled and the cable plus insulation passed through and soldered on top, the solder pad underneath is where it was joined to the brake hangers and I was a little over enthusiastic with its size but as the cable is insulated it's not a problem. Two extra cables will be added and pass between loco and tender disguised as water feed hoses, the loco and tender will be semi permanently coupled.

I did blacken the wheels after the soldering but they do not seem to be very black? maybe a second or third application is required, I left the blackening chemical on but it seemed to develop a green powdered fluff which when cleaned off (worn emery) seemed to take off some of the blacking. I supposed I should try polishing with a less abrasive material and see how that goes.
 
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