RobJ's 7mm and electronics workbench - Deltic & Class 06

[RobjUK]

Project: PRMRP 7mm Class 55 Deltic.

 

I've not been deliberately documenting this project so far, I usually forget to take photos unless it's for specific details.

Anyway, some bits to date since starting in January 2019.

 

The bodyshell etch, as received:

The start of the roof curve seemed a bit out of place to me so I reworked that.

 

For information, for a long bending rig, I used some B&Q aluminium U channel I had (around 20x20mm section) for sharp bends and some mini industrial "C" rail for smooth bends, pairs of either type clamped up solid with a small vice and a few small G cramps.

 

For small parts I use a couple of cheap pressed steel angle brackets with about 4" legs. They have good square edges and work well when clamped in a small bench vice.

 

Edited July 25, 2019 by RobjUK
title updated

[RobjUK]

Some of the bogie castings and part-built stages:

 

 

[RobjUK]

More bogie details, one with a motor fitted (and temporary paper shim for clearance).

If the wheel alignment looks odd, it's probably because the centre axle is in floating bushes for vertical movement and has more side-to-side play than the driven axles. 

 

There additional sprockets and a drive chain to add eventiall, to link the outer axles.

 

 

Edited June 2, 2019 by RobjUK
Added information

[RobjUK]

And the other, which has the outer frame drilled and screwed in place, though the castings still need some details cleaning up:

 

 

 

Edited June 2, 2019 by RobjUK

[RobjUK]

The body has also made some progress - some early photos while trying to get the overall end and nose shape correct, with the nose and window castings just resting in place, then recently with the body shape improved and the ends completely soldered up:

 

 

Edited June 2, 2019 by RobjUK

[RobjUK]

I have not done very much with the interior of the body shell yet, beyond fit the crossmembers for the fuel tanks and the fan mesh.

 

Although it looks very big (it's 18.5" end to end as it stands, without buffers etc.), once it has the cab interiors, space for the motors above the bogies, roof fans, smoke units and a pair of very large loudspeakers to to give a something like realistic sound, it's suddenly an extremely cramped space...

 

The smoke units (ESU ones) will mount crossways together in the centre and link to brass tubes feeding the roof exhaust ports. 

I'm still trying to get the fit on those just right, at the moment they may be a fraction too tall. The side "T" branches will connect to the ports on the respective speakers to pass some of the sound via the exhausts, plus put as much bodywork as possible between the port and the speaker itself in the base of the body, for the best acoustic baffle effect.

 

 

[RobjUK]

I need to complete both the smoke unit fittings and the cab interiors before progressing with the body, so I know exactly how much space is available; I can see the speakers needing to be shortened slightly to shoehorn everything in!

 

The cab interior is being made from a set of parts supplied by Peter Clark Models.

 

The quality of my painting should not be used to judge the parts! I did go totally wrong with the very first bit of paint. I got some pots of Railmatch paint in the appropriate colours. The last time I painted a model with enamel paint was a plastic kit for a young relative, a few decades ago and using Humbrol enamel.

 

I expected the Railmatch enamel to be the same stuff - it's not; it appear to be the same industrial grade paint as would be used on the prototype or other machinery, extremely thick and needing thinners to be usable even for brushing, slow setting and is nothing like the paint I remember. However, I'd already started on the front bulkhead so that now has to be completed with enamel, as acrylic just will not flow over the oil-based paint.

 

I got the equivalent colours in the acrylic versions, which are infinitely easier to use. I also already had a set of Vallejo acrylics suitable for some parts.

 

 

The body must still be enamel as there is no equivalent for the lower yellow-green band (of the green livery) in any paint series I've found so far. That will be airbrushed and is for another day, or more like another year...

On the subject of painting, I got a few different sets of small brushes from ebay; most are average but on particular set, branded "Maries" and some chinese characters, is outstanding. They have excellent shaped, fine tips for detail work.

 

So, the cab interior parts, as they stand at present, still needing rather more work. The white paint went very wrong, it did not quite mix fully and I got a brush of almost watery stuff that just ran on, so some rework needed there.

 

Plus the crew, three figures as I'm not sure which will fit best until the cab is nearer complete. These are from Hardies Hobbies, apparently 3D printed but with the best finish and detail level I've seen in any 3D prints.

 

 

Edited June 2, 2019 by RobjUK
typo

[RobjUK]

Well, I've made a bit of progress on this one, but as always seems to happen, when I complete one stage I find another problem!

 

I've finished painting the cab interior components and started assembling them - but I can only attach the front bulkhead to the floor & not the rear sections, as then it will not fit through the reinforcing angles in the bodyshell..

 

It looks like I will have to make up brackets and other supports to fit all the parts separately. I can't glue them together as they go in either, it all has to be removable to be able to paint the body and fit the windows.

 

I've also discovered that if I fit one the seat to the floor, the drivers head barely reached the base of the windscreen! Looking at other peoples Deltic cab builds, it appears the prototype has a multi-level cab floor, which the cab kit I got does not have - I need to add a couple of platforms under the drivers seats.

 

It's my first build; hopefully with any more that are this involved, I'll have a better idea of what is needed in advance & be able to plan parts a bit better.

 

Whilst I'm trying to come up with appropriate attachments for the cab parts on this, I've dug out another brass kit I acquired a few years ago - a Judith Edge "Barclay 0-4-0" I picked up on ebay, an untouched kit.

 

I started on it when I originally got it, then put it on one side waiting for (something) then work went crazy and I pretty much forgot about it...

 

The first two photos are of the stage it was left at; the etched sheets and the underframe / buffer bars.

 

Over the last week, I've built the footplate and separated & fettled some of the parts I will need next, plus doing some detail work and shaping of the various cab and body panels.

 

I have just started assembling the cab today - no photos of that yet.

 

 

 

[RobjUK]

A bit more done on the cab now, with the sides attached to the front and the handrails fitted.

 

After I did that I realised the sides of the instrument panel were open & probably should not be!

I found the two small triangular fillers in the etch sheets, but fitting and soldering them without other parts melting off was, well, interesting..

 

 

I've also started assembling the gearbox, which is a 40:1 ballrace type from Finney7.

 

That went quite well until I tried to get the full axle assembly with all spacers in place to check the end play - one of the small etched spacers that fits between the gear and bearings went "ping" and has not been seen since.

 

After some googling for appropriate spacers I've found that Tamiya make packs of bearing shims so have one of those on the way - it's got ten each 0.1, 0.2 and either 0.3 or 0.4mm so should come in useful for other axle spacing applications.

 

A couple of tips for anyone else assembling one of these gearboxes.

The various spacers that are supplied as part of the etch need cleaning up after cutting the tags that hold them in the etch.

 

I found the easiest way to hold them was to put the shank of an appropriate size drill bit through the spacer, then it can be held with a finger underneath while filing the top.

 

Also, the instructions say to use one small spacer on the motor shaft before the worm gear. The flat on the supplied Canon motor shaft starts too far away from the motor face for that to do any good and it needed all three spacers to give a good fit with no movement of the motor shaft.

 

 

 

 

 

 

Edited July 25, 2019 by RobjUK

[RobjUK]

I've made quite a bit of progress on the Barclay since my last post in this thread, though not without the odd disaster!

 

The chassis is finished and painted, though needing another coat on the buffer beams and the edges of those touching up.

The motor/gearbox, wheels and jackshaft are in. It's not quite as free as it should be, the alignment is not absolutely perfect - and as I've included the compensating system in the rear axle, I think the holes in the links are going to have to be rather a sloppy fit for it to run freely.

 

The compensating system as shown in the kit assembly instructions made me cringe (Sorry Michael..) - as an engineer, having perfectly good brass bearing bushes then taking the load on the edge of a bit of sheet, is just wrong!

 

I came up with a very simple mod to fix this; just a bit of loose brass tube cut to fit over the inner ends of both bushes, then a centre support for the tube to balance on - the load is then take by the bearings.

 

 

When I first fitted the buffer beams to the chassis ends, they were around 3 - 4 mm too close together and did not match the footplate ends.

I have no idea what I did wrong, but luckily I chickened out from using conventional solder for those, not wanting other parts to fall off in teh process, and used low melting point solder (for white metal).

That allowed me to remove them again without causing any other damage, and I added some packings to both ends to get the size matched to the footplate. 

 

I fitted the buffer bodies to the buffer beams using the same solder. The bosses on those were rather smaller than the buffer beam holes, but a few turns of single strand copper on the boss made it a good fit, then squared across the top with a straight edge to set them square before soldering. I used plenty of 6% phosphoric acid flux and put rows of tiny solder chips against the buffer bodies, which worked pretty well.

 

 

I have also done some rather more drastic butchery: The Canon motor body is just too wide to fit the footplate and body centre cutout, so after after soldering all the relevant I too a strip off either side of each cutout to allow it to fit around the larger (or rather differently oriented) motor.

 

With some other slight mods to the chassis, I managed to fit that a lot lower in the chassis frame, giving a lot more room in the engine casing for electronics & speaker etc.

 

The control console dropped off whilst I was soldering parts of the engine cover to the cab...

That is still to re-attach.

 

I've invented an alternate way of adding rivets? (I've never seen it, anyway).

 

The Barclay was the first brass kit I ever started and I had no clues about detailing such models or pre-punching the etches for rivets, when I started the chassis. I did not punch any of the buffer beam rivets, they are just open recesses, the way I assembled them.

 

I have learned a lot since then, but with my home made jig I'm still not happy doing very small parts that can bend easily, such as the rivet strips on the cab.

 

So, I wanted something else to form the river heads on the buffer beams and strips.

The answer is a load of balls - solder balls in fact, available in packs of thousands for a few pounds, sold for "re-balling" BGA typo integrated circuits.

They are available in many fractional millimetre sizes. I got a pack of 0.55mm, £3.50 for 25000, I think it was.

 

If these are added to the dimples where rivet heads should be, as the primer coat of paint is being applied so that sets them in place, the result is a perfect dome head!

Possibly a larger size would have been more appropriate on the buffer beams, but I think they should be spot on for the cab strips, once I get as far as painting that.

 

A few photos relating to the comments above, then a few more showing some techniques I use etc. in separate posts.

I'm learning as I go so a lot may already be standard, but just possibly some bits may be useful to other people.

 

 

Edited August 31, 2019 by RobjUK
typo

[RobjUK]

I've been refining my brasswork soldering techniques ever since I started the Barclay - I first used a 150 watt iron for larger parts, which provides plenty of heat but is incredibly messy. You can see the results of than on any photos above which show the inside of the chassis.

 

I now use my 50W Antex electronics iron for small parts, or a miniature gas torch.

 

A combination of the gas torch and carefully applied traces of solder paste seem to work very well for near-invisible joints and I have used that method a lot in building the cab and body, where the joints and any excess solder are in plain view.

 

The cab window frames and handrails in the photos above are good examples of that method, with very little other than occasional colouration beyond where the joint itself is.

 

I used the same method for the engine casing and access doors etc.

 

With laminated parts like the radiator, connecting rods and jackshaft weight etc. I again used tiny amounts of solder paste, plus metal bulldog clips to hold the parts together. I also used steel screws or the axle end etc. through any holes that needed to be aligned.

 

 

For soldering the fixing nuts to the engine base & footplate, plus the body to the the base while attached to the footplate, I did not like the idea of greasing things as suggested in the assembly notes, it seemed likely to make further soldering later on difficult.

 

I just put a tiny amount of 3 in 1 oil on each screw thread via a cotton bud before assembling the parts to solder the nuts in place. The nuts were soldered with a small iron and cored solder - and all the screws came out again without any problems.

 

For soldering the engine cover etc. to the body base plate, I put a piece of aluminium foil over the footplate before screwing the body / cab base down to it. It ended up rather scorched, especially where I messed up and got one side of the engine cover out of line and had to use a lot of heat to separate that joint - but nothing adhered where it should not have.

 

Photos - the "expanded" motor cut-out mentioned previously, then soldering bits:

 

 

[RobjUK]

More soldering and the "centering" adapters on the buffer bodies:

[RobjUK]

The aluminium anti-solder barrier mentioned earlier, just before the parts were separated - and the assembled engine housing, 

The slightly out-of-line door was reset after I noticed it in this photo, and nothing screwed down at that point, the footplate and body are just resting in place.

 

(I need to re-attach the control console, then I can realign the handrails that wilted during other soldering.)

 

 

The third photo is my "rivet jig" - a couple of bits of B&Q steel bracket & G cramps, with some tiny recesses made with small drill bits and a pin vice, plus the sharp point of a needle file (tapped with a pair of pliers) to act as the punch.

 

You can see the results in the engine housing brackets & general bodywork.

 

[Michael Edge]

Looks a nice neat job to me, with regard to your comment about the knife edge rocker I agree with you in principle but I've been using this system for many years now with no sign of any significant wear or deterioration in performance. If your rods don't run quite as free as you would like the probable cause is the crank quartering slightly out, I do occasionally have difficulties in designing things when the Slater's wheels don't have the exact crankthrow quoted but the 06 should be OK. Your suggestion of 3 in 1 oil apparently works, my suggestion is grease, others use wax - anything that stops the solder flowing is fine. We deliberately use steel screws and brass nuts to make it unlikely that the nut will solder to the screw thread - most modellers seem to use fluxes that won't touch steel anyway.

To put the missing rivets in the buffer beams get some Plastic Padding Super Steel epoxy, this is a very good epoxy anyway but it has one important propery - when it hardens it shrinks to a hemispherical shape. Mix a small amount at a time (it goes off very quickly) and use a cocktail stick to put the same amount on each rivet position - a bit of practice will get the right amount for each. This is a very useful trick for adding forgotten or accidentally filed off rivets.

I see you still have the fun job of rounding off the corners of the engine casing, look forward to seeing how you get on.

[RobjUK]

Hi Michael,

thanks for the comments. 

 

I've not locked one of the jackshaft cranks to the shaft yet, I want it to run free first. I think the links just need the holes opening slightly to allow a trace of movement on the compensating axle; they are a very close fit at present.

 

The buffer beams have the rivets - see the photo after painting, copied below.

I used the 0.55mm solder ball in the primer coat method I mentioned in one of my posts above; possibly a bit small for the buffer beams, but clearly visible. It's an experiment, they should be fine for the cab strips.

 

This is an ebay listing showing some of the sizes available; 25000 per bottle: https://www.ebay.co.uk/itm/1-Set-Lead-free-Reballing-Soldering-PCB-Heat-Universal-Stencil-Balls-BGA-NEW/352428570625

 

I will remember the plastic padding trick though!

 

Yes.. I'm not looking forward to that rounding-off stage... There does not seem to be much metal to give it such a large radius as the prototypes - do you fillet the inside to give more metal to work with? 

 

 

[Michael Edge]

Have you locked the nuts up tight on the Slater's crankpins? The bushes are a rather loose fit on the screws provided and tightening the nuts produces a random movement of the effective crankpin centre on each wheel - I always back them off a quarter turn and fix with Loctite on final assembly.

There isn't a lot of metal left in the corners of the engine casing after rounding it, a good fillet of solder inside is a wise precaution.

Plastic Padding Super Steel, don't confuse with ordinary PP or another variety of epoxy also called Super Steel (I think it's from Loctite but can't definitely remember). Sorry I didn't notice the last photo (reading in too much of a hurry as usual), that looks an elegant solution as well.

[RobjUK]

Progress!

 

The Barclay chassis is now finished, I believe!

I just ran a 2.5mm bit through the holes in the links by hand, which removed a few traces of solder - they then have just a small amount of play on the crankpin bushes and run nicely.

 

Those primed and painted and an extra coat on the chassis and buffer beams, then the buffers installed to complete it.

 

 

 

 

Plus I've finally got around to buying the new mesh for the Deltic roof fans. The original woven brass mesh just looked wrong to me and I was not happy doing anything else on the body until that was changed.

 

The new vent grids are etched nickel silver from the excellent "Main Line Diesel Locomotive Fittings Set" by David J Parkins:

https://www.djparkins.com/product.php?productid=18234

 

They have a major effect on the overall appearance I believe.

The fan & duct are just held in place on a fingertip for the photo & not quite perfectly centred, though now the parts are more visible it looks like the ducts need reprinting fractionally larger..

 

 

Edited September 10, 2019 by RobjUK

[RobjUK]

At long last, I believe the soldering stage is finished on the Barclay!

It still needs some cleaning up in details, priming and re-checking, but no more metalwork beyond screwing the cab & footplate to the chassis.

 

Some of the details are not quite right to the prototype, such as the cab controls; generic diesel types rather than the exact style & I'm not fitting a ladder as it will get handle by young relatives and the ladder would likely get mangled in minutes.

 

I'm hoping to fit working lights but I have not managed to source any of an appropriate style so far.

 

The cab roof is a sliding fit - I copied Andy Siddall's idea from his thread here, using the rain strips as retainers.

 

Photos of the cab & engine housing only, the chassis and footplate are already completed. The driver seems to be happy with it!

 

 

[Michael Edge]

That looks very neat and tidy - the ladders were later removed from many 06s.

[RobjUK]

Thanks Michael.

I'm not totally happy with some bits, but I think it will clean up OK and look reasonable when painted.

 

It is the first brass kit I bought and I have learned a lot in the process of building it!

Plus doing bits on the Deltic in between times, with quite a bit of back & forth between the two model as I've found info or discovered different methods & sources of info or materials.