Yorkshire Dave
Western Thunderer
With gold being a soft malleable metal how does it take to turning without deforming or is lower carat gold being used?
TFW’s workshop
- Thread starter Tim Watson
- Start date
With gold being a soft malleable metal how does it take to turning without deforming or is lower carat gold being used?
Tim Watson
Western Thunderer
This was some re-cycled 9ct from Cookson Gold, so quite hard. Previously, I have made lost wax/plastic castings for ‘large’ safety valve covers, which is normally nearer 18ct.
Tim
Tim
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Tim Watson
Western Thunderer
Tim Watson
Western Thunderer
Heather Kay
Western Thunderer
*nods sagely*
Tim Watson
Western Thunderer
Tim Watson
Western Thunderer
And now for the start of the fun and games. The main 1mm-thick brass chassis spars for the Coronation set have been made and can be seen located in the 3DP chassis; designed and printed by Mike Trice. The articulated joint is an overlapping design, with the extra layer beneath the main spar.
The (currently) simple articulated joint was made by making the additional tongue from 1mm brass, drilled as a strip and then cut off, as required.
These short tongues were then soldered to the main spar using the pivot hole for location - the separate components can be seen at the top of the image with the soldering in progress towards the bottom. The drill shank was pushed into a mica block and the underside of the tongue on the spar notched to make it easier to cut through and remove when finished soldering. This also reduced solder flow in that region and the same tongue coated with a black felt tip acted as an anti-flux: of course drill shanks won’t take soft solder, either. The plastic bottle with a needle tube is for phosphoric acid flux.
This close up should make clear the inherent flexibility of the simple joint, but that is probably not how it will stay…
Tim
The (currently) simple articulated joint was made by making the additional tongue from 1mm brass, drilled as a strip and then cut off, as required.
These short tongues were then soldered to the main spar using the pivot hole for location - the separate components can be seen at the top of the image with the soldering in progress towards the bottom. The drill shank was pushed into a mica block and the underside of the tongue on the spar notched to make it easier to cut through and remove when finished soldering. This also reduced solder flow in that region and the same tongue coated with a black felt tip acted as an anti-flux: of course drill shanks won’t take soft solder, either. The plastic bottle with a needle tube is for phosphoric acid flux.
This close up should make clear the inherent flexibility of the simple joint, but that is probably not how it will stay…
Tim
Tim Watson
Western Thunderer
The North British underground workshops (Jim Watt & Graham Roberts) have now completed the Gate Stock for YR. These will journey south for tweaking. fitting out and painting after the Christmas postal rush.
The last image is a close up of the two spare bogies showing just how compact they have to be - the wheels are 6.5mm diameter and rail level to the top of the frame is 14mm. Clearances between the gear on the worm shaft and the rear wheel on this side and between the motor and the wheels on the other side are to the usual 2FS standard, measured in microns rather than millimetres!
One of the spare motor bogies is for re-working the power car of the standard stock.
Very best wishes for Christmas & the New Year to all my friends on WT.
Tim
The last image is a close up of the two spare bogies showing just how compact they have to be - the wheels are 6.5mm diameter and rail level to the top of the frame is 14mm. Clearances between the gear on the worm shaft and the rear wheel on this side and between the motor and the wheels on the other side are to the usual 2FS standard, measured in microns rather than millimetres!
One of the spare motor bogies is for re-working the power car of the standard stock.
Very best wishes for Christmas & the New Year to all my friends on WT.
Tim
Tim Watson
Western Thunderer
As many of you will be aware, Hornby have produced a rather good Coronation set in 4mm scale with a streamlined canvas fairing cleverly modelled. I was kindly given images of these by Tony Wright & Jesse Sim to work out the mechanism, actually confirmed by seeing one in the flesh at the MRC. I thought this clever idea could be made to work in 2mm scale.
My previous streamlined Silver Jubilee set had thin rubber fairings (dental dam) fixed at one end and tucked into the neighbouring coach: unfortunately these have perished over the years. The Coronation is different because the canvas fairings were painted to match the body colour and so a solid structure would represent this rather better - as per Hornby.
The coach bodies therefore need to separate when traversing a curve: this is achieved by a mechanism based on two curved slots engaged by pins at each end of the bogie with the articulated pivot slotted to allow extension. As the bogie enters a curve, the pins move into the opposed curved sections and so the carriage bodies move apart on the articulation slot.
I realised that fabricating such an extending mechanism would require fairly accurate cutting out; some simple drilling jigs were therefore made to ensure commonality between the chassis and the bogie. As a reference, the centre line of the chassis spar was scribed between the articulation point and the conventional bogie pivot. The articulation end was then stabilised on a drill shank in a block of Tufnol. This also located the steel drilling jig and its centre line notch aligned with the scribed line, finally being held with a drop of cyanoacrylate adhesive at the free end. The first centre hole was drilled, then a pin placed in the hole to further stabilise the jig whilst the other two holes were drilled either side, being at the extremities of the prospective arc. (The nearer set of holes in the steel jig are for extra heavy-weight 10’ bogies.)
The two arcs between the holes were cut out with a piercing saw and filed to allow a 1mm diameter rod to freely pass through the shape. At this stage the articulation pivot hole had not been elongated to allow lengthening.
The same steel jig was then located within the underside of the bogie and the drive pin holes drilled at each end, directly above the axle in the midline.
Some provisional pins were made from 10 & 12BA bolts for the main bogie pivot shaft and the two drive pins respectively. The streamlined fairing was made from a 4mm thick sheet of very hard grade Tufnol, with two pegs milled into the bottom, a centre hole drilled and two 14BA studs drilled, tapped and Araldited into the two pegs.
[/URL]
The two holes for the fairing, either side of the bogie pivot post, were drilled using a steel and brass jig for drilling the stud holes. This was held in place (temporarily) with a 10BA nut and bolt whilst the 0.8mm holes were drilled (subsequently reamed to 1mm clearance).
The same jig was used to drill the Tufnol fairing it having already been drilled 1.7mm clearance for the central 10BA bolt, using this hole to locate the jig. The assembly was clamped in the vice, simultaneously holding the fairing for drilling as can be seen in the image below.
The bare bones of the articulated carriages worked together broadly as expected when placed on an 18” radius test track; they were also acceptable with the 3DP under frames and fairing in situ.
In order to work smoothly the fairing needs to be bevelled on its outer corners and the inverse on the carriage bodies. These were filed and smoothed accordingly.
3307a42c-aaf4-4767-a782-f6b85a35dc22.jpe
The mechanism at its most extreme can be seen with the temporary bodies assembled on the 18” test track. It looks as if the fairing is herniating sideways like a slipped disc, but it actually stays in position on the bogie and is lost within the carriage body.
It runs well enough on the test track (interesting beaver tail…), but the acid test will be trying it out on the layout.
The carriages are not a new streamlined LNER / GNER suburban service but the core for the etched sides for the Coronation set itself. Our curves are much more generous on CF than train sets so we might get quite a good prototypically subtle result, especially as our visible tracks are virtually straight.
Once I am content that the prototype is working as expected, then the other three pairs will be made. The inter articulated-pair ends will also be fully streamlined, probably much as Hornby have with their sets. It has certainly made me stretch the little grey cells getting this far.
If anyone has made it to the end of this post: well done! You deserve a New Year celebration drink.
All the best for 2025
Tim
My previous streamlined Silver Jubilee set had thin rubber fairings (dental dam) fixed at one end and tucked into the neighbouring coach: unfortunately these have perished over the years. The Coronation is different because the canvas fairings were painted to match the body colour and so a solid structure would represent this rather better - as per Hornby.
The coach bodies therefore need to separate when traversing a curve: this is achieved by a mechanism based on two curved slots engaged by pins at each end of the bogie with the articulated pivot slotted to allow extension. As the bogie enters a curve, the pins move into the opposed curved sections and so the carriage bodies move apart on the articulation slot.
I realised that fabricating such an extending mechanism would require fairly accurate cutting out; some simple drilling jigs were therefore made to ensure commonality between the chassis and the bogie. As a reference, the centre line of the chassis spar was scribed between the articulation point and the conventional bogie pivot. The articulation end was then stabilised on a drill shank in a block of Tufnol. This also located the steel drilling jig and its centre line notch aligned with the scribed line, finally being held with a drop of cyanoacrylate adhesive at the free end. The first centre hole was drilled, then a pin placed in the hole to further stabilise the jig whilst the other two holes were drilled either side, being at the extremities of the prospective arc. (The nearer set of holes in the steel jig are for extra heavy-weight 10’ bogies.)
The two arcs between the holes were cut out with a piercing saw and filed to allow a 1mm diameter rod to freely pass through the shape. At this stage the articulation pivot hole had not been elongated to allow lengthening.
The same steel jig was then located within the underside of the bogie and the drive pin holes drilled at each end, directly above the axle in the midline.
Some provisional pins were made from 10 & 12BA bolts for the main bogie pivot shaft and the two drive pins respectively. The streamlined fairing was made from a 4mm thick sheet of very hard grade Tufnol, with two pegs milled into the bottom, a centre hole drilled and two 14BA studs drilled, tapped and Araldited into the two pegs.
[/URL]The two holes for the fairing, either side of the bogie pivot post, were drilled using a steel and brass jig for drilling the stud holes. This was held in place (temporarily) with a 10BA nut and bolt whilst the 0.8mm holes were drilled (subsequently reamed to 1mm clearance).
The same jig was used to drill the Tufnol fairing it having already been drilled 1.7mm clearance for the central 10BA bolt, using this hole to locate the jig. The assembly was clamped in the vice, simultaneously holding the fairing for drilling as can be seen in the image below.
The bare bones of the articulated carriages worked together broadly as expected when placed on an 18” radius test track; they were also acceptable with the 3DP under frames and fairing in situ.
In order to work smoothly the fairing needs to be bevelled on its outer corners and the inverse on the carriage bodies. These were filed and smoothed accordingly.
3307a42c-aaf4-4767-a782-f6b85a35dc22.jpe
The mechanism at its most extreme can be seen with the temporary bodies assembled on the 18” test track. It looks as if the fairing is herniating sideways like a slipped disc, but it actually stays in position on the bogie and is lost within the carriage body.
It runs well enough on the test track (interesting beaver tail…), but the acid test will be trying it out on the layout.
Once I am content that the prototype is working as expected, then the other three pairs will be made. The inter articulated-pair ends will also be fully streamlined, probably much as Hornby have with their sets. It has certainly made me stretch the little grey cells getting this far.
If anyone has made it to the end of this post: well done! You deserve a New Year celebration drink.
All the best for 2025
Tim
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Tim Watson
Western Thunderer
Tim Watson
Western Thunderer
My Delphic comment about the Azuma, relates to the close kinetic coupling arrangement used by Kato on their excellent N gauge model. I thought this could work for the ends of the Coronation twins.
The design is a masterpiece of miniature plastic engineering.
As per the Hornby system, the ends are extended with half of the canvas fairing.
The prototype was cut out from 3.4mm thick Tufnol.
The visual effect is good on the straight, but obviously suffers a bit when entering a sharp curve; not a problem on the front of CF.
The testing on the layout was OK, but it was all a bit wibbly wobbly as nothing was definitively fixed in place. I think it will be OK,, once everything is positively located and fettled. The twin set ends will be 3DP extensions, being made by Justin Colson who is also making some rather fine tables and seats for the first class carriages.
The table shape is very characteristic and will show up through the windows.
As ever a team effort on CF.
Tim
The design is a masterpiece of miniature plastic engineering.
As per the Hornby system, the ends are extended with half of the canvas fairing.
The prototype was cut out from 3.4mm thick Tufnol.
The visual effect is good on the straight, but obviously suffers a bit when entering a sharp curve; not a problem on the front of CF.
The testing on the layout was OK, but it was all a bit wibbly wobbly as nothing was definitively fixed in place. I think it will be OK,, once everything is positively located and fettled. The twin set ends will be 3DP extensions, being made by Justin Colson who is also making some rather fine tables and seats for the first class carriages.
The table shape is very characteristic and will show up through the windows.
As ever a team effort on CF.
Tim
Tim Watson
Western Thunderer
It’s not that I haven’t been busy, it’s just that making 4x a fairly tricky expanding articulation mechanism takes time. The proof-of-principle articulated pair were cobbled together with nuts and bolts but something better was required for the production run.
l
The pivots would certainly work better in smooth brass and so this is what has been used, making turnings for the driving pivots (threaded 14BA on the end that bolts through the bogie longitudinal) and a simple plug type with a heavy top washer for the central pivot. This pivot locates up inside the fairing and holds it vertically. All of three extra of these have been milled from Tufnol and await final fettling and fitting.
The prototype unit has also been upgraded with the production components.
Justin has produced some superb first class seats and tables and the buffing /fairing ends for the pairs of carriages in 3DP. It will be fun to get on with some actual modelling in the near future!
Tim
l
The pivots would certainly work better in smooth brass and so this is what has been used, making turnings for the driving pivots (threaded 14BA on the end that bolts through the bogie longitudinal) and a simple plug type with a heavy top washer for the central pivot. This pivot locates up inside the fairing and holds it vertically. All of three extra of these have been milled from Tufnol and await final fettling and fitting.
The prototype unit has also been upgraded with the production components.
Justin has produced some superb first class seats and tables and the buffing /fairing ends for the pairs of carriages in 3DP. It will be fun to get on with some actual modelling in the near future!
Tim
Tim Watson
Western Thunderer
Slight change in direction today. I think a bit of 6 x 20mm gauge plate should just about be able to support a 2mm scale loco and a few wagons over a span of a few inches on the ramp line behind Goods & Mineral Jcn SB up to Mrs W’s goods yard. 
To make sure it survives, the bridge deck will be 1mm gauge plate Araldited to the beam. Better safe than sorry…
Tim
To make sure it survives, the bridge deck will be 1mm gauge plate Araldited to the beam. Better safe than sorry…
Tim
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Tim Watson
Western Thunderer
In other layout developments, with some exciting new stock in the offing, it has become obvious that CF needs significantly more fiddle yard storage space; something that has become increasingly apparent over the last few shows. This mainly affects the passenger lines, as the goods lines can easily be expanded by simply opening up more of the loops through the yard.
CF has evolved over the years and at the rear of the layout there were some fairly illogical S curves on the down mainline (DM). These were based on the cost-expedient re-cycling of some of the 1/4” x 1/16” track curves from the short, original, form of the layout. Straightening this line would make operation less onerous for the long expresses and at the same time capacity could usefully be increased. Following recent discussions it was decided that the down main loops could be doubled in length by moving the entrance turnout 5’ further up the line, giving two long tracks (shown in red on the photo below - after lifting the turnout). The new loop would easily be capable of storing two trains in two sections. The original DM track on the big fiddle yard board (BFYB) would be left-in situ and incorporated as a loop on the down relief (DR - new connection shown in black), merging just before the down goods flyover in the middle distance.
This overhead view shows the connection as proposed, with the original DR shown as a black dashed line and the curve of the original DM also visible on the left. The double red lines are where the new extended DM loops will be placed.
At the other end of the BFYB the reverse connections need to be made, with a significant re-alignment on the DM & DR. The latter would be straightened out a little and taken broadly parallel (red line) with the original DM. The extra DR loop is shown in black below, with the original as black dashes.
In this view the DM track has already been lifted and the extra line is roughly placed under the NLR flyover (removed in this view, but the board position is outlined in yellow dashes). There will be a facing point inserted on the DR (black line) and of course some of the original DM line would become the extra loop.
In order to make this all happen, careful widening of the supporting structures for the elevated goods lines was required: a multi tool saw was most useful for this. We now have yet more archaeology on CF with evidence apparent in some of these photos, such as lines lifted and some redundant structures remaining. I don’t recall writing up much about the CF fiddle yards, but our brass strip track as worked well over the years. Hopefully, we will have a more varied form of operation in a few weeks time at Ally Pally: if it is completed on schedule!
Tim
CF has evolved over the years and at the rear of the layout there were some fairly illogical S curves on the down mainline (DM). These were based on the cost-expedient re-cycling of some of the 1/4” x 1/16” track curves from the short, original, form of the layout. Straightening this line would make operation less onerous for the long expresses and at the same time capacity could usefully be increased. Following recent discussions it was decided that the down main loops could be doubled in length by moving the entrance turnout 5’ further up the line, giving two long tracks (shown in red on the photo below - after lifting the turnout). The new loop would easily be capable of storing two trains in two sections. The original DM track on the big fiddle yard board (BFYB) would be left-in situ and incorporated as a loop on the down relief (DR - new connection shown in black), merging just before the down goods flyover in the middle distance.
This overhead view shows the connection as proposed, with the original DR shown as a black dashed line and the curve of the original DM also visible on the left. The double red lines are where the new extended DM loops will be placed.
At the other end of the BFYB the reverse connections need to be made, with a significant re-alignment on the DM & DR. The latter would be straightened out a little and taken broadly parallel (red line) with the original DM. The extra DR loop is shown in black below, with the original as black dashes.
In this view the DM track has already been lifted and the extra line is roughly placed under the NLR flyover (removed in this view, but the board position is outlined in yellow dashes). There will be a facing point inserted on the DR (black line) and of course some of the original DM line would become the extra loop.
In order to make this all happen, careful widening of the supporting structures for the elevated goods lines was required: a multi tool saw was most useful for this. We now have yet more archaeology on CF with evidence apparent in some of these photos, such as lines lifted and some redundant structures remaining. I don’t recall writing up much about the CF fiddle yards, but our brass strip track as worked well over the years. Hopefully, we will have a more varied form of operation in a few weeks time at Ally Pally: if it is completed on schedule!
Tim
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Tim Watson
Western Thunderer
Just a few pictures of the production run for fitting the Kato extending couplings. In this picture the third class end of the set was tried out on CF. Setting up the articulated units needs a bit of fettling - one fairing needed a bit more clearance on one side - but they seem fairly robust on the layout. The blue colouration is some appropriately coloured masking tape used to hold the bodies onto the chassis.
These are the bits needed to fit the couplings.
This is the brass jig tgat is used to guide the drill to make 0.6mm diameter holes in the top piece of the coupling moulding. The 3mm-shank drill is simply turned by hand.
The coupling is then offered up to the rebated end of the carriage floor and the holes used as a guide to drill the same size holes in the under frames.
Once one side was drilled, tapped 16BA and temporarily pegged in place with a bolt, then the other side was drilled and in this image is being tapped; again holding the tap directly between fingers.
This picture shows the couplings in place with the bodies and attached 3DP fairings loosely in situ: the extension mechanism can be seen at work in the upper set. The lower set shows the top view of the couplings: they are very neat and will look prototypical in side view. The BA bolts were locked in place with nuts, the studs cut off with side cutters and then some cyanoacrylate adhesive run around the assembly. At the back of the coupling a little bit of steel shim was used to encourage the coupling to sit level.
Once the set is fully made up, I may model some subtle folds into the fairings. I am awaiting some long 10BA bolts to make definitive roof/ body fixings to the under frames, as per the old Triang carriages. Once that is done I get can get to work on the interiors and bodywork. The Kato couplings have made life so much easier!
Tim
These are the bits needed to fit the couplings.
This is the brass jig tgat is used to guide the drill to make 0.6mm diameter holes in the top piece of the coupling moulding. The 3mm-shank drill is simply turned by hand.
The coupling is then offered up to the rebated end of the carriage floor and the holes used as a guide to drill the same size holes in the under frames.
Once one side was drilled, tapped 16BA and temporarily pegged in place with a bolt, then the other side was drilled and in this image is being tapped; again holding the tap directly between fingers.
This picture shows the couplings in place with the bodies and attached 3DP fairings loosely in situ: the extension mechanism can be seen at work in the upper set. The lower set shows the top view of the couplings: they are very neat and will look prototypical in side view. The BA bolts were locked in place with nuts, the studs cut off with side cutters and then some cyanoacrylate adhesive run around the assembly. At the back of the coupling a little bit of steel shim was used to encourage the coupling to sit level.
Once the set is fully made up, I may model some subtle folds into the fairings. I am awaiting some long 10BA bolts to make definitive roof/ body fixings to the under frames, as per the old Triang carriages. Once that is done I get can get to work on the interiors and bodywork. The Kato couplings have made life so much easier!
Tim
Tim Watson
Western Thunderer
Last night, the full set of Coronation carriages was pushed around the front and also some of our new untested fiddle yard track on CF: as a scientist, I should have known better than to run an experiment with two variables. The train seemed a bit stiff and one pair of carriages (the first class set) was finding every track irregularity. The offending carriages were stripped down until all that was left to test was the heavyweight articulated bogie - 2mm FS doesn’t take kindly to a wheel 0.5mm out on the B to B…After a tweak it all ran OK. Until the next test.
Back in the carriage shops, attention turned to attaching the bodies to the chassis. Fixing a long bolt through the chassis to a plastic roof is bit of a challenge. I didn’t want to machine a heavy lump of brass and tap it to take the long fixing screw, but gluing on a nut is guaranteed to fail. The compromise solution was to solder a nut to some slightly curved thin nickel silver and bond that larger surface area to the underside of the roof.
In this picture the eight coaches are tucked up together with 24hr epoxy resin, bonding the fixings to the roof. The bolts are passively in the chassis fixing holes to locate the nut fixings.
Let’s hope the idea works…
Tim
Back in the carriage shops, attention turned to attaching the bodies to the chassis. Fixing a long bolt through the chassis to a plastic roof is bit of a challenge. I didn’t want to machine a heavy lump of brass and tap it to take the long fixing screw, but gluing on a nut is guaranteed to fail. The compromise solution was to solder a nut to some slightly curved thin nickel silver and bond that larger surface area to the underside of the roof.
In this picture the eight coaches are tucked up together with 24hr epoxy resin, bonding the fixings to the roof. The bolts are passively in the chassis fixing holes to locate the nut fixings.
Let’s hope the idea works…
Tim
Tim Watson
Western Thunderer
Well about 8 weeks ago none of this lot existed. At least they are now mechanically sound and should work OK on the next test on CF. 
Having tightened down the bodies with the new fixings, the brown Tufnol articulation fairings needed a bit of adjustment: they have to be completely free to move as any rubbing on the bodywork puts a bias on to the bogie wheels and stiffens the movement of the articulating bogie. Hopefully these adjustments will give a smooth running train.
The light grey inter-articulated pair fairings may be adjusted to be a bit closer, but they exhibit a much more dynamic movement when working on the layout and may need a little more slack.
Work can now start on cutting out the redundant side pillars in the bodies and making / fitting the glazing.
Tim
Having tightened down the bodies with the new fixings, the brown Tufnol articulation fairings needed a bit of adjustment: they have to be completely free to move as any rubbing on the bodywork puts a bias on to the bogie wheels and stiffens the movement of the articulating bogie. Hopefully these adjustments will give a smooth running train.
The light grey inter-articulated pair fairings may be adjusted to be a bit closer, but they exhibit a much more dynamic movement when working on the layout and may need a little more slack.
Work can now start on cutting out the redundant side pillars in the bodies and making / fitting the glazing.
Tim
Grahame Hedges
Western Thunderer
That's impressive micro-engineering.