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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