by Russ Elliott
|As an accompaniment to the main CSB page, here is a selection of pictures on CSB implementations. All visuals are courtesy of the builders.|
This is based on a Branchlines chassis, and Gareth used a homemade jig consisting of three correctly spaced holes drilled into a piece of plywood with a drill press. London Road Models axle alignment jigs were inserted into the holes and, one axle at a time, replaced the rigid bearings with High Level hornblocks. The jig was also used to assemble the two frames with their spacers. The loco has a High Level RoadRunner+ 54:1, with flywheel.
We throw mathematics and modern technology at our CSBs nowadays, but here's an extract from an article on a 7mm LB&SCR Terrier in the December 1954 Model Railway News by M G Foster. It's an underslung arrangement with only two frame fulcrums, with sawcuts in the hornblocks for the springs. The builder noted "the actual springs were obtained from an old watch".
Steve Duckworth managed to squeeze (just!) inside motion into this chassis with the use of High Level spacesaver blocks. (The inside motion is dummy.)
The gearbox is a High Level CompactPlus, with the articulated carriage replaced by the D2 Drivestretcher to set it back under the firebox. The D2 is inverted from its normal orientation to reduce its visibility below the ashpan, which involved some modification to the front drive shaft bearing bracket to stop it fouling the idler gear. A curved nickel-silver cover hides the the brass gearwheel.
The motor is in the tender, driving through to the loco gearbox via a cardan shaft. Some further details of the chassis can be found on the Scalefour Forum.
The loco is one of a pair being built for Steve's friend Charles Davidson.
A full description of the fitting of a CSB to the High Level Models chassis kit can be found here.
This is from a Caley Coaches Kit, and uses High Level hornblocks. The motor is mounted vertically, and there is sufficient space between the springs for the High Level gearbox sideframe. The torque reaction link is neatly fitted to the middle frame spacer. More details of this build can be found on this Scalefour webforum thread.
An S7 build of a JLTRT (ex-Malcolm Mitchell) GWR 517 0-4-2T kit by 'Ozzyo'. The CSB over the drivers is a symmetrical 3-fulcrum. Fulcrum support posts on both the frame and the blocks are the long Markits WD type.
The rear axle springs, not visible here under the rear frame spacer, are each fitted with a 'modified Bradwell', which enables the chassis to be adjusted for horizontality.
Full details of the build can be found on this RMweb thread.
James' High Level Pannier chassis with 'spacesaver' hornblocks and Markits short WD handrail knobs. The brass wire is temporary, to test the frame spacer clearances. In P4, there is adequate room for the gearbox between the standard hornblocks. For the front axle, the spacesaver hornblock was necessary because of the, yet to be installed, inside motion (the clearance designed in the kit for the front axle is too small for a standard hornblock plus carrier etch, but okay for a standard hornblock without a carrier etch attached.)
Some more pictures of James' chassis can be found in Mike Smith's article on fitting a CSB to a High Level Models Pannier chassis.
An otherwise conventional CSB 0-6-0 except that this one is split-axle. The frame spacers are gapped double-sided copperclad (Maplins) held in U-section brass (Eileen's Emporium) attached to the frame sides to strengthen the edges and provide a better surface for soldering. Frames are Craftsman etched nickel-silver cut out for High Level hornblocks (the 'spacesaver' variety being used on the driven axle), and wheels are Gibson brass-centred on split axles. This chassis will be featured in a forthcoming issue of Scalefour News, where Bryan will reveal how he prevents those frames shorting to the metal body.
Here's the Brassmasters chassis for the Bachmann 3F tender, with the beam mounted outboard of the inside frame. The internal half-etch aperture of the 'wrap-around' carrier is shaped in a slight crescent, ensuring the beam contacts the carrier only over a short length.
CSB chassis don't come much simpler than this.
Feeling that magazine gauge conversion articles often gloss over the subject of tenders, Dave produces tender kit etches himself under his Lanarkshire Models Supplies brand.
The kits are designed for the Bachmann Stanier, Fowler, Ivatt and WD tenders, but will also fit straight into DJH and other kits where the tank floor is flush with the footplate edge – the new Hornby tenders need more work to accept the chassis but it can be done.
The kits are designed for EM and P4, and feature multilayer etches and jigs for ease of construction. High Level 2mm-bore blocks, guides and carriers will be included in the kits.
Tender frame lengths are often a problem area with CSBs because there isn't much room fore and aft of the front and rear axles respectively.
Dave found some model tenders to be slightly front heavy, DJH because of the castings at the front, and these RTR tenders because of where the weight was placed, so he tightened up the front span a little bit – the front axle to frontmost fulcrum distance being set at 10mm and the rear axle to rearmost fulcrum at 11mm for the Stanier (7'6" + 7'6") tender, these distances being 9mm and 9.5mm respectively for the Fowler (6'6" + 6'6") tender.
In the photos, the scoop and brake cylinder are yet to be fitted.
The frame stretchers and brakegear are hinged to swing away from the wheelsets for removal if necessary, and a bracket is also included for the fitting of Jackson couplings.
Dave finds an all-up weight of approx 100g to be good for 6-wheel tenders with decent bearings.
Dave's WD tender CSB chassis kit (which includes guard irons and tender steps) fitted inside a Bachmann WD tender body.
The Ivatt chassis:
In this Bill Bedford kit, the bearings move vertically within guides bent out from the frame. The bearings are not attached to the beam, but simply bear up against it, the frame fulcrum points being clips bent out from the frame. To prevent the blocks falling out of the frame, the cosmetic spring etches can be soldered to the bottom of the frame or attached with 14BA bolts.
Will Litchfield's O4 2-8-0 and tenderHigh Level Kits blocks and preproduction carriers were used for this ex-Anchoridge kit. The handrail knobs are Markits, probably their 'medium' type M4HRKm, which has an approx 1.75mm frame to hole pitch, which aligns well with the axis of the HL preproduction carriers.
|Will's tender for the O4 dispensed with proper hornblocks, the axles running in small 2mm tophat bearings in a carrier plate moving in slots in the inside frames that came with the kit. A short (2mm) length of 0.5mm bore brass tube keeps the carrier plates vertical. A consistent distance from axle to suspension axis was achieved by drilling the carriers in a jig.
Will is currently working through the CSB construction of a J10 0-6-0 and tender, and further details can be read on the Scalefour webforum thread.
This is an Alan Gibson chassis fitted with High Level hornblocks and carriers. Paul used shoulderless Gibson handrail knobs for frame fulcrum points, setting them with the aid of a piece of guitar string threaded through the HL carrier tags. With the HL preproduction carriers, the distance from the beam axis to the inside of the frame is approx 1.75mm.
This Brassmasters chassis is fitted with London Road Models hornblocks and carriers. On the driven axle, the inside face of the LRM bearings was relieved to provide clearance for the High Level gearbox.
The middle frame spacer happened to be in the right place to act as a fulcrum point between the middle drivers.
Lateral space for CSBs and gearboxes is often at a premium, even in P4.
For the drive axle of the G2, CSB carriers were small angle pieces approx 1.5mm x 1.5mm and mounted on the top surface of the bearing.
The London Road Models carriers adopt and facilitate a liberal approach to the lateral placing of the beam.
This uses Markits handrail knobs fitted to the inside face of Brassmasters' blocks. In plan view, the beam is not quite in a straight line, there being a small lateral displacement of about 0.3mm owing to the width of the hornblock face, but this doesn't affect the intended vertical operation of the beam.
This Scale7 Jinty is being built from a Connoisseur kit. The cast hornblocks are Fourtrack (now available via Meteor Models), and the etched steel rods are from Slaters.
The loco is currently using 20SWG (0.9mm) spring steel for the beams.
Futher details of the build can be found on Adrian's webpages, and Adrian also has a thread on RMweb for his forthcoming MOK Standard Class 4.
|Adrian scaled up the 4mm plot for the fulcrum positions, and used small pieces of brass angle on top of the hornblocks and on the frames, lining up the holes with a length of silver steel before securing the hornguides.|
|Frame spacers added to one frame – some of the spacers had to be slotted to clear the spring wire.|
|The chassis awaiting its motor and gearbox.|
Bachmann Standard Class 4 tank in P4 using Comet frames set up for CSBs.
Preferring to use round parallel bar instead of the traditional handrail knob, Dave made his own fulcrum pillars from 0.9mm diameter wire drilled in a jig. These pillars were later made available in 1mm diameter from Markits, and named 'WD' after a batch of War Department locos Dave was working on at the time. (See here for an illustration of the WD knobs.)
Dave's favoured hornblocks are from High Level Models. A drawing of the High Level hornblock and new carrier is shown here.
Dave's J52, above and left, built for Retford. An advantage of parallel knobs is that they can be fitted through a hole in the frames from the outside to any suitable depth, enabling the CSB wire to be kept straight in its plan view.
The Fairburn chassis uses Markits handrail knobs for the frame and homemade 1.0 x 0.5mm strip pillars for the hornblocks. The plunger pickups have soft springs and very soft wire. Wheels are Ultrascale, valvegear is from MRJ.
In this narrow-frame application, the High Level hornblocks have been reversed to face through the frames, with the outside of the bearing thinned to suit. The Markits WD long pillar requires a little clearance arc in the hornframe.
Dave's Fairburn tank doing the corny old 'sleeper trick', and included here just to show CSB loco wheels are capable of doing what they should be capable of. (If track is that bad though, it should be fixed.)
Nearing completion, Dave's 8F, with Markits WD handrail knobs both through the frames and on the bearings. The 0.5mm thick frames and are set at the maximum width allowing for plunger pickups (Gibson). The valvegear is a much-modified MRJ fret and the wheels are Ultrascale.
Because the kit's chassis frames had cutouts in awkward places, Nick soldered some plates on the inside to mount the Markits frame handrail knobs. Clearance holes for the CSBs were made in the frame spacers prior to assembling the frame. The Gibson bearings slide in hornguides taken from an old Perseverance chassis kit, the corners of the bearings being rounded slightly to prevent them catching on the sides of the 6mm frame slots. The loco uses 0.012" guitar string beams, the lower photo showing some temporary brass wire to keep everything in place.
to be continued
© Russ Elliott
3 September 2010
Allan Ferguson 4-4-0 pic added 6 September 2010
David Murrell, Paul Willis and Will Litchfield sections added 9 September 2010
End-on view of G2 added 13 September 2010
LRM G2 carrier pic added 14 September 2010
David Knight J72 added 27 September 2010
Dave Franks tender section added 20 January 2011
Dave Franks' WD tender chassis added 25 July 2012
Brassmasters 3F tender chassis added 23 September 2012
Bryan Wolsey's 1F chassis added 9 October 2012
James Moorhouse' Pannier chassis pics added 27 August 2013
Ozzyo 517 chassis pic added 20 November 2013
David Knight 3F pic added 11 December 2013
Mike Smith's Pannier pic added 15 December 2013
Steve Duckworth's Class 812 added 24 March 2014
MRN December 1954 diagram added 25 October 2016
Gareth Thomas' Park tank added 13 January 2017
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