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New underpinnings for the one eyed wonder...


The Johnster
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Cyclops, as some of you may know, is my freelancy diesel NCB shunting loco, so named because of her single headlight.  She is, or was until now, a Triang Dock Authority loco which I had worked up a little bit.  She ran well for her age, but I was unsatisfied with her lack of visible wheels and coupling rods, being of the view that a 1950s loco of her ilk should have such accoutrements, and wanting to improve her slow running,  She will eventually have a spur road off the exchange siding at Cwmdimbath (my 1950s South Wales Tondu valleys layout, based on a real place but one that never in reality had a mining village or a railway.  It is much influenced by Abergwynfi, another branch worked from Tondu).  So, when one at a reasonably low price came up, I sourced an equally ancient Triang Polly chassis on 'Bay.  

 

Now, one thing has led to another and I have persuaded myself to take on quite a serious rebuild of this chassis.  To my slight surprise, never having had a Polly or any of her siblings as a child, the chassis is a simple but quite advanced piece of design from a company that was mostly using solid mazak chassis blocks; it has proper frames with holes drilled for the axles, though mazak blocks are used to mount the X04 motor and as ballast.  A lot of you will already have seen the first problem; the chassis is too long for a dokafority.  This is no problem, as I own a small bench vice and a hacksaw.  A chunk has been hacked off the rear of the Polly chassis and a further one is to come off the front.  The ultimate plan is to mount the Polly to Cyclops so that the driving wheels are reasonably spaced out beneath the loco, and to cobble up some sort of jackshaft drive from beneath the cab.  

 

Meanwhile, a trawl through the 'might come in handy one day' drawer has opened up the possibility of something a little more exotic than the X04 and the Triang 20:1 worm and cog gear.  I firstly discovered a forgotten Portescap with an RG4 gearbox, and a test run showed the motor ran perfectly but there was no drive.  There is a nylon bevel gear mounted across the Portescap shaft where it emerges from the can, and this engages with a larger nylon bevel gear on the left side as you come out of the motor if you see what I mean.  Only it doesn't, there's about a 1mm gap.  Foolishly, I tried to lever the larger bevel over to mesh, and managed to break a section of it, possibly brittle with age (I know how it feels), so that is the end of that experiment.  I can console myself that the gearbox was u/s in that state anyway and I haven't actually made anything worse...

 

But we are not beaten yet.  There was another forgotten motor and gearbox in the drawer, though I do not know what sort of motor or gearbox it actually is.  It is at the moment in a chassis which I think came from a Nu-Cast Taff Vale A which I have a body for.  It is a 5-pole motor which, with a bit of parsimoniously applied lube, a wipe over to get rid of the dust, and a gentle running in, runs very quietly and smoothly, and will fit into Cyclops' body once I've trimmed the shaft sticking out the back, in the engine compartment under the bonnet driving the rear axle where it should be, which will leave the cab clear for some detail .  I will go into town later and buy one of those divided screwdrivers for Romford wheel nuts, in the hope that Antics or Lord & Butler have one.  I have no idea where mine is and quite a bit of stuff has become as the snows of yesteryear since I last saw it in about 1997.  If not I'll have to order one which will delay matters for a few days. 

 

Does anyone know what this motor and gearbox are, and does anyone know if anything can be done about the useless RG4, or if it can be replaced with another gearbox.  I have a feeling I already know the answer to the second question.  I'm fairly confident I can make a running chassis out of the Triang frames and this unknown make motor/gearbox, but I will need new wheels as the Polly flanges, unlike the original dokafority which I think may actually be older, will not look at my Peco Streamline code 100 turnouts or flangeways; in any case, appearance demands something better than Polly wheels!

IMG_0612.jpg

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Hi the motor looks like a DS10, which were decent but pretty speedy. The gearbox looks like the one Gibson used to make. The 2 halves bolt together trapping the bearings for the worm shaft. Inside is a fairly fine pitch worm and gear, not sure if different ratios were available - I would say mine's about 50:1. I have a couple but haven't used them. They run OK on test though. 

As a recent Dock Authority botherer I'm interested to see the results !

Edited by Barclay
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A shortened K's 5 pole armature and Romford wheels in the old chassis would have been my preference.  Maybe open up the axle boxes and add Romford fly cranks and rods as well?

I always wondered how Dock shunter crews managed to see where they were going when reversing as there is no cab end light.    Might dig mine out. It has a damaged cab but I have a scrap Triang Pannier body with a good cab....

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Anchorage DS10 and Gibson gearbox rings bells, vaguely, and turning the armature by hand seems to turn the wheels at about the 50:1 ballpark, so that's prolly what it is.  This evening I've removed the wheels from the brass chassis block, using a home made 'split' screwdriver since I couldn't find a Romford one in town and didn't want to wait while one comes though the post.  Removing the gearbox from the chassis without separating it from the motor, which couldn't be done because the bolts in the gearbox housing are inaccessible to a screwdriver within the hole in the chassis, entailed cutting it out and destroying the brass chassis block.  Wheels. axles, and axle nuts have been salvaged for further use, and one axle in addition plus 4 axle nuts will be used on this project; the other axle is already sticking out of the sides of the gearbox.

 

I have fitted the motor/gearbox assembly to the cut down frames from the Polly chassis, and am pleased to report that the motor sits neatly and low on the chassis and that, with the chassis turned around and driving on the rear axle, clears inside Cyclops' engine compartment and there will be space for full cab detail.  The wheel spacing will be towards the rear of the loco, though, and if my plan to incorporate a jackshaft is implemented, there is more room at the front, so if the loco is to be a DM as opposed to a DE or DH, there will have to be some suggestion that the gearbox is at the front.  Having the Pollychassis the right way around would mean that the wheelbase is biased too far towards the front of Cyclops and the loco has plenty of room for a jackshaft in the more likely place under the cab, but will look as if it needs to be an 0-4-2 if it is to not tip back on the cab, not to mention that the motor would have to sit in the cab!

 

I'm using the DS10/Gibson motor/gearbox combination because it is immediately available at the right price and because of the low profile and clear cab.  Lining it up against the loco body shows that in fact this is better in terms of inside clearance and cab detail than the Portescap/RG4 combo.  I am going to be ordering Markit's 14mm Barclay wheels, all insulated which i think is a good way to minimise shorts with a steel framed chassis.  I already have everything else except the pickups to get the chassis working, hopefully with reasonable slow control and smooth starts and stops, but the wheels will have to wait for next pension day, so I will potch about with making up a cab interior module in the mean time.  Maybe.

 

Photo shows the frames with the motor/gearbox lined up against the loco body to show clearance of cab bulkhead, rear axle positioned in frames for illustration purposes but not actually fixed to anything.  I might need top hat bearings for it but it is not much more than a sloppy fit in it's axle holes, and might run satisfactorily as it is.  The lump of Milliput is holding the motor in position for now.

 

There might even be room for a lit cab with an on board battery, and I might even resuscitate the headlight!

 

IMG_0613.jpg

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  • 2 weeks later...
  • RMweb Gold

On hold for now but will not abandon the project.  But I’m wring this in the beer garden of Wetherspoons’ Ernest Willows having just ‘clicked and collected’ a Hornby W4 Peckett which will handle the colliery work with Cyclops, when she’s finished, as spare; the real situation might have been the reverse but rule 1 on my layout states very clearly that steam trumps diesel every time!

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