Metalsmiths "Ransomes and Rapier" 70' turntable build.

[JeffP]

Many years ago, an article featured in Railway Modeller about building an "O" gauge turntable from scratch. The only things I remember about it were, firstly, the two figures he had on the control platform: one apparently wound the handle to turn the table, the other apparently operated the locking mechanism. They were called Fred Turner and Bert Locke. The second thing was that he apparently built it into a round metal tray he found which was spot on the correct size.

 

The whole thing fascinated me, so I set out to build my own 4mm version.

 

I got as far as having a mate turn me a well from two bits of 18mm ply glued together, fitted it up with bearings and actually MADE a gearbox from some old clock parts, a pulley with a neoprene "O" ring on it and an old 12V motor. It turned at about 1rpm, which I though was pretty good considering the motor was rated at about 10,000 rpm. The clock parts were modified with a hacksaw and a Black and Decker drill mounted in one of their stands...real high tec.

 

The gearbox and drive worked well, but that was the limit of my success. I couldn't get the table to work properly and eventually it got put away after the birth of our first son, and a change of gauge to "O" made it redundant. I may still have the well and gearbox. If I can find them, I'll put pics up for interest?

 

Anyhow......this year at Telford I finally got my hands on a Metalsmiths Ransomes and Rapier 70' turntable kit and the associated installation module. I had wanted one last year, but they were currently unavailable.

It wasn't until I tried to carry the installation module out to my car, that I realised just HOW big this beastie is going to be: the package wouldn't go under my arm, my arms are too short!!!

 

Once I got it home, first problem: when the turntable kit WASN'T available, an amazing stepper motor and electronically controlled drive unit and indexing system WAS. I didn't buy one, as I wasn't certain Metalsmiths would re-release their kit and also wondered if the re-worked kit would work with the drive unit. And forgot to ask when I found the turntable wasn't available.

THIS year, the turntable was available, but no sign of the drive unit. Bah!...as my favourite Beano characters all used to say!

 

Asking on forums tracked down the makers of said drive unit, G F Controls, but, alas: no longer made. And no likelihood of any more being made.

However, an e-mail to the makers resulted in me being put in touch with someone who had one, but wanted to sell it, so a deal was done and I now have both bits.

 

I would like to thank Frank and Geoff at G F Controls, both of who have helped me no end and continue to do so. Thanks guys.

 

I would also like to say that Dave Smith at Metalsmith is very helpful and approachable.

 

So, onto the build. The first two pics show what comes with the installation module:

 

 

The three bits of mdf are from rear: top, middle and bottom parts of what will be the well and surroundings.

 

 

The second pic shows the bottom module with the installation guide at top, (the longer piece of mdf), the bits of 2mm ply that will make up the concrete sections of the well in centre, the 2mm ply strips that will be the well sides at right, and the five packs of bolts, nuts, washers, spacers and etc along the bottom. Not pictured is the huge drive disc that won't be used, or the race rail that will.

 

My first job has been to seal the mdf with two coats of Wickes water-based polyurethane, since, even though the mdf is the green water-resistant type, I don't trust mdf etc NOT to get moisture in unless sealed, so two coats, preceded each coat by light sanding.

 

And that's where we are.

 

Once the mdf is thoroughly dry, I shall begin the next stage: putting the bits together.

 

I would like to ask, at this stage, for anyone who has had anything to do with one of these, or similar, please DON'T hesitate to make suggestions, offer help, warnings, advice etc.

 

Thanks.

 

 

 

 

 

 

Edited December 4, 2013 by JeffP

[Rob Pulham]

Hi Jeff,

 

I have the same turntable (unfinished) but interestingly I started with the bridge so we might be able to swap notes Mine starts here

[JeffP]

Spent quite a while screwing the two bottom sheets of MDF together last night, 20 3BA screws and 8mm spacers to separate them. The edge now looks like this, with some of the spacers showing:

 

 

And the underside of the base like this:

 

 

Actually, that last photo was taken AFTER gluing, which is shown next...you can see where some of the PVA leaked through and stuck it to the card it was standing on. (luckily it wasn't on the carpet...). The bits of glue and card have now been removed by dampening and gentle scraping with a fingernail.

 

Next, glue was spread in a 100mm circle around the centre bearing hole and along the very edge of the middle board circular hole. The sections of 2mm ply representing the sloping pit concrete sections were laid in place, masking taped to avoid movement, and another not-very-high-tec bodge, two coasters and some folded envelopes places in the centre. These last to apply pressure to the centre when the large drive ring was placed over the whole lot, and a suitable weight stacked on top.....a few £££'s worth of vinyl.....

 

 

And when the LPs were removed:

 

 

It's stuck fast, but the PVA still needs time to dry in the centre where it was enclosed:

 

 

Once that dries, onto the next bit.

 

Now, a question:

 

Since the turntable will be DCC operated, I've been told that I don't need to split the race rail, and that current return is via the motor shaft. Should I go with this, or should I split it and wire in a link that can be removed later if required, so as to allow the turntable to be used on non-DCC?

Any hints and tips about DCC turntable wiring gratefully received at this point........thanks.

 

 

 

 

 

 

 

 

[3 link]

Hello Jeff,

 

Afraid I cannot help you with the wiring ( not one of my stronger points ), but I am enjoying the build so keep the updates coming .

 

ATB,

 

Martyn.

[Wogga]

Jeff to power the table via DCC you simply supply a 12v dc motor via a loco decoder big enough to take the current. That way you can control the speed, direction and get some steady alignment. Just a thought

[PAD]

Hi Jeff, very interesting. I'll be keeping an eye on this and Rob's thread as I fancy one of these myself.Look forward to your (and Rob's) progress. The wiring will be beyond me though, but my brother can sort that out for me. That's his department.

[Grovenor]

Jeff, DCC still needs a polarity change when the table turns 180 degrees so a split rail is OK as for DC.

However if you use sound and don't want a sound glitch as the table goes dead at the gaps in the ring rail then you need a fast switch and a non split rail. You can use a relay to do the switch, triggered when the table is half way round, this system works equally well for DC. Or you can splash out on an expensive DCC reverse loop controller that will do the same job but will not work for DC.

Regards

Keith

[JeffP]

Just restarted on this today...loads of interruptions last week and the week before, unfortunately.

 

I now have the bearings temporarily screwed in place in order to set the race-rail.

 

90 chairs are supplied as white metal castings, to be pinned to what is, at present, the top surface. (The real top surface will be fitted after the race rail is done accurately.)

 

The chairs are handed: they have keys, right and left. I'm ASSUMING, (yes, I know), that I thread them on, keys to the INSIDE, but alternately, one left, one right etc?

 

Please can someone say if that's right, before I get started? Thanks.

 

(I've asked Metalsmiths, Dave Smith isn't there and got no definitive answer from them...)

[JeffP]

If you haven't read the question in the previous post please have a look and post any answers. Thanks.

 

This afternoon and evening, I've been getting ready to lay the race-rail. Now this turntable is a lot like the real thing, in that it's NOT supported by the centre bearing, but at the wheels at the ends, which run on the race-rail. For this reason, the race-rail has to be perfectly circular, (or as close as possible), flat and even.

 

Thus, two hours rubbing the bases of 90 whitemetal chairs in a circular pattern on 400 grade wet-or-dry placed on a falt surface. Each was rubbed until an even colour was achieved on the base, then each had the two holes for the pins that hold them down opened out with an 8mm drill. The pins were measured at a nominal 0.84mm, so this should give a decent fit, tight, but not tight enough to damage/bend the chair when inserting the pins.

After drilling, each base was checked and any burrs removed..I want nothing that can make the race-rail uneven.

 

My eyes are crossing now, and my finger ends are sore...also I'm waiting to see if anyone knows the orientation of the chairs before starting tomorrow.

 

Metasmiths kindly and usefully include a jig for setting out the race-rail I'll include a pic tomorrow.

 

The first pic shows the centre upper bearing screwed in place.

 

 

The second set of  pictures  shows the support for the lower bearing, the method of fitting the support, and the lower bearing fitted so as to be re-usable: the flange is trapped UNDER the bearing plate, the screws being spaced with small washers.

 

 

The final pic shows the two packs of handed chairs, now ready to use, one open, and the pack of pins for fitting. I have a feeling that the pins for the keyed edges of the chairs might need filing flat on one edge to fit better...... tomorrow will tell.

 

[3 link]

 

The chairs are handed: they have keys, right and left. I'm ASSUMING, (yes, I know), that I thread them on, keys to the INSIDE, but alternately, one left, one right etc?

 

 

 

Hi Jeff,

 

I would have thought that the keys would be on the outside of the rail, the same as on the normal running lines but I am not 100% sure.  Do the support wheels have flanges or are they shaped like a pulley wheel if you get my drift ? If they were flanges then on the real thing I would think there might be some pressure exerted outwards so in that case I would have thought the keys would be on the outside, just a thought.

 

You really need to find some photographic proof or wait to talk to Dave Smith before you commit to laying the rail.

 

ATB,

 

Martyn.

Edited November 11, 2013 by 3 link

[JeffP]

The wheels are flangeless, completely flat across the running edge.

 

And the instructions definitely state keys towards centre.

[Ceptic]

 Hi JeffP

 

Some general views of the Ransomes & Rapier 70' T/T at the Didcot Railway Centre. (I wonder if anyone has any detail shots ?)

Ex-SR, recovered from Southampton New (Western) Docks. There was another 70' T/T, this time built by Cowans Sheldon, situated  north of the Terminus, at the loco shed coaling stage,there. 

http://commons.wikimedia.org/wiki/File:Turntable_Didcot_Railway_Centre.jpg

http://commons.wikimedia.org/wiki/File:Didcot_railway_centre's_turntable_-_geograph.org.uk_-_1041754.jpg

http://www.waymarking.com/waymarks/WM7DF8_Didcot_Railway_Centre_Turntable_Didcot_Oxfordshire_UK

http://www.gracesguide.co.uk/File:Im20100802Did-Ransomes1.jpg

http://www.railbrit.co.uk/imageenlarge/imagecomplete.php?id=22555

http://www.railpictures.net/viewphoto.php?id=301937&nseq=8

                                                                                                                                                                              

 Some, maybe useful, pictures here of the Cowans Sheldon 70' T/T at Yeovil Junction. Post # 118, near the bottom of this page.

 http://www.rmweb.co.uk/community/index.php?/topic/70133-photographic-survey/page-5

 

Regards.

Edited November 12, 2013 by Ceptic

[gordon s]

Not sure if these will help….

 

 

 

 

 

 

 

 

[JeffP]

The Cowans-Sheldon pics show a sort of chair-######-pedestal, the rail seems to sit directly on top of them, and be held down with a track bolt through a piece of plain plate at either side.

 

I think mine has been repaired at some time using whatever the engineers had to hand...old chairs.

 

Similar to the R&R one above...that post appeared as I was typing.

 

However, both those use a flat-bottomed race-rail, maybe a modern addition.

 

I think mine pre-dates them, and uses bullhead rail.

Edited November 12, 2013 by JeffP

[Adrian]

Hi Jeff,

 

I would have thought that the keys would be on the outside of the rail, the same as on the normal running lines but I am not 100% sure. 

Martyn.

 

I'd have "guessed" at them being on the inside just because they'll be easier to hit when you are swinging the hammer and also easier to spot when one has fallen out.

[ozzyo]

Hello JeffP, all,

 

up to now all of the photos have shown flat bottomed rail as the race rail and most of them have also shown flat bottomed rail on the T/T deck (when you can see it). This drawing also shows F/B rail in both places

 

Yes I know it of a Ransomes & Rapier over girder type. But the use of F/B rail makes sense as the rail can just be bolted down to the deck and spiked down for the race rail. The rail was not cambered in like a normal running rail as the wheels are flat faced, and the pivot makes sure that the T/T stays on course, the rail on the deck was also flat topped ie. no camber.

 

In this drawing the rails are bridge rails, on both the deck and race rail,

 

I think that Metalsmith have used bullhead rail as it's easer to form into a circle than F/B rail, 

 

OzzyO. 

 

Edit for PS, I would go with the keys on the inside of the rail using alternate hands.

 

.

Edited November 12, 2013 by ozzyo

[JeffP]

I think that's what I've decided, Ozzy.

 

I have my reasons all made up and ready now.........

[Siberian Snooper]

Hi Jeff

 

I would use alternating keys as per single track lines as the forces will be in different directions depending on which way the deck is turned and there are very low accelerating and braking forces due to the driving mechanism being mandraulic at least on the prototype.

 

SS

[JeffP]

Tonight's (not very) thrilling installment:

 

First off, I spent  about two hours yesterday and this morning making the heads of the pins smaller.

This photo shows the difference:

 

 

On the left: the pin with head diameter reduced, on the right: as provided.

 

Now no way am I saying that you NEED to do this, but I did so for two reasons: firstly, the smaller head diameter has more chance of fitting without fouling the rail-supporting parts of the chair, which might cause it to bend on fitting, and secondly, they are nearer to the size of a scale bolt head, although still round...I stopped short of trying to file a hexagon on 180 pins!!!!!!!

Even so, after locking the drill spindle, fitting each into the mini-drill, tightening, filing whilst turning in the drill, and then releasing, my thumb pads are sore......

 

Then I soaked the lot in Carr's Acidip*, before rinsing, drying, and treating with Carrs Brass Black*.

 

* Other brands are available.

 

In the next photo you can see the jig used for setting the race-rail diameter accurately from the centre pivot. The eagle eyed amongst you may also spot the pencil line drawn as a rough guide, (using a bow compass and extender, I'd previously centre drilled the centre pivot in the lathe), and the pencil marks marking where each chair should sit...the distance being worked out from the diameter x sin 2 degrees. The chairs are spaced at 4 degree angles, the above gives the straight line distance between points on the circumference, the chord length, if you will, then set using a pair of dividers. I checked it by also doing 1/90th of the circumference, which came out the same to four decimal places.

You can also see some of the now blackened pins.

 

 

Work has now stopped for the night...the wife objects to the sound of the mini-drill, which I need to drill pilot-holes for the pins: no way can I knock brass pins into mdf without a pilot hole!. More will be done tomorrow. I have to work on the living room floor, the turntable base is far too big for my modelling bench.

Edited November 13, 2013 by JeffP

[micklner]

Didcot

 

 

 

 

 

[JeffP]

Although a Ransomes and Rapier, not quite identical to the one I'm building.

[JeffP]

Race-rail laid. I've ordered some cast brass fishplates from C&L/Exactoscale to join the rails, which were supplied as two pieces. since this will be DCC and returns current via the centre shaft, the race-rail needs to be electrically one.

 

 

Hoping they arrive tomorrow

[ozzyo]

Although a Ransomes and Rapier, not quite identical to the one I'm building.

 

Hello JeffP, all,

 

IIRC the one at Carnforth is very similar to the one that your building, if you drop 11B (Ian) a PM he may be able to help you with some photos as he lives near to Carnforth. I think that the main difference is the one at Carnforth doesn't have the lighting holes in the main girders. 

 

Nice looking build.

 

OzzyO. 

[11B]

Hi Jeff,

 

If you let me know (by PM please) if I can be of any help, and what you need photos of, I'll see what I can do.... May need to go a rekkie to see what is possible....  

 

Hope I can be of some help

 

Ian

[JeffP]

Hi, thanks Ozzy.

Ian, ANY detail pics will help. The kit is pretty good, but in this scale, extra detail can make it.

At the moment, the area round the centre bearing will be flat?

Details of the retaining walls, any cutouts, steps down, etc?

The area surround in the pit?

The rails at the edge of the pit?

Anything on the turntable.

Thanks.

I've PM'd you my e-mail address, thanks again.

I particularly enjoyed Ozzy's thread about RE-building a Metalsmiths turntable for Ranelagh Bridge...even though he did baulk at turning up a couple of left-hand threads to be accurate. LOL