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Micro Machine - A Mendip Sentinel, completed


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Another year, another Sentinel. You may recall my - rather involved - conversion of a pre-war 200HP loco built for the S&DJR into a post-war machine (here's the finished result if your memory need jogging: http://www.rmweb.co.uk/community/index.php?/topic/67087-the-200hp-steam-sentinel-and-a-distant-cousin/?hl=sentinel.

 

This one is the smaller brother, a post-war 100HP loco from RT Models (with drive unit from High Level) and has, so far, been a complete delight to build with every part fitting exactly as it should and, because it's etched in Nickel Silver, nice to solder, too. Arthur built a coule of them and recorded his findings in this thread: http://www.rmweb.co.uk/community/index.php?/topic/81445-100-hp-sentinel-from-rt-models-kit/?hl=sentinel

 

I'll be basing it on one of the Roads Reconstruction (1934) fleet used in the precursor to the massive Whatley Quarry. There are plenty of pictures of these about so here's my personal favourite collection, from 1967: https://www.flickr.com/photos/boxbrownie3/sets/72157626030789364.

 

The chassis unit is mostly invisible and folded up without fuss. The gearbox and swinging gear train was a mite fiddly, but results in a smooth and very slow-running loco (but the real thing is only capable of 13 mph). Despite this, the flywheel does have some effect and once fully weighted, I'm hopeful that the thing will be relatively powerful - unweighted trials had it pushing 8 wagons perfectly happily.

 

post-256-0-47249400-1546701983_thumb.jpg

 

Thus far the only alteration I've made has been a cosmetic one. Sentinel made their loco steps from Durbar plating so I've added an overlay to represent this (the etch came from Intercity Models, I think Shawplan may do something similar). These Mendip locos only had steps at the rear...

 

post-256-0-51220600-1546701978.jpg

 

So here's the body assembly thus far:

 

post-256-0-72536000-1546701995_thumb.jpg

 

And finally, for now, body popped on chassis to check clearances. What this demonstrates is that there's plenty of room for adhesive weight when the time comes. The coupling hooks are from AMBIS - I think they are slightly overscale for usability, but the tininess of the loco accentuates this a bit (nothing wrong with the hooks supplied on the etch, by the way, it's just that I had these made up and ready to go!).

 

post-256-0-61729200-1546701989_thumb.jpg

 

Adam

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Guest teacupteacup

Another year, another Sentinel. You may recall my - rather involved - conversion of a pre-war 200HP loco built for the S&DJR into a post-war machine (here's the finished result if your memory need jogging: http://www.rmweb.co.uk/community/index.php?/topic/67087-the-200hp-steam-sentinel-and-a-distant-cousin/?hl=sentinel.

 

This one is the smaller brother, a post-war 100HP loco from RT Models (with drive unit from High Level) and has, so far, been a complete delight to build with every part fitting exactly as it should and, because it's etched in Nickel Silver, nice to solder, too. Arthur built a coule of them and recorded his findings in this thread: http://www.rmweb.co.uk/community/index.php?/topic/81445-100-hp-sentinel-from-rt-models-kit/?hl=sentinel

 

I'll be basing it on one of the Roads Reconstruction (1934) fleet used in the precursor to the massive Whatley Quarry. There are plenty of pictures of these about so here's my personal favourite collection, from 1967: https://www.flickr.com/photos/boxbrownie3/sets/72157626030789364.

 

The chassis unit is mostly invisible and folded up without fuss. The gearbox and swinging gear train was a mite fiddly, but results in a smooth and very slow-running loco (but the real thing is only capable of 13 mph). Despite this, the flywheel does have some effect and once fully weighted, I'm hopeful that the thing will be relatively powerful - unweighted trials had it pushing 8 wagons perfectly happily.

 

attachicon.gifSentinel_033.jpg

 

Thus far the only alteration I've made has been a cosmetic one. Sentinel made their loco steps from Durbar plating so I've added an overlay to represent this (the etch came from Intercity Models, I think Shawplan may do something similar). These Mendip locos only had steps at the rear...

 

attachicon.gifSentinel_032.jpg

 

So here's the body assembly thus far:

 

attachicon.gifSentinel_035.jpg

 

And finally, for now, body popped on chassis to check clearances. What this demonstrates is that there's plenty of room for adhesive weight when the time comes. The coupling hooks are from AMBIS - I think they are slightly overscale for usability, but the tininess of the loco accentuates this a bit (nothing wrong with the hooks supplied on the etch, by the way, it's just that I had these made up and ready to go!).

 

attachicon.gifSentinel_034.jpg

 

Adam

I have a kit for one of these too, I was doing some research into the RB Tennants Foundry in Whifflet, who had a fleet of these Sentinels

 

The site now lies under Coatbridge B&Q, I live very close to it

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Do you know if the chassis would fit into the South East Finecast (ex NuCast) Sentinel?  Might save me a bit of effort scratchbuilding one!

 

I haven't the fainest idea! It should as that's a bigger (taller) loco'. Chris Gibbon at High Level presumably has an outline drawing of the motor gearbox unit for comparison (it's his Quaddriver mech'): http://173.254.28.51/~highlev3/chris/Pages/quaddriverpage.html Obviously, it goes in a 48DS so...

 

Adam

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I haven't the fainest idea! It should as that's a bigger (taller) loco'. Chris Gibbon at High Level presumably has an outline drawing of the motor gearbox unit for comparison (it's his Quaddriver mech'): http://173.254.28.51/~highlev3/chris/Pages/quaddriverpage.html Obviously, it goes in a 48DS so...

 

Adam

Thanks Adam, I'll check the wheelbase of the SEF one to see if there's a compatible one in Chris's range.  With the whitemetal body there shouldn't be any shortage of hauling power!

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Because it's the end of the leave year, I've enjoyed a day at home so the Sentinel has gained some handrails (0.3mm wire, N gauge handrail knobs - it's a small loco so use smaller components to suit) and had a hole cut in the floor - the boiler unit will be attached to a sub floor and bolted directly to the chassis. Why? Because with this type of roof, I think it's more important that it fits properly and stays in one piece. This idea is pinched from Mike Edge's designs for industrials - the only downside is that painting the inside of the cab will be a bit harder.

 

post-256-0-75662800-1547754604_thumb.jpg

 

I only hope I've got enough to finish putting the handrails on the bonnet...

 

Adam

 

 

 

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I have a kit for one of these too, I was doing some research into the RB Tennants Foundry in Whifflet, who had a fleet of these Sentinels

 

The site now lies under Coatbridge B&Q, I live very close to it

 

I've been trying to relocate my favourite gallery showing these and I've finally succeeded (in good time for sorting out the sandbox linkages, happily). These are excellent:

 

https://www.flickr.com/photos/65480188@N07/albums/72157690496924111/with/38930158554/

 

Adam

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I've been trying to relocate my favourite gallery showing these and I've finally succeeded (in good time for sorting out the sandbox linkages, happily). These are excellent:

 

https://www.flickr.com/photos/65480188@N07/albums/72157690496924111/with/38930158554/

 

Adam

I've been trying to relocate my favourite gallery showing these and I've finally succeeded (in good time for sorting out the sandbox linkages, happily). These are excellent:

 

https://www.flickr.com/photos/65480188@N07/albums/72157690496924111/with/38930158554/

 

Adam

Note the orientation of the spring hangers are the only (last 4 built) that have these different to the rest of the locos built, why I don't know.

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Note the orientation of the spring hangers are the only (last 4 built) that have these different to the rest of the locos built, why I don't know.

 

Sentinel were the devil for this - the 200HP types display no pattern whatsoever and could be all manner of ways about. I sometimes wonder whether they ever built two alike...

 

Adam

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I've been trying to relocate my favourite gallery showing these and I've finally succeeded (in good time for sorting out the sandbox linkages, happily). These are excellent:

 

https://www.flickr.com/photos/65480188@N07/albums/72157690496924111/with/38930158554/

 

Adam

Thanks for these links on Tennants guys.  This is a site I find quite inspirational for small layout.  Do you know of any more photos available on the web or elsewhere?

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Thanks for these links on Tennants guys.  This is a site I find quite inspirational for small layout.  Do you know of any more photos available on the web or elsewhere?

 

Lots - it seems they were quite accommodating of enthusiasts.

 

http://www.geoffspages.co.uk/raildiary/scot75.htm

 

https://andrewstransport.smugmug.com/LesTindalls1970sBritishtrains/Scottish-industrials-1973/i-WBjDjFs

 

If you run a search for "tennent whifflet" you'll uncover plenty more.

 

Adam

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Lots - it seems they were quite accommodating of enthusiasts.

 

http://www.geoffspages.co.uk/raildiary/scot75.htm

 

https://andrewstransport.smugmug.com/LesTindalls1970sBritishtrains/Scottish-industrials-1973/i-WBjDjFs

 

If you run a search for "tennent whifflet" you'll uncover plenty more.

 

Adam

Getting way OT now but I've been looking and found this on the National Library of Scotland map site -

 

https://maps.nls.uk/geo/explore/#zoom=17&lat=55.8549&lon=-4.0199&layers=168&b=1

 

It's worth scrolling around to see the vast array of industrial lines in the area, some of which have really complicated track plans.

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Back to the Sentinel, and above the footplate, it's more or less complete, I've even added the first casting! Where the kit is lacking, slightly, is in the treatment of the sandboxes (though both types are supplied) and their operating linkages which are a bit more complicated than a length of 0.45mm wire could legitimately be said to represent:

 

post-256-0-00926700-1548625238_thumb.jpg

 

I made up a bit like the real thing, from multiple parts, in this case, individual lengths of wire flattened at the ends, though I used pliers rather than forging for the flattening, and soldered to spigots, also in 0.45 mm brass wire. At the back end, the pipework behind the cab step is concocted from more soft brass wire and a casting left over from the CSP Models-based 200HP machine which must be intended to represent the same thing (a valve of some sort) since it looks spot on.

 

post-256-0-84362500-1548625229_thumb.jpg

 

Lamp irons, next and the brake standard before I can think about lining the inside with lead and fitting the remaining castings.

 

Adam

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  • 2 weeks later...
Guest teacupteacup
On 23/01/2019 at 16:37, 5050 said:

Getting way OT now but I've been looking and found this on the National Library of Scotland map site -

 

https://maps.nls.uk/geo/explore/#zoom=17&lat=55.8549&lon=-4.0199&layers=168&b=1

 

It's worth scrolling around to see the vast array of industrial lines in the area, some of which have really complicated track plans.

The amount of earthworks and man made relics of former railway formations is fascinating around here, I live on an estate built on the site of the Calder Fireclay Brick Works/Briton Pit shown in the map linked

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  • 2 weeks later...

Well. It was progressing nicely; I'd made a start on the livery colours and then compared my work with pictures of the real thing and... someone had added far too many handrails - the Hapsford/Vallis Vale locos had very few, either side of the cab door and one on top of the bonnet. I didn't notice when looking at all the prototype shots I'd assembled and, small comfort, neither did any of you it seems!

 

So what to do? A bit more prototype research showed that the early post war locos (which is what we're talking about here) didn't have the extra handrails. Any of 'em, so far as I can tell. Oh bother. So what to do? Leave well alone? 

 

Nope. This evening it's been popped in some cellulose thinners and stripped back to bare metal, the offending handrails removed and the holes filled. Assuming it's still dry and warmish in the morning, I'll prime it again and have another go.

 

Frustrating, but the model will now be what I actually wanted all along and not a compromise that didn't quite resemble anything Sentinel actually built. It'll just take a bit longer...

 

Adam

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15 minutes ago, Down_Under said:

Nice Adam,

 

Going to to be a faded kind green? i Got the 1 step forward two back feeing too! 

 

J

 

Er no. It's going to be (and is, now) a fairly bold grass green which seems a decent match for the Roads Reconstruction locos by the '60s. Like this, in fact:

 

https://mickpope.zenfolio.com/p506284746/h21f7997b#h2261ab58

 

I don't have an airbrush, so for small things - wagons, small locos - I brush paint most things with several well-thinned coats of Humbrol so it started out looking quite anaemic. It'll be lined, too. 

 

Adam

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Bearing in mind even this small picture is twice life size on my monitor, I'm reasonably pleased with the hand-painted (inside a red Gill Sans 'O' transfer) Roads Reconstruction roundel and the lining (transfers - 1" black lining from Railtec). Glazing next...

 

Sentinel_050.jpg.7e42ed129ea22cfc5460b326cdb099cb.jpg

 

Adam

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  • 4 weeks later...
  • Adam changed the title to Micro Machine - A Mendip Sentinel, completed

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