A new project to design and produce a kit for a Sentinel steam shunting loco. is under way, following discussions between Ian T and myself.
The chosen design is the post-war 100HP model of the type represented in the National Collection by this loco.
http://en.wikipedia.org/wiki/File:Sentinel_4wVBTG_at_NRM_York.jpg
Do you know of any drawings of this type (especially the whereabouts of the General Arrangement drawing) or have information and photos you can contribute to the project?
The intention is that the model will be electrically powered (with battery/radio control or track-collection option) and the kit will be extremely simple to assemble, with the minimum of parts, mostly screw-together.
The aim is to produce a simple, low cost, model.
John Candy
Ian and I are progressing this project with a view to having something to show at the AGM.
It is early days but the preparatory work is under way.
The loco will have chain drive as per prototype and Ian is dealing with the running chassis parts while I concentrate on the body mouldings and detailing.
Question has arisen on whether the loco should be sprung, compensated/equalised or left totally unsprung.
It will be geared/powered to run at a around a max. scale 20MPH (even that is faster than the prototype at 17MPH) so derailments should not be a problem, even with "solid" suspension.
Does anyone have the GRS Y1/Y3 (either live steam or electric models) and does that have any form of equalisation/compensation/springing and, if not, is there any problem with derailments?
John.
John,
Seems the reply button has appeared now. So have copied the email I sent to you earlier for the record.
My GRS kit electric Sentinel is fixed axle no suspension, no compensation.
It has never ever derailed on cleared track.
It has only derailed on points set against it or twigs that have fallen from the trees.
So don't waste time & expense messing about with that kind of sophistication. Keep it simple.
:)
Dave
454
John,
I don't have any such loco and all of my own wagons are sprung because they ride smoother and sound better. But, this engine has a wheelbase not much longer than a wagon and there are plenty of GRS kits, early Brandbright kits and scratchbuilt vehicles is use with solid axles so I'm sure it would be fine, if a bit clonky over some joints.
Much cheaper to provide fixed axles and the whole concept is low cost.
Mike
P.S. John - will answer your e-mail about this engine tomorrow.
Mike,
Good point about wheelbase....in fact it is only half that of a wagon, being just 4ft 9ins.!
The wheels are just 30ins. diameter which is a slight concern, since they could well clonk over the crossings in turnouts, etc. (unless the crossing/"frog" has been infilled to flange depth).
I am wondering whether overscale wheel treads (to the "old" G3 standards) would be better than the newer slim standard, providing extended support over the gaps in crossings.
John.
John,
I do not believe that on the G3 GTG scene there has been an item of motive power with smaller wheels than my Fowler Railbus.
My Fowler Railbus has really tiny wheels & derails only sometimes when the gauge has been widened on curves.
But that could be speed related which is not an issue with the Sentinel. Yes is clunky over point frogs, but my GRS Sentinel has never had a problem in that respect.
So leap into 30" wheels with confidence & get the show on the road. If they clonk they clonk, tough.
8)
Dave
454
There is also Arty's little Ruston which seems to perform amazingly well, albeit on small indoor layouts. So far as I recall that is not sprung or compensated either.
As you well know, if you have a solid chassis you need to take a lot more care to assemble it dead square, whereas springing means all four wheels will be on the track however bad your soldering, but remind me - is this to be a kit, or RTR? If the latter, then its not a problem.
Mike
Mike,
Ian and I will be making the prototypes with a view to a "kit producer" taking over the moulds, CAD, etc. and offering a kit with RTR option.
Idea is that the kit will be (as far as practicable) "screw together" so a low skill threshold is required (which will also make it quicker for the kit producer to churn out RTR versions).
No idea who the kit producer may be but we have our "preferred option"!
Regards,
John.
I am pleased to confirm that our "preferred option" kit-producer has agreed to participate in this project.
The kit and RTR options will be offered by Mike (Williams Models).
The development work will continue to be undertaken by Ian T and myself, with additional input from Mike on various design aspects.
The provisional timetable is to have a working chassis by the end of the year and a completed model in time for the AGM in February.
John.
I hope the preferred supplier has consulted his financial director about this.
I suggest you also produce a small(micro) layout to display it, say a Cliff Barker 4' 11" radius turnout and sector plate/fiddle yard, on a board that fits in a car. Then it could be the subject of an article in the modelling press, and be exhibited at shows.
Dave,
The Sentinel will be as near-to-scale and as detailed as we can make it, while staying within budget (I hope it will be possible for the kit, complete with radio control and battery pack, to be sold for around 250GBP) but the final cost cannot be confirmed until quotes for wheels and other components have been received.
The aim is for the kit to be offered as a simple "screw-together" job.
The target date for the first models to be at the AGM is believed to be realistic.
The idea of the dockyard diorama was put forward as a longer-term idea.
Regards,
John.
This thread has been split....discussion of a diorama to display loco continues at....
http://lakes-pages.com/gauge3.co.uk/G3Forum/index.php?topic=1375.msg8332#msg8332
Ok, just a few words on the process we're using.
A 'master' drawing is being drawn 'full-sized' to the best available information to hand (not a GA but a pretty good dimensioned drawing). This is currently what I think of as the "MK1" type (non-bunkered, training torsion bars etc.). Not agreed yet but I believe that the version we will actually model is probably the "Mk2" (rear coal bunker, front torsion bars, various detail changes). It should be a simple progression from the Mk1 drawing to the Mk2 - as the original prototype engine was also evolved whilst retaining the underlying design.
Once completed to sufficient detail - the full sized 'master' will be scaled at 1:22.6 (exact scale) and from the 'scaled' version - component drawings will be made. At this stage we will start to move from "the way it really was" - to "the way it needs to be modelled" (given constraints of cost and ease of 'build' required) and some compromises will be necessary.
However, the essential proportions of the engine will be correct (or as good as I can make them). So whatever level of 'finesse' the engine is offered at - hopefully it will be a good enough foundation to bring up to what we would probably think of as 'Finescale' if the owner so wishes and has the necessary skills to do the additional work.
Cannot say too much more at the moment as quite a bit of the detail is still in flux but this is the design process being used and hopefully the end result will be useful to a range of modellers - both beginner and the more advanced.
Regards,
IanT
The Sentinel 100HP project is now well underway, with Ian T , Mike and myself all applying our minds to the best method of producing a loco with as near as possible scale appearance, while keeping the cost to an absolute minimum.
One item which is taxing our brains at present is the wheels.
These are of exceptionally small diameter (30 ins) which presents the following problem : If the wheels are cut to the G3 standard (as used by Slaters) will turnout crossings ("frogs") cause them problems?
Running a Slaters wheelset of a scale 33 ins diameter across a Cliff Barker crossing causes the wheelset to drop by about 1.5mm.
If the crossing were to be "infilled", the flange would support the wheel but we cannot count on that being the case, since CB supplies ready-made turnouts without infill.
Can someone with a GRS LNER Y1/Y3 AND Cliff Barker turnouts, please do the following?
1) Measure the diameter of the wheels (over tread).
2) Measure the depth of the flange
3) Confirm whether (or not) the loco will run through Cliff Barker turnouts (WITHOUT INFILLING OF THE CROSSING/"FROG") without the wheels dropping into the gap in the crossing.
Thank you!
John.
John,
My Sentinel has run on GRS track, Cliff B track, G3S track etc & I have not consciously noticed that there has been an issue whilst negotiating switch frogs. Cannot believe this would be a problem even with wheels that small. My Fowler rail bus just skips along happily with it's minuscule wheels & that has been run on every standard of track imaginable.
Has anybody witnessed a real 0-4-0 wander through a set of points in shunting mode when light engine or even hauling or propelling wagons? They rock & clunk & oscillate all over in every direction. To create & expect an 0-4-0 which simply glides silky smooth through siding pointwork seems a departure from reality.
Cheers
Dave
454
Dave,
The dimension which is critical is the width of the tread.
The current G3 standard is a minimum of just 5.2mm but we are proposing 6.4mm for our small wheels (overall width of wheel 8mm minus flange width 1.6mm).
I have just tried this over a Cliff B turnout and it gives a much better "ride" than a standard Slaters wheel.
I dis find that my GRS Peckett-based Bagnall 0-4-0 tank tilts right over (with the wheels at one corner "up in the air") and this is supplied with LGB wheels.
The GWR 1361 class, supplied with the same wheels, is an 0-6-0 so does suffer from the same problems.
It would be useful to know the widths of the wheels on the GRS Y1/Y3, for comparison purposes (I assume they cannot be Slaters).
Regards,
John.
John,
My Sentinel wheel width is 7mm & flange width is 1.6 mm for the record. So is not G3S minimum at 5.4mm but only just.
Dave
454
Thank you Dave.
Can you help?
The Sentinel 100HP project is advancing in "leaps and bounds" but there are still some "grey areas" where detail needs filling in.
1) Do you happen to have a photo of the small square (it may be rectangular but looks to be almost square) works plate which is positioned by the cab opening on all these locos?
I have "Googled" in vain but the only illustrations I can find are of the "Super Sentinel" type which are shaped rather like a church Gothic window and were not fitted to the loco type being modelled.
2) Do you happen to have a photo of the interior of the cab of one of these post-war 100HP locos, in particular showing the vertical boiler and controls?
Finally, do you happen to have an empty Carr's 50ml plastic bottle you can donate, of the type which they use to package flux and other chemicals?
Why? Well it happens to be 42mm in diameter and is exactly right to form the basis for the boiler pattern/mould!
I have several but they are either full or almost full.
Thank you,
John.
Thank you Dave ("454") for the photo of the works plate you sent by email.
John.
John
I have some 41mm copper pipe that you are more than welcome to if you think that it would do.
Regards
Jon
Jon,
Thank you, I would need a section 50mm in length and can increase diameter by wrapping it with thin plastic card .... it is to form the basis of a pattern to make a silicone rubber mould so I only need to do it once.
Will send you an email.
Regards,
John.
The Sentinel project update
A lot of progress has been made in the two months since the three of us (Ian T, Mike W and myself) decided it was time to try to "kick start" a greater interest in G3 by making a low-cost (but good quality) "starter set", to entice newcomers to "large scale" to take the plunge and go with G3.
Ian has been preparing the correctly scaled drawings (from available drawings in other scales and photographs of detailing) to enable me to the prepare patterns for the parts which are to be cast in resin and brass. Ian has also worked out the mechanical arrangement for the chassis, which (on such a small-wheeled loco) has posed a few problems, now largely solved, and is pressing on with the assembly of the two rolling chassis for "Arthur" and "Plantagenet" (yes, we have even decided on names for our locos...and the plates are on order from Guilplates)!
Mike, meanwhile, has been dealing with "contractors" to place orders for the brass castings (whistle, buffer guides, steps, etc.) and turnings (e.g. wheels and the extra large diameter buffer heads carried by industrial locos.).
Photos of a few completed patterns for brass casting are attached to show the level of detail we are aiming for.... this may be a low cost loco but it will NOT be "cheap" in appearance or quality.
Photo Buffer Guide Pattern (Note : buffer head is not of the larger type to be used on model)
(http://lakes-pages.com/wpimages/buff_guide_tmn.jpg)
Whistle Pattern
(http://lakes-pages.com/wpimages/whistle_tmn.jpg)
Cab Step Pattern
(http://lakes-pages.com/wpimages/sent_cab_step_tmn.jpg)
The power on the prototypes will be by 9.6V cell pack, Powermaster motor, 50:1 gearbox, Viper 10 ESC and 2.4GHz radio control. There will be drive to all four wheels, so with the small wheels (30 inch diameter) and plenty of weight provided by the steel, brass and resin superstructure, there should be plenty of pulling power at a realistic speed.
The patterns for the main body components (which will be resin) are well-advanced and expect more photos of progress early in the New Year.
Seasons Greetings from the Sentinel Team.
To put the record straight......
If you have received your G3S Newsletter, you may have read that Ian Turner and I will be displaying a "Muir Hill tractor" on our stand at the AGM but I have no idea from whence that information emanated.
Sorry to disappoint all you avid Muir Hill fans..... our project loco is a "Sentinel", which will be displayed alongside the latest "Flexikit" wagon designs (which will include the corrugated steel ended LMS 5-plank).
On the subject of the Sentinel, it is a "post-war" 100HP design which dates from 1945 ..... there is a misleading reference in the Newsletter to it being a 1957 design .... in fact this type was nearing the end of production by 1957.
Merry Christmas,
John
An update on the specification and progress of "Project Plantagenet".
Basic Specification:
Chassis : Steel mainframes with 1/4 inch Oilite bearings; insulated steel wheels; both axles driven.
Walsall 50:1 gearbox with "Powermaster" motor.
Outside cosmetic frames cast in re-inforced resin.
Body : Cast resin body/cab/bunker on steel running plate.
Detailing by cast and etched brass components (including etched brass cab roof).
Specification for the radio-controlled model :
9.6V 2000mAh rechargeable NiMh (low drain) cell pack; Mtroniks "Viper 10 Loco" electronic speed control; 2.4GHz transmitter/receiver.
There will also be an adjustable voltage regulator which will enable the maximum speed to be "fine tuned" to suit the owner.
State of progress:
Chassis:
Wheel sets currently being produced to special order by Peartree Engineering.
Other mechanical parts fabricated/sourced and ready for assembly (being handled by Ian Turner).
All power/control electronics/radio control parts are in stock and I will be installing the electrics and testing the chassis when received from Ian.
Body :
Metal components:
Large diameter steel buffer heads being produced to special order by Peartree Engineering.
Cast brass buffer guides (special order); delivery imminent.
Orders to be placed for cast brass components : Whistle; cab/running plate steps; lamp irons (patterns made).
Orders to be placed for etched brass components : Cab roof ; bonnet side steps; inspection door latch handles; spark arrestor mesh (CAD design being handled by Mike Williams).
A note of thanks to John Taylor who has kindly assisted by machining the patterns for lamp irons.
Resin components:
Bonnet pattern completed and ready for pouring of mould and test casting.
Cab/bunker pattern completed and ready for pouring of mould and test casting.
Buffer beams (two types : Sprung and "dumb") patterns and moulds completed and parts cast.
Cosmetic chassis frames (with springs/axleboxes/sand boxes, etc.) : Work to start within a few days.
Cab detailing : Work on pattern for boiler/flue casting to commence soon.
It is hoped that two completed prototypes will be available for running demonstration at the AGM but the schedule is tight and any delays by suppliers could thwart our plans but (at worst) there will be "substantially complete" models at the AGM.
John.
This website doesn't a button to click, so I'll just write
Geoff Likes this (very much)
For those of you not able to be at Biggleswade, here are some photos. of the Sentinel.
There remains the cosmetic, outer, frames to be fitted (they carry the axleboxes/springs/sandboxes and other detail) together with the brass castings for buffer guides/running plate & cab steps/ bonnet side steps/ lamp irons and the large diameter steel buffer heads.
There was a great deal of interest shown in the model, with several stating an intention to purchase the kit when available.
There were questions as to whether the "bunkerless" version would be available and a conversion option will be offered.
The parts for new Flexikit wagons with a steel-type underframe skeleton casting (to suit either 9ft or 10ft WB) were also shown.
The initial wagon types on offer being the LMS D1838 5-plank with corrugated steel ends, LMS D1927 3-plank dropside wagon (both to suit the 10ft WB skeleton underframe) together with the LMS D1828 all-steel vans (in 3 versions.... Gloucester/ Chas. Roberts / Metro Cammell) which fit onto the 9ft WB skeleton underframe.
John
Here are some photos (rather better than those taken on my workbench) sent to me yesterday by Ted Sadler and Ian T (taken at AGM) .
The buffers, brass castings and (Walsall M.I.) turned handrail knobs are still to be fitted and the cosmetic sideframes are work-in-progress.
All being well, should be completed by end of month.
John.
Hi John,
How is this project coming along?
Hi Simon,
I have to confess that not much has happened recently ..... there have been some small changes to the design to improve the strength/ease of assembly of the (outside) cosmetic frames.
The outside frames are now to be of laser-cut steel and the springs, axleboxes, etc. are to be of whitemetal.
The earlier spec. was for a one-piece resin casting.
More progress reports before too long.
Regards,
John.
The first Sentinel to be completed is "Arthur", destined for Ian T and finished to his specification.
The Sun was shining this afternoon, so I photographed it outside.
The second loco ("Plantagenet") is almost complete.
John.
And very nice he looks too John - well done.
Regards,
IanT
looks very good.Please could we have a photo of it posed next to a wagon, and another one with the body removed?
Very nice indeed John. When is production starting?
QuotePlease could we have a photo of it posed next to a wagon
Just taken a photo indoors with flash, so not ideal .... it is blowing a gale outside!
Quoteanother one with the body removed?
"Plantagenet" will be "undressed" later today for final wiring....will take photo. later.
QuoteWhen is production starting?
Mike will be producing the "production" locos from the patterns and moulds I have given him, together with laser cut steel parts from the drawings of the frames/motor/gearbox as provided by Ian T.
Mike is currently in the middle of a house move, so there will be a delay before he is able to get focused on the production side.
The plan is that the models will be offered RTR, complete with batteries and radio control installed.
Mike may be willing to offer more specific timing.
John.
I think you can stop calling it "proposed" now John.
It looks even better dwarfed by the wagons.
The second wagon looks interesting, I'd thought 16ton mineral, until I saw the 'LMS' lettering...
The wagon is a 16T steel mineral to LMS D2109 .... 2.599 of which were built from 1946 onward.
D2109 was basis for LMS D2134 which was produced from 1949 and was the origin of the BR standard design.
John.
That looks superb John. Is there any news on how much these will cost :)
QuotePlease could we have a photo .......... with the body removed?
Specially for Geoff, here is "Plantagenet" opened up on the operating table ..... entrails everywhere but no blood (unlike "Casualty" which Carol is lapping up on BBC1)!
John.
QuoteIs there any news on how much these will cost
When the project was begun (a little over a year ago) the target was to produce a full kit for around 300GBP.
Costs of some components have risen since then plus the spec. of the model has been upgraded (in particular more brass castings for detailing, instead of resin or white metal parts).
Mike and I will have to "put our heads together" and work out the precise costs involved.
The intention is to offer the model as RTR (not as a kit) since it has proven simpler to design for batch/jig construction than to design as a simple-to-assemble/screw-together kit.
I would hope that it will be possible (but don't hold us to that it is just a "guide price") to offer the RTR loco for circa 400GBP .........it will be for Mike, who will be doing most of the work from now on, to set his price).
John.
John, sorry, but my eye was caught by the 16T mineral, from which stable did this originate?
Thanks
Baz
Baz,
The LMS D2109 is a heavily (very heavily!) modified GRS kit (one of the old plastic card and whitemetal sort .... you couldn't do it with the newer resin bodies).
Various chassis parts were replaced (axleboxes in particular) and the body was extensively re-worked with resin castings being made for the pressed steel side and end doors.
If there is sufficient interest, it could be produced as a Flexikit BUT to make it worthwhile, Mike would need to have a fair number of advance orders (on past performance, the existing Flexikits have not been selling in sufficient quantities to make it worth the time, expense and effort involved).
John.
Thank you for the photos showing the insides, John. Having one 'off the shelf' suits my layout project, but I couldn't resist speculating whether it could be converted to one of the sentinels which carried a BR number, merely by altering the bodywork.
The GRS Y6 steam tram is currently £246, and you have to build it and buy and fit your own RC, so £400 for ready to run is not unreasonable.
Thanks John, it does seem a very reasonable price. I may very well order one when they are available :)
My thoughts exactly Geoff thinking one in black would be very nice.
If you are thinking the Sentinel is a small loco, then here for comparison (scratch-built to the same scale) is my 2ft 6in gauge ("G32") Ruston Proctor 20HP paraffin loco from my Royal Ordnance Factory line which tranships to the Powdermills Branch!
Tomorrow, I will take a short video clip to illustrate just how slowly and smoothly the Sentinel can crawl with its powerful 7-pole motor.
John.
Yes, it wouldn't be too obvious that they were both actually to the same scale John.
IanT
The first completed Sentinel ("Arthur" for Ian T) will be at Warley on Mike's (Williams Models) stand (stand C09), so if you are there, make sure you see "Arthur" in the flesh, so to speak.
I took the model to Ted Sadler this afternoon (he will be delivering it to Mike at Warley) and Ted will also be one of the team tending the G3 Society stand.
While at Ted's, he took took a few photos and one is attached....I have to say, his track ballasting does look good.
John
That looks fantastic John :)
Below is download link to short video clip of "Plantagenet" (32MB AVI file)
http://lakes-pages.com/wpimages/DSCN0585.AVI
A most attractive locomotive, especially in this dark green livery.
Robert. 492.
Very nicely detailed John. May I ask how you have produced the side grilles?
I have previously thought the prototype to be an ugly duckling, but you and the production team have 'almost' transformed it into that graceful swan!
;D Tim
Thank you Tim for your comments.
The main body comprises just 6 large resin castings (plus the grille inserts), with etched and cast brass detailing (whistle, steps, hatch latches, lamp irons, buffers).
The grille is a cast resin insert (I chose to make it separate from the cab side since there were two different patterns fitted over the lifetime of the production run and I wanted to keep open the option of offering the alternative).
The grille pattern was produced using "doctored" Cambrian Models mouldings parts (sample shown below of what you get.... each individual "fin" is a separate item to be cut from sprue and placed) grafted onto the Sentinel vent panel made of plastic card and rivets. Silicone rubber mould then produced.
Regards,
John.
Cambrian models produce some useful bits. I tried to pursuade them to get involved in G3, but they prefer to stick to 4mil.
The sentinel looks very nice the track is already laid at Lea siding ready for mine. Seeing the video made me wonder what the real thing sounds like. Does anyone know of any videos of the one at Tanfield?
Geoff,
I also wondered about the sound.
In fact I did ask in this forum some months back but got no reply.
I imagine, they could sound a bit like a traction engine ; a very fast exhaust beat relative to the speed but I really have no idea.
John.
We'll have to ask John Taylor at the G3 AGM. I think he's been to Tanfield.
Here is a YouTube clip of Sentinel 6515 a 1927 Centre Engine type; note the predominant noise is the 'chain rattle'. I will search for some clips of your post-war type.
https://youtu.be/zgWkrlrX9YQ
Ian the Gauge '3' Pirate
Probably that's a good assumption about the noise Ian but the (YouTube) poster is of course incorrect to call that engine a Sentinel 4wVBT - it's more like a Y1.
I've got a quite few photos of the GNR 6 wheeler it's pulling somewhere, taken a few years ago now. A very nice restoration job. There's a good view of the roof at one point in this video too, always something that's usually difficult to find photos of.
Regards,
IanT
Just wondering if there is any more progress with this model? :)
Funny you should say that ... I've just finished casting my first set of resin parts for it and also drawn out the frames this morning for laser cutting. So, after a far-too-long delay I've now got my backside into gear and hope to get a test one assembled in the next few months. I know that John has test assembled it, but I need to do one myself.
A member on here is also getting a set to play with, so between us something should start to happen.
Mike
Where are all the folks who, a few years ago, were asking me when the Sentinel loco would be available to buy?
Well, there are now three RTR models up for grabs (there were four but one has already been snapped up).
These are a LIMITED EDITION model (there will likely be no more) meaning that, including the two prototypes "Plantagenet" and "Arthur", there will be only SIX in existence.
They will surely become sought after in the future?
At only 660GBP each (600GBP to members of The Gauge 3 Society) plus shipping costs, these have to be a bargain loco, whether for a beginner in G3 or someone with an established line, looking for an unusual additional loco.
Supplied complete with radio control, you would be hard put to find another battery-powered loco at such a bargain price.
Think about it for too long and you will have missed out!
Short video clip of Plantagenet http://lakes-pages.com/wpimages/DSCN0585.AVI
For more details on purchasing go to https://www.gauge3.org.uk/news
John Candy