Alexander Seal

LMS Sentinels

Outline

S&DJR Sentinel for my Brassknocker Basin project.

Coal on tank top

Shopping - Carr's Yellow Label, plate glass

Prototype

The four ex-LMS Nos. 47180 to 47183 are part of the most numerous and recognisable Sentinel designs. The 100hp "CEDG" type featured a centrally mounted in the frames engine, with a boiler at the front and water tank / coal bunkers at the rear. They were delivered to the LMS in July 1930, Job Nos. 8209-8212 respectively.

(0F)

47180, 47181, 47182, 47183

Modelling

  Prototype N Scale
1∶148		 2mm Scale
1∶152		 Model  
Wheelbase 7ft 14.42mm 14.04mm    
Wheel Dia. 2ft 6in 5.15mm 5.01mm 6mm  
           

21mph? 36mph top speed?

Gear Ratio = Motor rpm x wheel diam (mm) x 0.018 / Prototype Speed (mph)

Gear ratio = 11000 x 6 x 0.018 / 36 = 33

Speed (mph) = Motor rpm x wheel diam (mm) x 0.018 / Gear Ratio

Speed = 11000 x 6 x 0.018 / 30 = 39.6mph

21:1 worm

20:14 gear -

(20x21):(1x14)

420:14

30:1

21 : 1
Gear Wheel O/D (mm): 5.72
Meshing Centre (mm): 4.27

Motor: Lawton 8mm motor or Farish/cheap eBay 7mm motor instead. The Lawton 6mm motor is a bit wimpy. Nigel Lawton 8/16 or the 7mm Coreless that Farish use in their latest models. Farish 7mm coreless motor, available from them as spares for around £15

Shopping List

Qty. Description Code Supplier
1 Sentinel Steam Shunter Loco Kit A151 P&D Marsh
2 6mm Disc Bogie/Tender Wheels 3-052 2mm Scale Association
3 of 5 Acetal Muff 3mm OD for Metric Gears 3-102b
1 Locomotive Axle Steel 1.5mm dia x 125mm 3-110
2? of 5 Drive bush - Brass 3-112
4 of 10 Frame bush - Phosphor Bronze 3-113
1 PCB frame Spacer 150mm long x 7mm wide x 1.6mm 3-157
2 Gearset: M0.25: 21:1 Skew Brass Gear 3.0mm Bore: Acetal worms 1.5mm and 1.0mm Bore 3-363
1 Spur Gear Brass M0.3 14T 3.0mm bore 3-390
1 Spur Gear Brass M0.3 20T 3.0mm bore 3-393
  Screws?
3-410 Setscrew: Cheesehead: 12BA x 1/4" no per 10 1 1.50 1.50
3-411 Setscrew: Cheesehead: 12BA x 1/8" no per 10 1 1.50 1.50
3-420 Setscrew: Cheesehead: 14BA x 5/16" no per 10 1 1.50 1.50
3-423 Setscrew: Cheesehead: 14BA x 1/4" no per 10 1 1.50 1.50
3-430 Setscrew: Cheesehead: 16BA x 1/8" no per 10 1 1.50 1.50 		 
1 LMS round base loco buffers (Turned Brass) 3-501
  Etched Handrail Knobs - Fret of 20 3-528
1 0615S 12V Coreless motor 6 mm x 15 mm (shaft 7 x 0.8 mm) 0615S Tramfabriek
1 Brass adapter 0.8 > 1.5 mm  
  STDDECO-MX616 Zimo MX616 standard micro-decoder - wires-only version £32.00 x1 £32.00 KIT-KAPTON33X19 Kapton tape, 33m length 19mm width £10.00 x1 £10.00 KIT-SHRINK1-5MM 1m length of 1.5mm Heatshrink £2.00 x1 £2.00 LIFELINK470FLAT YouChoos LifeLink stay-alive connection circuit with 1x 470uF Flat Tantalum £10.00 x1 £10.00 KIT-TANT470FLAT 470uF 16V Tantalum Capacitor suitable as stay-alive for Zimo decoders with energy storage connections (MX645, MX631 etc.) - wide/flat design £5.00 x2   YouChoos
 
  Frame material... 20 thou (0.51mm) nickel silver Denys Brownlee, 18 thou (0.46mm) Alan Barnes
0.020" (0.51mm) phosphor-bronze strip - Mark Fielder		    
  Phosphor Bronze Hard Wire 41SWG (Simpson Spring)   Eileen's Emporium
       
       
  Whistle 23068? N Brass
  Lamp Irons 23247? N Brass
  Tank Filler? 23123? N Brass
  Handrail Wire    
  Rivets    
  Primer    
  Paint Gloss Black    
  Gloss Signal Red    
  Transfers    
  Coal    
  DG Couplings   2mm Scale Association
       

DCC

DCC

Frames

References