Sango (Toma) SR&RL #18

2-6-2 Baldwin
Sango
HOn30 brass locomotive kit re-released by Toma at the end of 2015 (first release in 1982).

Prototype
Sandy River and Rangeley Lakes Railroad
S. R. & R. L. #18

Wikipedia: Built by Baldwin Locomotive Works in 1893 for Sandy River Railroad (No. 2) as a 2-6-0. Rebuilt in 1916 as 2-6-2. New tender built by Baldwin Locomotive Works in 1926. Scrapped 1936.

Maine Two Foot Gauge 2-6-2 Prairie Locomotives by Peter S. Barney

Chassis / Frame

Chassis / Frame

The new kit includes a coreless DC motor from Namiki, Japan, I suppose type CMS10-1346 (data sheet)! The 1:24 reduction gear seems to be the same as the one used in the SangoDachshund kit. The motor is excellent but way too fast, about 28'000 rpm = 467 /s. With reduction gear of 1:24 (19.4 /s) the speed at 12 V is (driving wheel diameter 9 mm) v = 9 mm * Pi * 19.4 /s = 550 mm/s = 0.55 m/s, vproto= 0.55 m/s * 87 = 47.8 m/s = 172 km/h.

headlight.jpg
Working Headlight (LED potted in clear 5 Min epoxy, 30 AWG magnet wire)

BOM

  • U-Joint 1.5 mm shaft NWSL #487-6
  • LED warm white for headlight e.g. PLCC2
  • LED red for ashpan e.g. PLCC2 VLMS30J1K2-GS08
  • LED yellow for ashpan e.g. PLCC2 VLMY3000-GS08
  • 2 PCS SMD Resistor 1 kOhm 1206
  • PC-Board ROTH Elektronik RE 437
  • Magnet Wire e.g. 30 AWG from Spark Fun
  • Mounting Tape Tesa 55740
  • Clear 5 Min Epoxy for potting the headlight LED
  • Ribbon Cable Wiremount Socket Assembly, 1.27 mm, 3x2, Mouser #517-45106-000030
  • Ribbon cable

483-6-web.jpg
NWSL U-Joint

Wiring

Color NMRA JST Pin# Loco Header Pin# Function
Red 8 1 Right Rail Pickup
Orange 7 2 Motor(+)
Gray 3 3 Motor (-)
White 5 4 Headlight
Green 9 5 FX3 (Ashpan Flicker CV 51: 23+128=151, F24)
Blue 6 6 Function Common (+12V)

3Mô Ribbon Cable Wiremount Socket Assembly, 1.27 mm (0.050") Pitch, 451 Series, Digi-Key 45106-000030, Mouser 517-45106-000030

Tender, Sound

Tender, Sound

BOM

  • TSU-1100 Steam-2 (1 Amp) Tsunami2 Decoder - Steam, SoundTraxx #884006
  • 20 mm Speaker, SoundTraxx #810053
  • 20 mm Speaker Gasket Kit, SoundTraxx #810118
  • Bipolar Capacitor 220 uF 25V, SoundTraxx #810128 (included in TSU-1100)
  • Ribbon Cable Wiremount Socket Assembly, 1.27 mm, 3x2, Mouser #517-45106-000030
  • Ribbon Cable

Wiring

Color NMRA JST Pin# Function
Black 2 Left Rail Pickup
Yellow 4 [Backup Light]
Blue 6 [Function Common (+12V)]
Purple - Speaker (+)
Purple - Speaker (-)
Blue 6 Current Keeper [Function Common (+12V)]
Green/Yellow - Current Keeper [Ground]
Green 9 FX3 not connected
Brown 1 FX4 not connected

Superstructure

Superstructure

DCC Decoder

DCC Decoder

Loco #18, ashpan F24

Sound Configuration

Function CV Value Type
Sound Configuration 1 112 4  
Fuel Type   +1+2, 0 Hand-shoveled Coal
Injector   +4, 4 lifting
Power reverser   +8, 0 disabled
3-cylinder exhaust   +16, 0 disabled
Articulated wheel-slip   +32+64, 0 disabled
Articulated exhaust   +128, 0 disabled
Engine Exhaust Control 114 90? faster, for 4 chuffs per revolution
Whistle 120 2 Baldwin Single-Chime
Bell 122 5 Light Brass (1)
Exhaust Chuffs 123 0 Light (1)
Airpump 124 0 Single-Phase (1)
Dynamo 125 0 Dynamo (1)
Coupler Select 126    
Poppet Valve Release Rate 200    

Motor Configuration

Function CV Value Type
Baseline Acceleration Rate 3 0 no momentum
Baseline Deceleration Rate 4 0 no momentum
BEMF Cutoff 10    
PID Kp Parameter 209    
PID Ki Parameter 210    
Low-Speed Compensation 211    
BEMF Feedback Intensity 212    
Low-Speed Compensation 211    
BEMF Sample Period 213   default 15
BEMF Sample Aperture Time 214   default 15
BEMF Reference Voltage 215   6 to 25.5 V (60 .. 255)

https://sites.google.com/site/markgurries/home/decoders/decoder-motor-tuning/soundtraxx

Notes from the Internet:

  1. CV213/14: Adjusting CV213 can achieve very good low speed at the expense of full speed. You have to strike a balance but try values between 5 & 10. The default setting of 15 in both CV213/14 appears to be too high for a lot of motors. But keep CV213/14 set to the same value what ever you end up with. Setting CV214 to a value 3x CV213 will stop the motor in its tracks unless you bring the speed step way up.
  2. There is a report that using the User Defined Speed Table CV 25 defeats the BEMF tweaks you make. The idea here was to make up for the effects CV213 had on the speed range. [3]
  3. Recent test that achieve good results with CV213/14 set to 5 first. Then set CV209 (Proportional) to max 255. Then reduce CV212 (Intensity) to get it to run smooth which was about 80. Playing with CV210 (Static) did not seem to change much at slow speeds.

Mark G Notes:

  1. It seems that CV213 is the first one to set for low speed performance before doing anything else. Given the BEMF is weakest at low speeds, you need to increase the sample rate (decrease sample period or make CV213 smaller) to increase the BEMF data to obtain any chance of good BEMF performance. The question is what to set the other CVís to allow you to determine the best setting of CV213. This concept appears to be correct based on one credible internet report. Procedure: Leave all other BEMF CVís at their factory default and only adjusting CV213 and 214 down between 5 and 10 but with identical values between the two will improve performance. A value of 8 is a good place to start.
  2. Given CV213 effect on top speed, it seems that CV213 should be dynamic and may in fact be the trick used by other BEMF decoders to get extended slow speed performance. Sample period goes up as the speed step goes down. Sample period goes down and the speed step goes up. This would get you the best of both worlds.
  3. Adjustment should be done with momentum and start voltage all set to zero. [1]

ToDo

ToDo

  • Front light, small LED
  • Chassis 1 mm Loch ausbohren, 1 mm Schraube
  • Piston verlšngern
  • Tender-Loco Coupler

Creative Commons License
This work by Peter Schmid is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

-- Peter Schmid - 2018-12-25

Topic attachments
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JPEGjpg 3mtm-ribbon-cable-socket-451-series-family.jpg r1 manage 10.6 K 2020-05-02 - 20:21 PeterSchmid  
JPEGJPG 45106-000030.JPG r1 manage 8.6 K 2020-05-02 - 20:27 PeterSchmid  
JPEGjpg 45106-000030.jpg r2 r1 manage 30.8 K 2020-05-02 - 20:37 PeterSchmid  
JPEGjpg chassis-no18.jpg r1 manage 713.6 K 2020-05-05 - 10:30 PeterSchmid  
JPEGjpg headlight.jpg r1 manage 133.0 K 2020-05-05 - 20:41 PeterSchmid  
JPEGjpg sango-srrl-18-1.jpg r1 manage 3738.4 K 2018-12-27 - 13:55 PeterSchmid  
JPEGjpg sango-srrl-18-2.jpg r1 manage 3573.8 K 2018-12-27 - 13:55 PeterSchmid  
PNGpng sango-srrl-18-b.png r3 r2 r1 manage 112.2 K 2018-12-27 - 11:52 PeterSchmid  
JPEGjpeg srrl-18.jpeg r1 manage 37.5 K 2018-12-27 - 19:22 PeterSchmid  
JPEGjpg tender-bottom-no18.jpg r1 manage 248.9 K 2020-05-05 - 10:30 PeterSchmid  
JPEGjpg tender-speaker-holes.jpg r1 manage 206.9 K 2019-01-05 - 18:26 PeterSchmid  
JPEGjpg tender-top-no18.jpg r1 manage 199.6 K 2020-05-05 - 10:30 PeterSchmid  
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Topic revision: r16 - 2020-05-06 - PeterSchmid
 
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