WifiTrax & SoundTraxx on my WORKBENCH
My current workbench project is a test of direct WiFi control of a DCC locomotive with DC track power. I have no layout and no DCC command station. My very old locos are DC. I have installed a WifiTrax DCC interface module and a SoundTraxx DCC decoder in a loco. I'm now testing this without a conventional command station. As best I figure, the WifiTrax Loco Operator App and the WifiTrax DCC interface module operate together like what I would call a "micro command station." I started with a total lack of knowledge about and experience with DCC but my first DCC loco works.
Here are the listed elements that made up this test.
- Loco is a Mantua 4-6-2 Pacific with a Mabuchi SF-266SA square can motor
- Loco has LED head and rear lights with resistors
- Loco is NOT DCC Ready so NMRA 8 pin socket harness soldered to the eight loco wires per the NMRA standard
- WifiTrax interface module is a WDMI-35 SN 31600101 Firmware 1.1.0 no wrapper
- WifiTrax Loco Operator App 3.5 (Android or Windows 10 smart device required.)
- Amazon Fire HD10 Tablet used in this test
- The WifiTrax 8 pin module plug connects to Loco's NMRA 8 pin socket harness
- Decoder is SoundTraxx MC2H1040P P.N. 852003 (Non Sound) in purple wrapper
- SoundTraxx NMRA 8 pin plug harness connects to WifiTrax NMRA 8 pin module socket
- The tender has removable oil bunker top for "stuffing" the electronics.
- A test stand that suspends the drivers is used.
- MRC Tech II 2500 power pack set to 14.5 volts with alligator leads to loco and tender is used.
The following documents were used in the test. Also, during the initial start-up the App has on screen instructions. All in all, both the WifiTrax module and the SoundTraxx decoder have excellent documentation. The step by step actions beginning with the set-up will not be described because the documents below can be readily accessed on their web sites.
- WifiTrax WDMI-35 WiFi/DCC Loco Interface Module Getting Started
- WifiTrax Loco Operator Online Help
- SoundTraxx Mobil Decoder, MC2 Series, User's Guide
The upper panel of the photo below shows the electronics set-up while the lower panel shows the test in progress. It took several days with lots of unsuccessful test runs to find and fix the one problem that was caused by me (see below). The motor controls all worked and it all was pretty cool to control using the Direct WiFi connections mode from the App to the loco. I was pretty excited learning while not having to invest in a conventional command station.
The two panel photo below shows screen shots from the Amazon Fire HD10 Tablet showing the module's SN31600101 and running the loco. The left panel shows the Function Keys on its left and the throttle and motor control buttons on its right. The right panel shows the Direct CV Programming mode on its left and the throttle on its right. I was able to read and make CV changes. I will not get into the details of everything on these screen shots because they are fully explained in the WifiTrax web site's Loco Operator Help file. It works and I am impressed. All the light and Loco Driving tasks are pretty cool. I have read some CVs and written some too with the App.
MY ONE BIG PROBLEM: In my first test run of Loco Driving the motor speed was erratic and the motor would not stop. Power had to be shut down to stop. Subsequent runs required a full restart only to have the same result. During one test run when it would not stop, I closed the App and shut down the Fire tablet but the motor continued to run - it was obviously running in DC mode. I did all kinds of electrical checks - found nothing. I did countless net searches that made me wonder what I had gotten myself into because so much of what I read was over my head. Then it hit me like a thud - I had a BEMF issue! My 79 year old brain began working again. When I first learned about the Mabuchi SF-266SA motor on the "Remotor-Regear Groups io" site it was stated that it had internal capacitors that might need to be disabled for some DCC decoders. However, other posters in that site stated they had no problems in DCC. Since I was going to use these motors in DC locos (I have 3 locos powered by this motor), I never thought of it again. I had originally purchased several SF-266SA so I got a new one out, uncrimped the metal end cap from the case and cut the circuit board wires leading to the 2 internal capacitors. After reassembly of the motor I used a spare NMRA 8 pin socket harness and attached orange and gray to the motor and plugged that in to the WifiTrax module/SoundTraxx decoder set up. I powered up the 2500 and booted the app. Motor speed was smooth under throttle control and the motor stopped as required. I immediately took apart the test loco and switched SF-266SA motors. Every test run since has worked perfectly.
Now I must study and learn how to fine tune the loco via CV changes (I need to update from the linear speed curve too). Also, I need to set-up an oval of track and pull some heavyweight passenger cars. I'm learning something new, DCC. It's FUN!!