Speedometer with NWSL trucks and DCS remote commander

[rbrown7713]

I took the guts out of an MTH F3 and put them into my bashed E8.  When using NWSL trucks, there is no provision for the speedometer readout.  I took the sensor and mounted it inside the shell of the NWSL truck with a .053 spacer, for proper clearance.  The gear ratio of the MTH F3 truck is 10:1 and the gear ratio of the NWSL truck is 25:1, so you can see,  some adjustment had to be made.  The number of stripes on the flywheel of the MTH truck, both black and white, was 48, so to obtain the correct MPH readout, the number of stripes had to be reduced to 17.5.  I didn't like that number, so I used 20 spaces, 10 white and 10 black.  There was one more adjustment.  The difference in wheel size from a scale 40 inch wheel to a scale size 36 inch wheel.  That difference was 1.14 slower.  1.14 into 48, so the 2.5 times slower wheel speed, plus the difference in diameter comes out to 17.5 spaces, again I didn't like the 17.5, so I used 20, 10 white and 10 black.  An odd thing happened when testing the readout of MPH.  I forgot to put the striped decal on the flywheel and I still got a reading of MPH.  I thought that was magic, but when I took the truck apart, I discovered that the flywheel had lines scored across the flywheel, I suppose chuck jaw marks.  The lines were shiny, so the sensor picked them up with, I am sure, erroneous numbers.  I then put the decal on and retried it and it appeared to read out correctly.  Boy, the 25 to 1 gear ratio sure allows for some slow wheel turning, good for scale like initial movement of the loco.  Here are some pics. of what the installation looks like.  If you have any questions, please feel free to ask. Bob.  This sensor is so sensitive, it would probably pick up a Zebra running from 20 miles away.

[Chuck]

Looking good! Actually it only reads the black stripes. Be sure to post a video of the E8 when its up & running 

[Rayman4449]

Yes excellent job and time spent working on it.  Please do share the videos when you get done, I like the looks of these motor blocks more and more

[rbrown7713]

After explaining the gear ratios above, here is what happened.  I have a 34 foot test track, and without going to a full page of math, I came to the figure of 1.833 feet per second at a 1:32 scale speed of 40mph.  It should take 18.5 seconds to travel the 34 feet.  With 20 spaces, 10 white and 10 black, it worked out to be 33.6 mph, so I decreased again to 16 spaces, 8 white and 8 black and at 40 mph readout, it took 18 seconds to travel the 34 feet, pretty close to the correct time.  Actually when you do the math, it should take 18.5 seconds, so the actual scale speed is probably 41 mph, close enough for the girls I go with.  There are no doubt some errors in measuring the 34 ft. of track and the timing, so it could be that it is dead nuts on.  8 black and 8 white stripes is the closest that I could actually put on the flywheel. Now the original number of stripes that I came up with was something like 17.4 or something like that.  I don't know, if the O gauge soundset figures in the factor of scale, O, as opposed to 1:32, I personally think that it is adjusted with the number of stripes on the flywheel, but I don't know that for a fact.  Here is the setup for the 1:32 E8, 1:32 3 axle NWSL trucks, 16 spaces on the flywheel, white and black, Proto2 O gauge E8 soundset.  The speed reads correctly and the sounds are fantastic. Robert Brown.

[enginear joe]

 I have several MTH G gauge engines that are exactly the same speed. So I use them as a reference when I do an upgrade. I think there are other guys that use their own engines the same way. I have noticed when I buy someone else's engines that are upgraded, that I need to tweak the speed to match mine. I guess the biggest thing with your engines, would just be to have them close so the sounds and the running seems right. If you are not paring them up in a consist with others, it would not matter if you were one stripe off, one way or the other.

 With all that babble, I have to say that I'm impressed with these Es that you've built. Congrats. I bet that they will tease a lot of jealous train guys out there!!! Very nice.

[rbrown7713]

Since Chuck asked for a video in this thread, here is a video of the E8 running on battery power. 

[Rayman4449]

Just outstanding Robert!  I'm still waiting to be able to buy E units in A and B sets on the market, maybe at some point we will get them but until them will just watch the video you provided

[rbrown7713]

Thanks again for your kudos guys, I appreciate it.  Sometime in the future, I will build another E8 and E7, haven't done the tooling yet on the E7, with a more correct cab that I have, should look even better, that is my dream.  I am now putting together a 1947 Pullman Standard observation car originally built for a one railroad that never bought it and then was used as a Texas Special observation car.  Since I do ATSF, I won't paint it in the Texas Special color of red and stainless, I am going to use it as an ATSF observation car that was purchased by ATSF, it was the same car, but had a smaller red light in the rear.  I might decrease the size of the light, I don't know, then it would be correct.  If I don't, don't tell anyone OK? Bob.