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Discussion Starter · #1 ·
Hi all. Several years ago at the Summer Steam-up there was an arch type structure that sat over the track and recorded the scale speed of any train that went through/under it. It could be adjusted for scale. Does anyone remember it and do you know who built it and if I could buy one? I'm sure I didn't dream it up but all the people I know in the hobby do not remember it.
 

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Yes Remember it.
2007, and here is proof, with you checking it against your Hot Wheels one.
No idea who made it, but I'm sure you can find someone with electronics knowledge to make you one.
Cheers,
David Leech, Delta, Canada
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60905
 

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Discussion Starter · #5 ·
I have made contact with Dave Bodnar.
 

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Dan,
I have always thought there is a different approach to "scale speed". If a real loco is running at 30 mph, then it's wheels are turning 'x' times a minute. (Shouldn't be difficult to figure out if you know the wheel size.) You can apply the same logic to a model to calculate its speed just be observing how many revolutions the wheels make in a minute. If they revolve at the same rate as the prototype did at 30mph, then your model is going 30-scale-mph.
 

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Pete,
That might be possible on a nice slow moving K27 or similar, but when a 1/32 express loco at a scale 90 mph passes, it is possibly impossible to count how fast the wheels are revolving!
Plus then you have to measure the wheels of any loco that comes to run!
Good idea in theory, but hard to actually make work.
Cheers,
David Leech, Delta, Canada
 

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Yes, true you can count rpm, but hard to do on a steamer, impossible on a diesel (but not sure Pete knows what a diesel is ha ha!)

I have the hoop for G scale, and Z scale, and also a car that transmits back to the base station it's speed and voltage:

(all in good fun Pete)

Greg
 

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For 1:20 to 1:22 scale trains I wrote this approximate miles per hour scale speed down from somewhere but I forgot where. It's easy to do when running. You time how many seconds the loco takes to travel 5 feet. I'm not sure where I got this from but a quick check of the train against a marked 5 feet and the second hand on my watch gets me in the ballpark so speak.
For a loco travelling over a five foot distance if it takes 2 seconds it's travelling at 38 to 40 mph, 3 seconds its travelling at 25-27 mph, 4 seconds and it's 19-21 mph and 5 seconds 15-17 mph. All approximate and I am not sure if its even accurate but the trains do look like the speed indicated. Saves building a special bit of equipment to measure speed, any way it's whatever you want to run the train at anyway but a slow speed makes our small layouts seem bigger?
Russell
 

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I was at a persons layout, he had a device built into a box car that transmitted the speed to his I phone, that's all I know about that one. Also saw on a forum or magazine someone built one made from a bicycle speedometer. Tried looking for it a few years later and came up empty.
 

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I don't claim to have originated the idea (I stole it from someone else's post somewhere) but here's my bike speedometer implementation.

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A couple of looks at the speedo's reed switch and the spoke magnet:

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The magnet is just taped to the wheel axle with black vinyl electrical tape. The speedometer's display and reed switch are attached using low temp hot melt glue. A closer look:

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Calibration for mine couldn't be simpler. The calibration factor is based on a bicycle wheel's circumference measured in centimeters. For this LGB wagon the cal factor = 3.1 x Pi x 22.5 = 219. (3.1 is the LGB wheel tread diameter in cm and 22.5 is my rr scale, 1:22.5.) The speedometer internally converts the reed pulse rate to kph or mph depending on the calibration factor and selected speed display. This was an old bike speedo I had. It was inexpensive at the time. I think I got it on sale for around $15 - $20. Similar wired speedos can still be had for about the same price today.
 

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Discussion Starter · #16 ·
Greg, I am in contact with Dave. He is not sure he has any parts left but he said he would look. I've seen the bicycle speedometer type and I made up a spread sheet for several different scales that gives you the speed when you time a train over an 18ft (three 6ft sections of flex track) distance. What I would like is a portable unit that does not need to have a special car in the consist. Though I run mostly 1/32 scale I do have some 1/20.3 scale and 7/8 scale so I would like to be able to change the scale speed read out, which I understand Dave's unit can do.
 

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Yes, Dave's unit is multi-scale which is really nice... the hoop can accommodate all kinds of scales. Also, the accuracy is pretty high, which I needed because I use it to set up custom speed tables in my DCC decoders, i.e. with 128 speed steps, my locos are pre-calibrated to equate the displayed speed step with actual scale miles per hour.

So, I can consist any 2 locos together and they match, and also just glancing at the throttle tells me the exact scale speed. It really helps when you have "junior" engineers that want to run at 200 miles per hour! (I also set the speed table to "flatten out" at prototype scale speed, so it's impossible to run over prototype scale speed.

Once done (done once in the loco's lifetime), everything just works smoothly together.

Greg
 

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Yes, Dave's unit is multi-scale which is really nice... the hoop can accommodate all kinds of scales. Also, the accuracy is pretty high, which I needed because I use it to set up custom speed tables in my DCC decoders, i.e. with 128 speed steps, my locos are pre-calibrated to equate the displayed speed step with actual scale miles per hour.

Greg
Running 1:32 live steam with no RC, I can only dream of having 128 speed steps - some of my locomotives are best described as either on or off

I've adopted a much simpler approach based on how fast I need to walk to keep up.....

Shuffle along <30 mph
Leisurely walk = 60 MPH
Brisk walk = 90 MPH
Running = too fast!

Robert
 

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Discussion Starter · #19 ·
I only run steam and it looks much better running at a scale speed.
 
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