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How do you measure scale mph in HO?

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  • Member since
    February 2005
  • From: Vancouver Island, BC
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Posted by selector on Wednesday, March 13, 2019 3:51 PM

The early QSI decoders would tell you via voice what the scale mph was at the time by pressing one of the function buttons, F10 or F9...I forget.

I have run enough trains, and have essentially correctly spaced telegraph poles, such that I can get pretty darned close watching the trains move past items how fast they are going.  Also, with steamers, I can make a rough estimate of their speed by recalling their driver diameters and counting the cyclic rate of the crosshead or the turn of the main crank per second. 

Also, for steamers, their maximum horsepower at the rails would be produced, across driver diameters, at about 4 cycles of the piston/main crank per second, a bit less truthfully. So, if I need my head-end producing maximum horsepower for a given consist and speed, and terrain, I make sure it's not in 'drag' configuration, as a Y6b would be on the Blue Ridge, but churning quite nicely at 'express' speed.

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Posted by BATMAN on Wednesday, March 13, 2019 3:42 PM

I just push two buttons on my NCC controller and get an audible report.Smile, Wink & Grin

Having a somewhat inquisitive mind I decided to test the accuracy by timing trains around a 20' x 6' loop that I can isolate from the rest of the layout. The audible report was dead on as far as I could determine. 

I just wish the audible report was a sexy babe voice instead of Bob from accounting.Laugh

Brent

"All of the world's problems are the result of the difference between how we think and how the world works."

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Posted by Bayfield Transfer Railway on Wednesday, March 13, 2019 3:16 PM

Here is a nice, easy. low-tech solution.

HO scale is 1:87.1somethingsomething.

60 MPH is 88 feet per second.

So, for HO scale, you can say that 1 foot per second is 60 MPH HO scale, close enough.

1 inch per second is close enough to 5 mph, 2 inches per second is 10 mph, etc.

All you need is some colored pins an inch apart and the timer on a cell phone.

 

 

Disclaimer:  This post may contain humor, sarcasm, and/or flatulence.

Michael Mornard

Bringing the North Woods to South Dakota!

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Posted by wvg_ca on Wednesday, March 13, 2019 2:58 PM

did both the stationary, and the mobile versions a few years ago , worked well ..based on arduino's ..

if you want an inexpensive way to measure speed, just a stopwatch and two spaced markers will do it ...

i use 28 speed steps, and geared steam engines, one smph per speed step ..pretty easy to set up, in jmri or just cv's

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Posted by Wolf359 on Wednesday, March 13, 2019 2:49 PM

Thank you all. You've given me some interesting food for thought. I have no urgent need for this, but like I said, I was just curious. But, you never know what you might need and when.

  • Member since
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  • From: Bakersfield, CA 93308
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Posted by RR_Mel on Wednesday, March 13, 2019 2:31 PM

mbinsewi

Excellent Mel, I didn't know.  Now have to find a stop watch and play around with it.  Maybe just to check out my throttle readings.

And NO, I don't have a smart phone or a computor hooked up the my lay out.

Mike.

 

Mike
 
I have some parts on order to attempt a wireless speedometer from a towed car similar to the Boulder Creek Speedometer using a pair of Arduino Nanos.
 
I received the magnets yesterday but the Hall Effect sensors didn’t clear China Customs until the 4th so it will be a while.  I have everything else for the project.
 
 
Mel
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
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Posted by mbinsewi on Wednesday, March 13, 2019 2:16 PM

Excellent Mel, I didn't know.  Now have to find a stop watch and play around with it.  Maybe just to check out my throttle readings.

And NO, I don't have a smart phone or a computor hooked up the my lay out.

Mike.

  • Member since
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  • From: Bakersfield, CA 93308
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Posted by RR_Mel on Wednesday, March 13, 2019 1:37 PM

I have 121’ of HO mainline which equals 10539’ or just a few feet less than 2 scale miles.  I time a full trip (average with 3½% grade) 2 minutes = 59.9 MPH. 
 
From the NMRA site:
 
 
 
 
Mel
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
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Posted by CGW121 on Wednesday, March 13, 2019 1:24 PM
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Posted by mbinsewi on Wednesday, March 13, 2019 1:21 PM

My eye.  I think I'm a pretty good judge as to the speed of my train.  While watching the real thing, and listening to the box detector, I was surprised that the train was actually doing 46 mph.  As it went by, it seemed like it was much faster.

I place myself "trackside" on my lay out, and watch how it passes track side structures.

I have discovered that with the DT400 I use, the speed step number on the screen seems to be real close.

I've watched enough Amtrak, and when I run passenger trains, I use the same judgement.

But I don't to get any closer than that.  I've never encountered a problem where I needed to know, or needed to measure the exact speed.

Maybe for some that's important, knowing the exact speed.

Mike.

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Posted by gmpullman on Wednesday, March 13, 2019 1:20 PM

Try this:

http://www.stonysmith.com/railroad/speedcalc.asp

I use an Accutrack IR readout but it is more of a fun accessory than a necessary tool.

http://cs.trains.com/mrr/f/744/p/260149/2923972.aspx

Good Luck, Ed

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Posted by oldline1 on Wednesday, March 13, 2019 1:15 PM

Boulder Creek Engineering has a speedometer you can buy. I don't have one but I do have their working scale  and it's very reliable and well made. A nice video and description is on their site.

https://bouldercreekengineering.com/

I'm sure there may be other speedometers on the market too.

oldline1

  • Member since
    December 2014
  • 443 posts
How do you measure scale mph in HO?
Posted by Wolf359 on Wednesday, March 13, 2019 1:04 PM

Here's something I've been thinking about for awhile. How do you measure scale mph in HO, and what is the simplest way to measure it? For example, there is a staff review of an Atlas ALCO RS-3, and in it they said the locomotive reached 78 scale mph at 12 volts. I'm just curious as to how this works.

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