Legacy scale MPH?

Someone at some point did a conversion table for this and I believe it was posted in the DCS section so that they could MU MTH and Legacys.  I'll see if I can find it.

MTH has a patent on the patent on the idea of presenting scale MPH, so the Legacy doesn't actually show scale MPH.  You can do a test and calculate the scale MPH if you like.  Here's a Scale MPH Calculator that you can match the Legacy control setting to actual scale MPH.

this comes up all the time.

should this be in the reference section?

Compliments of Mr. Hikel...

Speed Conversion Chart for Legacy, TMCC and DCS

Marty,

Thanks for digging up that conversion table.  Very handy.

George

I wonder why he stopped at 71MPH?  Too fast for Excel?

Thanks for finding this Marty, I've been wondering about this for awhile. 

I like to run my trains at scale speeds but I never even look at my cab 2 to see how fast it may be going. This whole smph is not even worth thinking about IMO. 

Thanks MARTY, and YUZ GUYZ.  I just never knew and figured I'd ask.  Now I can run all my engines at breakneck speeds.

Also gonna print this out and have it on the layout.  Tanks again.

I reformatted it so you could put it on one page.

According to what I have, Legacy speed step 75 is 21.5 SMPH.

The Legacy speed steps vs. SMPH plot will have a slight curve due to a slightly increasing speed increment per step across the full range. At the low end you have 0.1 SMPH increments, at the high end you have 1 smph increments.

I don't know what Dave's graph is comparing really. He should have a SMPH column (measured by a known length standard vs. time) and a DCS column with speeds averaged for several models. For the TMCC measurements, there should be several different columns for Odyssey engines based on DCDRS version, driver size, and gear ratio. Like the DCS info, the Legacy column speeds should also be averaged across several models.

Awesome!  I've been wondering about this too, occasionally hoping that there was a conversion chart out there.  This will be useful at the club.  Thanks Marty for digging it up, and John for the reformatting

-Dustin

Not quite correct.  The Legacy system of speed steps are non linear and varies with the type of engine (Road, Subway and switcher). On my layout 10 smph is between 37 and 39 speed steps depending upon the MTH engine and the Legacy engine for road engines.(Big Boy at 37 equals the MTH GN Challenger and Reading Camelbacks and H8 and the Legacy FEF runs at 39 to equal my MTH Rats and P5a's at 10 smph). Legacy Subways (R27) at 34 speed steps which is equal to my MTH North Shore at 20 smph. My Legacy Gensis (UP) runs at speed step 23 at 3 smph (4 MU of Readings - Heritage, Uboat, Trainmaster and GP30). My Legacy GP 9 GN runs at 38 speed steps to equal my Chessie Gold Train and an MU of B&O Diesels at 10 smph.

The chart shows the Legacy speed step non-linearity, but I won't comment on the absolute accuracy of the numbers.  I doubt trying to collect all the different Odyssey I versions and engines would be a worthwhile exercise, I think this was just intended to be a decent ballpark guide.

Good point about the Legacy speed steps for switchers. The plot may be a little different with finer speed increments at the low end (only guessing here - don't have any). The plot I have may be true for road engines only.

Guys, keep in mind I calibrate things for a living so when I start seeing stuff like this I get kinda stoked on it. Not trying be Mr. Legacy or something....

Can you post the plot you have?

Let me ask...

Who do you have to ask and why?

I was going to question a some of the TMCC stuff.  The basic DCDR is common in many engines but depending on wheel size and gear ratio (not common between models and manufactures) how can you even have a Scale MPH?  Same with Ody unless lionel standardized a code.

MTH can do it because they built the system to do it.  They count stripe so they know when one revolution of the engine motor has occurred and they know wheel size and gear ration.  So each sound file has a specific curve for the specific engine built into the software. 

TMCC is a common R2LC and a Common Motor Driver with everything else a variable between models.  G

It would be rude of me not to ask first as some of this info was shared with me when we did a little Legacy stuff on my old layout a few years ago.

Anything can have a scale speed if it's measured by a scale speed standard. All closed loop speed control systems whether they are factory or aftermarket have a fixed set of speed settings. These can be laid out in any manner of a curve or straight line and can have any amount of steps as long as the hardware can support it. These can be compared against a known speed standard and plotted and now you have your complement of scale speeds vs speed step.

MTH/DCS can do it because they counted encoder pulses through a gear ratio and driver size measured against a speed standard when all was said and done.  As a certified MTH technician, I'm sure you could tell me that the DCS personality files probably contain gear ratio/driver size calculations to adjust displacements and speeds to help match up all their different models.

Lionel pretty much did the same thing with Legacy, although speed is reported as RR speeds (actually really brilliant if you ask me). 7-8 years ago I used to cry about getting calibrated speed step arrangements and was pretty happy to see that Legacy addressed it.

No, be careful. At least with the motor drivers, there were at least two major Odyssey types with different speed curves and modes (cruise on or off).

The only real variables were gear ratio and driver size for speed.

Norm, got it so not your data.

Sure anything can have a scale speed, but I did not question Legacy, I questioned TMCC Scale speed.  I take a R2LC and a DCDR out of a Lionel diesel with .75" wheels and 10 to one ratio and put it into an Atlas (Atlas did) with a different gear ratio.  How can you say Click 7 on a 32 step TMCC is 9.8 SMPH on both units? It won't be.  Unless manufacture agreed to a standard and used the same wheel dia and ratio.

Also, it would vary I believe with Track Voltage. So it must assume a set voltage.  18V would get different results than 15V.

But not for MTH.  Track voltage doesn't matter.  It measures, calculates and adjust.

 Yes to MTH, that was what I was saying para 3 of my last post.  G

If you truly want to know your Trains Scale MPH in any scale you model or with ant control system, then you want to install a HotShot™ Speedometer this give you the Train speed based on distance no math or guess needed. 

http://bouldercreekengineering.com/hotshot.php

http://drews-train-layout.blog...w-to-icg-layout.html

And if you compare against a known speed standard you will see that your engine is now faster or slower, with the same relative curve. These are still scale speeds, they are just not matched to anything other than another engine with the same drivetrain/speed control system.

TMCC DCDRS drivers didn't try to match speeds because there was no clean method of using correction factors for gear ratios and driver sizes. The TMCC command system via the CAB-1 didn't have any fixed way of sending speed command destinations, just relative step commands.

When DCS and Legacy were developed they did two things - they made their closed loop speed control systems able to be adapted to different drive trains for speed consistency between models via firmware, then made a way of commanding fixed speed command destinations with their remotes. DCS did it with SMPH, Legacy does it RR Speeds and speed step readout.

To compare speeds of different models and cruise systems, you need to compare them to a speed standard first.

Thanks John

Norm I think we agree on many of the points but you got me on this speed standard thing.  I agree about the relative curve.  The scale is O so it is 1/48 scale and the equivalent speed to meet that standard.  You can't use units in the table but then say they are relative.  An inch is and inch and a foot is a foot.  A 1/48 scale foot is 1/4".  If an atlas is notch 7 and a Lionel notch 7 and they travel different distances in 6 seconds.  They are not Scale speed equivalent.  Which I think you agree with.  If so the chart can't say for O scale engines that everything will go 9.8SMPH at notch 7.  They won't for reasons stated above. 

The chart may be accurate for Legacy, but for TMCC either the units need to be removed or some of the constants need to be provided.  Like Track voltage, gear ration, and wheel dia.  G

The only method of commanding fixed speeds to TMCC engines is with the Legacy remote which has mapped the RR speeds to some fixed TMCC absolute speed step. The scale speed response will be different for TMCC engines with different drive trains. And if you ran these all by Drew's box, they would still be running at some scale speed, just not matched to each other.

Now...if Lionel really wanted to they could create new RR Speed maps for different types of TMCC engines and by using different absolute steps mapped to a given RR Speed, they could get some TMCC engines with different drives to run a bit closer to each other. The only drawback is they have 31 nonlinear responses to play with so there is not much resolution for speed response tweaking, that and it wouldn't be worth their time.

I don't think locomotives without cruise control that has a tach with absolute position accuracy will ever run at the same scale speeds.  Even the ERR Cruise doesn't have 100% positive feedback at all speeds.  It does a great job of holding speed, but I suspect differences in motors make the back-EMF sensing sufficiently varied to kill any idea of a lock of input speed step to actual track speed.

It should be possible for any Legacy or PS2/3 locomotive to be locked to a calibrated speed.

A really nice comparison chart or plot would be RR Speeds vs. scale speed response for various Legacy and TMCC engines (set up for TMCC control on the Legacy remote). The speed response would be measured by Drew's device. I might have to buy that thing, it looks really cool:

Thanks NORM, neat concept.  Now can Lionel introduce this into their LCS SensorTrack?  Not only would you have the identity of the engine going over the track, but also the speed in witch it did?  Can this be done with the sensor track?

Norm,As I said earlier Boulder Creek Engineering product are great add on to any model railroad.and I can see several OGR member also using there product like your self.  If you order the TrainBoss™ Talking Defect Detectoron let them know you will need Axle Sensors for 3-rail Code 333 track.

Personally, I see trying to get calibrated speeds from any non-cruise engine pointless, minor variations in load will toss all of that out the window.  Add a couple of cars and the chart is meaningless.  It would be interesting to see how close to calibrated speeds the ERR Cruise products would stick.

I'd be interested in what adding a load did to the speeds as well.  Try the speeds with just the locomotive, then add 15 cars and see how much, if any, it changes.

John I will see if I can perform your request and post the finding. 

Well, you can only really calibrate a dimension (a measurand).

You can then verify performance, a measurand vs. time.

But can a Legacy engine make the Kessel Run in less than twelve parsecs?

As long as it measured in furlongs per fortnight (a favorite unit of measurement of my engineer pals).

Lionel made a track side speedometer years ago.

Clem k

The equipment used to perform the scales miles per hour speed test

Atlas O GP 35 diesel locomotive with train America studio EOB set at 128 speed steps

Lionel GP 30 diesel locomotive with legacy

Boulder Creek engineering hotshot speedometer (IR sensors installed 11 inches between sensors equaling 44 scale feet)

Using Lionel legacy control system V1.5 (using Lionel official railroad speed control in manual V1.5)

• restricted speed = 5 SMPH (a speed that will permit stopping one half the range of vision looking out for train, obstruction, switch not properly line, or broken rail and not exceeding either 15 or 20 mph as per operating railroad)
• slow speed = 20 SMPH (a speed not exceeding 15 or 20 mph as defined by the operating railroad)
• medium speed = 35 SMPH (a speed not exceeding either 30 or 40 mph as defined by the operating railroad)
• limited speed = 50 SMPH (a speed not exceeding 45 or 60 mph as designated by the operating railroad)
• normal speed = 70 SMPH (the maximum authorized speed)
• highball (maximum speed of locomotive) = not a prototypical speed

Atlas O GP 35 diesel locomotive with train America studio EOB set at 128 speed steps with a matching Atlas O GP 35 dummy diesel locomotive and 12 freight cars

• restricted speed = 5 SMPH
• slow speed = 10 SMPH
• medium speed = 30 SMPH
• limited speed = 40 SMPH
• normal speed = 56 SMPH
• highball = 87 SMPH

Atlas O GP 35 diesel locomotive with train America studio EOB set at 128 speed steps without matching Atlas O GP 35 dummy diesel locomotive and 12 freight cars

• restricted speed = 6 SMPH
• slow speed = 12 SMPH
• medium speed = 36 SMPH
• limited speed = 50 SMPH
• normal speed = 67 SMPH
• highball = 101 SMPH

Lionel GP 30 diesel locomotive with legacy with a matching Atlas O GP 35 dummy diesel locomotive and 12 freight cars

• restricted speed = 7 SMPH
• slow speed = 19 SMPH
• medium speed = 36 SMPH
• limited speed = 55 SMPH
• normal speed = 78 SMPH
• highball = 125 SMPH

Lionel GP 30 diesel locomotive with legacy without matching Atlas O GP 35 dummy diesel locomotive and 12 freight cars

• restricted speed = 7 SMPH
• slow speed = 20 SMPH
• medium speed = 37 SMPH
• limited speed = 57 SMPH
• normal speed = 82 SMPH
• highball = 138 SMPH

Now there is a High end and a Low end to all Lionel legacy control system official railroad speed but for this test I simply selected the railroad speed icon. 

Wow the Legacy engine was pretty close.