UPDATE #2: Observations on the Lionel American Flyer SD70ACe Diesel Locomotive with Scale Wheels

This message is an update of a message I distributed earlier through the S Scale Yahoo group. The update is  based on additional observations & operations with the Lionel American Flyer SD70ACe.  As a result of additional deliveries from the good folks at Des Plaines Hobbies  & Port Lines Hobby Supplies, I've now got the benefit of three units to use & examine.  Run time of the units continues to increase. My updates have been edited into my  original message and the message is now divided into specific sections. Some of the updates are as a result of additional examination and testing I've done, while others are due to specifics inquiries from folks on this list, friends' comments, and direct emails I've received.

I must say that overall I am very happy with the locomotive. It is a very nicely detailed loco and runs very well. As with any model, it's all about compromises and choices that the manufacturer makes. IMHO Lionel made a pretty good set of choices at a very reasonable price point.

Since there have already been reviews of the Scale version of the SD70ACe posted by Rich Gajnak on the O Gauge Railroading (OGR) forum and by Ed Loizeaux on the S Scale SIG web site, I will try not to replicate that material here.

Here's some additional observations I have: 



Prototype Fidelity

Fidelity to the prototype is very good -- I checked several key attributes like length, cab width, and height. They were either spot on or very very close.  Height and Cab width measure spot on, overall length is very close. Wheel  diameter is also very close (prototype is 42", model is 40").

Starting in 2003 more than 1400 units have been delivered by EMD. Rated at 4300hp, according to EMD's data sheet three SD70ACe locomotives will replace five SD40-2 locomotives. Further information on the prototype SD70ACe can be found on these sites:

• EMD's SD70ACe page
• The Diesel Shop's SD70ACe data page

And a large collection of SD70ACe photos can be found on the RR Picture Archives web site.

Wheels

Lionel released some of the road names in this model under unique catalog numbers for American Flyer compatible wheels and different catalog numbers for Scale Wheels. (At this time of this writing, there are reliable reports that Lionel will release a Scale Wheel kit for this locomotive to enable the conversion of any of the units to Scale Wheels.) I reviewed the models with Scale wheels and the model passes NASG Standard S-4 wheel standards. Using the NASG gauge, Back-to-back is spot on and Flange depth is spot on. No Traction tires (as expected).  Wheel Width measured at  0.126".  Contrast this wheel width to S Helper Service locos at 0.110" and  American Models in the 0.129" range.

Couplers

Couplers in the S scale world are in some respects a matter of choice, with  various modelers using some or all of the following: Kadee 802/808, S Helper Service (SHS) 01295, Walthers Proto MAX, and Kadee #5.

On the first SD70ACe, I easily installed Kadee 802 couplers. Lionel provides a coupler mounting pad and screws to mount the Kadee 802/808 couplers. On my model they were about  0.010"-0.015" too high -- not a big deal. It is easily correctable with a piece of  0.010"-0.015" styrene between the coupler and the scale coupler mounting pad. And the Lionel supplied screws for mounting the couplers to the scale coupler mounting pad have room for that 0.010"-0.015" styrene.

During operations pulling the load of a train, the drawbar weight actually pulls the pivoting pilot up to its highest position (almost like it has been permanently screwed in place, but still has the option to move). This is very nice, but at the same time it also increases the delta in coupler height significantly. On my model under load, it caused the Kadee 802 coupler to now be about 0.030" too high.  As a result on the next two models, and eventually on the original model itself, I have now replaced the Kadee 802 couplers with SHS 01295 couplers.

The SHS 01295 couplers have the knuckle face about 0.045" lower. So I opted to use the SHS  couplers on my models. They also have a slight delta (now being slightly too low), but overall it is more too my liking. If you are going to use Kadee 802/808 couplers on your loco, you probably want to install a shim between the coupler box and the mounting pad.

Drawbar pull

Drawbar pull of my model SD70ACe is ~7.4oz as measured with the Micro-Mark Digital Pull Meter. A single locomotive has been running for more than 10 hours now on my Lenz DCC controlled layout pulling 30-36 cars, including up a 2.5% grade, all at a very slow speed. I noticed the wheels started to slip as I approached the 32-36 car range (it could pull more cars, if the cars were of lighter weight). Compare this drawbar pull measurement to these other locomotives I measured using the same technique:

• American Flyer SD70ACe Diesel: ~ 7.4 oz
• S Helper Service SW-9 Diesel: ~ 4.2 oz
• S Helper Service 2-8-0 Steam: ~ 4.9 oz
• S Helper Service F-7A Diesel: ~ 5.4 oz

Multi-unit (MU) consists will definitely increase the pulling power. Here's the drawbar pull I measured for my MU consists:

• 1 SD70ACe:  ~ 7.4 oz
• 2 SD70ACe:  ~ 14.8 oz
• 3 SD70ACe:  ~ 22.2 oz

I did not actually create a train longer than 42 cars (which the 2 unit MU consist easily pulled over the 2.5% grade), but based on these measurements we'd predict that the 3 unit consist might pull 90 or more cars! Of course that is dependent on the weight of the cars involved, grades, etc.

Smoke Unit

The model has a fan driven smoke unit. The smoke units in my models work fine, but I generally prefer a smoke free environment on my home layout -- I just used the easily available switch to turn it off.

Sound

Along with a variety of sounds built in, Lionel also provides an easily accessible volume potentiometer next to the Smoke/No Smoke switch, so if you prefer no sound at all, just use that potentiometer to turn it all the way down. I enjoy sound on the layout, although at a low volume, so that it remains near the locomotive.

Motor control

With three units available I could also compare locomotive speed. Running on DCC in 128 speed step mode where Lionel implemented direct motor drive, I did notice some small differences in speed of the locos. I started them all separated by 20" and ran them all for a fixed time. They did not all end up still separated by the original 20". But it was not enough that I noticed any issues when creating multi-unit consists (see below).

Layout control

I did not test the locomotives on layouts controlled via Lionel Legacy, Lionel TMCC or AC, but the locomotive supports all of these control systems, in addition to DC and DCC. I must say it's really nice to not have to do any installs. And with all the different control options, running at home or on the club layout even with different control systems becomes very easy...

DC Operations

Speed on DC is very impressive. If I did the math right, the locomotive starts at 8.2V DC (4.7 SMPH) and at 12VDC it is at 49 SMPH. Max speed for the real loco is 70MPH, and since this locomotive model can run up to 18V, it likely will make that speed with no issues, but I did not test it.

I tested using a MRC Tech 3 Power Command Model 9500 DC power pack (this unit does not have pulse power). On DC power there are good lighting and sound effects:

Forward:

• Front Headlight on at ~2V
• Cab light on at ~3.8V
• Engine start up sound at ~5.5V
• Ditch lights on, Cab Light off, Forward movement starts at ~8.2V

Reverse:

• Rear light on at ~4.2V
• Cab light on at ~4.2V
• Engine start up on at ~5.2V
• Cab light off, Reverse engine movement starts at ~8.1V

DCC Operations

On DCC, programming is very easy. The locomotive comes programmed at the standard address 3. I changed it to the 4 digit road number on the programming track. It also has a special method documented in the manual to allow changing the address right on the mainline if needed -- no programming track required. Decoder Pro 3.3.2, with SPROG II USB on a Windows 7 PC had no problem reading all the Configuration variables (CVs), although there is not yet a Decoder Pro decoder profile for this decoder. I also used it to modify some CVs. (I do plan to develop a DecoderPro decoder profile for this locomotive's decoder, and also plan to work with Bill Clark on one for the Y-3 as well -- these should be available in April/May 2013 time frame.)

For DCC Operation on my Lenz DCC system, I did need to change two manufacturer unique CVs (CV59 and CV60) for some decoder filter settings. Just reduce the values of these two CVs to a value of 1. The locomotive ships with some higher values in these CVs which are tuned/tested on NCE DCC and Digitrax systems, but the manual provides guidance on when changes to these may be required.

One nice DCC feature I noticed is that the locomotive will, transparently to the user, process both 14 and 28 speed steps. It is not necessary to do the normal user required synchronization of the speed step mode between the decoder and the command station by programming a CV29 value in the decoder and setting the speed step setting on your DCC cab. The built-in decoder just handles it for you. It's a nice touch to reduce user complexity. The built in DCC decoder also comes preloaded with the 28 speed table, and uses the table in both 14 and 28 speed step mode. In 128 speed step mode, it does not use the speed table.

The built-in decoder also has some nice use of functions beyond the basics of turn on the headlight, blow the horn, & sound the bell. It has functions assigned to increase and decrease the volume, start up the engine, shut down the engine, etc. There appears to be no automated crew talk in DCC unless you activate it via a function. Use the functions if you like or ignore them if you prefer. You can see all the details in the Lionel SD70ACe Owner's Manual.

DCC Multi-unit Consists (aka Lash-ups)

With three units, I've also been able to test DCC operation of multi-unit consists. Using my Lenz DCC system I was able to quickly set up a multi-unit consist. Quite impressive to see a three unit SD70ACe consist running!

Further I should note Lionel has implemented a simple to use manufacturer unique DCC  Configuration variable (CV50) to set each locomotive's MU consist position (lead, middle, rear). Setting this CV in each locomotive in the consist adjusts how sounds and lights are handled. Examples of the further refinements you get by setting CV50 appropriately are:

• the horn only sounds in the lead locomotive 
• all the lights except number board lights are off in the middle position locomotive 
• the rear loco only has the rear light on & only when the consist is operating in reverse 
• the power down function on each locomotive only uses the appropriate sounds (lead locomotive gets engine shutdown and crew talk to dispatcher, middle and rear locomotives only get engine shutdown).

In doing the testing I did discover one additional piece of information that may be helpful to those operating consists. If you want to have one or more units in the consist operating in the reverse orientation, as a trailing SD70ACe might be, you need to follow these steps outlined below. For this example we will assemble our consist using Consist or MU address 10, but you could use any consist address between 1 and 127 that is supported by the manufacturer of your DCC system.

1. Assemble your consist as prescribed by your DCC system manufacturer, using address 10 as the Consist or MU address; when the consist is fully assembled proceed to step 2 
2. Using Programming on the Main programming mode (also known as Operation Mode or Ops Mode on some DCC systems), for each locomotive that is running in the reverse orientation, program CV19 to a value of 128 plus your consist address. In this example, it is 128 + 10 or 138. Do this step ONLY for the locomotives that will be running in the reverse orientation. 
3. Now use Programming on the Main mode to set the appropriate value for CV50 in each locomotive.

Note: While setting a value in CV50 is generally optional, if you wish to run any locomotives in reverse orientation as part of a consist, then for the locomotives in a reverse orientation, you must program both CV19 and CV50, as described above, and in that order (program CV19 and then CV50).

It's also worth mentioning that while Lionel has already simplified the control of lights and sounds in a consist using CV50, they are also continuing to investigate to determine if they can make setting up reverse orientation units even easier.

Ditch Lights

In DCC mode the ditch lights are on the same function as the light (forward light). When you turn the forward light on with the F0 function, the ditch lights come on as well. And when you sound the horn using the F2 function, then the ditch lights also flash if the forward light is on. 

If you were running a single loco in reverse and have the lights on with F0, obviously in reverse it is the rear light that is on, and thus the ditch lights are not on and do not flash when the horn is sounded  (and I don't believe they should).

In a multi-unit consist, with CV50 set correctly in each loco, the ditch lights will only be on on the lead loco and only when the lead loco is running forward, and sounding the horn will also flash them. If your MU is elephant style (head to tail), only the lead loco's ditch lights will operate. If you are running your MU with the rear unit in reverse orientation, then the rear unit's forward light and ditch lights will be on when the MU is operating in reverse direction, and the ditch lights will flash on sounding the horn.

Summary

As I said at the beginning I really like this model. Very impressive product in my opinion. I think Lionel has a real winner here, and has really delivered a well appointed model that should well serve most S standard gauge modelers interested in modern motive power. I'm really looking forward to running these double or triple headed at the front of a long intermodal freight...

Hope this might be of interest to others...