3rd Rail China Drive

Ted,

I have, in fact, run the Sunset E unit models on my railroad. It started the heaviest train I have on a 3 percent grade and pulled it without a hitch. They are very nice. I've also seen the MTH F units run on a local layout last week and they seem very nice, too. Errors on the MTH version were pointed out on the 2 rail forum last week. But THAT isn't the point.  

The point is this:

The Sunset version will be able to start and stop slowly without any special electronics, which is a nice touch in my opinion, and the root of the advertisement lingo I believe. That's it in a nutshell.

I wouldn't hesitate to buy an MTH diesel if there is something I wanted. It is only that I'd PREFER the drive to be set up the way Sunset is doing it now. There is beauty in the mechanism.

I currently run all steam but have been considering some diesels lately. I'll be looking into the N&W diesel on the newest catalogue for sure.

Actually, for the most part they send to this country exactly what this country tells them to send.

U.S. companies tell them what to make, and the quality and price point they want. China just builds to the specs they're given and sends it.

Weren't these the first classic 'China Drives'?:

http://www.robertstrains.com/Identification.htm

I always thought Samhongsa developed this system in the early-mid 90s and then it was adapted and copied from there.

Williams had the drive prior to Custom Trains.  The earliest (mid-80's if I recall correctly) ones had can motors without flywheels.  It's interesting that the first "China drives" were all built in Korea.  Never let the facts get in the way of a good derogatory term though...

Can't seem to get Ted's plea copied.  He asked "has anyone actual experience. . ."

I do a lot of the maintenance for the O Scale part of our museum.  I stick an "opinion" at the end of my posts to avoid getting bashed for my "facts", and it seems to have worked for the most part.  I described my experiences on the MTH in a prior post, and of course my experiences are best characterized as facts, not opinions.

I have no experience with Lionel, but I do have experience with Weaver, K-Line, and Atlas.  For some reason, Atlas and Weaver chose a slightly different design, involving axle bearings and in some cases extra shafts.  These are exceedingly difficult to disassemble, then get back together properly.  If the flat spots on the bearings do not go in precisely as designed, you get noise, loss of power, and sometimes slippage.  Maintaining these is not for the occasional mechanic.

MTH and K-Line (at least the Train Master) are easy in comparison, very long-lived, and completely and totally repairable.

I build my own Diesel drives, and prefer a horizontal motor above each truck, but so far I have not personally seen a better engineered commercially available affordably priced gearbox than the MTH.  I have not enjoyed the presence of the Atlas SW or the Sunset E-7 - they could well be better.  Donate one to our museum, and we will tell you next year.

Wow, didn't realize this thread would get so much "traction"!!

While everyone has talked about the mechanical drive systems that could be better nobody has mentioned that the electronic drive systems could be better. I've experimented with an older Williams trainmaster in order to get more pulling power out of it. I swapped out the existing bridge rectifier with a new unit with a lower forward voltage drop which could handle more current. I also swapped out the transistors in the H bridge motor drive circuit with a similar model which had a lower on state resistance. For you non electrical engineers out there these two mods allowed more of the supplied voltage to get to the motors. At this point the DC motors are still is operating on a rectified sine wave. I then added a 50V 10,000uF capacitor to the output of the bridge rectifier. This really smoothed out the rectified sine wave to near perfect DC. The engine pulls a lot better now. The only drawback to doing this was that I had to move the engines light bulb circuits to the output of the bridge rectifier to drain the capacitor in order to reverse (circuit board voltage has to fall to zero? to reverse direction). The bulbs also glow extra bright. I may do something different in the future. At the time I didn't want to use a load resistor across the output of the bridge to drain the capacitor.

I have pictures from what i've seen on the oscilloscope. If someone wants to help host them I can put descriptions with them.

I have not attempted to modify my MTH PS2 engines.

More of the same, from the 1980 Train World Catalog.

Williams version of current RMT Beep (1980 Train World Catalog.)

Thanks Norm, Bob, Bob2 and KMK.  Thanks to you guys we have some FACTS!

So, it turns out the twin vertical motor drive mechanism has its origins in Maryland and Korea.

Bob's comment deserves quoting again!

Never let the facts get in the way of a good derogatory term though...

And thanks to Bob2 we have an actual informed opinion from someone who has actually worked on drives from several manufacturers.  It seems that the least refined vertical motor drives may come from the manufacturers with a larger historical presence in 2 rail.  Could that explain a good portion of the two rail prejudice against superficially similar products from other makers?????

Probably not.  They are not pleased with the gear ratios.  They think the performance issues are related to motor orientation - all that is needed is a better reduction between worm and axle.  Some think that unsprung anything is junk.  I have not been able to tell any operational difference until I get to ten coupled steam on superelevation.  Opinion.

Opinion maybe, but it's mine, too. 

Again, I am certain the motor doesn't care about its orientation, and the right types of gears and gear ratio (both are important) make all the difference in the world. 

Living (or at least running,) proof of this is the WBB Baldwin ten-wheeler - perhaps the smoothest running low-price loco available.  It's not the motor orientation that does this (I've taken them apart and I think they have horizontal but I can't remember - its been a while).  Regardless I know that does not matter at all, and I know it definately does it use a premium type motor - just a normal cheap can and not terribly big at that, nor does it seem to use electronics as some companies do to try to give it a sweet running character (RMT says they do this and I believe them based on played with BEEPs vs. BEEFs, etc).  The WBB ten-wheeler is just geared so well for smooth, low speed behavior - that is it alone. 

I do think that some motor orientations are both easier to manufacturer than others, as well as easier to "package" in the sense of putting the same exact assembly in my different loco applications.  Further, some motor orientations/mounting methods probably permit more corners to be cut with production costs and more money to be taken out of total cost, etc.  I imagine the popularity of china drives has more to do with these aspects than anything else. 

Well, seeing that Lionel had twin vertical motors in the their F3's and Train Masters in the 1950's...

Rusty

Thanks Bob for a bit of background. I tend to think that the refined CT FM drive of the 90s was the one that really became the standard 'China Drive'  - dual Mabuchi RS385 cans with brass flywheels, horrible (IMO) 12ish:1 gear ratio, solid cast truck block, traction tires.

It's easy to see why this setup succeeded. Cheap to make, easily adaptable to different models, and easily adapted to closed loop speed control of all types. No detailed cab interior has been safe though.

Despite some missteps (flange depth screwups, ride height issues - and single axle drive???), I think Lionel refined this setup the most in their current Legacy stuff. It couldn't have been cheap though just judging by parts count alone. The newer driveline has a much more reasonable gear ratio (north of 20:1 I think) and zero backlash.

Ted,

I took the E7's out of the box, put them on the track and ran them in conventional.

I have several PS2 models but they are steam engines. There is some wonky thing I have to do in conventional, raising the voltage and then lowering it to get them to start up. If that is or was the case in diesels then I could see why it would have been annoying for people who are doing allot of switching. It was annoying to me and I'm doing very little switching. 

For all of Bob's analysis, as far as I know, he is running trains in circles for hours on end and that is fine for his purpose. I don't think his meets the same criteria that sparked the requests for the Sunset drive.

The bottom line: To compare the performance of the mechanism, you'd have to take the electronics out of each model and compare their operation without the electronics.

Christopher,

Did you run your E7s conventionally with the DCS handheld remote thru the TIU, or did you just have a transformer hooked up?

I've been running my conventional engines with the DCS handheld remote thru the TIU and there is some "procedure" you have to go thru to change from DCS to Conv and back.  Not a big deal but it's something I recently forgot how to do and had to write it down!

I don't have the 3rd Rail E7 yet, my Seaboard unit should be in the 2nd run which hopefully is coming out before the end of the year.

What features/sounds do you not get running it conventionally, any idea?

I need a TMCC Command Base to run it as a TMCC engine thru DCS, but don't know what features/sounds I'll get or lose.

Bob D.,

I ran the train using a regular 10 amp DC power pack. I typically run DCC but occasionally flip the toggle and run straight DC. A friend brought the E7s over to show the local group, but I didn't really get much into what the bells and whistles were.

Thanks Christopher!

It hadn't occurred to me to run it with DC, is that something that can be done with any new engine (like my MTH NW2 with PS2) or just engines that have DCC capability?

From the 1983 Train World Catalog:

Bob D.,

You could use conventional DC, AC, or DCS. For one of my engines I ripped out the DCS and installed DCC.

For all of the touting of facts, we really have not heard anything about the gear ratios MTH puts in their diesels or their history. Bob T. says that 2 railers would still ask for higher gear ratios and I'd like to see if he is correct about that. I'm guessing since he works on them, he could tell us what the MTH gear ratios are in diesels. I still expect I'll buy a PS3 diesel engine down the road, but it'll be interesting to know the facts regarding the gear ratios. 

Sunset chose their drive train with smooth starts and slow speed operation in mind first and then applied the electronics. To me this is the way it should be.

My take on the history of the China drives is they were used to cut corners, and then the electronics were applied to correct the drive. Reading Norm's and others' facts confirms that for me. If the drive has been refined most recently then I think that is great, and 20+ to 1 also sounds great to me. It sounds like they've come around to a really nice drive. For the 30 plus years before legacy and those hundreds or thousands of products, I think Lionel may earn the China drive title along with the others Ted wants to blame for the bad reputation.

By the way, do you guys know who coined the term China drive? I think it was Ed Reutler who seemed to stick it to Atlas from time to time. I don't think the term was born with any origin in time in mind at all of when the drive was developed, but rather the origin of the country where many of those drives were coming from when the term was coined.

Thanks again Christopher!

My take on the history of the China drives is they were used to cut corners, and then the electronics were applied to correct the drive.

I expect that's pretty accurate.  I would also think that putting better gearing on engines would be cheaper than designing electronic circuits and components, but maybe they didn't have any mechanical engineers available, just EEs.

I wish it was easy to pull the gears off and put gears on that would give us better slow speeds, but from what I've heard and seen it's almost impossible to remove the current gears, let alone the wheels to get to the gears, especially MTH wheels/gears.  They must heat the wheels up and cool the axle down to slip them on, or use some kind of super strength glue to keep them from moving.

Also, did you mean Ed Reutling?  I know Ed said he'd been booted from the Atlas forum a couple of times.

For all of the touting of facts, we really have not heard anything about the gear ratios MTH puts in their diesels or their history.

Christopher

To date MTH has used 10.5/1 gearing in their diesels.

There have been several evolutionary steps in the development of MTH Diesel trucks.  If you are interested in exploring that topic another thread might be appropriate.  We are headed for page 3 here as it is! 

MTH has contemplated changing their gear ratios.  If I learn any more at York I will pass it along.

Sunset chose their drive train with smooth starts and slow speed operation in mind first and then applied the electronics. To me this is the way it should be.

After seeing and running the Sunset E7, Talking with Scott, reading Scott's posts and reading John Smith's old OST column I have a different take on how and why they were made.

Certainly marketing plays into it as evidenced by the add behind the original post and

the "this is the way it should be" inclination of a segment of the market important to Sunet.

Cold economics may be the strongest driver.  As I recall, Scott said this is the first Diesel produced by this manufacturer.  Sunset is a small importer compared to Atlas, Lionel and MTH.  The cost of the tooling to make a diecast truck block for a relatively small production run probably wouldn't pencil out.  And the builder might not have the ability to make it without subcontracting the work out.  Sunset's construction method might not make sense for trucks that were made by the thousands but it can keep a small run priced only a little higher than locomotives produced in larger volume.

I think Lionel may earn the China drive title along with the others Ted wants to blame for the bad reputation.

Take a look at the post about the Lionel locomotive again. 

By 1983 Lionel was making diesels with horizontal mount in truck DC can motors (like the K-Line MP-15s and Alcos.)  These were dual motor units with an electronic e-unit.

Those were tiny horizontally mounted motors without a flywheel mounted inside a plastic truck.

I think Norm and KMK are on the right track.  If we want a historically accurate geographically based name Maryland Drive is the leading contender.

By the way, do you guys know who coined the term China drive? I think it was Ed Reutler who seemed to stick it to Atlas from time to time. I don't think the term was born with any origin in time in mind at all of when the drive was developed, but rather the origin of the country where many of those drives were coming from when the term was coined.

Atlas seems to keep coming up in this discussion.  I have had a chance to operate several of their RS-1s.  They just don't run as well as an MTH Premier Geep or Railking RS-3.  I have yet to see an MTH diesel that wont run smoothly at 4 SMPH and most will run smoothly at 2-3 SMPH.  My experience with other Atlas Diesels is limited but I have seen comments on different threads about other models of Atlas Diesels not being smooth starters.

Williams, the orphaned Custom Trains FMs and all the first MTH diesels had twin vertical can motor drives in the early 1990s.  They are rugged and run well.  I have run several early MTH Diesels that have been converted to Proto2 and they run just as well as the diesels built with Proto2 a few years later.  MTH made many of their early diesels in two rail versions so they were in the hands of two railers in the 90s.  But the derisive attitude towards twin vertical can motor drives keeps getting linked to later entries into the then emerging 2 and 3 rail scale market.  It sure would be nice to do a side by side operational test and mechanical tear down and see how things really compare.

A few years ago I bought an unpowered Atlas GP9 lettered for Seaboard Air Line when they first came out (2004?).  The Atlas trucks didn't come with the Power Transfer Gear Assembly (P/N 687076) that meshes with the worm on the motors.

I soon found I had no need for an unpowered engine so I bought a MTH Railking F3 with PS2 on Ebay.

I installed the PS2 guts and motors in the Atlas GP9 and got the power transfer gears from the parts folks at Atlas to complete the trucks.

The engine runs just like my other PS2 engines, running smoothly at 2-3 SMPH.

I don't know what gear ratio MTH or Atlas use, but they must be close.

Bob and Ted,

Thanks for the info about the MTH and Atlas gear ratios.

Ted,

I think PS3 will move more two railers to at least consider MTH engines even with the China drives. I'm pretty sure that is where my first diesel purchase will go, anyway.

There's a prototype for everything. 

Looks like it can move a few freight cars .  Any information on this engine besides being electric?

Sorry, I forgot to mention. It's a PRR DD1 with the body removed. I couldn't resist posting the picture after reading some of comments above. 

But, they are horizontal motors!

Rusty

Nice to see all those copies of the DD1 mechanism.  I would post it again if I could figure out how.  

I would also post Ted's request for side by side testing and teardown, and reference my previous posts.

Once again - we get decades of daily running out of MTH.  They are repairable with minimal tooling.  All Nation wear to the point of uselessness after a year.  Atlas are repairable, but exceedingly difficult to reassemble correctly.  We have not yet fully tested to destruction the horizontal Atlas or the new Sunset E-7.

One reason Scott went for the horizontal drive for the E7 (and future diesels) was because his O scale  two rail customers want detailed cab interiors and smooth running on straight DC like those found on brass units from Key, Overland (late production) and C&LWS. The point about cast truck blocks being prototype specific and a product development cost item is well taken.  Now that  Sunset 3rd Rail has a good drive axel gearbox,  reduction tower, motor, flywheel, and U joints, the drive train variables between prototypes is largely reduced to the side frames and wheel diameter.  Hopefully Scott has found a market niche large enough for him to profitably produce a series of O scale diesels that will meet the preferences of 2 and 3RS'ers.  For those who prefer the twin motor vertical drive setup, there are plenty being produced by other importers.

I can't claim nationwide perspective, but in a fairly large circle of Washington area O scale 2 rail friends we're not shelf model collectors .  We run what we own and do so in a generally prototypical fashion.  I find Bob's positive experience with MTH drives standing up well to hundreds of hours of continuous running interesting and informative - but not particularly relevant to my operating environment.  Call me old fashioned (though I do DCC), I place motors intruding in to the cab in the same category as engineer-dispatcher crew talk on steam/diesel transition era railroads - a distraction.

Ed Rappe