3rd Rail China Drive

I saw the same ad and thought the term "China drive" referred not to a specific type of design of a drive mechanism, but to a drive mechanism made in China.  I took the ad to mean that 3rd Rail was advertising its current locos had a motor/drive mechanism made somewhere other than in China . . .  

That's what I assumed as well, but perhaps Scott will chime in and clarify.

"China drive" = vertical can motor over each driven truck.  An OGR 'Search' for "China drive" tells all.

SZ

noticed that the Third Rail ad on back cover mentions horizontal Cannon motor design that is not a China Drive.   I am unfamiliar with the term "China drive" and would appreciate a short mechanical explanation.

"China Drive" refers to the common Current O gauge drive system of a vertical can motor with flywheel screwed on top of the truck block that it is powering. This term is widely used on the 3 rail forum as well as the 3 rail scale forum.

Current "China Drive" Mfg's/importers are:

Lionel

Atlas O 

MTH

Weaver

WBB

RMT

K-Line - now a fallen flag.

What Scott is referring to is his "new" drive system that has the can motor in a horizontal position powering the truck block. This set up is common in many 2 rail O scale locomotives and some 3 rail Altas O locos such as the SW switchers and AEM7as well as the Older issue Weaver Ultraline GP's & Rs3's. 

But why the term China Drive? Lionel mounted their motors vertically to the the trucks, seems like forever. How else would we get all the electronics inside. The term sounds derogatory to me. Maybe it's just the way I read. 

But why the term China Drive?

Because all trains with this vertical Flywheel motor set up were/are made in China.

Yes Lionel did have the Pulmor motor mounted on top of the truck block but a Pulmor motor was made in the USA and has different operating characteristics and more maintenance than the current can motor with flywheels.

The reason why the term sometimes has a derogatory connotation associated with it is that a good horizontal drive starts more smoothly and has better slow speed operating characteristics than the current vertical drive systems.

As Clem mentioned, the reason why this drive has become standard is to leave room for all the electronics. Admittedly, some of the electronics (such as speed control) can give these drives good slow speed operation, but some still would like to see operating characteristics less dependent on electronics and more dependent on good mechanical design and slow speed gearing. 

But, few will be willing to compromise the sound systems and command features that depend on having lots of room for circuit boards. 

Jim

The other reason horizontal drive is not as popular in three rail is the turn radius issue.  A horizontal drive generally can't handle the tighter turns common in three rail O.  This is less of an issue for engines with 3 axle trucks and long wheel bases.  They have trouble with tight curves anyway.

Interesting stuff!  One can learn something new every day here!

Check it out here:

https://ogrforum.com/d...878#3259945172567878

I can't wait to get my 3rd Rail Seaboard E7

I get beat up a little every time I chime in on this one.  The motor has no idea which way it is pointed.  All an importer would have to do to get a great slow speed version of the China Drive is to change the gear ratio.  The usual customers of such drives like high speed, reliable power, and do not give a darn about slow speed starts and stops, so the China Drives became the predominant power for O Gauge 3-rail Diesels.

We run MTH at the San Diego Museum using these drives.  They are absolutely bulletproof in a continuous run museum setting.  I am stunned at the reliability.  Some have run daily for almost 20 years (with minor component replacement, of course).

And of course, opinion.

Opinion I agree with completely, bob2.  having looked at many "China drives" I have pulled out of locos (without knowing what they are called) I'd think the popularity rested with manufactuering simplicity, repeatability of application, and manufacturing cost (goes with the simplicity).  I do understand how it is easier to engineer this to fit into locos that will accomodate sharp curves, but even that can be done easily with horizontal motors, so I really think it comes down to ease of manufacture, at least for diesels. 

Actually I think the term was something like "China-Block-Drive".   Most of the early ones were diecast blocks without removable base plates.   The wheels were pressed on to axles while in the "block".    It was nearly impossible to convert these to 2-rail or do much to them.   At least for me, any time I tried to remove the 3-rail wheels, all I accomplished was breaking off the flanges.   It is a very tight press fit in my opinion.

As for low speed control, I don't find it as good no matter how much electronics you add.   I find I can slow them down, and reduce the top speed, but I can't get the low speed torque.    They tend to stall under load if they  hit a curve or anything at low speeds and require "goosing" the throttle to keep them moving.   The other issue is that both motors never seem seem to start and stop at the exact same time.   When starting, one will start and jerk that truck, then the other will start and the loco will move.   Stopping works the same way.   One motor will stop and the loco will jerk, then the other motor will stop.    In some cases these jerks are reduced to a minimum, but if you watch the trucks, you can oftern still see them.   In addition the trucks mounts in the frame are "sloppy" in that there is a lot of play, so the trucks can adjust to track bumps or whatever.   This also allows them to jerk back and forth starting and stopping.  

As far as sound and electronics, Atlas can put the stuff in the SW8/9 switcher which is pretty cramped to begin with, and it is a single motor drive.   So it seems there is space, if the market were there to insist on single motor drives.

I will not buy any more 2 motor drives.   The new E7s from 3RD Rail and the older stuff I have with single motors just run so much better than two motor drives I have.

"VERTICAL MOTOR DRIVE" sounds good, but then what about the motors in steam engines that are at an angle, "ANGLED MOTOR DRIVE"???  Would that still be a "China Drive"?

I had a HO 4-8-2 Mountain that had the motor in the tender, along with the gears, and pushed the engine.

the issue with operation is not the angle of the motor - it is the lack of reduction gearing.   The darn things are geared like slot cars.

And I think the "block" is what brought about the name as in "china block drive"

That is my impression too.  But this is the first time I have seen the term "China Block Drive".

I get in trouble by asserting that the market is what determines what we are offered.

Has anyone ever taken 1 of the 2 motors out to see how an engine performs with just 1?

Every time I run my RailKing NW2 I notice the motor sticking up in the cab of the engine.  I don't know if 1 motor would do the job (although 1 seems OK in a steamer) or if taking 1 out would upset the balance or traction of the engine.  Of course if 1 motor was removed the drive gears would have to be removed as well so the truck would roll freely.

The market does indeed determine what we are offered, no argument there.    We two-railers who like mechanisms that are smooth running at low speeds and start and stop nicely, are in a minority.   

As for one motor in the NW2, it would run, but it would loose more than half of its pulling ability in my opinion.   I have had over the years a couple of the old General Models NW2s with one motor and they did not pull nearly as well as 8 wheel drive no matter how weight was added.   I think the physics of the weight distribution onto both trucks would explain why if I understood it.

prrjim wrote:

who like mechanisms that are smooth running at low speeds and start and stop nicely, are in a minority

True, but I don't get it.  Would folks rather have an engine that speeds around the layout (don't they realize this also causes derailments and electronics to go poof?) than one that goes around at a realistic speed, especially on some of the small layouts folks say they have?  Maybe a 5 year old kid likes to see things go fast but they're not the ones buying these expensive trains.  I just don't see the thrill in it.

I do like the way the RailKing NW2 pulls with 2 engines.  Anybody know if MTH has given any thought into going to a horizontal drive?  Wouldn't it be less expensive in the long haul?  1 less motor and less electronics (to keep 2 motors in sync).

Jim, Look at 3rd Rails solution. One LARGE motor driving all axles on both trucks. I don't have the specs on the motor they are using but would guess power is close to the two smaller Mabuchis most other manufacturers use. Chuck said it best when he noted 3rd Rail's drive limits turning radius. Lack of smoothness IMHO is due to use of diecast gears between the drivers that Lionel and MTH use more than type of drive. A Williams engine with bronze gears and cruise will be as smooth as anything out there.

Pete

It seems to me the smoothness or not in stopping and starting is not in the gears, it is in the motors.    The two very inexpensive looking (ie cheap) motors just don't seem to start and stop simultaneously especially after some use.

Another issue is that these small cheap motors develop their torque at relatively high RPM.   The drives need reduction gearing similar to why your car needs a transmission to allow the motor to get up to some decent speed to generate the torque needed to move the loco.

With a DC motor the maximum torque is at stall. Here is some data on the Mabuchi RS385 including the torque curve which most of the train manufacturers use in the their diesels and small steam engines.

Pete

Actually, you can take the motor out and the truck rolls freely.  You would have to keep the mounting plate for the motor so the truck would stay attached to the frame.

For locomotives that have the motor showing in the cab, I build a little doghouse of heavy black cardboard and mask them.  You can even get creative and print some gauges and levers on the box to make it look like controls.

I must misunderstand what torque is.

My experience is if I am creeping a loco and it goes into a curve - it stops - stalls.   If it is running at slot car speeds, it keeps going.    And my power supplies are capable of 6-8 amps. 

I have had this experience with the two motor locos and with the Weaver C1 switcher.   

prrjim:

Torque is force or power. It has nothing to do with speed.

Speed is power overcoming friction and other forces until they balance.

I suspect you are running conventional, IE controlling speed with Transformer Voltage.

The reason your engine stops in the curve is the increased friction of the flanges on the rails in the curve. It's just like hitting a grade, you need more power.

I can run my DCS or TMCC engines all over the layout at 2 Scale MPH. No change in speed for curves or slopes.

The PS-2 controls monitor the flywheel rotational speed and adjust the DC volts tot he motors to maintain that speed.

Since there is 18VAC on the rails all the time the system has tons of reserve power for track changes.

And yes, the engines all have China Drives. And they go as S L O W as 2 scale MPH smoothly. (not sure about the speed of the TMCC ones, but they are slow too)

Now just how slow is that ?

1 mph = 88 feet a minute (5280 feet / 60 minutes)

88 feet * 12 = 1056 inches a minute

1/48 of that is 22 inches per minute at O gauge scale.

So 2 smph = 44 inches a minute at 1/48 scale.

On my layout that's about 24 and a half minutes for a full loop on the main.

Heck, I run 5 or 10 smph in the yard.

2 is for that first half foot out of the start before I ramp up to running speed.

I can get most of my Legacy locomotives creeping along at about 1/2" a second, or 30 inches a minute quite smoothly.  The ERR Cruise Control models do almost as well.  The PS2 locomotives are pretty close as well, some of them seem to do better, but pretty much any of them will be pretty smooth at around 3 scale MPH.

As far as conventional, or locomotives without speed control, that's why that's the primary upgrade I do to any locomotive here.

Below are several elements IMO favoring a single motor  all wheel drive architecture for scale oriented diesels over the China Block drives we've been getting for the last 15  or so years in 2 rail (excluding brass)

- enclosed gearboxes keep crud out of the drive train

- quieter running due to not having numerous noisy spur gears 

- lower current draw - one less motor

- smoother starts due to better choice of gear ratios, simultaneous turning of all wheels, and more robust motor

- detailed cab  - drive is below cab floor

 - fewer parts in drive train 

- with side frames carrying the load, trucks equalize so that all wheels are in contact with the rail head at all times

It will be interesting to compare performance of the recent China block drive MTH F7 with the upcoming single motor horizontal drive Sunset FP7.  My order is with Sunset...

Ed Rappe (2 railer)

Thanks to everyone for making this an interesting thread to read.  There are several good comments and I have to give credit to BOB2 for pointing out one essential fact.

The motor has no idea which way it is pointed.

Sometimes we get isolated in our own individual corners of the hobby and not be aware of what is going on in other market segments.  This can lead to some prejudices over the "right" way to do something.  Like most prejudices they can melt away when we get exposed to the wider world and see other ways of solving problems that work just as well or better than what we have seen before.  Or, we can find out something that works well for us doesn't do so well under other circumstances.  Since this is on the thee rail forum my comments will focus on the 2 rail side of things since it is less familiar to some on this forum.  3 railers have certain prejudices too and I think we would all be better off if we understood where they come from and how they might be holding us all back.

O scale 2 rail trains generally require very wide radii for large locomotives and cars.  Relatively few people have the space to run multiple unit diesels or a Northern pulling a 10 car passenger train or a 20 car freight.  Of the people who buy large O scale locomotives and cars a high percentage collect but rarely run their trains.  Of those 2 rail O scalers who run their trains often a high percentage have smaller layouts with switching as a main operating activity.  Due to the lower market share for DCC in O many 2 rail O scale operators are running with conventional DC power supplies, often with limited voltage or amperage capacity to suit the needs of their small switching layouts.  Therefore there tends to be a high emphasis on slow speed and short train performance with low amperage draw among 2 rail O scale operators. 

Atlas and MTH both started offering 2 rail O scale Diesels in the 1990s.  MTH pulled back from the 2 rail market in the early years of Protosond 2 when the electronics were AC only.  Atlas was a familiar name to 2 railers due to the Atlas O scale line in the 1970s and the long time Atlas presence in HO.  The Atlas O EMD switcher has a very nice mechanism with a single horizontal motor.  That is the "correct" way of doing things for many HO or 2 Rail O scale guys and the locomotives perform well with low amperage draw in conventional DC operation.  That makes them a double thumbs up for many two rail operators.

In contrast the Atlas RS-1s have twin vertical can motors and tall gearing.  They are not good slow speed performers although the TMCC version with speed control is better.   But the TMCC electronics draw more amps.  This has tended to confirm some prejudices about gear ratios and vertical motors that some times results in complaints about Atlas cow towing to the 3 rail rocket ship market, daw gonned new fanggled wiz bang electronics, etc.  Some of those comments would fit in with John Armstrong's musings about 2 rail O scalers frugality and their tendency to find reasons to not buy anything.  It is less expensive to complain about how a locomotive wouldn't need fancy electronics if it were just designed properly than to upgrade their HO power supply by spending $100 on a O scale train set transformer and a few more bucks on a rectifier at Radio shack.

While a motor doesn't know which way it is mounted there are other factors that do mater.  Gear ratio is an important consideration, but not the only one.  The final drive ratio should be matched to the motor's torque curve.  A good mechanical design won't just be concerned with gear ratios and the motor it will minimize friction, especially the thrust load created by a worm gear.  And a modern design will use advanced motor control techniques including motor feedback and pulse width modulation.

Many drive mechanisms found on 2 rail O scale models have horizontal motors so they meet the first criteria for the "right" configuration but are otherwise poorly designed.  Belt or chain drives are common despite their high friction and high noise at more than yard speeds.  While plastic U joints are sometimes used they are less frequently used in a pair for constant speed rotation. Rubber or plastic tubing is often substituted for universal or CV joints to save cost.  And although gear reduction may be great, high friction through poor bearing design can ruin the overall effect.  Poorly matched gears may be enclosed but friction so high that heat thinned grease leaks out of the unsealed enclosure after a few scale miles at modest mainline speeds.  The result is that many 2 rail O scale locomotives have to be rebuilt to run adequately. 

Despite the large number of poorly built horizontal motored locomotives many 2 rail O scalers have only experienced a locomotive with twin vertical can motors from Atlas and since they don't want to spend money on anything new anyway their prejudices against twin vertical motors persist as does the derogatory "China Drive" name.

Contrast any diesel made primarily for the 2 rail O scale market with a Lionel Legacy GP.  The Lionel Geeps have a wonderfully engineered truck with very low friction and excellent thrust bearings.  And check their slow speed performance, it is fantastic.  But Lionel does not offer a 2 rail version so few 2 railers have been exposed to a prejudice shattering product.

MTH has been offering 2 rail Protosound 2 diesels since the introduction of the AC and DC compatible 3 volt electronics.  Protosound 3 has provided 2 Rail O scalers with out of the box AC/DC/DCS and DCC compatible locomotives with excellent sound.  MTH locomotives are winning a 2 rail following, especially from younger guys with big club layouts to run them on.  Again, the Diesels have vertical motors with good mechanical engineering and electronic motor control for smooth operation as low as 3 SMPH. 

Both the Lionel and MTH twin vertical motored diesels are made by the thousands by major companies who warranty their product for customers who expect to run them.  And run them.  And run them!  They will provide smooth slow speed operation, are great for switching and stand up to heavy duty mainline running.  Very few "correct" O scale locomotives with horizontally mounted single motors but a host of other mechanical flaws could survive this kind of operation.  Few brass companies could survive if they had to warranty a product like the larger builders.

The more crossover their is between the 2 and 3 rail segments this hobby the better.  We can all enjoy better detail, better slow speed operation, better mainline pulling ability and better mechanical design and reliability.  But getting their might require an increase in open mindedness and a focus on performance and less prejudice about the "right" way to do things.  Just because the top of the Lionel Line diesels of the 1950s had dual motors doesn't necessarily mean that new diesel models should too.  And just because our favorite HO or 2 rail O builder used a single motor doesn't mean that is the only way to make a smooth running locomotive.  If we continue to provide a growing market for highly detailed great running locomotives the manufacturers will find the right engineering solutions to give us what we want at a competitive price.

I actually read all of that.

Further, I agree with pretty much all of it.  Good thing it wasn't posted on the 2-rail forum.

Only one small comment.  I agree that high speed worm shafts should be protected with ball bearing thrust and radial bearings, and I have actually modified gearboxes to do just that - but - we have never had a failure of the MTH Chinese Windshield Wiper motor, even though the motor shaft absorbs the radial and thrust loads with porous bronze bearings and even though the shaft is skinny.

Our MTH runs daily for hours at a time.  We replace axle gears at three year intervals, worms at about every third axle gear change, and axle bearings were changed on one unit after twenty years.

We get a year out of horizontal drive components (All Nation) and then they are junk.  We get maybe five times around the big loop on older imported brass (Overland?) and it is time for mechanism replacement.

Good post, Ted.  Opinion.

I actually read all of that.

Bob, now that was funny! 

Further, I agree with pretty much all of it.  Good thing it wasn't posted on the 2-rail forum.

Actually we did go over some of that ground on the 2 rail forum earlier in the year.  The thread ended up going on for three pages.  I was pleasantly surprised by how many people who posted on the thread found similarities in their experiences or perhaps found out why they have different impressions of what appear to be similar mechanical designs.

https://ogrforum.com/d...ent/5512461180974714

Only one small comment.  I agree that high speed worm shafts should be protected with ball bearing thrust and radial bearings, and I have actually modified gearboxes to do just that - but - we have never had a failure of the MTH Chinese Windshield Wiper motor, even though the motor shaft absorbs the radial and thrust loads with porous bronze bearings and even though the shaft is skinny.

Ball bearings are super.  But as your experience shows a simple bronze bearing can do its job well and help keep the cost down.  MTH makes O scale models of modern high horsepower diesels that come with sound and command control and will run smoothly at 3 SMPH for under $500.  You can get worse performance for a lot more money but I don't know where you can a better sounding and better running model for less. 

"China Drive" is a derogatory term rooted in prejudice.  I see no problem with any manufacturer touting what they believe to be distinguishing features of their products or comparing them with others but it is it is time to drop the use of this term.  It doesn't shed much light on the real technical merits of a locomotive.  But it can be used to exploit prejudices.   

I would love to see more great performing and moderately priced locomotives.  It is going to take some good engineering to design and build them profitably at an attractive price.  The engineering will have to involve a lot more than the way the motor is mounted.

At the risk of throwing a live hand-grenade into the room, I believe that a major reason why many steam locomotives, and almost all smaller scale locomotives use horizontally arranged motors is simply a question of available space. O scale diesels, and some steam locomotives normally have enough vertical space for a motor to be fitted vertically, whereas the others do not. Good gearing, quality motor(s) and good power collection arrangements have far more bearing upon smooth running that the orientation of the motor. 

Bingo...

Back in the 60's and 70's, AHM (Rivarrossi) used a three pole motor vertically mounted in most of their HO diesels (Yugoslavian and Italian Drives???) and horizontally mounted in most steamers.  They all ran at what could politely described as fair.

Mantua/Tyco had a horizontal 5 pole motor in their diesel power truck that required a rather high voltage to get going, then could be throttled back to a slower speed and was a fairly smooth runner.  For some reason however, they always seemed to run better in reverse than forward.

Rusty

I think Ed R. pretty much summed it up in an incredibly concise manner. Maybe too concise for some readers.

I like the idea that the new Sunset drive will run smoothly at start up and slow speed under any control system including conventional. This is without relying on any special electronics.

I've seen what can be done with the electronics and I like them, but I'd still RATHER have the engines made in such a way where they didn't have to RELY on the electronics to run smoothly at slow speeds. I see Sunset as giving people a high quality choice in that regard for a reasonable price.

I agree, O scale China Drive are the worst of the Model Railroad industry, even an Altas N scale run better than their O scale with China Drive. Will be interesting to see  what a company like Kato can do with a similar vertical drive, and then China manufacturers  will copy it...

You've never experienced Athearn's old Hi-F(rubberband) drive!  

It's only advantage was it was nearly silent.  Other than that, it would leave a cruise missle eating dust, under load the rubberbands would slip, could do boing-boing stop and the rubberbands had to be replaced frequently.

And it had a horizontal motor.

Rusty

Ah yes, I remember them well. Lionel had those when their HO first came out.  And if you forgot which way the bands went on the shaft, the engine ran backwards or worst, if you got one band or set reversed from others, nothing happened or funky movements!!

In Minneapolis in the 60's we called a rubber band a "binder."  So the Athern locos were called "binder bombs."

Well, my opinion is that China Drive is quite well suited for what it does, and given its application the term is indeed no more derogatory than is Swiss watch, or German engineering.  It is not a setup that the average 2-railer likes, so they do not have to buy them.  In the museum environment they are better than anything else we have tried (at least the MTH version; we have had problems with some others).

If the Chines object to the term, I would be the first to drop it and use some other term.  There is no need to offend another group with poorly chosen names.  But if I were Chinese, I would be proud of the performance of these drives in the 3-rail and museum environment - just like the Swiss are proud of their clocks.

I like the idea that the new Sunset drive will run smoothly at start up and slow speed under any control system including conventional. This is without relying on any special electronics.

Christopher

You like the idea that the Sunset diesels will run smoothly. Have you had a chance to run any yet?  If so please share what you have observed.  Sometimes folks have different experiences with the same hardware.  Often that comes back to differences in operating environments related to power supplies, track, train length, grades, etc.

I have had the opportunity to run both the 2 rail and 3 rail versions of the sunset E7.  And I have had a chance to compare them side by side to a Lionel Legacy E7 and MTH E6s and E8s.  It is a commendable first diesel effort from sunset and I welcome the new competition to the marketplace. 

In detail all three manufacturers have competitive products.  Each has strong and weak points.  The Lionel and MTH diesels all had better quality decoration.  We have seen photos of the less than crisp nose decoration on the CB&Q units posted here.  The GN E units I ran had a bad case of orange peel and both the orange and the green colors were off the mark.  Hopefully the accuracy and quality of the decoration will improve with subsequent production runs.

The Sunset E7s ran and pulled well.  But they did not exceed either the MTH or Lionel E units in slow speed start up, smoothness or pulling ability.  The Lionel and MTH units were also quieter, especially above 10-15 smph.  The Sunset models had a noticeable whir from the belt.

I agree, O scale China Drive are the worst of the Model Railroad industry, even an Altas N scale run better than their O scale with China Drive.

PC-Quebec

Is this an industry problem or an Atlas problem?  All the MTH and Lionel Legacy diesels that I have run perform very well.  They will start at 2-4 SMPH and run smoothly at any speed above that.  They will pull trains of realistic weight and length.  Could it be that Atlas has a less refined vertical can motor mechanism than Lionel or MTH and the Atlas presence in 2 rail has undeservedly given the products of other superficially similar products a bad rap?

If anyone here has first hand experience working on Atlas, Lionel and MTH vertical can motor drives I'd love to hear about it.  Is Atlas behind the curve on their mechanical design?  I have never had to take an MTH diesel tuck apart for repair so I can't offer a first hand comparison.

We have plenty of opinions.  How about some good empirical observations?  With enough of those we might even be able to agree on some facts!