Large Scale Central

Does the gearing really not matter?

General Discussion
#1

Help me here…I’ve always been taught that correct gearing is the crux on most anything mechanical…see added bold below…

Quote:
. . Posted by: "Stan Ames" Fri Dec 5, 2008 2:17 pm (PST)

— In [email protected], dave funk <dsfunk2@…> wrote:

Stan, I always thought gear ratio had a huge

impact on a model locomotives ability to pull a train. Gearing must

also match the size and torque specs of the motor. My Bachmann K-27

runs ok but it would run and pull much stronger if it had a gear ratio

in the 28 or 30 :1 range ( like most other model steam locos do ).

The way the K-27 is geared Bachmann is relying on the torque of the

pitman motor to compensate for an incorrect gear ratio ! Why not just

correct the mistake and issue the correct parts for the locomotives

that are already in service? I enjoy my K-27, I just wish it ran as

good as it looks!

Dave Funk

Dave

You are correct gearing is critical to proper operation. But there are
limits.

If the motor stalls under any load then indeed the motor/gear ratio
combination

would not be sufficient and would greatly effect the ability to pull a
train.

In the case of the Bachmann K27 the wheels will slip when the load is

greater then the ability of the locomotive to pull the train. This is

exactly as it should be.

In order to increase the pulling power of this locomotive you must

increase the traction on the wheels by adding weight (or dare I say it

traction tires) [b]Changing the gearing alone would have negligible

effects. [/b] On the other end, if the gear ratio is to high then the top end

speed of the model will suffer and you may not be able to achieve

prototypical speeds. The gearing, the motor, and the entire drive train

all contribute to the locomotives operation. In the case of the

Bachmann K27 they do indeed rely on the excellent motor they have in the

model as well they should.

On my railroad my K27s will pull trains up the grade that are longer

then the longest sidings on my railroad, it will start a long train on a
steep grade smoothly

and with ease (see the video I posted). So for me it works just fine.

I have extremely good slow speed power under all load and grade
conditions.

INcreasing the gear ratio of a model is not always the right solution.
For

example if you were to replace the gearing from 1:14.5 to 1:30 the top

end speed of the locomotive would decrease substantially/ likely by

1/2. I say likely because if the K27 is over tasking the motor (I do
not think it is) then the

max RPM will increase as well as you increase the ratio so the decrease

in top speed may not be the full 50%. When you drop the top end speed

you run into the other side of the problem. The model would not be able

to operate at its prototype top end speed at 18 volts DC. I have some

locomotives that my operations always run at their top end speed because

they run to slow and others where you can not get a reasonable speed at

all. For the K27 my operators typically operate them at a speed step

from 16-24 out of 28. This is great because they will change the speed

as the the train traverses the railroad. In the video the speed was

about 16/28 which is close to 15MPH or so.

If you ckeck out the Bachmann K27 videos various folks have posted on

you tube, you may be as surprised as I was at the speeds they run them

at. I point this out because there appear to be a substantial number of

modelers that enjoy operating their trains at perhaps a little faster
then

prototype speeds.

[b]What the manufacturers need and we as modelers could provide is the

desired top end speed at a specified voltage.[/b] Myself I believe that

prototype top end speed at 20 volts DC would be just about right. That

would allow faster speeds at 24 volts DC while allowing modelers to

lower the voltage and still get excellent speed range for their models.

For the K27 I think a speed of 40MPH at 20 volts might be a good

compromise between those that always run their locomotives at a crawl

and those that would like to run them prototype running speeds.

As for having a replacement gearbox, thats a question you should bring

up with Bachmann.

Stan

www.tttrains.com/largescale http://www.tttrains.com/largescale
.
.

#2

I certainly would like to describe him in one, simple, 5-letter word that sounds like a certain railway of old.

What he fails to account for is what the K would run like with the 29:1 it should have had.

He can crank in the curve on his decoder to cram it all at the bottom end, but if you have to compensate with electronics, you’ve automatically lost.

The rule was, is and always shall be:

The locomotive must run well on straight DC BEFORE you add the MANDATED electronics someone appears to be presenting as a solution to a design issue.

Screw him.

He can take his ideology and shove it where the sun doesn’t shine.

I have a K, but it is now stored until I have a gearbox I can be happy with.

If this person is NOT a spokesperson for Bochman, then whatinthehell is he doing trying to perform damage control in public?

The gear ratio IS 14.5:1.
NWSL uses about that ratio (even with double-lead worms) for small-drivered diseasemals.

One of the experiential things in my career was when they came out with their .6MOD gearbox.
I got one of the first.
It made the Bochman 4-6-0 with said gearbox (and small Sagami can motor) a freaking rocketship.

First 6’ radius curve, it became a 2-3-0.

They, of course, thought I was confused and didn’t understand (Stanley is not the first cretin to think that).

Whatever made me think the .6MOD gearbox I had received for a LS Steamer was 15:1?

Because I counted the turns.

Oh.

Next morning they called back.
Seems THEY had the cretin on-site, who had loaded the steam gears (30:1) into the diesel bin and vice-versa.

You see, I do have some great experience in gears, gearing, and know exactly what happens when you screw up.

I also have the original recommendation from 18 months ago on motor/gear combinations to Bochman.

9000 series Pittman, 30:1 ratio, double-lead worm.
And, AND, in conjunction with BBT, OFFERRED to SHARE the technology he has developed over the years, but that THEY would have to call HIM.

No Calls.

And that, folks, is IN PRINT.

Let’s guess for a minute that to be difficult, they made it 29:1.
Hey, I can live with that.

Then, oh, let’s speculate that someone found it did not have a double-lead worm.
Let’s further let our minds wander and guess that the alarm went up, the factory fixed the single-lead worm and worm-gear to double-lead worm and worm gear, and what if nobody checked that the final drive had not been re-addressed?

Your 29:1 is now 14.5:1.

But, that’s just hypothetical, right?
I mean, nobody could be that careless, right?

#3

Cale, I know exactly what you mean.

Now you’ll ge it :wink:

The temerity of it . We can’t go questioning Mr Ames about it now, can we?.
Next thing we will have rebellion in the ranks of the faithful. :wink:

Of course the K-27 performs really well. That is because it is well made.
It would have so much more lugging power with the designed for ratio.
Even 14.4 volts lets the long legged beast bound away at a pretty fair clip. So fast, it will derail on any but the most superb track laying.
It would be OH so much better with the lower ratio. Much smoother starts without loading up the power supply with an unneeded higher starting current than it would with a 1:29 ratio.

Even Stan agrees with that and concedes the top speed need not necessarily by halved.

““For example if you were to replace the gearing from 1:14.5 to 1:30 the top end speed of the locomotive would decrease substantially/ likely by
1/2. I say likely because if the K27 is over tasking the motor (I do not think it is) then the max RPM will increase as well as you increase the ratio so the decrease in top speed may not be the full 50%.””

Something else.
If the motor was not being loaded down, how come Bachmann needed to fit a fan. Do you think that just might be to keep the motor cool?

I am eagerly looking forward to the explanation from Mr Ames as to why the Mallet, which has, I believe, the same motor and driver size as the K-27, will be getting fitted with a 1:28 ratio and not the 1:14.5 fitted to the K-27.
Likewise I am sure Mr Ames will eagerly demonstrate to us all why that fact makes no difference to the “reasons” why he thinks the K-27 really was better off getting the 1:14.5 ratio instead of the 1:29 it really was supposed to be fitted with.

#4

This should give you a giggle - http://www.mylargescale.com/Community/Forums/tabid/56/forumid/9/postid/65661/view/topic/Default.aspx

-Brian

#5

“Changing the gearing alone would have negligible effects.” – Stan Ames

If as the rest of that paragraph suggests, he means the effect on traction, I concur. Changing the gearing alone would have NO effect on the coefficient of friction between the locomotive’s wheels and the rails … to do that one would indeed need to add weight to the locomotive, change the surface of the wheels and/or the rail, or if one was really a horse’s patoote, add rubber traction tires to an already sufficiently powerful locomotive.

Unfortunately, how much TRACTION the locomotive has was NEVER the question at hand. Either the respondant was … er… confused when he attempted to answer the question, or was deliberately trying to introduce a red herring to disrupt the orderly discussion of the issue.

That said …

I had a 1990 pickup truck with a standard transmission. It was indeed possible to run the entire way from zero to my “maximum desired prototype speed” of about 80 miles per hour in fifth gear. The truck was equipped with a very powerful six cylinder engine that would actually manage to turn the wheels in the zero to forty range until the usual place for such a gear to be used was achieved, and then behaved quite efficiently.

Whether it was the usual way to drive such a vehicle, or an intelligent way to drive a vehicle is, apparently open to question.

So … instead of the usual hail of red herrings and non sequiturs, I propose the following:

Let’s have a gearbox that will drive the K-27 with a gear ratio of about twice what the current one has. Let’s see which one pulls the string of 30 cars (by itself this time) up the grade. Let’s see which one shunts the five hoppers full of rocks up the grade. Let’s see how fast both run at 5 volts, 10 volts, 15 volts and 20 volts … and how easily each can be made to accelerate without the assistance of a computer. Let’s see what the wide open top speed of each model is. Let’s film that top speed and see from a poll on MLS or Youtube which looks more ridiculous to most modelers. Let’s put an ammeter on the track, and see how much current each draws while doing the above (we did mention “efficiency” at some point in this baitfest, didn’t we?) and then let’s get Bob Grosh to run them both under load for two weeks until one quits.

And then maybe, once and for all, someone will shut up, and we can figure out what to do with enough stinking rotten red herring to bait every hook in the Gloucester fishing fleet for a year.

I, for one, am SICK TO DEATH of this. I am sick of the patronizing, I am sick of being told it’s all for my own good, and I’m sick to death of the nonsense.

If the gear ratio really makes so little difference, if it’s all the same to someone, I’d prefer the next time that someone tell Bachmann what they’re going to build, that someone would choose the one that works for the rest of us.

Before the Red Herring ends up on the endangered list from overfishing!

Matthew (OV)

#6

Hey Brian.

I suitably giggled.

Aaaaaaaahh!!!

Stanley!!!

What a guy.

#7

Matt I concur! it’s the principal behind the matter that gets me…

I buy a 5700 lb camper, my 2003 Avalanche with a 3.42 rear end (gear ratio) doesn’t like it…not enough ‘grunt’ to take it to the Mnts. Now a similar equipped 2003 Avalanche with the 4.10 rear end (gear ratio) can tote it and the mail…Both trucks equipped with a 5.3L 327 CUI V8.

Now if I understand Stanley’s argument, all that is needed to compensate for the higher gear ratio 3.42 vs 4.10 is to add more voltage (or in my case, more throttle)…trust me, I did that all the way home…it didn’t cut it…I could have changed the rear end gearing and compensated…no matter what I could have done to the “engine”, performance wise would have changed the fact the gear was wrong for towing…

so dropped the trailer at the house and went and traded the Avalanche for a 250 PSD…with 525 ft lbs of torque and a lower ratio rear end…now camper, mail and kids all get toted!

Brian, funny post…!

#8
Cale Nelson said:
Matt I concur! it's the principal behind the matter that gets me...

I buy a 5700 lb camper, my 2003 Avalanche with a 3.42 rear end (gear ratio) doesn’t like it…not enough ‘grunt’ to take it to the Mnts. Now a similar equipped 2003 Avalanche with the 4.10 rear end (gear ratio) can tote it and the mail…Both trucks equipped with a 5.3L 327 CUI V8.

Now if I understand Stanley’s argument, all that is needed to compensate for the higher gear ratio 3.42 vs 4.10 is to add more voltage (or in my case, more throttle)…trust me, I did that all the way home…it didn’t cut it…I could have changed the rear end gearing and compensated…no matter what I could have done to the “engine”, performance wise would have changed the fact the gear was wrong for towing…

so dropped the trailer at the house and went and traded the Avalanche for a 250 PSD…with 525 ft lbs of torque and a lower ratio rear end…now camper, mail and kids all get toted!

Brian, funny post…!


Been there, doing that. Can’t afford to upgrade the truck or the gears. Avoiding the BIG mountains :smiley:

The MLS post is hysterical :smiley:

#9
Brian Donovan said:
This should give you a giggle - http://www.mylargescale.com/Community/Forums/tabid/56/forumid/9/postid/65661/view/topic/Default.aspx

-Brian


The Rodney Dangerfield of Large Scale.
Doesn’t get any respect anywhere! :slight_smile: :slight_smile: :slight_smile:

#10

Matthew, et al,

I too am getting tired of this. How many ways can one phrase an argument to prove the same erroneous point?

Since I was in this in the beginning, I feel somewhat obligated to respond.

The first conversions I designed for the Bachmann Big Haulers were dependent upon my experience in slot cars, which were all 48P gears. All spur gears except for the 1/32 scale cars with Pittman open frame motors.

I offered two 48P gear ratios 20:1 and 40:1. The 20:1 was a forty tooth double thread worm gear, with a double thread worm. The 40:1 was a forty tooth worm gear with a single thread worm. They both worked very well, but I had problems with the motor mount which was adjustable. This provided too much probability for error, either by me or by the customer. The performance of these two drives was quite different. The 40:1 was an excellent slow speed performer, with adequate top end. The 20:1 handled the low end, but nearly as well, and the top end could be too much. To solve the reliability problem, I needed a fixed motor mount and a compromise in the gearing. I studied Stock Drives hand book on gearing, which told me a lot more than I wanted to know. But I ordered a variety of gears in 32P, worms, worm gears, single thread. Assembled a drive with 30 tooth worm gear and single thread worm. This became my new standard. Sometime, later I received a phone call from TOC, with an observation. On his long (80ft) 4% downgrade witha heavy train my drive was surging badly. A short time later my wife and I went to Seattle to visit my step daughter and her family. I also visited with Dave (TOC). He demonstrated the problem. This had to be solved. Arriving back home I tried various approaches including flywheels (larger than the one found in the K-27), totally ineffective in any form or level of performance.

I examined how others were geared, who didn’t have the surging problem, they all had double thread worms! Dave and I discussed each potential solution, together we solved this problem. I all ready knew that the ideal gear ratio was in the neighborhood of 30:1, but needed a gear set up with the double thread worm and gear. So I designed a counter shaft drive. The worm is a double thread, driving a double thread worm gear, on the same shaft is a 16 tooth spur gear, which engages a 30T spur gear on the axle. This approaches 30:1 gear ratio. This is the final design. The variables in the design were primarily in the size of the spur gear on the counter shaft, from 12T (excellent slow mover, but you have to get used to it, Dave still has one today) to 20T. The video on my website shows two Circus locos double headed pulling 83 cars (that’s all they had). Those locos had the 20T spur gears. Comparatively, too much high end and not enough low end “pull”. I settled on the 16T spur, which is the one in use today. With my fingers crossed, Not one gear failure to date.

The reason for this little story, is simply to state that how we best get from A to B, isn’t theory, but theory put in practice. Obviously, the K-27 had no or very little practical testing, normally Alpha and Beta testing, but went from the design bench to the model. I am sure Bachmann isn’t happy with this state of affairs, evident by the significant design change in the new 2-6-6-2.

Barry - BBT

#11

Un F beliveable, I did velocity ratios at school 40 years ago and I see the collective might and intellect of a manufactures resourses still Fs up.

I mean its not that difficult is it, I understood it when I was 10. We had to take our bikes in to the class room hang weights on the pedals and measure the distance the rear wheel turned and from that we also worked out the mechanical efficiancy, Mind you it involved some thought, some practical work and recording what we observed.

Sheesh

#12

Rod-
You think maybe the official/unofficial spokesperson eschews thought as a process?

I love one of the definitions of “eschew”:
“to avoid habitually especially on moral or practical grounds”

Must be morally abhorrent to him, and we know in practice he cannot use it.

The REALLY bad part is they were given (free of charge) the information they needed and look what happened.

I am certainly glad I have the original submittal AND the reply accepting said submittal.

He can run (and squirm), but he cannot hide, even if he tries on the yahoo group.

Anybody yet figure out why he is so insistent on defending this?
Even in the face of experience and facts?

#13
Curmudgeon said:
SNIP Anybody yet figure out why he is so insistent on defending this? Even in the face of experience and facts?
No. But I could hypothesise as to why.

Like, if Mr Ames admits he is wrong on this issue it throws into question his reputation in past lives.
Starting with the still unresolved issue of his conflict of interest in the DCC field with his wife being the Lenz importer in the USA.
That conflict of interest still exists even though the NMRA got him out of the hot seat in the DCC sector and shoved him sideways to inflict his conflict of interest on the Large Scale community.

What I will find engrossing is how Mr Ames is going to explain why Bachmann saw fit to install 1:28 gears the Mallet and not the K-27.
Seems to me that will be a grovelling admission someone stuffed up on the K-27.
The real question is, who was that someone?

#14

further back a day or so…more nonsense…see bold

Quote:
. . Re: K-27 Posted by: "Stan Ames" [email protected] stanleyames Tue Dec 2, 2008 9:31 am (PST)

— In [email protected], pthornto@… wrote:

Stan,
While not disputing it is good value for the money, I wonder about
‘excellent
slow speed’ despite the 14:1 gear ratio?

Pete

No problem. I can provide as much detail as you desire. The criteria
most use for good slow speed performance is measured in the range of 1
to 2 scale miles per hour. I can run my K27s all day at 0.2 scale mph.
Put in perspective that means it would take over 20 hours for the
locomotive to go from one end of my layout to the other end of my
layout. I think that is slow enough. The first few seconds of the
video I posted shows the locomotive at speed step 1. I gradually raised
the speed to demonstrate the power the locomotive has and because it can
be kinda dull to watch a locomotive running at 0.2 scale mph. The top
speed in the video has about the same chuff cadence as the 464 has on
its runs at the Huckleberry Railroad which is still rather slow.

http://www.youtube.com/watch?v=s-0iUbSXl2s
http://www.youtube.com/watch?v=s-0iUbSXl2s

Phoenix is an excellent sound system but with the K27 you have to turn
off the automatic start and stop sounds. Why? Because the K27 goes so
slow that the Phoenix sound system thinks the locomotive is stopped
between chuffs.

And I can run light or pull a full load at 0.2 scale mph on the flat or
up the grade. The same smooth performance is there across the
performance range of the locomotive. So from my perspective on my
railroad the K27 has the best slow speed performance of any of my
locomotives and is and is likely to remain my favorite locomotive.
(unless of course a K37 should appear sometime)

A gear ratio by itself is not a relevant number. If I put a small motor
in the K27 such a ratio would not work. But the Bachmann K27 has a
large Pittman 9000 motor which is a powerhouse and has more than
sufficient torque to power the locomotive across its full performance
range.

I have a challenge for you. You seem to question the excellent slow
speed performance of this model. No problem. Lets put this to a test.
Why not provide this group a criteria for a smooth slow speed
performance that can be measured. I would be happy to attempt to try
your criteria to a K27 record and post the results. Might be worth the
effort to try out should you have such a measurable criteria.

How about some full disclosure of any potential conflict of interest

on your part?

Sorry I see that I accidently omitted my tag line from my earlier
message. I am proud of my accomplishments and list them on my home page
and disclosure statement page.

I currently do not have any conflict of interests or potential conflict
of interests that I know of. The WIKI has an excellent write-up on the
topic.

http://en.wikipedia.org/wiki/Conflict_of_interest
http://en.wikipedia.org/wiki/Conflict_of_interest

I am a modeler and model primarily outdoors in 1:20.3. I provide
assistance as requested to a wide variety of manufacturers on a wide
variety of topics. It’s my way of giving something back for all the
enjoyment this hobby has given me and such assistance has become a hobby
in itself.

We are blessed by having a lot of excellent product in 1:20.3 to choose
from a variety of manufacturers. This was not always the case. I for
one hope it continues and I will continue to do my small part to help
our hobby grow.

Stan Ames

http://www.tttrains.com/largescale/
http://www.tttrains.com/largescale/
.
.
.

#15

Tell me, Cale, and maybe inform all of us.

Is this cretin doing his level best to convince the entire world of his abject cluelessness, or what?

#16

Oh, wait…“he’s just confused and doesn’t understand”.

Yeah, that’s the ticket!

#17

Today’s Secret Word is:

PROPARIAHTERY. (pro-pa-RYE-uh-tear-ree) (adj)

Discuss.

Richard C.

#18

LOL …

I think that’s one of those New York Times word games where you change part of a word to make it mean something else…

So… if I’m correct, “Propariahtery” information (combining “Proprietary” and “Pariah” here )would be information bound to you in such a way that you couldn’t disavow, or distance yourself from, that made you about as popular as if you’d rolled in something stinky… like getting caught publicly in a real whopper of a lie!

Matthew (OV)

Except, shouldn’t it be “Propariahtary?”

#19

He could be a politician. He, like them, think we’re too stupid to really know wanything and if he repeats it enough we’ll believe it. I find it incredible that Bachmann still use him as a consultant …

#20
Curmudgeon said:
Tell me, Cale, and maybe inform all of us.

Is this cretin doing his level best to convince the entire world of his abject cluelessness, or what?


David and all participants…I’m not sure what or whom said poster is trying to convince…

it’s like a big circle…no beginning and no end…infinite roundy round-ness…

I’m nothing more than a College Drop-out, Business Owner, Dad…But I do understand how “things” are supposed to work and by one trying to convince others that a flaw is not a flaw is asinine…meaning; to me it makes no sense to talk ‘horsepower’ (voltage) when the issue at hand is incorrect gearing…

To,
Mr. Bud Reese, Lee H Riley and others involved…I’m not Beating up Bachmann, you make a pretty nice product (you must; most everything I own in LS is from your company and I plan to buy more!)…but if there is/was a design flaw in the Gearbox of the K…that now appears to be corrected in the 2-6-6-2…come out with it, gimmie an honest “Wuuoops” and shut up the idiotic rhetoric that is going NOWHERE!

cale