HOW SLOW CAN YOU GO? about scale speed!

[lupo]

This morning I tested a small H0 switcher I just serviced, and was amazed by it's speed, or better it's lack of speed. It ran slowwww !

I timed it over a 12 inch piece of track, it took 70 seconds to complete
I tried to calculate the scale speed and came up with 0.9 scale MPH, but I am not shure about that, so stick to how many seconds for 12 inch.
If anyone knows the correct scale speed calculations feel free to educate !
any tips on how to slow down your models are welcome as well!

btw the engine that did this was a Lilliput ( made in austria for Bachmann europe )



twin engine, ran on DC

so for anyone looking for another reason for running trains on a sunday morning:

HOW SLOW CAN YOU GO ? what is your slowest running locomotive ? DC or DCC ?

[Anonymous]

My slowest running locomotive is my P2K SD7. With my MRC Tech 4 220, I can make it crawl. I've actualy clocked it at about .5 inches a minute. It's stand still motion, can't even tell if it's moving or not.

[Anonymous]

my slowest running is actually an athearn PA-1. Stock motor! the slowest i have hoticed it moving was about one minute for about 6 ties.

[Anonymous]

Hard to say. Probably my best slow runner is the first loco I bought, an Athearn SD9. I can run this slowly enough to count the splines on the driveshafts, and it doesn't stall. Next best would probably be my Athearn SD40-2 and SD40T-2 - these have the new one-piece driveshafts and are a close second to the SD9. After those would probably be my Bachmann GP50 - no flywheels, but it will creep very slowly and without stalling. These locos now have decent can motors in them, which seems to make all the difference.

[Anonymous]

I've got a p2k SD9 with an uhlenbrock decoder. It takes about 3 or 4 seconds to turn the flywheels around without stalling. While running it's hardly visible to see the engine moving but after a minute it moved about 5 ties.

[Anonymous]

That's all Diesel. What about Steam??
Ray, any thoughts from the Illinois side of the Mississippi?

[Anonymous]

My slowest is a P2K 2-8-8-2 with a Lenz 1035 switching decoder equipped with BEMF. It can move so slow you have to look twice to make sure it is moving.

Guy

[Don Gibson]

Most DC Power Pack's have a 'nudge' circuit or half wave rectification at the low end to make engines creep. n_n_n-n_n_n as opposed to pure DC --------------------- .

MRC has a name for it. Bachmann 's Spectrum' throttles have it. .Filtered DC isn't needed for most layout requirements, and if it makes 'balky' engines with higher friction 'run slower, who's unhappy?.

A 'Scope' across the track will show it . I have Analog sound in the track, so need pure DC - but I'm a nut. As a result, my meters show stock Athearn engines require 5 volts to keep moving.

[BRAKIE]

All of my locomotives will creep from tie to tie..You see I tweak my drives so they will do exactly that..Now I do have 2 standout performers.One is a well worn in Athearn GP7 that is 29 years old and the other is a 8 year old SW1500.These two units will cover my 6' test track in 10 mintues..I use a MRC Tech II 1400 on my DC test track.

[Don Gibson]

QUOTE: Originally posted by BRAKIE

All of my locomotives will creep from tie to tie..You see I tweak my drives ....I use a MRC Tech II 1400 on my DC test track.

WHAT do you do to 'tweak' your ATLAS drives?

QUOTE: "Most DC Power Pack's have a 'nudge' circuit or half wave rectification at the low end

That includes your Tech II 1400. What did they call it ? "Linear tracking"?

[lupo]

So I understand that the powerpack used to achieve these slow speeds is also an issue, and not all DC is the same, gonna try another powerpack and see if the trains can run slower ( maybe dig up my scope an SEE the difference )

[markpierce]

Real trains don't go so so slow!

[lupo]

QUOTE: Originally posted by markpierce

Real trains don't go so so slow!

how slow does real trains go ?
what do you think should be an accurate slowest speed in real MPH ?

[BRAKIE]

Don,Very simple..I use the same technique on my Atlas,Atlas/Kato,P2K,Stewart's my 3 Walther's GP15s and yes even my 4 Kato GP35s as I do my Athearns.[:D] I believe that been explain several times..
I don't know anything about this nudge feature you are talking about but,do know my engines will also creep from tie to tie with the CM20s we use at the club and the one I was using before I went DCC in HO.Of course only 6 of my units is DCC/Sound equipped for home use..I doubt if any more will received DCC or sound any time soon if ever,as the DC units are the units I use at the club..I am now using my CM20 on my N scale industrial switching layout.And yes Don,my N scale locomotives gets tweak as well...Its a thing I love to do as I explain before on the Atlas Forum as well as other forums..[:D]

[Don Gibson]

QUOTE: I don't know anything about this nudge feature you are talking about but,do know my engines will also creep from tie to tie with the CM20s we use at the club

Since published MR test reports give very different results for 'minimum speed', it strongly suggest 's your Tech II and CM20's are doing it ("Creeping tie to tie").
"Oiling' , 'Lubrication, (and removing headlamps) just will not do this, Larry.

Ask anyone at the club if they have an Oscilloscope.

[BRAKIE]

Don,A locomotive must be ABLE to run SLOW..All the power packs or DCC decoders in the world will not help a locomotive to run any better if they are not well maintain and lubricated..In plain english a locomotive must be able to operate smoothly to get that slow tie to tie movement..I suspect you already know that.

[markpierce]

QUOTE: Originally posted by lupo

QUOTE: Originally posted by markpierce

Real trains don't go so so slow!

how slow does real trains go ?
what do you think should be an accurate slowest speed in real MPH ?

I've never seen a loco go slower than about a slow walk (2mph or 3kph) except when going to/from a dead stop. Diesels also have a minimum speed when under heavy load or the electric motors burn out. This could be 5, 10, or more mph depending on the locomotive. Of course, the slower the better for our models for smooth starts and stops.

[Jetrock]

My Bachmann 44-tonners and my P2K S-1 can crawl at about 10 MPH at lowest speed settings. Slow-speed operation is most important for switchers, because they DO go slowly--a model that has a low end of 0.9 HO SMPH is nice because, even if prototype engines didn't run that slow, it's nice to know that they COULD and thus will have no problem maintaining 5-10 MPH yard speeds.

And some engines really ARE supposed to be slow--traction engines, which used low gearings and had maximum speeds of 10-20 MPH, for examples, or small trolleys that weren't much faster.

[railman]

yeah, even if they never went that speed, it's nice to know that if you do want yard speed, as Jetrock stated, they can do it, no problem.

[AggroJones]

My P2K GP-7. Can creep at about 2 mph steadily. Even slower than my P2k Y3 2-8-8-2.