MTH Scale Wheels

The scale wheel version means it comes with scale wheels. They have smaller flanges and are insulated for running on two rail track or three rail. No couplers are included. There's the mounts ready to accept KD's couplers.

 Throwing the switch for two rail, moves the power to the wheels instead of picking up from the center rail and tying the outside wheels together. Either way the electronics package still can run on AC or DC. It automatically adjusts for either.

 There are no electro couplers on scale models to unplug. If you're talking about changing a three rail model over to two rail, then yes, you can unplug the electro couplers if you choose and install KD's.

The scale wheeled models (-2 suffix) run just fine on 2-rail track with the switch set to 2-rail and the pickup rollers removed. I have a bunch of them and have run them on both 3-rail and 2-rail track. They'll also run on AC or DC voltage (AC allows operation of the horn/bell in conventional mode; DC does not). The Proto-3 engines will run on DCC as well as DCS for command operation (another switch).

 

Note that scale wheels don't always run properly on all types of 3-rail track.  I had the MTH Premier Mikado with scale wheels, and it could not reliably run on O72 Fastrack.  At least half the time, the front pilot would climb out on the turn.  It ran flawlessly on Atlas track.  I had a friend bring his identical Mikado over, and it did the same thing.  He still has his, I sold mine.

 

Tubular track  and Lionel Fast track appear the same to a scale wheel tread and flange.

Actually, FasTrack has a square enough rail head that scale wheels work fine, but the turnouts will be problematic because the curve extends through the frog. You do have curve restrictions, though -- O-72 or larger.

My MTH Mikado with the scale wheels didn't go through O72 Fastrack curves, it would derail at least half the time.  You're right, it ran fine on straight track, but you usually have curves.

 

I have/had several -2 scale wheel MTH steamers and one set of GP-35's.  All run great on my home 2 rail DCC layout. 

 

All have done okay on our 3 rail tubular K-line Shadow Rail equipped modular club layout equipped with Ross switches and under DCS control. HOWEVER, I run them on the modular layout outside loop which is a combo of 096 and 120 diameter curves.  They run fine on a good day. I would not expect them to run well on, say, 072 tubular track.  BUT I would expect them to run well on 072 T-rail track like Atlas O or MTH Scaletrax.   And ALL 3 rail switches are problematic -- as has been discussed here on the forum many times.

 

BOTTOM LINE FOR ME:   Make a crisp decision on being a 2 rail guy or a 3 rail guy.  Or choose one for home and the other for, say, a modular club.  Don't try to mix them.  Then just do what you have to do to make it happen.  Go for it!  It'll greatly simplify your life.  I would know as I dwelt in the 3 rail/2 rail twilight trying to do 3 Rail Scale for a couple of frustrating years and then switched my home layout from 3 to 2 rail and never looked back. Wish I had done it sooner.

Can't argue with that. I'm in the DMZ between 2-rail and 3-rail. What I've found is that the four-axle diesels run pretty consistently on the club layout. My six-axle diesels are hit-or-miss on some parts of the layout, especially when MU'd. I'm still going forward with the "-2" MTH locomotives as my eventual home layout is going to have broader curves than we have at the club.

 

To update on my Diesel control system,Atlas diesels run on Variable DC,which my Atlas diesel does fine on. MTH,runs on AC so their DCS System will run MTH 2or3rail diesels fine.

 

NOW. What do I do when running 1 or the other or both? Disconnect the DCS when running Atlas&vise versa when running MTH? Not that big of a chore,just kind of inconvenient.

 

My DCS box states 24VDC,12AMP. It also has a picture of 2 Variable terminals on the back of the power unit 7 2 Fixed terminals.(?) I called MTH,but only talked to a gal,their Tech people are only intuesday,Wednesdays & Thursdays. So am at a slight loss here. I know how to run both types of Diesels,so I'm ok for the moment.

 

Al Hummel

The Variable channels on the TIU can only vary AC voltage. What we do at the club is switch them over to fixed mode which disables the internal voltage adjustment in favor of whatever comes through the input side. I know that the TIU's will work with a DC voltage source, so in theory you should be able to put a variable DC source on the input side but it defeats the purpose of being able to adjust the voltage via the remote control.

I think being eleltrically challenged,(lol),it sounds about as easy to uncouple the lead wires from the track & hook them up to a direct Variable DC transformer,until I learn more. Would you say I'm 100 safe that way?

I hooked 20 cars up to my AtlasGP15,but with or without the diesel on the track,all I got was a hum of electricity-no diesel movement. Since I had some 3 rail wheels on this consist,is it possible they were causing a problem,i.e., touching something they shouldn't as they're on 2rail track? I removed them, then the diesel started moving,a bit jerking,but as the track's old & dirty & I only have 3rail joiners 'till I can get 2 rail,I figure that accounts for the sloppy electrical performance of the GP15.(?)

 

Thank you for the previous input plus your help here.

Al Hummel

Al, 3 rail wheels are not insulated electrically. It's like putting a wire from one rail to the other. Your 3 rail wheels were causing a short circuit.

Al, recent (at least the last 10 years) MTH diesels or steam locomotives can run on AC or DC. These are PS2 or PS3 locomotives. I'm not sure if early PS2 locomotives had this ability perhaps someone can chime in. MTH PS1 locomotives run on only AC. To make matters a little more complicated when MTH first offered 2 rail locomotives in the late '90s they ran on DC only. This was the same time MTH was selling 3 rail locomotives with PS1 but they 2 rail versions did not come with the PS1 sound system.

I run all my Atlas and MTH (PS3 only) locomotives under DCC. As with any Command Control system it has its pros and cons but overall I am very happy with it.

Is this model number MTH 22-20426-2 a 2 Rail engine?
I am not sure if Scale Wheels is the same thing as 2 Rail.

I am researching before I start the hobby.

II think it's High Wheels, but I don't like the way the fronts of those look. The pilot is attached to the wheels and the aesthetics of the engines are diminished.

I looked for an FAQ, so now it's time to ask. Thanks guys!

 

Thanks Martin! This is good news.

To avoid confusion, MTH changed the prefix on 2-rail locomotives to "22-" and retained the suffix "-2". They've also gone to cataloging the different road numbers under different numbers to help buyers avoid duplicates (I have an interesting story on that one). On older locomotives, you have to make sure it ends in "-2". When in doubt, do a search on the MTH site for the part number.

Thanks for the info Matt. I didn't know that all the scale wheel versions will have a prefix of 22. That definitely makes things less confusing. I wish MTH would have thought of it earlier.  I just got a call from the LHS and the Hudsons are in from last Octobers catalog. That locomotive did have the 22 prefix. It will be my first ever Hudson with a centipede tender.

here U go.

Thanks Matt!  Yeah, I noticed those 22- #"s and I like the different part numbers for each road number.  Definitely helps since there already so many dashes in their part numbers! 

 

 

 

Are 2 Rail Scale products smaller than 3 Rail?

Nope. Same size.