MDC/Roundhouse/Athearn 2-8-0 and 2-6-0 pulling power

[ATSF_Ron]

Has anyone who owns these locos noticed a difference in pulling power between the Athearn production and MDC/Roundhouse production?  I have several of each wheel arrangement, and without fail, ALL of the Athearn units pull less than the MDC/Roundhouse units.  In particular the 2-6-0s.  I have two that pull only two overland cars up a 4% grade.  Three cars if they are freight.  Yeah, I know 4% isn't ideal, but it is what it is given the space I'm dealing with.  I suspect, but haven't had time to test, that the drivers on the weaker pullers aren't all making 100% contact with the rails.  Two of my SP locos seem a bit "stiff," particularly going through turnouts.  Even on level track with no load, they will sometimes get stuck taking the alternate route and just spin their drivers in place for a couple seconds, then move on through the turnout.  This doesn't happen all the time, but I'd say close to half the time.  Yes, wheels have been checked and are in gauge.  I plan to do a full tear down on the loco section of each one and see what's going on, but I doubt I'll have time until after Christmas.  The 2-8-0s have a similar pulling power issue but not the stiffness going through turnouts like the 2-6-0s. 

I'm curious if anyone else has had the pulling power issue or stiff running through turnouts on the Athearn units.  Thanks guys!

ATSF Ron

[brokemoto]

I have both and now will have to try them both.  I have a 2,2% grade going into Short Creek Junction on the Short Creek &
 Nopedale.  The SC&N still uses steam on the passenger trains.  One of the locomotives is an MDC 2-6-0 that I altered slightly to reflect an old engine rebuilt repeatedly over the years.  The other is an MDC 2-8-0 that hangs around because it is so old and no one seems to want to white line it.  It makes an occasional appearance as the Short Creek terminal switcher.  It has to push or pull no more than three or four cars on level track to do that job.

The funny thing is that despite its two traction tires, the consolidated does not pull as well as the mogul.  If the mogul does pull a freight, which it does, on occasion, it actually can get eight 1950s freight cars plus a caboose up that 2,2% grade.  The consolidated can pull only four and the caboose.  SC&N freights usually are six cars and the caboose.  The mogul will pull three Atlas or B-mann shorty passenger cars and an express box car up that grade.  The consolidated will pull two minus the express car.  The mogul can work as the Short Creek Junction switcher, which requires it to shove cuts of six or so cars up that hill, or pull them up it.  That job also requires serving as a helper, when necessary.  That is probably the most demanding job on the pike.  Not many locomotives can do it well, but the MDC mogul can.

I always wondered, as does Original Poster, if the wheels on the 2-8-0 are making contact.

I do not run my Athearn power on the SC&N, but now I will have to try it on the 2,2% and see.

That grade appeared as an error.  It was supposed to be level but I made a boo-boo somewhere and it came out at 2,2%  So I left it and explained that it was the only right of way available.

It might take me a few days, but I will try a few and let people know.

[Mike C]

  Does the 2-8-0 Have bearing boxes Like Kato or  Bachmann  locos? I bet that if you put a small sliver of Scotch Tape on top of the bearing block  on the TT driver you may get a bit better performance out of it .       Mike

[ATSF_Ron]

Thanks for the replies guys. I may have an hour or so Monday to explore the locos in question and pull the drives from the locos. It’s been a while since I’ve opened one up, but I do believe these have what appear to be brass bearing blocks. The tape idea sounds like a good place to start. Years ago I recall reading something similar to help the weak pulling power of the Bachmann light mountain. I’ll report back what I find. To keep things consistent in checking pulling power, I’ll use my Overton cars for passenger equipment and micro trains 40 ft cars for freight.

[ATSF_Ron]

 
This is the loco in question: SP 2-6-0 in Sacramento green.  Don't know if the paint is prototypical for a mogul and I don't care.  I have two of these and they look great!  First thing I noticed was the gears looked quite dry, so they got some lube.



Second thing I noticed (which may be hard to see in the close-up pic) is the upper rear driver (engineer's side) traction tire does not sit completely down into the slot for the tire like the firemen's side does.  That could be one of the issues affecting pulling power.  I'm thinking I'll just replace both tires with aftermarket traction tires.

Third thing I noticed is:  Engineer's side driver is not perpendicular with its axle.  While I had the bottom plate off for lube, I put power leads to the wheels and ran the loco at very slow speeds upside down.  I could definitely see a wobble from side to side of said driver.  I checked the wheel gauge and found that all wheels are fine except for the rear driver.  When rods are down and counterweights are up, as in the final photo, the gauge is fine.  When rotated 180 degrees, it's narrow.  I suspect in addition to (or maybe instead of?) the driver not being perpendicular to the axle, I may have a rear driver that is warped!

Me thinks the first step might be to try and correct the gauge/warpage issue with the rear driver.  Problem is, Athearn won't service these out of production locos anymore.  Can't get parts either, unless I can find a basket case with good wheels.  I also don't have a NWSL wheel puller, so getting that rear driver off and corrected could be a bear.  Any advice out there from those of you who may have wheel pulling/regauging experience?

Thanks,

ATSF_Ron

[ATSF_Ron]

For whatever reason, two pics are missing, but it's not a big deal.  The two most important ones did.  One other thing...I do not notice any side to side or up and down wobbling or humping motions as the loco goes down the track.  I find that odd, since I can literally feel the difference in traction tires by running a fingernail over them.

[peteski]

Ron,
Thos gears are molded from a slipper plastic. They really do nto require any lubrication (but I guess it won't hurt either).

I found your 3rd photo, but there is not fourth one. Maybe it did not get uploaded. 


Looks like you've been uploading photos to the "general"section of the gallery - it is harder to find specific photos there. Would be easier to keep your photos organized if you uploaded them to your gallery which you must have created in the past. https://www.therailwire.net/forum/index.php?action=gallery;su=user;cat=1565;u=4525

[ATSF_Ron]

Update on the pulling power test:  I have 4 of the 2-6-0s and all of them are far weaker pullers than the 2-8-0s.  I guess I got my info backwards.  Three of the 4 will only pull 2 or 3 MT 40 ft. cars up the 4% before slipping.  The fourth 2-6-0 will pull 4 cars before slipping slightly when adding a 5th.  Three of the 4 moguls are Athearn, one is MDC/Roundhouse.  I'm not seeing a notable difference between the brands.  As a comparison, 3 of my 2-8-0s will pull between 10 and 12 cars up the 4%.  One of them only pulls 4 cars.  I don't know what the deal is with that one.  These 2-8-0s are all MDC/Roundhouse.  I planned on comparing pulling power with the one Athearn 2-8-0 I own, but I couldn't find it earlier and wanted to get the rest of the testing done.  If I can find it tomorrow I'll report back differences I notice, if any.

I believe both types of locos use the exact same drive motor and connecting mechanism.  The 2-6-0s have only one traction tire driver, while the 2-8-0s have the rear 2 drivers with traction tires.  My guess is that extra set of traction tires accounts for the improved pulling power, minus the one 2-8-0 that can only pull 4.

I've ordered replacement traction tires for the one SP 2-6-0 in the pics at the beginning of this thread.  Hopefully it will help with pulling power.  There is also the issue of the one wheel which seems slightly wobbly.  For now I'm leaving that alone until I see what improvement I get with new traction tires.  These little moguls pull 4 overland coaches just fine on the flat.  On the 4%?  Only 2.

[ATSF_Ron]

I was able to locate the Athearn 2-8-0 as well as one more MDC/Roundhouse version.  The Athearn version pulled 11 cars up the 4% before slipping.  The other one?  Only 3.  Since I bought bought all but one of these little gems off eBay, I have no way of knowing which releases these were.  However, I suspect my V&T connie, my best puller, was from a later release.  Spookshow Mark mentions that later releases had a larger pilot coupler pocket, allowing use of MT couplers, as you can see in the pic of my V&T connie.



Since I only own ONE Athearn 2-8-0, it's difficult to say if it's typical for the Athearn releases to pull better than the MDC/Roundhouse releases.  However, from testing the four 2-6-0s I own, it would appear they all pull significantly LESS on grades than the 2-8-0s.

I'm very pleased with the performance of all these little steamers.  They are pretty much the only decent running early era steamers available, and getting harder to find at reasonable prices!  They will glide smoothly through all turnouts I've tried:  Micro Engineering code 55, Atlas 55, Peco 55, and Kato unitrak.  It'll be interesting to see what Bachmann does with their recently announced "old time" 4-6-0.  IF it ever gets released.

[mmagliaro]

My experience with extreme grades like this (and I consider 4% to be almost unusable, especially for a small steam loco like this), is that so many small factors can affect the pulling power, that it will be very difficult to really assess what makes one engine pull better than another.   My advice is to do these tests on level track, because you will have finer measurement resolution.  For example, a small addition of weight, or new traction tires,  might gain you one more car's worth of pulling power on level track (say, you go from 9 cars to 10), and then you would know you are "moving in the right direction".  Whereas if you test the engine before/after that modification on that 4% grade, you might see no difference at all and never know that you are improving the situation.
--
About the two traction tires on the same axle not being exposed equally about the metal surface as much... that is not good.  If you can actually SEE that one sticks out more (and therefore makes better contact with the rail), you need to fix that.  Replacement tires might correct it. But they might not.  The actual grooves may not be cut to the same depth on those two wheels.  An easy fix for this is to remove the tire that doesn't project enough, cut a thin strip of cellophane tape with an xacto and steel straight edge, and line the bottom of the groove with it before putting the tire back on.  You might need a second layer of tape to get the two tires to project evenly off the wheel.
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As for your wobbling wheel, I doubt the wheel is bent.  It is much more likely that the wheel itself was not pressed squarely onto the axle.  That is a very hard thing to fix without a jig of some sort.  A perfectly cut piece of brass pipe with nice square ends can be placed between the wheels, and then you press the wobbly wheel off and back on with some epoxy in the hole, holding it square in the jig aginst the pipe until the epoxy sets.  You are essentially trying to correct for a deformed hole by filling it in.  It's really hard to fix this once the hole has been messed up.   AND THIS IS ONE OF THE REASONS I really discourage people from widening wheel gauge by prying on the wheels with an Xacto blade or a screwdriver.  You can really egg-shape the hole and create a wobble.  It takes a dishearteningly small amount of deformation on that hole, just a few thousandths of an inch, before you'll see it wobbling with your eye.

[ATSF_Ron]

Thanks for the comments, Max. I realize 4% is a bit extreme and not ideal, but it’s what I had to work with and it’s a very small section leading to a visible staging yard.  Point taken about pulling  GM power tests on level track though. That makes more sense.

Hopefully the traction tire issue is simply a bad tire. I’ve had some in the past that were actually different thicknesses. Hopefully, it’s just an old tire and things will be better with a new one. I will definitely try your tape idea though if I need to.

The wobbly driver wheel is a bigger issue for me. I’m really not a fan of pulling driving wheels off axles. I’m going to keep my eye open for a donor mechanism on eBay in case I need to go that route. Thanks again for your help!