The Challenger Challenge

[Cajonpassfan]

In my opinion, Athearn's Challenger model is a great looking, good sounding, impressive locomotive. Given the complexity of the two independent driver assemblies and their siderod assemblies, the pilot and engine trucks, and the seven-axle centipede tender, it's an impressive feat of miniature engineering and design.

But, and I mean BUT: the electrical pickup is marginal, especially given the weight (6.7 oz.!) and the number of wheels available for electrical pickup: 34!!! My engine, with its ten axles only picks up power on the three rear drivers, and one of them has traction tires, pretty much negating its use for electrical pickup. The front engine, pilot and trailing truck have no pickup, as far as I can tell. So that's two out of ten axles...

The centipede tender has a fixed, five axle frame with the front four of the five picking up current, and a four wheel truck that's designed to pick up power except it doesn't. I haven't yet figured out why not; there are copper strips that should but don't. The four axles  that do only have a 1.5" wheelbase, too short for reliable pickup.

And, issue number two (if I can overcome the pickup problem): my engine is a wimp as to its pulling power, as delivered. A much smaller and lighter Kato or BLI mikado will outpull it, hands down. I'm having a hard time understanding why a loco of this size and weight should have so much trouble pulling six MT (lightly weighted) Pullmans up a 2% grade. The mikes do it with no sweat....

I'm not here to bitch, just looking for solutions others may have found. The prototype was a powerful locomotive designed to handle heavy freights (and passenger trains unassisted). My Challengers (I own four ) just don't do the job...
Suggestions and advice appreciated.
Otto K.

[mmagliaro]

Are these old release?  2017 release?  Do all 4 of yours have the exact same symptoms? (i.e.  electrically dead front engine trucks, dead front tender truck).

Those sound nothing like the couple of early Challengers I had here once to repair (for some of the motor and internal wiring problems that plagued some of the 1st release).  They definitely are supposed to pick up power on both engine trucks and the front tender truck.  At first, I'd say you have a broken wire or something like that.  But not if all 4 of your engines have the same symptoms.

[NDave]

As pointed out by mmaglario, your challenger SHOULD pickup from the loco's front driving truck (four wheels, since 2 have traction tires) AND the all four wheels of the front tender truck. I found the wiring on my 2017 release to be pretty sloppy... poor solder connections, pinched wires, the wiring connections of the front tender truck shorted out sometimes on curves, and more. As part of a decoder swap, I eventually re-wired the entire tender of my challenger, and it has great pickup.

As for tractive effort... my challenger isn't really a wimp, but does not pull as well as might be expected for it's wheel arrangement. It can pull 20-22 MTL freights/caboose around my small layout, which has 1.8% grades on 17" radius curves, before it starts to slip. Another challenger sent to me directly from Athearn (as a replacement/loaner when mine went back to the factory in China for warranty refurbishment, long story...) would barely pull 8 MTL freights around my layout. I watched it pretty carefully, and it became clear that the traction tires of the second were not actually making contact with the railheads (confirmed with a feeler gauge slipped under the wheels). As I was communicating with Athearn about this problem, mine came back from its trip to China, and I was able to do a direct comparison... and chose to keep my original and return the "loaner."

One of the things I contemplated doing with the anemic pulling challenger, should I need to keep ti, was to try to re[place the traction tires with something thicker, either from Athearn or maybe Love Hobbies. Another remedy I considered was to either scrap the tires and try building up the wheels with Bullfrog Snot, or maybe try a thin layer of Bullfrog Snot applied over or under the existing traction tires. I never did try any of these... so if you do, I'd be curious what (if anything) works.  I wouldn't mind increasing the pulling power of my challenger... Good luck!

[Cajonpassfan]

Are these old release?  2017 release?  Do all 4 of yours have the exact same symptoms? (i.e.  electrically dead front engine trucks, dead front tender truck).

Those sound nothing like the couple of early Challengers I had here once to repair (for some of the motor and internal wiring problems that plagued some of the 1st release).  They definitely are supposed to pick up power on both engine trucks and the front tender truck.  At first, I'd say you have a broken wire or something like that.  But not if all 4 of your engines have the same symptoms.

Hi Max, thanks for your response. Good questions. I have one of the original MRC equipped ones, two of the 2013/2014 releases, and another 2017 (couldn't help myself when the TTG scheme came out; too pretty even though they never ran over Cajon).

I spent a part of the day cleaning the wheels and contact points and only one has the dead front engine pickups, the others pick up okay when cleaned. I'll get in there to see what's going on when I have time, but I think I'm on my way to fixing the pickup issues.

The lack of pulling ability is another story. I can only get about 11 40' cars up the Hill, and maybe five plastic MT heavyweights. One of them threw a traction tire, again, so instead of replacing it, again, I ordered some Bullfrog Snot. (I find the very idea of it somewhat distatesful, but at this point I'll try anything: I need one Challenger to to pull the eleven car Pony Express, the last UP steam powered train in and out of Southern California, up and over Cajon Pass unassisted, just like the prototype. That was the whole point of assigning these engines to the train...

Dave, thanks for your comments also. One would think an engine that size and weight should pull stumps. No such luck. I'll try the snot I mentioned earlier, and also check the TT wheel contact with the rail...interesting observation.

If there is anyone out there who owns one or more of these, I'd be interested in your experience with the pulling ability of these things.

Thanks and kind regards,
Otto K.

[mmagliaro]

Honestly, Bullfrog Snot isn't going to grab as well as a rubber traction tire.  You might be able to build it up thick enough to make better contact and work better than what you had, but not as well as getting the rubber tire wheels to really touch the rail properly.

There are some things you can try.

Cut a super thin strip of masking tape, (the width of the traction tire), with a steel straight edge and an Xacto.
Wrap it into the bottom of the traction tire groove (while the tire is out).  Make sure you trim it so the ends
just meet together, do not overlap or leave a gap in the tape, or you will get a tiny hop or blip in the running.
Then put the traction tire on over it.  This effectively makes that driver just a few thousandths bigger so the
tire will touch the rail better.  Do that on both sides of the driver that isn't making good rail contact (which I would bet is the forward one)  If that doesn't help, try a strip of electrical tape, which is thicker.

Do both engine trucks really swivel freely up and down so that over curves and imperfect track, those TT wheels
really lay down on the rail? Try to run it ultra-slow and shine a bright flashlight at the rail-to-wheel contact to see if there is a gap.

Do both engine trucks really drive?  If it is sitting on its back running in a cradle, slowly, and you gently put some pressure on the forward drivers, do they by any chance stop and let the rear drivers keep turning (or vice versa)?
I fixed an early one that had a joint/ball problem that caused one engine truck to not really be powered, just free-wheel along the track.

[peteski]

As pointed out by mmaglario, your challenger SHOULD pickup from the loco's front driving truck (four wheels, since 2 have traction tires) AND the all four

Ah, thanks for this explanation.  I was confused by the "front truck" nomenclature.  To me front truck (or more properly named "leading truck") is the 4-wheel free-rolling truck at the front of the locomotive, and rear truck (or properly named "trailing truck") is the free rolling truck in the back of the loco.

What you guys are calling "trucks" are the powered parts of the drive train. They have 8 wheels, siderods and cylinders. Those are actually called engines.

I was confused because the "front truck" you were describing, does not pick up power from the truck. Same goes for the "rear truck".  But both engines are supposed to pick up power through all 8 (not 4) wheels (well except the traction tire driver which does have electric wipers, but the traction tire is an insulator). So actually 6 wheels on that engine would pick up power

[Cajonpassfan]

@mmagliaro Max, thank you for the response. Yes the engine assemblies swivel freely, and both sets of drivers exert equal effort. I took your flashlight advice and it seems that all wheels are seated on the rails. When I apply power and grab the tender, the wheels spin freely but the tractive effort is quite obviously weak. When pushed gently along the track, without power, the loco slides along quite easily, with very little apparent friction.

I did notice the TT slot is only .031" wide and the non-grooved part of the tire .022". Looking at where the wheels sit on the rail, it looks like the non-grooved outside surface rides the rail? This would be good news for electrical pickup, not so much for traction, pics attached. I do need to dust the old girl....

With all the Athearn Challengers sold, I'm surprised no one who has one has chimed in about their personal experience with these engines' tractive effort. It would be good to know whether this is common, or whether I got lemons...

Thanks,
Otto

[NDave]

What you guys are calling "trucks" are the powered parts of the drive train. They have 8 wheels, siderods and cylinders. Those are actually called engines.

I was confused because the "front truck" you were describing, does not pick up power from the truck. Same goes for the "rear truck".  But both engines are supposed to pick up power through all 8 (not 4) wheels (well except the traction tire driver which does have electric wipers, but the traction tire is an insulator). So actually 6 wheels on that engine would pick up power

Yes, on the prototype I would refer to them as "engines"... but it just didn't seem right referring to them as "engines" in the model (and what you refer to as forward and rear trucks I refer to as leading and trailing trucks). Since it is a challenger (4-6-6-4), and each "engine" has one pair of drivers with traction tires, there would be 4 wheels picking up power in each engine.

[peteski]

Otto, even with those thin tires located close to the flanges I believe they will be in good contact with the track.  If you have short piece of track, place it against the driver whit the loco upside down (so you can clearly see where the track will touch the wheel treads).  That will likely show you that the traction tires are in optimal location, even if you shift the track from side to side until it hits each flange.  Assuming of course that the wheels and track are in-gauge.

If the traction tires aren't working then I suspect that either the driver sits too high in the frame (not enough  weight on that driver, or the tire  lost some of its elasticity (stickiness).

[peteski]

Yes, on the prototype I would refer to them as "engines"... but it just didn't seem right referring to them as "engines" in the model (and what you refer to as forward and rear trucks I refer to as leading and trailing trucks). Since it is a challenger (4-6-6-4), and each "engine" has one pair of drivers with traction tires, there would be 4 wheels picking up power in each engine.

You are correct of course - for some reason I had a Big Boy (4-8-8-4) on my mind. Sorry.

As for the names, I prefer (and think) it is clearer when using the names used for the 1:1 locomotive. There is nothing wrong with using the proper lingo.

Also, I did use "leading" and "trailing" truck names, but for some reason you edited that out your when you quoted my post.

[mmagliaro]

Okay, Otto.  This is good work so far.  You are narrowing it down.

What you said about the traction tire width made a lightbulb go on.
Have you carefully checked the wheel gauge on those drivers?  The tires are thin, and set close to the flanges.
So if the driver gauge is narrow,  then the tires will tend to ride inside the rails, as you are observing.  I'd set the drivers on the "wide side" of "in gauge" in the NMRA notches to get the flanges a little more up against the insides of the rails, and see how that does.

[NDave]

Also, I did use "leading" and "trailing" truck names, but for some reason you edited that out your when you quoted my post.

I missed that reference in my (too quick) reading... and just grabbed the later paragraph in my quote. My humble apologies.

[peteski]

I missed that reference in my (too quick) reading... and just grabbed the later paragraph in my quote. My humble apologies.

No problem Dave. I too can too often be guilty of this.  I just wanted to set the record straight.

[Lemosteam]

Is it just me or does it look like the wheel opposite the driver with the TT, does not have a TT?  Maybe the image is just blurry.

[peteski]

Is it just me or does it look like the wheel opposite the driver with the TT, does not have a TT?  Maybe the image is just blurry.

I think you are onto something.  If the TT is supposed to be black, the wheel at the top of the photo doesn't seem to show a black TT in the groove. It is just shiny metal.