2-6-6-2 problems and fix

[rartac@cox.net]

Hi all,

I got my second 2-6-6-2 and have now experienced the same problem twice.  In turns, the front engine skips and jumps but is OK on the straight track.  After some investigating, I found the center axle, left driver, front engine had some flash left over from the injection process that was catching the frame/gearbox assy.  I cleaned it up with a hobby blade and WOW what a difference.

Also, 2nd time the tender had no continuity with the loco.  I found the copper wires had been installed incorrectly and after some slight reforming got a good contact and that helped a lot.  A small amount of conductive silver lubricating paste placed on the bearing surfaces of the locomotive improved the conductivity tremendously as well.

A very nice locomotive now.

[brokemoto]

Do you have to remove the cover plate on the front engine to find the problem?  Where on the axle is it?

Thanks.

[rartac@cox.net]

I'm not advocating a bypass to Bachmann's process of repair, but it's easy to do and I like this type of thing. 

Yes, you'll need to remove the bottom plate of the front engine by carefully backing out the 2 Phillips screws and lifting it off.  I suggest making a cradle out of foam or a few soft towels to support the loco.  I electrically rotated the mechanism until the left side center wheel revealed the flashing which is located on the inner surface of the driver.  Look carefully, it can be hard to see against the black plastic gearbox.  Gently slide a sharp hobby blade along the back surface of the wheel and it should slice off clean.  I checked the remaining drivers in the same manner but found no problems.

Hope this helps.

[taz-of-boyds]

Wow, thanks!
Charles

PS, had a similar problem with the drawbar...

[brokemoto]

I am assuming that you mean the round dot that appears on the back of the driver in back of the counterweights.  It appears that this is how they hold the spoke insert on the driver.  There appears to be only one.  Mine did not appear to have the flashing, but I ran the knife over it, and the other drivers, as well.

I have the same problem that you do, the front engine seemed to have a pronounced hitch in the apex of the curve, or close to it.  I am running mine around a seventeen inch radius curve.  As I ran mine in, the hitch became less pronounced, but it was still there.  I tried your suggestion, and it helped a bit, but the hitch is still there. It becomes more pronounced at speeds between fifteen (about the slowest speed that I can get this thing to hold) and twenty-five SMPH.  At speeds over thirty SMPH, the hitch is less pronounced.  The hitch is not enough to make it stop running, but it is there.

These things usually operated at speeds between fifteen and twenty-five MPH.  At speeds greater than thirty MPH, they tended to vibrate excessively.  Some roads did have 2-6-6-2s that they could operate at greater speeds.   CMStP&P even had a 2-6-6-2 that it used on passenger trains in the Dakotas, but the USRA 2-6-6-2 was not meant for speed.

I have noticed the contact problems with the stiff wires in the drawbars of the following SPECTRUM steam locomotives: 
2-8-0, USRA light 4-8-2  and USRA 2-6-6-2.  All that is required is that you bend in the stiff wires on the locomotive end of the drawbar and use an emery board (or sanding stick) on the contact posts on the locomotive.  Do be careful when you bend in the wires lest you cause the contact wires on the tender truck to pop out of their seating.  I usually grip lightly on the drawbar with a pair of average sized needlenose pliers.  This prevents much of the reaction to the bending from traversing the length of the stiff wires.  Once you get proper contact through the drawbar, the 2-8-0 and 4-8-2 are good runners.

I have not experienced similar problems with the USRA heavy 4-8-2.  This might be due to the numerous blue wires between tender and locomotive for the smart decoder, but I can not be sure.

I always liked the 2-8-0.  The light 4-8-2, with a few minor adjustments, has turned out to be pretty good, as well.  I also like the two heavy 4-8-2s that I have.  I have only one
2-6-6-2, and have never been completely happy with it. 

Some of the non-DCC users have complained about the presence of the decoder in the heavy 4-8-2.  I have absolutely no problems with its presence.  Yes, I know, I am paying for something that I am not using, but I am not currently using it.  At some point, I may want to go to DCC, and this means that I will have two fewer decoders to buy and install.  There was a time when I did not want to use knuckle couplers, now I use them.  The smart decoders have not impaired this one's performance on straight DC (or as 'straight'as rectified DC can be).  I tend to avoid using pulse (I use MRC 2400s, with the ON-OFF pulse switch), but when I  have turned it on just to see 'how slow can you go?', the decoder has had no adverse effect there, either.  The locomotive did not even heat up, as does happen on some locomotives when you apply pulse for any length of time.