The original Athearn 'BB' engines came with the sintered iron wheels - They collect dirt and the result if poor electrical pick-up(note the 'sparking & arcing?). The n/s wheels from NWSL and Jay Bee are much better. The original wheels provide by Athearn are 42" - Most of the prototype engines at the time had 40" wheels. You can use either type on your 'BB' engines The key item is to check and see if you have trucks with the older metal sideframes(with the bearing) or the newer type that have the bearing in the trucks. There are usually two different styles list ed for most of the Athearn 'BB' engines.
For DCC, the n/s wheels are really a plus. I have converted a number of Athearn engines to DCC for friends. A complete 'hard wire'(get rid of the metal sliders) and n/s wheels are really a must. You need to isolate the lower motor pick-up and use a decoder with at least a 1 amp rating - Those old 'BB' engines can draw some serious juice!
I got rid of the last of my 'BB' engines several years ago. The current Atlas/Kato/P2K engines are just much better runners, and the detailing is light years ahead(those old 'BB' engines were 1970's technology and it shows). Even the new low cost Bachmann 'DCC Onboard' engines will run rings around this old 'BB' engines.
Jim
Modeling BNSF and Milwaukee Road in SW Wisconsin
I still have a number of Athearn Blue Box mechanisms, all of which have received machined wheelsets from Northwest Short Line, JayBee, or newer Athearn parts. The difference in electrical pickup and dirt accumulation is very noticeable, whether in DC or DCC. The prototypes for all the locos I have (from an F7 through an SD40-2) used 40" wheels, despite the Athearn originals being 42".
I also have Atlas, Kato and other newer and "better" diesels, but the old Athearns with replacement wheels, can motors, and other tune up run so well I keep them in service.
Rob Spangler
Two of the simplest things you can do with a BB loco to make it run better are to replace the wheels witht he NWSL ones, and replace the clip between the truck towers and top of the motor with some flexible wire. The improved electrical contact is instantly evident even on good old DC power.
Traction suffers slightly, the rough sintered wheels tend to grip the rail a bit better, but any loss of traction is more than made up for in the improved electrical pickup. Unless you have one of the Superweight F7's that already has an extra large weight added, most BB locos can stand a good bit of extra weight, which will bring the pulling power right back up. The NS wheels will allow it to slip if the train gets too heavy to pull, which will keep the motor from burnign up. Locos should spin their wheels when held back by the couplers, not stall and jam the motor.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
I have replaced the sintered wheels on my BB diesels with the NWSL wheels and have soldered a wire from the truck tower clip to the top of the moter. Both changes make a big improvment in how they run. I recomend that you do it.
George In Midcoast Maine, 'bout halfway up the Rockland branch
In addition to the oft-mentioned replacement of the metal clip atop the motor, also hard-wire from the opposite side of each truck to bypass the contact between the truck bolster and frame. Doing so yields another huge improvement in electrical continuity, and makes an Athearn BB loco no less reliable electrically than Atlas, Kato, etc.
That last applies also to many of the newer RTR locos as well. They may have a wire feeding the power in to the circuit board, but if you look where that goes, it connects to a ring terminal captured by one of the board mounting screws - the pickup is still from the bolster and into the chassis. Soldering a wire from each truck sideframe the metal part, fo course) to that point on the circuit board will improve those newer models as well.
I always use the 40 wheels and add the wire between the rivets. Better conductivity all the way to the motor. Then a strip of wheel weights running the length of the long hood. Also do a clean and lube.
The last piece of the puzzle is a new motor but definitely do the other items first.
I know this is an old thread, but I'm looking for part numbers for 42" NWSL nickel silver wheels or newer Athearn wheels. I can't make sense of the NWSL charts and get nowhere in Athearn parts. Loco is an old BB Ath GP38 with plastic sideframes, the square bearings and iron wheels. Thanks for your help!
Dan
dbhone...I'm looking for part numbers for 42" NWSL nickel silver wheels or newer Athearn wheels. I can't make sense of the NWSL charts and get nowhere in Athearn parts. Loco is an old BB Ath GP38 with plastic sideframes, the square bearings and iron wheels.
The prototype should most likely have 40" wheels, so the replacement would be 37141-4, assuming you want to stay with code 110 width like the originals. Athearn used oversized wheels in their diesels for many years.
If you really want to stay with 42" you could use 27142-4.
Page 3-9 of the NWSL catalog should break all the sizes down. http://nebula.wsimg.com/8e0447237058b48781159b49163fee67?AccessKeyId=08BEE66B97B387F20C0D&disposition=0&alloworigin=1