Atlas F9 drive in Williams BL2

Hmm...not a bad idea, I suppose.

I have several of these old Roco builts, and they run very nicely. They are simple, well designed and constructed units, and are quite easy to obtain, with replacement gear/axles available from NWSL.

Mark in Oregon

I put All Nations into an MTH BL.  It was trivial.  My impression of the Atlas/Roco is not quite as favorable as the poster above - I would not waste my time.

...ouch!  

I did put a large open framed CLW motor into one of my Atlas units; it added a lot of weight and produced a rather nice " growl"  to boot...

Mark in Oregon

I'm going to try it.  I've had good luck with the Atlas/Roco drive repowered with can motors and flywheels and I have a lot of them. If it doesn't work out I can take it out.

I guess it did come across as a bit contrary.  If you guys have good luck with those Roco transmissions, go for it.  Whatever works.

I wanted opinions, I didn't consider it contrary.  I also have a lot of them so if it doesn't work out I'll try something else.

Thanks!

the biggest issue with the Roco drive is how the truck is mounted. the drive is 'pinned' at the top of the gearbox and becomes the center of rotation, so pulling a heavy load causes the trucks (especially the rear) to 'wheelie' and lift the forward axle, reducing effective pulling traction quite a bit due to unloading that axle.

there is an article done by John Armstrong that addresses this problem by the fabrication of a lower truck bolster that mounts to the frame, virtually eliminating the wheelie.

if you are so inclined, I have included the article.

I watched and ran John Armstrong's modified Atlas F9's pull heavy trains up steep grades on his Canandaigua Southern for over 20 years.  I can testify to their durability and smooth running.  IMO the two biggest shortcomings in the drive were mounts and flanges slightly thicker than NMRA spec.  Depending on the weight of the train and steepness of the grade truck mount wheelies may not be a problem for some operators - especially a BL2 in local freight service.  If wheelies are a problem definitely go for John's "sure footing" fix as detailed in his MR article.  The flange width problem can cause the unit to bump through some turnout frogs.  Our fix for the flange issue (before NWSL offered replacement geared wheel sets)  was to hand file the back of the flanges to NMRA gauge width as the unit ran upside down in a cradle.  Not very elegant - but it worked.

Ed Rappe

Hi   This is my solution to side frame mounts, and pickup problems. the parts are brass and phosphorous bronze.

I decided to go ahead with the conversion.  I had to lengthen the frame and alter the front truck mounting method.  More to follow.

The Roco drives are a little lighter weight than the old CLW or AN drives.  But with newer cars, run fine.    The Intermountain GP9 came with the same drive.    They just added some tabs to side of the trucks to make them more stable.  

I have had both and good luck with both.    On most home layout in normal service they should do fine.    On club/display layouts where they are expected to pull very heavy trains for many hours at a time, they will probably wear out faster than the AN or CLW.

Those CLW and AN drives were very well built but very expensive when you can find them.  I have two dozen of the Roco engines I've picked up over the years, so it was a matter of using what I had.  I  do belong to an O scale club but we only run once a month and I don't think it will log that many miles there and when it does it will be double headed with another Roco engine.  I'll post some pictures of the completed drive once I finish lengthening the frame.