Changing Couplers

[wb2002]

I have 2 Bachmann F7A's & F7B's locomotives however the couplers are too long. When in a 4 loco consist, it doesn't look right with the distance between locos. Is there a coupler or modification I can use to shorten the distance between the units?

Thanks

wb2002

[Doneldon]

wb-

The unsightly excessive distance between model railroad equipment, including locomotives, is one of the ongoing frustrations of the hobby. For what it's worth, there is a reason: the comparatively tight curves we use require greater distance between cars and locos so they don't hit each other. And we do have tight curves. Even the folks with curves most of us can only dream about, say 48" or 60" radius, have extremely tight curves compared to what the twelve-inches-to-the-foot railroads use. So make sure that you won't have clearance problems if you tighten up your draw bars.

Kadee makes replacement couplers of different lengths. They are high quality and easily installed. However, there may be an even easier and less expensive alternative for you. If you keep your diesels connected most of the time you can make a rigid drawbar from brass or styrene. Just experiment to learn what length you need to maintain clearance, drill two holes and hold your locos together with screws. If you regularly run your locos separately, use the Kadees. By the way, solid drawbars are prototypical; many railroads connect locomotives with drawbars rather than couplers. They are cheaper, require minimal maintenance and are more reliable.

                                                                                                                                                                  -- D

[wb2002]

Thanks for reply. In my case the problem is not the distance needed for adjacent connected units. The problem is the proximity of the trucks. On the original Backmann F7 units I cut off part of the truck that was interfering with the installation of the short  kadee couplers I had installed. I was hoping that I did not have to shave off part of the new trucks I have used to replace the original trucks.

[electrical whiz kid]

Hi; I go with Doneldon's thinking.  Prototype operations usually installed drawbars on units [that] were going to remain together in a designated operations.  The only drawback waas if one is down, two are down-as for maintenence or repairs.  I have two Proto E-6's, a pair of DL-109s as wenn as two New Haven PA-1s coupled and DCC'd for tandem operation.  What is really good is that I don't have to re-fuel them....
Rich C.

[jward]

while many very early diesels were drawbar connected, i don't think many f7s were. by that time railroads had experience with diesels and were strong proponents of the building block theory. that is, rather than have standard sets of motive power, you add or subtrack units depending on how much power you need. semi-permanently coupled units hindered that flexibility. as near as i can tell, most drawbar connected units were ww2 era, or slightly thereafter. that would include the fts...... the f7s came much later, 1949-1953.

that said, while not strictly prototypical, the drawbar may be your best solution.

[RAM]

I may be wrong, but I think that the FTs were the only units that came with the drawbar connecting the A & B units.  The Santa Fe took one look at that and said no way.  we want couplers, so I don't think that the Santa Fe ever had any of the drawbar units.

[jward]

the pennsy's baldwin centipedes were also drawbar connected. those units were also paired in sucha way that they shared certain components. neither unit was a complete stand alone unit, each one of the pair needed some of the other's components to be complete.

[RAM]

Baldwin did thing their own way.  As I recall the mu controls were different from every one else.

[CJCrescent]

I have 2 Bachmann F7A's & F7B's locomotives however the couplers are too long. When in a 4 loco consist, it doesn't look right with the distance between locos. Is there a coupler or modification I can use to shorten the distance between the units?

Thanks

wb2002

I would go to the KD website, and download their conversion list. It gives you what coupler would fit the locomotives. At one time KD made a complete close coupling kit for Bachmann F units, similar to the ones they made for Stewart units. I don't know if there has been a change in the setup of the loco that would make this set obsolete, and no longer sold. It wouldn't hurt to look.

http://www.kadee.com/

[wb2002]

I tried using the recommended coupler KD suggest (#452) however, it contacts and interferes with the trucks. I have both the older model of the F7's and the latest and the problem is the same.

wb2002

[wb2002]

I might add that I have used these couplers before and as the instructions indicated hacking away at the trucks - it was so involved. I hated it then and not looking forward to doing this again. I was hoping by now, either Backmann or KD had made some improvements in this area.

I would also like to know how the couplers are connected to the real F7's - connected to chassis or trucks?

wb2002

[jward]

as with most if not all real railroad equipment, the f7 couplers were attatched to the frame. truck mounted couplers would perform even worse under full scale conditions and immense buff forces common on real trains than they do on models.

the couplers on most cars and locomotives are mounted to the center sill of the underframe, which is specifically designed to handle both tension and compression forces. the f units were designed more like a truss bridge, without the huge center sill found on other equipment. while the mounting was similar to other rolling stock, they were structurally weaker. look carefullly at photos of f units and you can sometimes see wrinkles at the end of the carbody, or on the nose, caused by hard couplings. they would also buckle right behind the cab but ahead of the engine in a collision.