What's a good source for a lash-up bar to link Athearn F-7 A and B diesel power units, replacing hook-horn couplers? Are there different length bars as might be appropriate to provide clearance for different minimum radius curves? Thx.
Thanks. Recommended KD model number and shank length?
Frank A. Rosenbaum wrote:
Probably the KD#5 or 58. But, you will have to be careful of the orientation of the B unit. If you reverse it there will be a short from the A to the B. There is a KD with a plastic shank for just this problem, but I am not familiar with it. OR, you can flatten the coupler pad and use the KD plastic box that comes with the couplers.
The #5 is a large knuckle and the 58 is more to scale and looks much better than the 5.
RWM wrote:
According to the Kadee conversion chart in my 2004 Walthers book the A unit wants a #36 in the pilot and a #38 in the rear. The B unit takes a #38 in both ends. Athearn is a hot chassis locomotive so you want insulated non-conductive couplers. Secure the plastic Kadee coupler boxes with the supplied nylon screws and you will be OK. You will need to drill and tap the Athearn frame 2-56 to accept the screws. A pin vise is good enough for drilling, and ordinary hardware stores carry
2-56 taps and tap drills of the proper size. The resulting coupler installation will be much more durable than just slipping #5's into the Athearn plastic snap on coupler pockets. If you don't have the Walther's book, the Kadee web site also as the conversion chart. Although the #5 does most all freight cars, and can be warped into anything, you can save a lot of filing or shimming on locomotives by using the recommended coupler.
Outstanding. Thanks, David.
- Bob
I used Athearn chassis's for some Highliner kits so the couplers I used will work for you
Have a look at
Nigel
Western Pacific Model Railways
Nicely illustrated and quite a few desirable mods. Thanks, Nigel.
- Bob
"I guess the potential for shorting is resolved by use of delrin couplers, such as McHenry or Intermountain?"
Yeah but the chance of breaking the coupler increases. Never ever use plastic couplers on locomotives.
Use a kaydee. You can mount it within the it's own box by drilling and tapping a hole in the frame mounting pad and then screwing the kaydee box and coupler to that.
Eric
If you isolate the trucks and the motor from the chassis the potential for shorting doesn't exist any more. You can do this with Athearn or Hobbytown units. Atlas and Life-Like units are already done that way.
The other way to do it is to use plastic mounting boxes with plastic screws holding them on. Then the metal couplers are isolated from the loco frame.
A hobby shop that sells plastic screws is as close as
For the case of the Athearn F7, the Kadee recommended #38 and #36 couplers come with plastic coupler pockets and nylon 2-56 screws to secure them. I had no trouble drilling and tapping my Athearn frames and the resulting coupler installation is both rugged and electrically insulated. In principle you can rewire a hot chassis locomotive as suggested above. I have never done that, it just seems easier to use insulated couplers. Although I prefer the metal Kadee couplers, there is nothing wrong with plastic couplers (Kadee or clone) from a strength standpoint. I have never seen an HO coupler break under load. The coupler box pulls out of the car first. Or the plastic knuckle spring fails, or the coupler is at the wrong height and slips out of the mating coupler. Or the coupler jams hard over and fails to mate. Or the snap-on coupler box lid pops off dropping the coupler on the track. Currently, the Kadee is as good as it gets and doesn't cost any more than the competing McHenry and Intermountain couplers, so why not buy the best when buying conversion kits? Rolling stock comes thru with McHenry or Intermountain. I run them with the factory couplers until/unless I have coupler trouble, at which point I replace them with Kadee's.
David Starr
It is. When you can do it. Isolating the chassis from the electrical system is more difficult, but ir relieves 100% of the problems associated with "hot chassis" locomotives. It is not always possible to use a coupler box. But, as always, it depends on your interest, ability and modeling skill. For all the praise they get ( not underserved) modelers who are old enough to remember will have to admit that Athearn was just half a step ahead of the toy train category for most of Irv's life. Hot chassis was easy, cheap and nobody cared back then.
CH>
It is always possible to use an isolated coupler box! Even if nothing else, the removal of the hot coupler mounting and the adding of a plastic shelf to the the shell of the loco and application of a coupler box is possible as this is what I've done with all of my diesels. My steam locos all have isolated couplers by using the plastic box on both ends. For the diesels, I actually cut off the whole end of the chassis and provide a good strong mounting on the end of the body. I've had no troubles with coupler height moving about on the locos because the bodies are solidly mounted to the chassis.
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