I am hoping someone can provide some information that will help with a coupler issue I am having. I would like to know if there is a coupler avaiable that I can use to swap out the Bachman Spectrum 1:20.3 Body mounted ones, with one that has a longer shank to allow running on tighter radius curves. Most of the curves on my layout in progress are 4 to 5 foot radius and do not present an issue with me running my 1:20.3 , 2-8-0 consolidations and rolling stock, but I have one return loop that has a 3.5 foot radius across a 10 foot long curved trestle 28 inches high. The locomotive will negoiate this curve, but with body mounted couplers, the cars can not as the couplers are short in length and bind and cause the cars to tip over. I can not increase the raduis of the curve as it would interfere with the gate leading into the back yard. This radius worked ok for all my 1:22.5 equipment, but ever since I started purchasing 1:20.3 equipment to eventually go F scale completely, it has been an issue. So I am hoping that someone can tell me if there are any couplers with longer shanks that will fit in the Bachman coupler Pockets that will solve this problem.

Thanks;

Dan Stuettgen

Dan,

I convert all my Bachman stock to AMS couplers. as part of the process I cut off the Bachman shank and fit a piece of K&S rectangular tubing onto it. you could do this and just make it longer. both ends get lots of super glue and pins.

Al P.

Or, maybe, you could trim back the sides of the pockets a bit, so the couplers can swing a bit more.

Or, file the inside sides of the coupler pockets to give the couplers more swing.

How much more swing do you need? I have been known to notch the coupler gearbox to allow the wheels to enter the coupler. As long as it isn’t too radical, that would work.

I was thinking if I could fine couplers with longer shanks of about 1/4 to 3/8 inch would all I need. Maybe Ill cut a couple up and see if I can make them a bit longer. I am not opposed to switching them out to another brand as long as they can be uncoupled using the lift bars.

Dan Stuettgen

Dan, if I remember correctly, the Bachmann Spectrum couplers have a 2-piece shank, with the coupler fitted into a notch on the shank with a screw holding it together. I have modifed a few of them for various reasons.

If you’d rather not cut them, then maybe the AML [Accucraft] 1/29th couplers will work. I have a few pairs and they are very similar to the Bachmann box type - and they have a spring that allows the coupler to be pulled out I don’t have a Bachmann handy, but these AML ones are 7/8" between the mounting holes in line with the pivot, and 7/8" from the back of the actual coupler body to the pivot center. They extend an extra 3/16" in you pull on them.

Pete Thornton said:

Dan, if I remember correctly, the Bachmann Spectrum couplers have a 2-piece shank, with the coupler fitted into a notch on the shank with a screw holding it together. I have modifed a few of them for various reasons.

If you’d rather not cut them, then maybe the AML [Accucraft] 1/29th couplers will work. I have a few pairs and they are very similar to the Bachmann box type - and they have a spring that allows the coupler to be pulled out I don’t have a Bachmann handy, but these AML ones are 7/8" between the mounting holes in line with the pivot, and 7/8" from the back of the actual coupler body to the pivot center. They extend an extra 3/16" in you pull on them.

Isn’t that what Al just said …probably a typo on Al’s behalf

Those are what I have and what I need to do is extend the chank of the coupler so it is longer and that cars are farthur apart so they will take a tighter curve. the truck are not the issue as they have plenty of swing. Being that these are 1:20.3 and supposed to be true to scale they are designed to look like the prototype with cars having closer spacing, but if I had 1/2 more spacing between the cars, I think they would take the one tight curve I have.

Dan

It might be easier to upgrade that tight curve… Is that possible…?

You are running a 2-8-0 through a 3.5 foot radius curve?

Even if it makes it, it cannot be good for wear on the mechanism nor reliability when running trains.

I see you say it is on top of a curved trestle, so you probably cannot correct this nasty curve easily.

Greg

42" radius is a nasty curve? 8 Foot diameter, or 48" radius, is considered a wide curve and will pass most anything. Yes it’s tight, but no where near as tight as R1; 24" radius or 4 Foot diameter. Now if he said 3.5 foot diameter, then that is really tight (http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-surprised.gif)

That’s probably why a simple coupler adaptation/modification, should solve the issue. Because its just a bit tight, but it isn’t very tight, nor extremely tight, nor pizza layout tight.

No I cant widen the curve as it would extend into the gate opening into the side yard and block part of the walkway. If the HOA would have aloowed me to move the fence 3 feet furthur to the from to the house I would have been able to do a 4 ft or 4.5 ft radius curve, but it took over a year to get them to let me move the fence to where I have it now. If it becomes a big problem I guess I could install a turntable and just do and out and back and then turn the engines or use the 2-6-0’s and 4-4-0’s for continous running.

Dan

I convert all my 1:20.3 stock to Kadee type E. With Bachmann 1:20 cars it is a drop in replacement.

To ensure my Accucraft passenger cars can be packed up smoothly over 10 ft radius turnouts I cut the sides back on the coupler pocket which provides a wider play of the coupler

The same technique should work on freight cars to get them around tight curves.

Stan

Dan Stuettgen said:

Those are what I have and what I need to do is extend the chank of the coupler so it is longer and that cars are farthur apart so they will take a tighter curve. the truck are not the issue as they have plenty of swing. Being that these are 1:20.3 and supposed to be true to scale they are designed to look like the prototype with cars having closer spacing, but if I had 1/2 more spacing between the cars, I think they would take the one tight curve I have.

Dan

Dan,

Those are NOT what you have - it’s a photo of the AML 1/29th couplers. I don’t have a Bachmann coupler handy to measure, so I gave you the dimensions so that you could see if they are the same size. If they are, note that the AML coupler is sprung and will extend another 3/16" from the mount. That may be enough to handle your problem.