Question about Athearn trucks

I have used Athearn Delrin trucks a lot.    A solution to the leaning on many cars is to put a washer in on the screw that fits inside the truck bolster.    Walthers makes/sells a 2-56 brass washer in little packets of about a dozen.    The ID works great with 2-56 screws, either wood or metal threads.    The OD just fits the inside of the hole on Athearn bolster.

The problem is that the top of hole inside the bolster on the athearn trucks is not level or flat.   It seems to be curved or beveled.   The washer fits snug enough to create a flat surface for the screw head to tighten to.   

The same washers work with Weaver trucks.    I am not familiar with Wiseman.   

If you look at the top of the athearn bolster, it has a ridge which I think is intended to mate with some bolsters.   

I have used this technique on Wood cars.  

A more aggressive approach if  you have one that this does not solve, is to get a spring that fits into the hole in the truck bolster and around the body of the screw.   The spring has to be soft enough to compress when you tighten the screw and still allow the truck to swivel.    Finding such springs is very hard.   I have done it a few times from my parts box.   I know of no commercial ones.

Had a similar problem with some cars I was converting. Since the under-body detail wasn't an issue, I placed 3/8" flat washers across the bolsters which allowed the trucks' crossbars to rest on the washers. Since the trucks (Weaver) were equalized the cars track fine.

Precision Scale makes a truck bolster spring that I use on pretty much all my 2 rail kit cars, as I rescue them and rehab them (from shows). Part #350.

That should solve your problem.

Bolster spring and/or washers will fix many things, but what are you using to mount the trucks to that car bolster?  You might be using too small a screw......or you can use a slightly longer srcew and run a bit of styrene tubing into the truck bolster cavity that the screw would go through to eliminate the rocking.

Thanks for the replies. I sanded off the round ridge on top of the Athearn bolster, and that seems to be all that was needed to solve the problem. 

On this particular car, I'm using a #4x1/2" wood screw. I've been experimenting with different truck mounting hardware for awhile now. It seems like it will work fine.

In general, I mount an Athearn truck to a wood bolster by turning down the head of a #4 wood screw until it is a loose fit fit inside the mounting hole of the bolster. Doing this allows the head of the screw to contact the bottom of the hole in the bolster and stabilize it. Run the screw in just enough to prevent rocking, without binding the truck.

The head can be easily be turned down in diameter chucking the screw in a Dremel or electric drill and then holding a file to the head as it rotates. I also remove the little ridge on the top of the bolster, as you did. I use this same approach with 4-40 machine screws and their metric equivalents. On cars that came with shouldered mounting screws and springs, I remove the springs and use thin washers between the head of the mounting screw and the bottom of the bolster to prevent rocking. I don't like springs because they still allow the car to rock unless they are tightly compressed, in which case they can interfere with the ability of the truck to turn smoothly around the mounting screw. A small drop of Loc Tite will hold the screw at the right position if it is not shouldered and can't be snugged down.

Hi ya-all,  I have had the same problem.  To my good luck I do have a small lathe and I turn hat shaped bushings that fit into the truck bolster.  The center hole will take a #2 wood or metal screw and the main body will just fit in the truck bolster.  The brim diameter will just fit inside the large hole in the truck bolster.  I make the spaces out of brass, aluminum and even plastic.  I like this method of truck mounting because I can adjust the spacer to get a friction free fit with a little filing insuring free truck movement.  I'm planning to use the same method on a brass caboose with Precision Scale brass trucks.  I have done some 25 cars this way.  I hope this helps.  

prrjim posted:

I have used Athearn Delrin trucks a lot.    A solution to the leaning on many cars is to put a washer in on the screw that fits inside the truck bolster.    Walthers makes/sells a 2-56 brass washer in little packets of about a dozen.    The ID works great with 2-56 screws, either wood or metal threads.    The OD just fits the inside of the hole on Athearn bolster.

The problem is that the top of hole inside the bolster on the athearn trucks is not level or flat.   It seems to be curved or beveled.   The washer fits snug enough to create a flat surface for the screw head to tighten to.   

The same washers work with Weaver trucks.    I am not familiar with Wiseman.   

If you look at the top of the athearn bolster, it has a ridge which I think is intended to mate with some bolsters.   

I have used this technique on Wood cars.  

A more aggressive approach if  you have one that this does not solve, is to get a spring that fits into the hole in the truck bolster and around the body of the screw.   The spring has to be soft enough to compress when you tighten the screw and still allow the truck to swivel.    Finding such springs is very hard.   I have done it a few times from my parts box.   I know of no commercial ones.

 

 

I like to use 4-40 screws to hold trucks on freight cars.  Springs are easy to find and they are free!  Most of us have a drawer full of old event hand-out ball point pens that no longer write.  Unscrew them and save the spring.  It can later be cut to desired length using a Dremel, wire nippers or a Zona type saw.  Got the idea from the old Japanese (Max Gray and others) freight cars, which used a spring to hold trucks tighter to the kingpin yet still allow swivel.

prrjim posted: ...snip... Finding such springs is very hard.   I have done it a few times from my parts box.   I know of no commercial ones.

No, actually it is quite easy. Just save the springs from retractable ball-point pens, cut off the end and about two or three (depending on how much tension you want or need) windings. You only need to do one truck, the other should remain a little loose. That allows the car/truck to negotiate rough track and not rock excessively.

General hardware screws.  #2, #4, #6   Second from bottom is an Atlas track screw.   Weaver trucks used a #2 machine screw, though often the screws, 3/4" to 1" in length were too short.  Slightly longer 1 1/4" were too long, would push through the bottom of a coal hopper.   #6 Screws top, #4 screws middle, #2 screws bottom  

I use those little simulated rollers on the bolsters to constrain one truck.  There are usually matching pads on the car bolster.  Real rail cars use them on both trucks.