Trailing Truck Springs

    The first attempt to build trailing truck springs combined the separate spring leaf method with the clamp and post as was done for the locomotive springs.  The difference here is that the trailing truck spring is angled upwards which would not suite the flat build method used for the locomotive springs.  Instead the springs were built on their side but with increased thickness and spacing in an attempt to eliminate the bleed-over from one leaf to the next.  As can be seen in the above photo the spring leaves did bleed into their neighbor occasionally.  Further, the spring clamp and post arrangement did not come out well.

    Another problem with the side build was that the ends of some of the leaves did not print well.

Another view of the bleed over between leaves along with extraneous material running from the top spring at right to the mount post at bottom right.

    Further, some of the short leaves came loose from the raft and support material before completion leading to the tangled mess shown above.

    Above is another view showing the bleed over between adjacent leaves and separation of leaves.

    The spring clamps and post parts were overly fragile and tended to come apart when being removed from the support material.

    The second attempt was to lay the spring leaves down on their bottom which required a angled support structure.  The resulting leaves where rough, distorted and incomplete as shown above.   

    The rough incomplete leaves would fall apart during removal from the support material due to extreme thin spots.

    Although the leaves did not work out, the beefed up spring clamp and post parts are good.

    So back to the drawing board.  The next attempt was to separate the leaves further and make them a bit thicker.  During printing several of the leaves came loose which resulted in a large tangle of ABS material in the middle.  Obviously this would not work,  For this print attempt the short end was on the left side of the printer with the wide leaves toward the middle.   

    Another view of the third attempt showing the leaf separation from the support material, also the breakage of the clamp with very little handling.

    For the fourth attempt the pattern was the same as the third, but rotated so the short leaves were towards machine middle and longer leaves towards the outer edge.  This time the leaves came out good with no appreciable bleed over or extraneous material.  The post and clamp are the same as before and appear equally fragile.  The pattern was not modified to beef those parts up as was done for the second attempt.  
The parts made during the second attempt will be used to assemble the springs and the design pattern changed for any potential future build.

    The above photo was made showing the collection of parts made to iron out the proper method to orient and build the trailing truck spring leaves, clamp and post.  The printed structure at bottom right is the fourth attempt and resulted in usable good parts.

    A second set of fourth attempt parts was then made and is both sets are shown at bottom right.

    The only extra material to be removed consists of some support material and a few small strings of black ABS material between parts when the extruder transitioned between sections.  These will come off easily.

    The first attempt is made in a similar manner as the fourth except two spring sets were made together.  The above photo clearly shows the bleed over between the leaves which were spaced too little.  Also the post structures in the top middle are poorly made being too thin and oriented incorrectly.

    The first attempt parts with back lighting show the significant amount of bleed between parts along with misalignment of extrusion head leading to bridging material.  The left set of springs is aligned for the photo.

    The right set of spring leaves is aligned with the back light in the above photo showing similar interleave bridging of material.

    The first attempt also exhibited poor build of the clamp bottom with posts in the middle and extrusion skips which are caused when the material does not adhere properly.

     The above photo of the ends of the first attempt shows the distortion of the leaves, particularly on the left side set. 
    The selection of part orientation is very critical to printing success.  It has proven repeatedly that several attempts are generally necessary to get the desired results.  With the completion of two sets of usable springs all the parts are now ready to build the back section of the locomotive frame.  However, it will be necessary to also build the trailing truck to check alignment and fit during assembly, so that assembly will be built and assembled next.