This past spring I did a massive 3d resin printing job printing off bolsters and side frames to replace the USAT trucks under my modern equipment. The files I got online and included pre designed holes for 3mm x 6mm roller bearings.
At the time I was dumb and sold off all but a few of my USAT friction bearing trucks because I thought this was the forever replacement.
Then about 3 months later I go to grab a car and the wheels fall out. Inspection of the truck shows the bolster had deformed and flexed under the weight of the car.
So stupid me, prints off a few more and tries again. Same thing a while later. So I say screw it, and run a RTV mold of the few original truck bolsters I have left and cast a bunch in casting resin. Replace all the bolsters…
Then a few months go by and I’m in the same boat…
I’m at a loss so I figured why not put a styrene strap across the bottom to flex it back.
I do that and it seems to help but some of the trucks still are flexing inward. I really wasn’t consistent on the length and the hole where the screws goes through so some pieces might be longer/shorter by 1/16 to 1/32"
All of them have minor deflections a month later but a few have issues like before
Ideas for solutions?
Option 1. Have someone print me ~100 bolsters from a FDM printer
Option 2. Try a different casting resin
Option 3. Try a different 3d printing resin.