The two Bachmann DDA40X's that I put axle gears in on the preceding page also had missing and broken frame isolators. There are four of these used in these locos. I designed some with Fusion 360 and printed them with an AnyCubic Photo M3 resin printer using Siraya Tech 'Build' Sonic Grey resin. They seem to work well but you have to modify how they are screwed to the frame. The stock ones use self-tapping screws. There isn't much material in these between the inner bore and the outer circumference. If I made those dimensions the same as the stock ones the screw would crack the resin print. I tried to make the inner bore larger but that didn't really help the situation. The solution and it works as well as the stock method is to drill and tap the inner bore for a 2-56 screw. With this method the screw is not trying to expand the inner bore resulting in cracking and the screw holds just as good. It takes a little bit longer to do this but there are only four that need to be done or less if you still have some good stock ones. I decided to not use any of the stock ones myself and converted to these so they would all be identical. First step is to use a #50 bit and drill to about the center from one side. Turn the piece around and drill all the way through from the other side. Take a 2-56 tap (same as used for some coupler installs) in one hand and hold it still. Twist the pieced in with you other hand, cutting threads. We want to be sure we are cutting them. As the tap gets past the tapered part of the tap it will become tight. Back it up a half turn and go forward 3/4's of a turn repeat this and don't force the tap. I found I had to take the tap back out a couple times and blow the cuttings off of it. When you take it out run a screw in and see if it will screw in to where it is hitting the end of the frame isolator. When it does you are finished with that side. Move to the other end and repeat. On my prints one side of the rectangular area was bulged up a bit. You want these surfaces flat against the frame. I took a small file and filed that side flat. I used the file to touch up a few other small areas of the print also. This is easy to do with the print in the tap as you can use the tap as a handle to hold onto the print. Above are the items you need. I use the 2-56 screws, bit and tap in decoder installs. I'll use the screws to hold solder lugs to the frame halves at times when I need to pickup track current from the frame half to go to the decoder. You can run the screws in tight and the frame halves are held every bit as tight as with the stock isolators and screws. . Hope these help someone as I don't think you can buy them any longer. You can find the print file on my thingiverse.com account ( HERE ). You can bookmark the link to my website for this info ( HERE ). Sumner
