Y linear rails offset or profile twisted
Hello. I have had my V-Core 3.1 Drucker for 3 years. The two linear rails for the Y axis have never run really smoothly since they were first installed. Now I reassembled the printer for the third time new and here's what I saw. If I only attach the 2020 profile to the right joiner plate and move back and forth, the profile remains slightly below the left joiner plate, but is always at the same height. But if I mount it to the left joiner plate, the height on the opposite side changes when moving. You can see it quite well in the pictures and the video. There is also a gap between the plate and the profile. I built the frame twice following the RatRig instructions. The third time, I started at the top with lying upside down with the profiles and added and aligned all the others one after the other. The left profile would therefore have to be a little lower, or the right one profile a little higher. But aren't the dimensions specified by the profiles? Am I making a mistake in my thinking?
3 Replies
Have you double-checked the profile's length? Straightness?
Yes, I measured the profiles as best I could. I don't have any professional equipment, just a caliper, some squares and steel measures. Here's what I noticed. The corner plates are not completely flat. When I look at the aluminum profiles with a small angle, in many profiles the groove is curved outwards. I place the profiles on one level and connect them to the corner plates. It's absolutely rectangular. But as soon as I attach a profile at a 90 degree angle perpendicular to it, it is pulled outwards or inwards through the sheets. Maybe even twisted. In order to get an angle at the top of the front to align the X-axis, I have to screw the idler sheets and push the Profiles with my hand so that it becomes an angle. With all the sheets for idlers and engines, I see that if they are attached to one profile and I screw them to the other, she pulls it to the other profile. This means that they never laying plane completely, but are pulled upwards. I also suspect that if I prepare the front, rear and frame for the electronics as in the RatRig instructions, the corner plates will warp the profiles.
Here is a simple Picture example. The prefabricated frame is absolutely rectangular (red angles). If I now screw the long aluminum profiles that carry the linear rails to the respective corner plate, they are pulled outwards (blue angle). This is certainly because the sheet metal from the previously manufactured frame has twisted the profile (yellow). I can't say anything exactly about the angle (green). The angle is at the beginning and end and the same and there is a minimal gap in the middle. If I now attach the linear rails with the 2020 profile upside down, the other end of the 2020 never comes out flush on the opposite side of the other joiner plate. The rails are twisted because the 3030 were forced through the corner plates. The small picture shows the cross section of a 3030. In almost all profiles, at least one, sometimes three, grooves are curved outwards. The cut edges, on the other hand, are all right-angled.
