I want to add a shelf to a small desk and I made this support so that I can use a piece of some home depot 1.5" x 2' ABS SCH 40 CUT PIPE piece. It's what I bought since it wasn't too big in diameter but strong enough for a small shelf to hold a lamp, soldering station and small charger. This was plenty for two supports. So you will need to at least print four of these or however many you need depending on your shelf. Note: I just put the shelf together and it's lose and wobbly, so don't use this just yet. I'm making a few changes and will update once that is done to make sure it's more stable. Okay, I have fixed this and now the pvc fits the way it's supposed to. There is now more support on the height. I also increased the base by 3 mm to give it a bit more surface area. So you should be able to make a nice shelf now. Sorry about that, I had not built the shelf but now I have and it works. The file old file has now been replaced with the updated one.This was printed on a craftbot 3D printer. I used the default settings of .200 mm/s and 220c/60c bed temp. So the higher resolution may give you an even more rounded diameter. I used the medium setting and I think this will work for me since once the rings are screwed down it should not move and my shelf is pretty small too. The good thing is that if you cut your pvc too long, just pull the shelf up, take out the pvc and cut again to whatever height you need the shelf at. Let me know how it turns out in the comments or any constructive feedback is always welcomed. I will add a picture once I get it finished. Just make sure to measure the center of the shelf anywhere yo add these so that they all sit aligned in the center. And also measure the bottom supports too so that you don't have to drill one too many holes. I got lazy and just eye balled it and had to make a few more holes.