I am currently attempting to build a huge printer (1500mmx1500mmx1500mmish). In order to make this work I need to know what alloy (I am assuming 6061) the aluminum extrusions are made of. I am also trying to find a 1500mm lead screw which is proving quite difficult. Anyone have any suggestions?
The extrusion is 6063-t5. (6063 anodizes better.) McMaster-Carr has a wide selection of screws in 6' lengths and Dumpstercnc has the anti-backlash nuts to fit them. If you're looking for TR8*8 in a 1500mm length there is a source in Canada listed somewhere here on the forum but be advised that it may be subject to whipping when using it in lengths that long. Some users have had problems even using it in 1 meter lengths.
Thank you for the speedy reply! One thing is still proving difficult. Finding a large build platform is quite difficult. May I ask, what is whipping? Would you suggest a belt driven Z-axis?
Whipping is when you spin something attached at the ends along its axis and the center kicks out sideways and swings in a large arc, kind of like a jump rope. No, screws will give you a better layer resolution.
The longer it gets, the less beefy it feels. You'll find it flexes with minimal pressure. So yes, you should go up a size. As to what size, I really can't say as I've never used any of it.
If I sized down my build to 1000mm^3 would I be pushing it to get the 8mm screws working? I plan on using two (NEMA 23) and having it attached to a stepper at the bottom and a bearing at the top. It would make a build platform much easier to get. I have been having trouble finding aluminum in pieces that are large enough for 1500mm^2.
Best suggestion would be to look around the 3d printer section of the forum at some of the larger builds there and ask those builders about their results. Anything I could offer would only be speculation.
I have almost completed my build but have a question or need some input. Super "C"-OX I have lead screws that are 1000mm long on "X" and "Y, for the most part it runs pretty well but I have noticed that the bearings that I get from the parts store are not very accurate. I can move the screw up and down in the center hole meaning the hole ID is not very close the thread OD. when I travel I can hear clicking of the screw moving up and down in the bearing then the drive gets close to it.(not a deal breaker just annoying). I also have some whipping although not to terrible. My question is should I tear it down and reverse my plates so I can put the drive screws in tension instead of compression or just leave it alone and move on. (move the locking nuts to the outside.) I have seen others suggest this but I am not sure I want to do a complete tear down to accomplish this. Your thoughts...anyone? thanks in advance..
That is something I thought of but the whipping is not to hateful, unfortunately that is probably more of a tear down than I want to do right now. Putting the locking nuts on the outside pulls the "X" and the "Y" not pushing which would be better for whipping, but is it worth doing I guess is the question. I may try one axis and see what happens.... Thanks for the feed back..
In order to fight it in my build I was thinking of a similar solution. Having the motors at the top of the printer so it is essentially guiding the build platform down assisted by gravity reducing stress on the lead screws.
