I again made some measurements to get an impression about the sag in the static situation, with the gantry sitting in 0/0 position.
My measurements show that the tube is very uneven. From left to right it differs max. 0.2mm.
And no distinct drop in the middle I would say.
But I am also not very confident in the measurements as I use my wooden base as the reference.
I also rotated the smaller y-axis tube (980mm length) and the measurements while rotating differed up to 0.3mm.
Not sure if the tube is bend completely or if the tube is uneven simply.
Overall I am satisfied with the results.
I would start without mid span support and just get an impression how it behaves.
Something you should not do if you want to be fair to your machine:
Lean yourself onto the tube and say: “Hey, see, it is flexing. This machine is bad.”
(You should also not let anybody else do that)
I thought of moving to solid stainless rods that have a given tolerance (h9) when updating, but the price is 50 to 60€ per meter.
I leave it for later…
Thank you again, this is very informative! I have also noticed that the pipes are quite uneven. A friend of mine who is an engineer in mechanical drawing says that I shouldn’t worry to much about these variances, since it’s not going to be used for high demanding precision mechanics. I guess he is right
Advice taken with gratitude, I could’ve easily tried something similar! (and it wouldn’t be smart, since I have quite a lot of tonnage to help me…)
The update to the trucks is, as far as I understood it, just a mm more material at the place where there is the “dent” for the screw to go through because a lot of printers have problems with it. Somewhere above in this thread there is a picture of a purple truck that printed it wrong. It just looks bad but does not hinder function.
/edit: July 19th, post 2552. Scrolled through it all to find it for you.
The truck update addressed an issue with some stepper motor mounting screws bottoming out in the stepper by making portions of the mounting area thicker.
Hi all. Ryan, I upgraded from the burly to the primo, bought your upgrade kit. I’m using 25.4 stainless for all the rails. My Z rails don’t make contact with the lower 2 bearings. There’s also a slight rocking movement where there shouldn’t be. I’ve also had some looseness in one of the gantry rails, but that could be from a flat spot in my SS tubing, as it got a little better when I switched it out with another rail. Could all this be caused by the misaligned bolt holes? Do you think I should reprint the core? Should I also reprint the updated core z clamps and core clamps. I don’t mind doing the reprints if it will solve the problem. Thanks again for everything.
This is really hard to articulate, without dismissing people’s concerns. But it is so true. You do not need to stay perfectly rigid with an 80kg human pushing it around. It just need to keep a 3mm bit from wandering. From a “support” perspective, people occasionally come in and say their machine is too floppy, or they push things around and see something flex, then want to make that part more rigid. You can’t just say, “It’s fine, stop poking it” because sometimes there is something wrong, and we have made improvements over the years from suggestions like that.
Not gonna start a new thread for this cause its a pretty quick question. Will the 23.5 mm core fit on the 23.5 mm burly? I designed a bunch of parts that for a project I’m working on and they all fit on the burly, but none of them go on the core, and I kind of want the primo core.
No, the gantry rails are going to be off a bit. The only interchangeable part is the Z-Axis/tool mount assembly. The rail spacing on that is unchanged. But the bolts are different, so you have to match the tool mounts to the nut traps.
Alrighty. Probably won’t then. Kind of a bummer, I think all the bolts in the burly core are points of failure and I think you recognized that in the Primo core and the Primo core looks pretty cool too.
But close.