Precision Linear Shaft and Bearing Questions about 3030_haribo_edition HOT 6 CLOSED

@doubleoerik - Interesting note on the LMU8 and the shaft diameter. I ordered the LMU8 bearings, but assumed similar 8mm tolerances to the default LM8UU bearings from Prusa that shipped with the MK2.

The primary developer of the Haribo 3030 ( @jtktam ) suggested that I try the double-length Misumi bearings in Z - I don't recall if he was also OK with using them in the X carriage. But - as you point out, I wonder if there will be a tolerance issue.

You may get more discussion going in the Slack group. If you aren't already a member, I can send you an invitation.

John

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Sure thing, @doubleoerik - I need your email address -- I don't see it in your GitHub profile.

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Quick follow-up on this - I went ahead and replaced the back-to-back bearings on my z-carriage with double length Misumi LMUW8 bearings. I had to design new z-carriage brackets as I wanted a precision fit for the 45mm long Misumi bearings and I also wanted to incorporate anti-backlash spring loaded nuts into the bracket. It then made sense to redesign the rest of the z-axis brackets (top and bottom) so everything played together nicely but that's for another thread. I've been printing with this setup for months and couldn't be happier with it so anyone out there hesitant to do this upgrade - it's perfextly fine.

I also replaced the back-to-backs on the extruder with a single double bearing. I had to design a adapter to keep the bearing centered in the OEM x-carriage body but otherwise this is working great as well. Next on my list is to mess with the bed as it's not proportionally as rigid/sturdy as the rest of he machine has become. The first thing I may try to do is to replace the single left side bearing with a double length bearing. I suspect Joseph designed it this way so it isn't over-constrained but I'm hopeful I can get it lined up well and bank on the compliance of the system to absorb any overconstraint. The goal is to eliminate the rocking that can occur on the side of the bed with the single bearing.

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Great info, @doubleoerik - you might also want to post this in the Haribo3030 channel on Mattermost. (the community moved from Slack a few months ago. https://3dprinting.community/login

Your account name is the same as you had on Slack, but you'll need to request a password re-set which will be emailed to you.

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