How many bushings are in the linear bearings?


I’ve taken over a M300 dual after somebody else in the company and noticed there are single plain bearing bushings in each of the 4 slides on the axes even though the X (?) axis ones can fit exactly 2 of them each (6 total - 2 for Y axes, 4 for X axes).

Is that right or someone misplaced 2 of them?

I can’t find the proper length bushings anywhere on the market, they cap at L=25mm. They should be added to the Zortrax store…

Can’t edit the OP.

Apparently one bushing is placed there by design - The other printer has the same setup.
A bit different issue appeared in the meantime - I assembled the whole thing (we were experiencing axis issues once again), used silicone-PTFE grease for axes. I run the axis test and it completed with stellar results. I run a small test print - completed great. Then I run a bigger print (11h).

The latter print failed after about 8-10h. The extruder got stuck. Turns out two bushings (on on X, one on Y axes) nearly welded to the guide rails…One set is unusable.

Now, Zortrax doesn’t offer either of those. Those bushings are not typical (longer than available) so I’m going to order and use shorter ones combined.

Aside from the irritating fact that there are no replacements available - the grease supplied with the printer has literally no specification attached and there’s only some vague info that it’s PTFE. The tube has like 3g only…I used a similar if not exactly the same one (same consistency, devoted to printer guide rails and bearings), tests were successful, axis alignments was fine.

Can we get the exact grease alternative description and rails/bushings added to the shop?