Prusa Bushing Warp

Hey all,

I'm running a stock Prusa Mendel with a custom extruder, and my bushings keep loosening. They remain attached to the x-axis, however they no longer grip the smooth rod tightly.

I'm suspecting that this is due to the temperature of the heated bed (Printing ABS on Kapton so I'm heating the bed to 120 C) but I'm wondering if anyone else has seen similar issues.

My extruder barrel may be too short causing the x axis to get closer to the heated bed than in other setups... but short of switching to linear bearings (for which I've yet to find a good supplier in Canada) I may try using ABS bushings instead of PLA.

Has anyone else seen anything similar?

Many thanks!

Jesse

One of the best upgrades you can make to a Prusa is to replace the bushings with Linear Bearings - search ebay (and thingiverse) for "LM8UU".

You might want to attach a fan to cool down the x carriage if it gets too hot. Close contact with even low to medium heat will soften the PLA over time. I've had a couple extruder bodies warping, due to the small amount of heat crawling up through the hot end mounting bolts.

Also, yes LM8UU are great, I just upgraded my sells mendel y axis, and it runs really smooth! You can get them from china pretty cheap on ebay.

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-Nudel
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Are your bushings hollow (no fill) or solid? Mine are hollow, and my guess is that this allows air to circulate freely, thus, no warping.

I would recommend that you butt up an additional bushing to the outside edge of each one, and bond them with a dab of acetone.