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gregsaun / prusa_i3_bear_upgrade

Stronger frame for Prusa i3 MK2(s), MK2.5 and MK3
GNU General Public License v3.0
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Y Motor Mount Lower Extrusion screw too short #100

Closed ctilley83 closed 4 years ago

ctilley83 commented 4 years ago

The new revised Y motor (2.1) mount no longer utilizes the same length screw for the bottom screw hole. For those with version 2.0 frames, this conversion requires a screw that is 4mm longer than the v2.0 version. This could be remedied by deepening the pocket for the lower horizontally facing extrusion mounting hole so the existing screw will properly engage the t nut. Would make it easier for people upgrading parts to utilize the same hardware.

gregsaun commented 4 years ago

I tried to do that but it isn't possible. The minimum acceptable would be M5x15mm screw to not hit the M3 screw. However, 15mm screws is not a standard length (even if sold by Openbuilds) and to give us the choice to use better screws and user to source easily the parts we went to M5x16mm screw.

If you make it shorter you will have a hole in the M3 screw path which can affect the tightening of the stepper (lots of vibrations at this location).

You can see all this in the drawing bellow. The 11mm length in bottom is the M5x16mm length (5mm goes inside the t-nut). The 5mm on the left is half of the space needed for the M5 screw head. bear_y_motor_mount_01

ctilley83 commented 4 years ago

Gotcha. I see now.