Z Axis Top Printed parts  

Re: Z Axis Top Printed parts

this is mine.

Re: Z Axis Top Printed parts

😛 hi joan
i got my kit in november last year and the z-axis top elements look identical:

🙄 but from the *.stl (from the i3 mk2 package), i can see that there is a small "support structure" in betwen the gaps at the first layer:

❓ maybe it's designed this way to avoid warping when you print it with abs.

➡ i would take a sharp knife and cut the infill out of the gap.

Re: Z Axis Top Printed parts

I would recommend this design with 608 bearings :

http://www.thingiverse.com/thing:1850288

Thomas

Re: Z Axis Top Printed parts

I would recommend this design with 608 bearings :
http://www.thingiverse.com/thing:1850288

as of today, there are only urban legends and reasons to NOT recommend that on the original prusa MK2

Re: Z Axis Top Printed parts

Why not ? It can only get better 😉

For example the wobbling of the z-motors.

Thomas

Re: Z Axis Top Printed parts

Why whould Z motors wobble? How?

Re: Z Axis Top Printed parts

Look here :

Thea axis (drive rod) wobbles at the end. There is much space between the axis and the holder (z-axis top).

Thomas

Re: Z Axis Top Printed parts

I have printed a pair of standard brackets and two pairs of bearing brackets,

if I need to replace them before the bearings arrive I will use the plain ones, if not I will try the bearing ones, and if they are successful for me, I will fit bearing brackets when I build the second printer

regards Joan

Re: Z Axis Top Printed parts

Why not ? It can only get better 😉

For example the wobbling of the z-motors.

Thomas

That will make wobbling worse, not better.

What needs to be straight and not move are the smooth rods. They are held firmly in place and keep the X carriage in the same position on the X as it moves up and down, even if the threaded rods are not perfectly straight. That's because they're allowed to flex and move a bit at the top by that extra space around them.

If you hold both the threaded rods and the smooth rods tight, then any defect in them will just cause stress for the steppers and the plastic. Eventually something breaks.

Otherwise what need would there be to have both the threaded rods and the smooth rods?

Re: Z Axis Top Printed parts

My rods are smooth und running well, just wondered why there is so much space between the rods and the "plastics".

Thomas

Re: Z Axis Top Printed parts

The space is to allow restraint without restriction

my right hand top piece broke some time ago. I cable tied the smooth rod, to ensure it kept the alignment required for good printing, but left the leadscrew totally unsupported, and all is well, however if I were to accidentally catch the leadscrew on something, I may bend it, ir damage the motor.

regards Joan