[Chiuso] Fine tune your MK3 Z axis  

Re: Fine tune your MK3 Z axis

Ooh, I would not do this. I already had a discussion with someone who wanted this but I talked them out of it (I hope).

Why? It sounds reasonable. Do you have a link to the other discussion?

Re: Fine tune your MK3 Z axis

Have any of these issues been confirmed by Prusa? By confirmed I mean, does the Prusa R2 part release look to fix any of these issues?

They did adjust all the areas of concern, but I have not done accurate measurements since I am using the other solution.

Re: Fine tune your MK3 Z axis

Ooh, I would not do this. I already had a discussion with someone who wanted this but I talked them out of it (I hope).

Why? It sounds reasonable. Do you have a link to the other discussion?

It does sound reasonable, but it is likely to cause new problems. This edge is not flat, both on the powder coated frame and the print. The print will have a few problems, first is the Z direction is the most challenging to get straight in FDM printing, Z wobble, etc. Second, you would need to carefully design it so the cooling is uniform across the width, other wise it will shrink non-uniformly (PETG does shrink). The inside corner needs a relief or else it could interfere with the frame to.

In the end, this new edge you are counting on to be a perfectly straight reference (to solve a non-issue IMO) will not be straight. So now your screw holes may not line up. I know, we'll solve that by loosing the screw holes, and we are back where we started. All parts need to be carefully viewed from FDM printing realities and manufacturing tolerances. You might get away with it, but Prusa would be wise to avoid a solution like this on their scale of production.

Re: Fine tune your MK3 Z axis

I see, very reasonable.

Re: Fine tune your MK3 Z axis

Now the components of Fine Tune Y and Z are in place. I'm really pleased with the low skew value.
Unfortunately, I forgot to look at the value before the conversion, but I don't think it was better before.
Perhaps it was the new design of Z axis-left/right as improved skew when Z top now becomes absolutely equal on the right and left sides.

Re: Fine tune your MK3 Z axis

Now the components of Fine Tune Y and Z are in place. I'm really pleased with the low skew value.
Unfortunately, I forgot to look at the value before the conversion, but I don't think it was better before.
Perhaps it was the new design of Z axis-left/right as improved skew when Z top now becomes absolutely equal on the right and left sides.

Hi RHD,

I am still using your original Z axis parts from post #1 of this thread. I notice the top you have in this pic is different, is there a set you'd suggest using at this point? 🙂

Re: Fine tune your MK3 Z axis

When I now checked which component was crucial to the Z-level's highest position, I saw that the screw heads were the part that determined the height and not the plastic part that I thought first.
So when I designed Z axis top, I cheated myself 😀
The new top part just became a cosmetic change 😳 😳

Re: Fine tune your MK3 Z axis

My skew measurement with the new parts that came with my kit = 0.02, so yeah, I'm pretty happy with this as well!

Re: Fine tune your MK3 Z axis

Isn't skew primarily caused by how much you've tensioned the screws holding the aluminium extrusions to the frame?

Re: Fine tune your MK3 Z axis

Isn't skew primarily caused by how much you've tensioned the screws holding the aluminium extrusions to the frame?

Yes, it's true, but even misplaced Y-axis front and back holder affect skew. For example, if the traces of the Y-axes are not cleared from filament residues, the Z-axes can be placed at different heights.
Before I tightened the screws to the Y-axis holders, I placed a weight of about 10 kg on the bed to push down the holders to the same height.

Re: Fine tune your MK3 Z axis

I was wondering if it is still worth it to print this Z upgrades, or is this problem fixed with the new Prusa Z mounting parts ?