DX + Bracing Kit: Flex and Z-Offset-Problem

Since a looong while I have this problem that with the DX after auto calibration my nozzles usually were too high by 0.3-0.4 mm: DX Z-Auto off by 0.3-0.4mm: Reason found, no Solution? My theory was, that due to the considerable pressure the DX needs to trigger the force sensors, and the flex in the bearing/sled construction of the linear modules, the measurement procedure gets off (having the original, 8mm lead Kickstarter linear modules).

Now I’ve got the bracing kit, and my hope was that this would reduce the flex enough to get accurate. Turns out that either my theory is wrong, or the added rigidity is not as good as I was hoping for. In favour of my theory is, that the error in Z is now, with bracing kit (and QSK) installed, more like 0.2 mm, but it is still there. Applying some pressure to the DX module (one finger, but considerable force in that one finger), it visually flexes - see the video below.

I am not sure what I really expected from the bracing kit, but admittedly perhaps a bit more… Am I disappointed? Not really - I’m very positive that it will reduce or even eliminate the problem of the loosening slider and the need to tighten it ever once in a while. Well, we’ll see…

Here’s the video:

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Well, if you install a large, heavy tool module on a bracing kit + quick swap kit starting from the slider and a large, heavy tool module, and there is a deflection in the Z direction that contacts the machining workpiece or heat bed even slightly, the starting point of the moment is further away than normal, so you would have those symptoms I believe this is because the starting point of the moment is further away than normal.

I have written something similar to that in the past on this forum.

Looking at the construction of the bracing kit from the images and videos published when the bracing kit was sold, I did not think it would be effective against rotational torsion as in the video you posted.

Nevertheless, I purchased a set of the bracing kits and they still had no effect on the rotational torsion.

The same thing happens as in your video.

I complain, but I am writing about the results of my purchase and experience.
It is against my policy to complain without purchasing.

If I don’t write that, the antis will be very loud.

Yep, I guess that’s an accurate assessment. Adding to this is that they made the wheels that run along the beam a bit flexible, and I guess that even makes sense, since dust and milling debris may get stuck there, and you want the wheels to have a chance to give way to that at least a bit. So, it is a compromise still.

Regarding the impact, I guess I’ll accept it and not do much about it. Correcting Z on the fly is easy enough. And I guess it still reduces the problem of the loosening of the slider bearings, and if that’s the case, it is already an improvement. For Milling, I suppose dimensional accuracy will still be affected by the limited rigidity, but for me as a hoobyist I guess it’s good enough.

Some people argue that it’s wrong to expect high machining precision from the Snapmaker 2.0, which is essentially a hobbyist tool. However, if Snapmaker has specified certain capabilities for CNC machining, the machine should meet these specifications to be considered up to standard.

In the end, the fact that they had to sell a bracing kit to meet these specifications implies that the machine can’t fulfill its advertised capabilities without it, which is rather disappointing. Whenever I bring this up, critics inevitably emerge. But it’s clear that the cantilever moment specifications for the table mean it can’t maintain accuracy. This is why some users have had to modify their machines (such as adding auxiliary rails to the A350) to solve the issue.

Issues like twisting or rotational play, as shown in your video, are probably not something Snapmaker wants people to focus on.

Ultimately, if someone who isn’t very knowledgeable about machinery buys the Snapmaker 2.0 and handles it roughly, there’s a high likelihood they’ll damage the equipment before they get to enjoy machining or molding. This raises the question of whether Snapmaker profits from selling replacement parts due to such damage.