Strange Geometric Anomaly

[jd52wtf]

I am having quite a strange geometry issue with my newly built Max V2 and I am a little concerned with what it could mean.

As I am no stranger to delta bots I did perform a modified leveling procedure on my new system. Not going into detail but it involves a lot of adjusting and I have performed on a number of other delta printers with no issues. Combination of switch height adjustment, Z height adjustment, and adjusting if the Radius value.

The good news is I was able to level the bed completely using this method as well as account for the "doming" of the movement through the center of the build plate. It is important to mention that this method uses three points on the bed, each directly in front of each tower as well as a central point.

As mentioned above using this method yielded great results for the most part. The hot end glides perfectly along the bed when I move from the X axis point to the Z axis point. Also when moving from the Z Axis point to the Y axis point. Also from the center point to all three outer axis points everything looks great.

The issue comes in when moving across the front from the X axis point to the Y axis point. There is about 1-1.5 mm "doming" at the highest point. This makes no sense whatsoever in that if everything else in in a flat plane then this should be as well.

This concerns me somewhat as I then parked the hot end where the apex of this was and attempted to adjust the X upright and Y upright to account for this. Unfortunately the hardware does not have enough adjust-ability to account for this. I was able to "null" out the doming effect by applying some force and observing, however I believe I was adding some bending to the uprights which I should not have to do and it wasn't possible to hold them in that position with the hardware of the unit.

I will move forward assessing the situation further however I wanted to see if anyone else has seen anything similar.

Thank you!

[Polygonhell]

There is a big thread on this, it can be caused by a number of things.
The towers not being at exactly 60 degree separation, not being equally distant from the center, or just a combination of settings for rod length and delta radius.

[jd52wtf]

Thank you for the feedback. I did a fair amount of searching and was not able to locate the thread of which you speak.

Could you point me in the right direction?

Thank you.

[Polygonhell]

It's here http://forum.seemecnc.com/viewtopic.php ... lit=Saddle
The short version is almost any geometry error results in this effect, and it can also be caused by correcting for delta radius with diagonal rod or vice versa.
The current in vogue fix, assuming you can't get the geometry perfect is using one of the auto calibration scripts, which will adjust the tower offsets to reduce the error.
Depending on which delta bots you've used before, you may never have seen the issue, because it becomes more prevalent as the printer radius increases.