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If you find that the carriage lifts or dips close to one tower and does the opposite next to one of its neighbors, it's probably the rotation on the remaining tower. Look for Alpha A, B, and C in the EEPROM. You will see the values 210, 330, and 90. Reducing a number rotates the tower clockwise and increasing it rotates the tower counter-clockwise. You should only need to change the rotation by 1/2 to one degree. This is where you have to think of terms of pushing and pulling. On my printer, it was lifting near the X tower and dipping near Z. Y was OK, so I assumed it was the culprit. Changing Y's rotation from 330 to 331 fixed the problem, because that gave Repetier a better idea of where it was starting from. It then knew to move the Y tower a little faster when going towards X, and a little slower going towards Z.

• For each iteration, I printed out this Onyx bed leveling aid to see where the lines were too fat or too thin: http://www.thingiverse.com/thing:50505
• The object was printed without adhesive each time. I wanted the bed totally clean.
• You will notice some tower re-leveling. Ideally this should be done each time you think you're done with a tower, and then you should confirm it with another test print. If only Repetier's Z probe logic wasn't horribly broken
• There is an option for radius delta in the firmware, one for each tower. Leave these at 0 unless you want your parts to climb to one side like a 1980s surfer hairdo. I wasn't able to fix anything at all by adjusting these settings.

Legend
---------------
 High: ^
Level: =
  Low: v

Example: "X to Y: = ^ ="
Meaning: "Level around X tower, then high between X and Y, then level around Y tower."


Problems
---------------
- Lifts between X and Y towers
- Dips between Y and Z towers
- Lifts between Z and X towers

Base calibration - towers centered, towers at stock angles and radius deltas.

	     X: =
	     Y: =
	     Z: =
	X to Y: = ^ =
	Y to Z: = v =
	Z to X: = ^ =


Focusing on fixing Y-Z arc first, Z-X arc less significant but will watch.

---------------
Changing Y rotation from 330 to 330.5:

	     X: _
	     Y: =
	     Z: ^
	X to Y: = ^ =
	Y to Z: = v ^
	Z to X: ^ v

Looks like the X and Z towers need to be releveled - did that.


---------------
Testing again:

	     X: =
	     Y: =
	     Z: =
	X to Y: =
	Y to Z: = v =
	Z to X: = ^ =

Y-Z and Z-X (both of which are next to Z) are off. However, X to Y (opposite Z) is fine. Therefore, the Z tower probably needs some adjustment.


---------------
Changing Z rotation from 90 to 89.5:

	     X: =
	     Y: =
	     Z: =
	X to Y: =
	Y to Z: =
	Z to X: = ^ = (better than last time though)


---------------
Let's try releveling the towers and changing Z from 89.5 to 89.25: (note: this was lazy... don't change two variables at once)

	     X: =
	     Y: =
	     Z: =
	X to Y: = ^ =
	Y to Z: = ^ =
	Z to X: =

---------------
That made Z-X better at the expense of X-Y and Y-Z, so let's backtrack and try going the other direction to 89.6:

	     X: =
	     Y: =
	     Z: =
	X to Y: = ^ =
	Y to Z: =
	Z to X: = ^ =
	
This produces the least vertical deflection of anything tried so far and is "Good Enough."
In other words, close enough to stick and far enough not to block the nozzle.

cassetti wrote:Thank you!!

I'll try to dig into this when I have time over the next week and see if I can try to resolve my issue.

jmpreuss wrote:
So things are fine at the towers and the center but all 3 in betweens are high, by a fair amount (plastic barely touches).
It seems that if I adjust all 3 tower rotations it would cancel out. Anyone have a clue what the issue might be and how to address it?

626Pilot wrote: Can you print out the Onyx calibration as it is now, then change one of your tower rotations by one degree and try again? Post both before and after images.

626Pilot wrote:I did have to change my delta rod length to get prints to go over a certain height after installing my Trick Laser arms. I don't recall exactly but I think the stock was 269 and I had to change it to 271 or so. The specific phenomenon I see here makes me wonder if you might need to try doing the same thing. I'm not sure what else would cause it to lift exactly opposite all three towers

MSURunner wrote:

626Pilot wrote:I did have to change my delta rod length to get prints to go over a certain height after installing my Trick Laser arms. I don't recall exactly but I think the stock was 269 and I had to change it to 271 or so. The specific phenomenon I see here makes me wonder if you might need to try doing the same thing. I'm not sure what else would cause it to lift exactly opposite all three towers

I was having trouble trying to dial mine in across the entire platform this weekend and came across what I think is the solution. I was having to alter things rather drastically to get results, so I dug out a scale and went about measuring all of the critical components to confirm sizing. My tricklaser arms are very close to the 269 (I have them currently set to 268.5 but I think 269 would still have worked). I did have to adjust the Y tower to 209.5, but the biggest fix thus far was the carriage offset. I believe it's set to 35 mm as a default in the .91 and I am betting older Repetiers. Mine actually averaged out to 37.5 across the three carriages. Because the computer thought the arms were further from center than they were, as they were getting to the extremes across the platform from where the tower is, they were lifting up. Amazing what the one little number did to fix about 3 issues...

geneb wrote:This is the kind of thing that a short video would REALLY make it crystal clear as to what exactly the user needs to do... hint, hint..

g.

geneb wrote:This is the kind of thing that a short video would REALLY make it crystal clear as to what exactly the user needs to do... hint, hint..

g.

enggmaug wrote:If I can manage it, I'll write an excell sheet where you can enter measurments you get on specific coordinates, to give you correction to apply to parameters.
I'll surely share it if it does work.

626Pilot wrote:Cool. I don't understand the instructions on Thingiverse.