HumanLiberty wrote:10k Thanks Rollie!
Cancel it though - I re-installed Repetier again and is seems to have resolved. Thanks again!
Ok, glad you figured it out! Sorry I hadn't replied sooner, was busy the past two days.
teoman wrote:
For the tower lean you would ideally need x y position.
For this, what one could do is cut a straight piece of aluminium foil and then stick it to the bed. With the nozzle and the Al closing a circuit to detect position.
The nozzle should touch down on the Al and then when it passess off the Al will be detected and the point recorded.
Several linear passes, and you check in your software if those points are linear.
How will the software determine the true X and Y positions? I am not sure I fully understand your method. The lean of the towers are actually able to be found through measuring a single point at the tower, at the center, and at the opposite of the plate. A requirement here would be for the delta radii, horizontal radius, steps per mm(for each tower), diagonal rod length, to be corrected prior to this testing.
-The horizontal radius can be corrected through modifying the parameter until the average of all the values is equivalent to zero. This allows the a lesser amount of change in the delta radii by adjusting all at once - essentially.
-The delta radii can be corrected through comparing the height at the tower and at the opposite side of the plate. If the values are inversely equivalent(the sum of the two is zero) then the radius is correct - otherwise needs corrected.
-The diagonal rods need to be accurately measured from the center of the joint at the effector plate, to the center of the joint at the carriage. There is no way for this value to change, it is static. The only reason that this value was previously changed in my calibration method was because it
was the only solution to the error that was found - this error was truly induced from an error in the steps per millimeter.
-For the steps per millimeter, at the moment there is no way to find the steps per millimeter automatically for each tower UNLESS the towers of the printer are perfectly square. This would have to be done manually. The calibration will supposedly correct the SPM, however, it will be correcting for error that is not produced by the SPM. This causes horrendous scaling issues - checked through physical testing.
Given this information however, it may be best to just use an angle finder and adjust towers if possible - by if possible, I mean by a situation which was similar to mine, where all of my towers were angled inward from 1.3 to 2.1 or 88.7 to 87.9 degrees.
Edit: The majority of the error in the X and Y dimensions leave some vestige which can be traced and corrected through a corresponding relationship with the Z-dimension.
PikachuPorkChops wrote:
Hello,
I've been trying to calibrate my bed with the manual HTML script over the last few days now and I can't seem to get good results from it. I'm using electronic calipers to measure and after 4-5 iterations I get the 6 points to +/- 0.01mm. The problem occurs when I switch out the calipers for the hotend and actually try printing. At about 5cm from the centre of the bed I get height deviations of up to 0.6mm. I don't understand what's causing this. Am I not supposed to change the zheight once I finish calibrating? Should I zero the calipers for every iteration?
Another thing I noticed was that when running your gcode, the probe ends up about 2mm lower when going to the bed centre as opposed to when I bring it down manually through MatterControl.
This is the mount I'm using for the calipers:
http://repables.com/r/614 though I don't think it's the source of the problem.
Unless the answer to my problems is painfully obvious, it might be good to update the tutorial.
Since you did manage to calibrate to that tolerance, there are several issues that may cause this.
1. Your towers may be off significantly - enough to change calibration issues due to the change in Z-height change from the height of the calipers to the height of your hotend.
2. "Should I zero the calipers for every iteration?" Yes, you should. Any change in offsets/horiz rad/etc. will change the height at the center of the bed. This is very important to do
every iteration.
3. Do you home your printer before bringing the probe down in MatterControl/when lowering manually?
Your mount will not be a problem, but if the height between the end of the calipers/effector plate vs. the end of the hotend/effector plate, this may cause issues. This is the main reason that I switched to FSRs over a Z-probe; the carriages are lower when you print than when you calibrate(with a z-probe), thus the calibration will significantly differ(not by 0.6mm at that distance though).
For updated instructions/tutorial/video/etc.: I have planned on adding a well documented set of instructions for both versions of the program, however, finding the time is quite difficult. At the moment, I am only able to be near the printer one day a week(Friday nights) and I usually juggle four things at once. The lack of documentation has just not been a priority - I was hoping the automatic version would phase the manual out. During the weekdays, I have been slowly working on a paper detailing every step about the calibration, in hopes that everyone will find issues which will help improve the program. I will try to push better instructions for the manual calibration higher up on the list and this will come with an additional video using the program.
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