Does Your Rostock MAX v2 Hold Its Calibration?

[Xenocrates]

Heh. I mostly do my tower endstop adjustments in software (Firmware really, since it gets written to the EEPROM). What sort of CNC's do you work with? I'm also a CNC guy (Or at least a fledgling one, I know the difference between M98 and M97 without needing to look it up, and know that M08 means you probably want to close the door, or get a mop, but I'm still a student)

[Eric LB]

So I used the Escher.com calculator to attempt to get those Opp tower z heights down -with little success. That program mainly just had me reduce horizontal radius, which just made my z heights low at the towers and a little less high at Opp tower positions. The bed is no flatter than before. I asked trick laser if their CF300 arms would help and they said no. Can anybody tell me why people upgrade to those arms if they won't improve calibration out at the advertised perimeter of the build area. So after resetting the HR and getting bed center and all towers equal and talking with the folks at Matter Hackers, I have run the 13 point software bed calibration software and am about to try a 260 mm. diameter test circle (after successfully printing a test cube). Does anybody know of anything I missed here or why Trick laser says their arms wont help? I've got cyllindrical objects 260 mm in diameter that I want to print. It's the whole reason I selected the Rostock.

BTW Before running the calibration software you have to go into the EEPROM and reset z max 2mm higher in order to probe the 13 points. Then after running the program you have to go into settings printer print area z offset and set to .2 mm to be able to extrude that first layer..

[lignumaqua]

I'm having the exact same problem as reported by Eric LB. That is, my zero positions at the bed center and at each of the towers are very accurate, however there are significant errors at the points half way between towers at larger radii. In particular all those points have larger gaps so it's very difficult to get first layer adhesion in those areas. Fine for smaller prints, but I was trying to print a part that is 250mm long and one end is always in mid air!

I understand that using the 13 point correction in Matter Control would help fix (or actually mask) this issue but I would rather not be tied to Matter Control. I much prefer other slicers.

Has this been solved by anyone else in any other way? For example, if this is actually a math issue, does the math running on the Duet board do a better job? I know it calculates individual points rather than line segments so perhaps it knows about this issue with deltas?

Other than this issue with large prints, I'm *very* happy with the Rostock Max V2. Got good prints from the very start. If I could solve this one then all would be perfect.

[rogertheshrubber]

I was having the same problems as Eric LB and lignumaqua. I was certain my Onyx was warped since the numbers didn't even make sense. I spent probably weeks trying to calibrate by hand. I am certain now that the process in the manual can't reasonably work for some machines. Here's how I solved it-

1. Printed a dial indicator mount out of PLA. I used this one- http://repables.com/r/320/ but wound up cutting off the bottom part which recesses into a hole. Didn't want to drill a hole that big. It didn't affect my repeatability any.

2. Bought a dial indicator. I should have got a Metric one (to avoid wasting time with conversions) but HF had english ones very cheap so...

3. Dial indicator extensions. About 3" is needed. I didn't want to spend the money on extensions so I used blue painter's tape to secure a small drill bit, upside down, into the dial indicator thread. I made absolutely sure that it was "bottomed out" and repeatable. My macros don't drag across the plate so I didn't have an issue with leaving marks.
You could also use a set of calipers and zip ties.

4. Set Z=0 to actual 0 using the machine controls. Meaning, do the paper test and then move down about 0.1mm until the nozzle is actually on the glass at [0,0].

5. Make some macros. Basic process is to go to 0,0,50, then 0,0,2, wait 5 seconds, then go to 0,0,50. You want to probe each measuring point in exactly the same way, every time, so dragging the indicator across the glass is not recommended. You'll need to sample 7 points total: [0,0,2], [-113,-65,2], [113,65,2], [-113,65,2], [113,-65,2], [0,125,2], and [0,-125,2]. From 0,0,50, go to Z=50mm above each measuring point, probe it at Z=2mm height, then go back to Z=50mm at the measuring point, and finally back to 0,0,50. Don't go from a point near the edge of the bed (like 113,65) directly to G28, this was creating snags with my wiring harness and "bumping" my dial indicator, which might have given me some errors. You'll want to go back to [0,0,50] first before a G28 so that the homing process is always the same.

6. Get the latest version of OPENDACT - http://forum.seemecnc.com/viewtopic.php?f=36&t=8698 This image - http://forum.seemecnc.com/download/file ... &mode=view is very helpful for understanding that almost ANY issue may be fixed by firmware calibration, even if it seems like it is impossible.

7. Run setup and then run the program. Calibrate using the manual process. Click on "advanced" and then "manual calibration". Enter your actual Zmax length according to the machine. Z probe height should be 2 (or whatever Z-height you choose to use in your macros above in step 5). Set Horizontal Radius and Diagonal Rod to whatever settings are in your machine. You'll be staying on the "manual calibration" and "accuracy" tabs which are enabled by the "advanced" button. I did not change any other settings anywhere else in the program.

8. Measure at 0,0,2 and zero your dial indicator or calipers. All of the numbers you enter into OpenDACT for towers/opposite towers are relative to the center point. So you must always be 0 in the center, every run. You can zero your dial indicator/calipers each run, or you can take readings "as they are" and subtract in excel to zero out the Z height of location [0,0]. Zeroing the dial indicator is more time consuming but I found it worthwhile to ensure every measurement was correct. Incorrect inputs into OpenDACT lead to incorrect advice on how to calibrate and should be avoided at all cost.

9. This is very important. OpenDACT manual calibration is set up for calipers. If you use calipers, the reading should get smaller as you get closer to the built plate. So if you use calipers, you'll be entering measurements into OpenDACT as you read them: + as + and - as -.

If instead, you use a dial indicator, the reading may get larger as you get closer to the build plate. Check your dial indicator, mine may be different than yours. If you use a dial indicator, you'll probably have to flip the sign and enter + readings as - and - readings as +. Get this right and you will make noticeable progress in 3 or fewer calibration runs. Get it wrong and your calibration will get worse and worse. Make sure you understand this and are entering the numbers correctly.

10. Take a full set of readings, then recheck 0,0 to make sure the calipers/indicator are still 0. If it isn't redo your measurements. Enter the data into OpenDACT manual calibration, and click "manual calibrate" ONCE.

11. The numbers on the right side will change. You may want to keep track of these in a spreadsheet, it was very helpful for me to track input numbers and measurements.

12. After clicking "manual calibrate" ONCE, take the updated numbers on the right side and enter them into your EEPROM settings.

13. If you choose to ignore the program's advice, or if you can't enter a number that precise (144.3875 -> 144.39), update the numbers in OpenDACT. Whenever you click "manual calibrate", it is vital that the numbers shown are the numbers the firmware had when you took your caliper/dial indicator readings. It's OK to ignore OpenDACT's advice, as long as you feed the program only correct information about the parameters that were set and the measurements that were taken. Every time you click "manual calibrate" the numbers must reflect reality!

14. Repeat. It took me more than 30 calibration runs, but I was doing some things wrong in the beginning. The program will first calibrate your tower heights (points in front of towers) to as near to 0 as possible. Then it will work on the opposite towers. You will be jumping back and forth between horizontal radius, and tower offset adjustments. Then, when those are close, the software may make a alpha rotation change, which may send you back to the beginning. Then when alpha rotation is correct, you may have to change diagonal rod. This is a "sawtooth" kind of process, if you click over to the "accuracy" tab after a couple of runs, you should see that you are getting closer to 0, then farther away, then closer than ever before, then farther away, etc. I eventually got to around 0.05 which is good enough to use almost the entire build plate. I kept notes (yellow highlighting) in my excel sheet of which variables were changed during each run. This helped to establish a pattern.

15. Ignore any request by the software to change your steps/mm from 80mm. This happened to me when I was getting very close to calibration- my towers were 0'ed out and the opposite tower errors was all approximately the same. Instead of changing steps/mm (which is a very bad idea), change your diagonal rod instead. At this point in my calibration, the numbers "made sense" and I could see that a diagonal rod adjustment was the way to fix the problem. My tower were all "0" and my opposite towers were all very close to +0.015" / 0.375mm. I used this figure- http://forum.seemecnc.com/download/file ... &mode=view to try to make a better educated guess on how much to change the diagonal rod. Note that making a diagonal rod change will mess up your calibration. Every time you change diagonal rod (or alpha rotation, for that matter), it will be a big temporary setback for your accuracy, and require 2-3 runs to get back "where you were". Don't lose hope. You should be able to see that successful calibration is possible by this point.

16. Keep at it. Even if your machine's calibration is a tangled, complicated mess, like mine was, eventually the numbers should start to make sense and "look" correctable. If not, you may be measuring wrong - I certainly made a few mistakes that way. I wasted several hours being confused about the sign convention I explained in step 9. When you are all done, don't forget to set Z=0 to nozzle actually touching the glass. I had to make significant changes to horizontal radius (~+0.6), Alpha rotation A(~-0.3?), and diagonal rod (~+4.0). The other parameters got smaller corrections. I can put on my dial indicator and get +/- 0.002" or 0.05mm now anywhere on the plate though. Finally.

Next step for me is to get a Zprobe system and a firmware that can calibrate automatically. Now that I know the machine actually can be calibrated, I'm a lot more confident now that this will actually work. I had tried manual calibrations for weeks, using every guide out there. Nothing worked. I was at my wit's end, and thought calibration was nearly hopeless. But I got it. The key was to eliminate all the possible sources of error and be absolutely fanatical that only accurate and correct information was being entered into OpenDACT.

[geneb]

FYI, there's an upgrade coming that will make your lives a LOT easier...

g.

[Tincho85]

I'm constantly recalibrating and adjusting Z. However, this printer is awesome and prints fine if you don't care and just calibrate it once and leave it alone. I'm always picky and trying to get some real accurate #s and I just can't. Here's what my v2 does;

1. My Z height moves if I check it everyday. Literally. It moves .10-.30.

Me too. But the horizontal radius remains ok. It might be due to an environment issue. Humidity here is a bit high.
To fix it, I only need to update the "z max length" on the eeprom and the "Printable height" on the printers shape tab.

FYI, there's an upgrade coming that will make your lives a LOT easier...

g.

Please!!! I want to buy the new effector-arms combo but I'm waiting so it all comes in one package.

[dchauran]

Gene - When? I'm eagerly awaiting...

[geneb]

Possibly late June. Or so I hear...


g.

[Tincho85]

Possibly late June. Or so I hear...


g.

any updates on this gene?

[Qdeathstar]

Pure speculation on my part, but the if you check out the Eris thread, there are some people having issues with the autocalibration, so i'm guessing they might be delaying the ROMAX rollout until they get the Eris dialed in. But i really have no idea what i'm talking about most of the time.

[Qdeathstar]

I had to recalibrate mine 4 times since i've gotten it, but i havn't had to recalibrate it in about 4 weeks now. So maybe everything as settled in?