I figured out the problem with the auto-calibration this morning...

I managed to get a decent calibration last night, and printed off some "bed level adjusters" for the da Vinci off Thingiverse last night, as my thumbs were getting sore from all the wheeling that was happening.

When I was installing them, I noticed a large blob of white ABS sitting in the bottom right hand corner of the base supporting the heated bed (and when I say "large", I mean about 15 mm round, and 15 mm high...) - under the bed itself, but on the plastic base the springs are attached to. This must have been created on one of my early prints, when I forgot to put glue on the bed, resulting in the prints getting stuck on the exrtuder, and ending up being somewhat of a mess.

It would appear that this blob has been interfering with the bed levelling, as, as soon as it was gone, I was once again able to get a decent bed level using the "auto" calibration...

Thanks all for your comments, they were all greatfully appreciated.

Cheers,

Jeff

For some quality of life on da vinci's. Please forget about calibration forever. Never ever use it. Just launch a print get a feller gauge and calibrate. It will take eons less time and it's way more reliable. Some users do a clearance of 0,15.

This. Someone might create a printer with working auto calibration someday. This one isn't it.

http://www.soliforum.com/topic/8408/bed … beginners/

PS I also replace the calibration wheels with M3-0.50 Wing Nut it helps know how much you are moving the bed.

I think I see where your issue is. The Numbers shown on the screen after calibration are actually reversed from the order of the screws. So lets say on your screen from left to right is value 1, 2, and 3. Value one represents the value for the screw that is on the right hand side at the back. Value 2 is the screw at middle front and value 3 is for the screw at the back left. The manual is wrong.

One other thing to keep in mind is the the right side and left side pivot on the center screw. When you lower the right side, the left side will raise slightly and like wise when you adjust the left side.

Hi carl,

Thanks for the response.

Yep, I understand the principle and process, and have used them quite successfully on a number of occasions in the past.  Today, however, the methods I have previously used successfully do not work...

Cheers,

Jeff

Hi boxcarmib,

Thanks for the quick response and the advice.

What you describe is my normal method for calibration.

Today, however, one "turn" of a wheel sends everything out of whack (one "turn" being the distance you can turn the wheel by starting as far on one side as possible of the exposed wheel, and moving it to the other side, which works out to be about a third of a full turn of the wheel, or a height change of around 15-18 mm (I believe).

For example, if the reading for "1" is +185, I make one turn to the left at wheel "A", expecting the reading to change to somewhere around +200 (and the reading at "3" to dip a little).  However, the reading on the next calibration is something like +285 at "1", a full 100 more than the former one.  This makes no sense to me.

I don't know how to fix that...

I have checked everything I can think of, including checking the the plastic components around the extruder, and the heated bed and its supports, in case they are cracked or broken, and everything seems to be in order.  I have cleaned everything I can think of, as well.

I've turned the machine off for now, and am taking a break, before I do something I, and my machine, both regret...  :-)

I'm still open to suggestions as to what I can try next.

Cheers,

Jeff

I think I see where your issue is. The Numbers shown on the screen after calibration are actually reversed from the order of the screws. So lets say on your screen from left to right is value 1, 2, and 3. Value one represents the value for the screw that is on the right hand side at the back. Value 2 is the screw at middle front and value 3 is for the screw at the back left. The manual is wrong.

One other thing to keep in mind is the the right side and left side pivot on the center screw. When you lower the right side, the left side will raise slightly and like wise when you adjust the left side.

Thanks for the quick response and the advice.

What you describe is my normal method for calibration.

Today, however, one "turn" of a wheel sends everything out of whack (one "turn" being the distance you can turn the wheel by starting as far on one side as possible of the exposed wheel, and moving it to the other side, which works out to be about a third of a full turn of the wheel, or a height change of around 15-18 mm (I believe).

For example, if the reading for "1" is +185, I make one turn to the left at wheel "A", expecting the reading to change to somewhere around +200 (and the reading at "3" to dip a little).  However, the reading on the next calibration is something like +285 at "1", a full 100 more than the former one.  This makes no sense to me.

I don't know how to fix that...

I have checked everything I can think of, including checking the the plastic components around the extruder, and the heated bed and its supports, in case they are cracked or broken, and everything seems to be in order.  I have cleaned everything I can think of, as well.

I've turned the machine off for now, and am taking a break, before I do something I, and my machine, both regret...  :-)

I'm still open to suggestions as to what I can try next.

Cheers,

Jeff

But without a doubt the XYZ approach to calibration is the most colossal POS design ever, and there are a variety of different approaches owners have taken to try and deal with the problem. I like you tried the manual approach as suggested by some but never had much luck with it. What works for me (although 'works' may be somewhat charitable... it can still take me 45 minutes to get my machine back into whack), is to concentrate on one number at a time -- I never adjust more than one screw between calibration cycles.
I use the back right screw to get the first reading to a number in the range of 220~260. Then I move on to the second number manipulating the screw at the front until i get the 2nd number within 10+/- of the first number. Then finally I work on the back left screw to even things up.
The most important thing I've learned is that the smallest tweak of the screws can result in large degrees of magnitude. The documentation says a whole revolution of the screw will change the adjustment by only 50, but that doesn't seem to have any bearing in the real world. A 1/4 revolution can change things dramatically way beyond the 12.5 that the docs would suggest.

Best of luck... sure hope you meet with some success!

I have had nothing but grief with this printer, from the original purchase, to receipt, to hardware failure, etc.

These are the problems I have had with the printer to date:

. This printer was supposed to be delivered within five working days, and took three weeks to arrive;
. When it was delivered, the door was broken, and the extruder was not locked into placed on the Z axis (replacement door ordered);
. After using the printer for five days, the extruder stopped heating (loose connectors, which I believed I had fixed);
. Extruder unit lost power after another day, probably due to a circuit board error (cause still not known);
. Replacement extruder ordered, which took three weeks to be delivered;
. Prints have not been of the same quality (which was not fantastic to begin with) since fitting the replacement extruder (I am positive it is fitted and seated correctly);
. The printer has failed to recognise XYZ cartridges when I swap then out, sometimes new, sometimes already used, and previously recognised by the machine.

I know the majority of these are not issues with the printer itself, but it all leaves a bad taste in my mouth...

Now, however, I have reached my breaking point.

The extruder has started having heating problems again, today.  Checking the issue, the release pins on the connector snapped off when I touched them, presumably having been made fragile due to excessive heat (the two white wires leading from the connector to the mainboard) show scorch marks at the ends where they meet the connector.  I guess I will have to remove this connector altogether, and just connect them directly.  IS THIS A GOOD IDEA, OR NOT?

I left a job running overnight, and went to remove it from the printer this morning.  It would appear that the print bed is out of calibration (once again, no surprise there).

I have previously had no difficulty with calibrating the bed using the printer function, once I figured out how that worked.  I know how "sensitive" the bed is, and that turning the wheels a third raises or lowers the bed around 16 mm.

Today, however, the calibration seems to be well and truly stuffed.  A minor turn of a wheel can change a reading by as much as 100 mm when running the calibration again, and running the calibration without making any adjustment to any wheels gives gratly different results, sometimes on one reading, sometimes on all.

I have cleaned the print bed (just on the off-chance that the "weight" of the glue was affecting the readings), the metal flats the extruder contacts to get the readings, and the extruder and the nub itself.  I have pushed the print bed down on all corners, and lifted it up on all corners, in case it is not sitting properly. Everything is clean, and particle free, but the problem remains.

DOES ANYONE HAVE ANY SUGGESTIONS AS TO HOW I CAN FIX THIS?

For the record, I have previously tried to do manual adjustments to the heated bed, as per another post on this forum, but was never able to get decent prints with this method, but have had success with semi-decent prints using the "out-of-the-box" method.

Any help greatly appreciated!

Cheers,

Jeff