Beginner Needs Help - Anycubic Kossel Plus + Duet WiFi -- HOW?

mindbender9

@danal - Thank you for explaining these things that a newcomer is unaware of - and I mean that. I really appreciate the time and patience you (and everyone) are putting in with me.

—Here’s what happened last night:

Test prints of a 1mm circle start off with the nozzle laying down filament for half the circle “skirt?” and scraping the bed for the other half, with filament being pushed and scattered all over the print area.

At roughly 5-10% of the way, the nozzle grinds into half of the circle itself and then lays down filament from 2-3mm above the bed for the other half for a ragged, stringy result. This implies that the bed is lopsided.

I’ve rescrewed the “clamps” that hold the bed in place, but it’s still lopsided.

Dumb question #1: How do I flatten the bed? Do I put shims in under the low side? Is the software supposed to compensate for the bed during calibrations? Not sure how to proceed with this.
Dumb question #2: What is the ideal height for a nozzle to be above the bed during printing? What should I aim for during a calibration? 1mm? 2mm? This is one of those “I should know but I don’t” questions.
Dumb question #3: What is the config-override.g file used for? Several people and sources suggest that I should delete the contents of this file if I’m having issues, but I haven’t done so unless things go really bad. Am I doing something wrong?
Dumb question #4: Do I have to perform a manual calibration before every print? By this, I mean the Auto Delta Calibration or (I think) G32. If I do a back to back print (all of which fail), the failing prints get worse in scale each time.
Dumb question #5: Is it wrong to do multiple manual G32’s? The amount of Z height I have to enter for each test point keeps increasing with every attempt.
For example, let’s say I have to adjust the first attempt by -5.5 on one particular endpoint. The next attempt on that same endpoint might be -26. Is this normal? What is happening here for the values to keep increasing or the nozzle to keep setting itself higher and higher?

Thanks again for the help and encouragement. I really appreciate all of this.

Danal

@mindbender9 said in Beginner Needs Help - Anycubic Kossel Plus + Duet WiFi -- HOW?:

@danal - Thank you for explaining these things that a newcomer is unaware of - and I mean that. I really appreciate the time and patience you (and everyone) are putting in with me.

Question #1: How do I flatten the bed? Do I put shims in under the low side? Is the software supposed to compensate for the bed during calibrations? Not sure how to proceed with this.

Eventually, the combination of G32 and G29 will fix this. Just to confirm: Homing is now working, correct?

Question #2: What is the ideal height for a nozzle to be above the bed during printing? What should I aim for during a calibration? 1mm? 2mm? This is one of those “I should know but I don’t” questions.

The first layer works best with the nozzle roughly the thickness of a business card above the bed. For PLA. (Some filaments like to be 'squished' on and some like to be 'dropped' on. PLA likes business cards)

Question #3: What is the config-override.g file used for? Several people and sources suggest that I should delete the contents of this file if I’m having issues, but I haven’t done so unless things go really bad. Am I doing something wrong?

Several commands, like G32, only update things "in memory" and a power cycle will reset to whatever is in config.g

The M500 command really just writes (creates or updates) config_override.g). M501 reads it.

The "delete it" advice comes from all of us humans who look in config.g and FORGET that config_override.g exists !!

Dumb question #4: Do I have to perform a manual calibration before every print? By this, I mean the Auto Delta Calibration or (I think) G32. If I do a back to back print (all of which fail), the failing prints get worse in scale each time.

Not if the results are saved via an M500, and loaded via an M501 near the end of config.g. In theory, you should only need to do a G32 and/or G29 if something changes. Like you've removed the bed and replaced it, or changed nozzles, or similar.

Personally, I only run G32 M500 G29 when I've done maintenance, and/or when the first layer "just doesn't work" for some reason or another.

By the way, just like dogs can smell fear, 3D printers can smell both frustration and complacency. A printer that was working fine will just "be cranky" one day. Maybe it didn't get enough sleep, who knows...

Question #5: Is it wrong to do multiple manual G32’s? The amount of Z height I have to enter for each test point keeps increasing with every attempt.

You shouldn't have to enter anything, if you do an M500 to save. The Z Height (H on the M665 in config_override.g) may change a little up or down with each calibration. A few tenths. It should NOT increase after each one. Again checking a basic: Does G28 now cause all three screws to hit all three switches?

Thanks again for the help and encouragement. I really appreciate all of this.

No problem. We'll slay this dragon together. Obviously, I enjoy it!

Danal

Oh, and to clarify:

Inconsistently enough:

G32 (auto calibrate) requires an M500 to save and a M501 to load. The M501 is most often placed near the end of config.g.

G29 (mesh bed level) saves itself... but requires a G29 S1 to load. The G29 S1 is most often put in the start g-code script of the slicer (because several different things can turn it off, best be sure its on just before a print starts).

Danal

One more thought: You asked if you should wedge or shim the bed, and I kind of ignored the q. Here's the full answer:

A basic assumption check: Be sure the frame of the printer is "Square". Yeah, I know, it is a triangle!!! Seriously, do the best you can to be sure the towers are 90 degrees to the base and the top, the base is flat, etc, etc.

This does include doing the best you can to get the bed 90 degrees to all three towers. If the base extrusions are flat, and the towers are dead upright, this should happen naturally... but it is ALL worth checking.

Even when G32 and G29 are fully working, they will work best in a square and true set of mechanics.

.

When I did the final assembly and alignment of my BFD (Big Fast Delta), I used a granite slab to do the final alignment of the bottom frame and the top frame. I didn't trust any tables or the floor. (Yeah, I just happened to have access to a granite "flat", machine shop quality, to use for the final assembly).

mindbender9

Hi @Danal ,

I'm able to home successfully now that I've raised the values higher.

A basic assumption check: Be sure the frame of the printer is "Square". Yeah, I know, it is a triangle!!! Seriously, do the best you can to be sure the towers are 90 degrees to the base and the top, the base is flat, etc, etc.

So if the bed is lopsided, then something is not aligned right on my delta? Or the three pillars are not set well? How would I be able to check this, because everything seems rigid?
I still cannot print a base layer - only half is possible and the nozzle drags along the bed which prevents filament from being laid down.

Barracuda72

Seems that you have still some mechanical Problems with your frame.
As others stated before..make sure that all angles are near perfection. Put the Printer on flattest surface and check if the printbed is at same angle as the frame. On thingiverse there are some bed holder that works good. _( Prob..how to print without a working printer? )
Manual calibration could be PITA. Tried it on my Anycubic Kossel too before i upgraded to a duet. If Money is not that big prob, get the smart effector ( working with it is like heaven) or if you want a cheap solution, get a foil switch. Its cheap and works quite well to do a autocalibration and make a highmap. Before i used that switch i tried BLTouch and the original Anycubic switch ( both expensive crap..Delta and a z-probe with a XYZ Offset dont work good)
The autocalibration and bedmesh can only compensate mechanical errors to some degree..its not a simsalabim magic wand

Danal

@mindbender9 said in Beginner Needs Help - Anycubic Kossel Plus + Duet WiFi -- HOW?:

So if the bed is lopsided, then something is not aligned right on my delta? Or the three pillars are not set well? How would I be able to check this, because everything seems rigid?

Loosen the bolts/nuts on the "corners" (really triangles) and move the frame to be more square as you tighten them.

Literally use a "Carpenter's Square" or a "Try Square". This may be where American English and British English confuse things a little, so here are some pictures:

0_1527575176226_2cb59a93-7c46-4326-9c61-11b9dbf29fd4-image.png 0_1527575211725_82df1121-ccb3-4541-be86-572fff967c39-image.png
0_1527575250159_3e7cc0bf-5ba6-435f-bf54-2b8e0378a2b4-image.png

dc42

@mindbender9 said in Beginner Needs Help - Anycubic Kossel Plus + Duet WiFi -- HOW?:

So if the bed is lopsided, then something is not aligned right on my delta? Or the three pillars are not set well? How would I be able to check this, because everything seems rigid?

Are you sure the bed is lopsided? If you have an engineer's or carpenters's square, use it to check whether the bed is at right angles to the towers.

I still cannot print a base layer - only half is possible and the nozzle drags along the bed which prevents filament from being laid down.

That may simply mean that your endstop corrections are not set correctly. Calibration (G32) will fix that.

mindbender9

@dc42 said in Beginner Needs Help - Anycubic Kossel Plus + Duet WiFi -- HOW?:

Are you sure the bed is lopsided? If you have an engineer's or carpenters's square, use it to check whether the bed is at right angles to the towers.

Am I supposed to add shims under the bed? There doesn't appear to be a way to raise/lower the bed mechanically with the Anycubic Kossel Plus. It's just lopsided on one of the three sides.

I still cannot print a base layer - only half is possible and the nozzle drags along the bed which prevents filament from being laid down.

That may simply mean that your endstop corrections are not set correctly. Calibration (G32) will fix that.

I performed a manual calibration (G32) and the nozzle did a HARD nose bury into the bed when a test print was attempted. It tore up the blue painters tape that I had on the bed and the test 1mm circle print was a mess. Half of it was missing (the side where the tape was pulled up) and the other half was stringy and a mess.

This is not working.

mindbender9

@danal

I don't have a way of acquiring those right angle guides at the moment.

I loosened and readjusted the three pillars as best as I could. The nozzle still buries itself into the bed hard and tears up the surface on half of the print, then releases filament 1-2mm above the bed on the other half.

And this happens after I do a manual calibration (G32).

Could this miserable delta hardware be so screwed up that this kind of results will repeat over and over?

Danal

If you can't get a carpenter's square, use anything that you are confident is 90 degrees, and is about the right size.
A heavy card, a plastic cover, your mobile, something.

With the towers reasonably square, and the bed sitting in consistent clips or supports of some sort, there is almost no way for it to be off that much over a span the size of the circles in your photo. Something else is wrong.

By the way, when it digs in like that, TURN IT OFF. Don't let it continue to tear tape, or the plastic bed, or whatever.

Now, back to basics:

Are all six rods the same length? To within 1/10 of a MM? I've seen Anycubics with rods that vary by as much as 1mm across the six. This will cause all kinds of problems.

Is everything at all six attach points to the effector the same? Like this:

0_1528001181977_de7c6044-e7cf-4737-99ba-8e444f605833-image.png

Is everything at all three carriages the same? Etc, etc.

Can we please re-verify what is in your latest "config_override.g", after you've done your latest series of G32 and M500? Please post the whole thing.

Danal

Oh, and can you please post a video shot in such a way we can see the carriages, the home switches, and the bed, while the printer does a full G32 sequence?

Post to youtube or vimeo or something, and link here.

mindbender9

@danal

Here is my config_override.g:

; This is a system-generated file - do not edit
; Delta parameters
M665 L271.000 R152.869 H301.792 B85.0 X6.799 Y4.280 Z0.000
M666 X2.286 Y-0.607 Z-1.679 A0.00 B0.00
; Heater model parameters
M307 H0 A90.0 C700.0 D10.0 S1.00 V0.0 B1
M307 H1 A340.0 C140.0 D5.5 S1.00 V0.0 B0
M307 H2 A340.0 C140.0 D5.5 S1.00 V0.0 B0
M307 H3 A340.0 C140.0 D5.5 S1.00 V0.0 B0
M307 H4 A340.0 C140.0 D5.5 S1.00 V0.0 B0
M307 H5 A340.0 C140.0 D5.5 S1.00 V0.0 B0
M307 H6 A340.0 C140.0 D5.5 S1.00 V0.0 B0
M307 H7 A340.0 C140.0 D5.5 S1.00 V0.0 B0

I'll have to work on making the video, but I'll measure the arm lengths soon.

Thank you.

Juice

Hi mindbender, i'm currently in a similar situation as you so i've been following this thread for info. I have a new anycubic kossel plus that i just upgraded to metal corners and duet control. I just noticed that you have your rod lengths set to 271mm. If you got your kossel plus in the last 7 or so months, then you most likely have the "upgraded" rods which are now 268mm in length.
Also, do yourself a favor and throw away those mounts that the bed sits on, they don't hold the bed at all and allow for bed tilt if they aren't perfectly level themselves. Secure the bed directly to the horizontal beams if possible. The heated bed has 3 holes spaced equally around the perimeter that take M3 bolts. Mine sits on top of standoffs and I modified the bed so that the bolt heads sit below the surface. If you don't want to make that kind of mod, then you can decrease your bed size to avoid running the nozzle over the bolt heads.

Danal

Juice may have hit part of it, if the rods are different than specified. Do check that... and, normally, this makes a very symmetric "dome" or "dip", not a "tilt". So lets keep measuring some other things as well.

Also, his tips on the bed look great!!

M666 looks reasonable. These are tower angular offsets, and almost all printers will have some small corrections here.

However, the M665 X Y Z offsets look quite large. These are the "uneveness" in the limit switches. It certainly possible these accurately reflect what's happening in the physical printer, because Anycubic Kossels have a couple of things that can throw these off mechanically. Still, it would be better if they were more even. Therefore:

Loosen the top plastic things on which the endstops are mounted, and use some small object as a "spacer" to get them as precisely as reasonable possible from the top frame. The key being to make the even.
Use something small as a spacer to set the screws in the top of the carriages, so they are all the same length (height). Again, shooting for even/consistent.
Run a G32 (maybe a couple) and an M500, and post the override file again.

We'll keep plugging away.

mindbender9

@juice

Thanks for the tips. If I measure the arms from end to end (including the chrome eyeholes at each end), all arms measure to the same 279mm. Does that seem right?

I’ll have to get the M3 bolts to address the bed angle. I think you’re 100% on the money with those horrible bed mounts. Will advise. Thanks again.

mindbender9

@danal

Thank you for the tips regarding the endstops. I’ll measure and space them evenly - will report back. Thanks.

mindbender9

@Danal @Juice

I just noticed something when trying to screw the arms back to the slide arms at the top (these are what connect with the end stops).

It looks like three of the arms have M3? bolts that do not tighten back on the slide arms - they just spin and spin but don’t tighten. Is this a sign that the slide arms are defective?

3mm

@mindbender9

Hi, there is a floating 'nut' located inside of the slider. That nut has likely slipped out. I had that same exact problem. If your luck is holding it may not have actually fallen out. But you'll likely have to disassemble the carriage assy, use tweezer to reposition the nut while you thread the bolt into it, provided its still inside. On one of my sliders, the plastic cracked and I was forced to glue it together using a clamp.

Your rod-end bearings appear to be superior quality compared to what AC sold me.

good luck.

3mm

Juice

@mindbender9 said in Beginner Needs Help - Anycubic Kossel Plus + Duet WiFi -- HOW?:

@juice

Thanks for the tips. If I measure the arms from end to end (including the chrome eyeholes at each end), all arms measure to the same 279mm. Does that seem right?

I’ll have to get the M3 bolts to address the bed angle. I think you’re 100% on the money with those horrible bed mounts. Will advise. Thanks again.

The measurement you need is from center to center of the eye holes. I haven't measured all of mine but i doubt they are all exactly 268mm since my bed still calibrates to a slight dish.