Convering to ABL and having issue with Z axis

[sniffle]

no sorry.. I was not talking about beckdac :-)

[Roxy]

OK Roxy and sniffle. I'm on the home stretch. Got the firmware loaded and mostly configured. The ABL switch has a twitch and moves out of the way too early. I took a video of it. This will make more sense. http://youtu.be/0xArq2F4sUA.

First, it kind of looks like you have the angles wrong for the fully deployed probe. If the probe leg pointed straight down it wouldn't deflect so much when switch is pressed. And something else you should consider: Can you re-print your pieces for the Z_PROBE so the probe leg gets locked and can't rotate any further? That would help repeatability. I have mine set up so when it is deployed and the switch starts to get pressed, there is some force trying to rotate the probe leg but it can't because the leg is already pressed against a 'stop'.

One thing you might be able to do is turn the #define PROBE_SERVO_DEACTIVATION_DELAY 500 into a number like 10000. If the servo was still on during that G28 it wouldn't move around so much. But that won't help you on the G29 unless you re-engage the probe for each point. You could do that just to confirm you have everything close. But I think a small redesign so the probe legs gets rotated and pressed into a stop is a better idea.

Shouldn't the Z axis move up first before it retracts? Notice how it keeps moving around. Is this controlled by firmware or the slicer software. I use slic3r. Can you enlighten me on how I should configer slic3r for this new ABL?

Thank you again for all your help

There are a number of #define's you can play with.

#define Z_RAISE_BEFORE_HOMING 9 // (in mm) Raise Z before homing (G28) for Probe Clearance.
#define Z_RAISE_BEFORE_PROBING 9 //How much the extruder will be raised before traveling to the first probing point.
#define Z_RAISE_BETWEEN_PROBINGS 5 //How much the extruder will be raised when traveling from between next probing points


You might have one of those too small ????

For Slic3r, go to the Printer Tab and then click on Custom-GCode. My custom GCode looks like this:

G1 Z15 F2000 ; lift nozzle
G28
G29 V4 n 3 T ; Do bed leveling probe
G1 Z15 F2000 ; lift nozzle

Basically, you want a G28 followed by a G29 in there.

[huntleybill]

Hi Roxy...Thank you. In response to the first paragraph, I have the probe set to be straight down. The bottom surface of the probe is completely parallel to the bed. It just keeps moving back and forth , or jerking around. When I use Ponterface to extend the probe, it is parallel to the bed.

What thingy file did you use to make your pieces for the Z_Probe? I'm not sure I fully understand your suggestion of: Can you re-print your pieces for the Z_PROBEso the probe leg gets locked and can't rotate any further?

Also, I think I should clarify...I keep saying it is the PROBE that keeps jerking around when it is the SERVO that is causing the probe to jerk around but you probably already knew what I meant.

The G-code I have been using is almost the same as yours.The stuff you have that I don't, I don't know what it means. Do you recommendusing the code you use?

My g-code:

; 8" i3 & i3v 3mm ABS for .40mm Magma 4-5-14
G1 Z5 F50 ; lift nozzle
G28 ; home all axes
G29 ; auto bed leveling

Also, these are my firmware settings bbefore any changes.

#define Z_RAISE_BEFORE_HOMING 4 // (in mm) Raise Z before homing (G28) for Probe Clearance.
// Be sure you have this distance over your Z_MAX_POS in case
#define XY_TRAVEL_SPEED 6000 // X and Y axis travel speed between probes, in mm/min
#define Z_RAISE_BEFORE_PROBING 15 //How much the extruder will be raised before traveling to the first probing point.
#define Z_RAISE_BETWEEN_PROBINGS 5 //How much the extruder will be raised when traveling from between next probing points

Thank you again.
Bill

[Roxy]

Hi Roxy...Thank you. In response to the first paragraph, I have the probe set to be straight down. The bottom surface of the probe is completely parallel to the bed. It just keeps moving back and forth , or jerking around. When I use Ponterface to extend the probe, it is parallel to the bed.

There is a bug in the Arduino Servo library. There is debate on what to do about it. One thing you can try is changing the engaged angle 1, 2, or 3 degrees either way. There are certain spots where the servo won't twitch. Some times you can find one of those spots and not have to do anything else.

What thingy file did you use to make your pieces for the Z_Probe? I'm not sure I fully understand your suggestion of: Can you re-print your pieces for the Z_PROBEso the probe leg gets locked and can't rotate any further?

Check out the .STL file here: http://3dprintboard.com/showthread.p...nsive+extruder

If you look at the probe leg and where it rotates, you will see there is a 'stop' on it. It can only rotate so far and then it presses the stop against the main extruder body. And notice where the switch goes. The arm of the switch will be pressing a little bit off center from where the probe leg rotates on the servo. What this does is press the probe leg's stop against the extruder so it is always in the same position when taking readings. Also, because there is a stop, you can set the servo angle anywhere close (or past) where the stop will allow the leg to travel. This is good if you need to set the servo angle so it doesn't twitch.

I was wondering if you could do something similar to that.

Also, I think I should clarify...I keep saying it is the PROBE that keeps jerking around when it is the SERVO that is causing the probe to jerk around but you probably already knew what I meant.

Yes.

The G-code I have been using is almost the same as yours.The stuff you have that I don't, I don't know what it means. Do you recommendusing the code you use?

My g-code:

; 8" i3 & i3v 3mm ABS for .40mm Magma 4-5-14
G1 Z5 F50 ; lift nozzle
G28 ; home all axes
G29 ; auto bed leveling

Mostly, you just need a G28 and a G29 to get the Auto Bed Leveling going. The other stuff just moves the nozzle to different places.
Lifting the nozzle is probably a good thing so you don't scrape the bed on the first move when it starts the print.

[huntleybill]

Thanks Roxy...I'll look through that. FYI tho...I clicked on your link (Roxy's_Big_Gear_Extruder_With_Embedded_servo-v4.stl ) all I get is a blank page. Also, if the servo is set to "go past" the stop and the stop won't let it, wouldn't that mean that the servo would be "humming" away and over heat?

BTW, all is not lost. I have been up and printing all day! The twitching is somewhat annoying as it did not do it when I had the dual extruder on the printer. The ABL however is working perfectly. The original issue I had (at least for this post) is pretty much solved. So, if we need to close out this thread we can. Unless you want to continue here solving my twitch!

Either way, I thank you

[Roxy]

Thanks Roxy...I'll look through that. FYI tho...I clicked on your link (Roxy's_Big_Gear_Extruder_With_Embedded_servo-v4.stl ) all I get is a blank page.

There seems to be some problem uploading and accessing .STL files. Here is a picture of what I was suggesting. It isn't as good as a .STL file because you can't rotate it, but you will get the idea. You can see where the servo goes and you can see the stop on the leg that presses against the main body of the extruder.

Also, if the servo is set to "go past" the stop and the stop won't let it, wouldn't that mean that the servo would be "humming" away and over heat?

No... For several reasons. First, you would only be going 1 or 2 degrees past the stop. Just enough to have a tiny bit of force pressing the probe against the stop. But secondly, you would probably have your servo shut off delay at 500ms or 1 second. It would not be sitting there constantly trying to go further than it has to. And, the way this probe is constructed, any time the switch gets pressed, there is a tiny force trying to rotate the probe into the stop. So it is very repeatable when doing measurements.

probe_leg.jpg

BTW, all is not lost. I have been up and printing all day! The twitching is somewhat annoying as it did not do it when I had the dual extruder on the printer. The ABL however is working perfectly. The original issue I had (at least for this post) is pretty much solved. So, if we need to close out this thread we can. Unless you want to continue here solving my twitch!

Either way, I thank you

Let's get rid of the twitch. When you get a chance, try changing the angles slightly and see if you can find a stable position. And then see if there is anything you can easily do to have a 'stop' on the probe leg.

[printbus]

There seems to be some problem uploading and accessing .STL files.

Roxy - FWIW, since the latest round of server problems a number of weeks ago, 3DPrintBoard lost the ability to properly deal with many prior thread attachments and images. It's not just STLs. Before posting a link to an old thread, it's now a good idea to review the old thread first to see if the content is intact.

EDIT: BTW - If you look close, those troublseome STLs and perhaps some other attachments are now displayed as a 1-pixel white dot in the center of the screen. Something causes 3DPrintBoard to display a file named clear.gif instead of the desired file.

[Roxy]

Thanks for the info PrintBus! I'm going to pass that up the chain and maybe that is helpful information!

[printbus]

Roxy - Good luck with reporting the issues up the chain. There are unanswered threads about the issues in the site discussion subforum. A message to the webmaster link went unanswered. PMs to Brian K and Eddie both went unanswered.

EDIT: But in 3DPrintBoards defense, I've been flabbergasted at the lack of user concern over this. Other than issues being mentioned in buried threads like this one, to my knowledge only a very few top-level squawks have been made about it. For all I know, the admins figure there's no need to fix something hardly anyone has complained about.

[huntleybill]

No... For several reasons. First, you would only be going 1 or 2 degrees past the stop. Just enough to have a tiny bit of force pressing the probe against the stop. But secondly, you would probably have your servo shut off delay at 500ms or 1 second. It would not be sitting there constantly trying to go further than it has to. And, the way this probe is constructed, any time the switch gets pressed, there is a tiny force trying to rotate the probe into the stop. So it is very repeatable when doing measurements.



Hi Roxy
I had the deploy and retract settings at 85/5. I chnged them incrementally by one and wound up at 87/3. It has NOT eliminated the problem but it is less noticable. As for servo shutoff, It must not be set because the probe continues to jump around throughout the print process. (and i don't see anything in RC Servo Support section that references a shutoff)