Problems with the leveling Hi guys, I built my SmartRap a few months back and have been really pleased with it so far. Got some help from my friend Cliff to get everything up and running and it has been working fine until I started to try and print larger objects. The problem I have is that close to the frame the print gets smeared onto the glass and on the far end of the glass it barely sticks to the glass. I noticed early that the glass was flexing when performing autoleveling and printed a support for the glass. I use a ballhead hex screw to be able to adjust the height easy as can be seen in the pictures. [attachment 38305 IMG_20140813_093241-1024.jpg] [attachment 38306 IMG_20140813_093257-1024.jpg] I have executed the autoleveling according to Serge's instruction several time and although I think it works properly it does not make the printer print evenly. Any tips anyone ? /Pontus https://reprap.org/forum/read.php?344,394338,394338#msg-394338 Fri, 17 Jul 2026 23:00:53 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?344,394338,421502#msg-421502 Re: Problems with the leveling https://reprap.org/forum/read.php?344,394338,421502#msg-421502 the funny thing is : i did the same at home but didn't put it online .. i had one bad printer i couldn't manage to know why it wasn't straight on Y .

and it works, right ?]]> smartfriendz Smart_Rap Sun, 19 Oct 2014 08:38:25 -0400 https://reprap.org/forum/read.php?344,394338,421440#msg-421440 Re: Problems with the leveling https://reprap.org/forum/read.php?344,394338,421440#msg-421440
#define Z_PROBE_OFFSET_FROM_EXTRUDER_DELTA_Y 0.4 // smartrap: This is my own addition to tweak my slightly crooked printer.

and added the following to the set_bed_level_equation_3pts function

// My own mod:
z_at_pt_2 += Z_PROBE_OFFSET_FROM_EXTRUDER_DELTA_Y;]]> SweetPeas Smart_Rap Sun, 19 Oct 2014 06:07:10 -0400 https://reprap.org/forum/read.php?344,394338,418201#msg-418201 Re: Problems with the leveling https://reprap.org/forum/read.php?344,394338,418201#msg-418201
for the flex, i've setup a hack in marlin on our github. It's in configuration.h at line 412 :

#define Z_PROBE_OFFSET_FROM_EXTRUDER_DELTA_X 0

you can enter a value here , like 0.2 to ..whatever you feel is good :)

this will add an offset to the last Z probe to recover from the extra Z coming from the flexing . It gave very good result until now ( logically ) .]]> smartfriendz Smart_Rap Sun, 12 Oct 2014 02:24:47 -0400 https://reprap.org/forum/read.php?344,394338,418138#msg-418138 Re: Problems with the leveling https://reprap.org/forum/read.php?344,394338,418138#msg-418138 I suppose the further from X0 you go to take the probe point the more flex you will have in the X axis. Try probing closer to the start position. So, if you are currently probing X180, Y0 try changing it to X100, Y0 and see if it still flexes.]]> mikefiatx19 Smart_Rap Sat, 11 Oct 2014 18:10:36 -0400 https://reprap.org/forum/read.php?344,394338,418000#msg-418000 Re: Problems with the leveling https://reprap.org/forum/read.php?344,394338,418000#msg-418000 Shootquinn Smart_Rap Sat, 11 Oct 2014 10:55:10 -0400 https://reprap.org/forum/read.php?344,394338,407859#msg-407859 Re: Problems with the leveling https://reprap.org/forum/read.php?344,394338,407859#msg-407859 zackary Smart_Rap Tue, 16 Sep 2014 03:00:23 -0400 https://reprap.org/forum/read.php?344,394338,407811#msg-407811 Re: Problems with the leveling https://reprap.org/forum/read.php?344,394338,407811#msg-407811
Quote
mikefiatx19
The G29 in the slicer code takes care of any angle in the plane of the glass. The 3 point level reads the height of the bed at 3 points and records the angle to use as a reference for the gcode commands. If you watch a print after the 3 point level has happened you should see the Z screw constantly turning to compensate for the uneven bed.
The only time I can think of when this would not work correctly is if the glass was somehow bent and like you said i think thats unlikely to happen.

One thing I will pass on to you guys about this particular subject.
Glass is slightly flexible and will bend.
If the bed that the glass sits on is bent and you use four spring clamps or paper clips, it will bend the glass to the shape of the bed underneath.
In this case it is best to use only two clamps so that the glass plate is held in the centre (Australian spelling) of the front and back edges only. That way the glass will not bend and will stay flat.

If using wooden rails as some of us are doing, the four glass clips can be used because there is nothing in the centre to make the glass bend.]]> regpye Smart_Rap Mon, 15 Sep 2014 22:33:02 -0400 https://reprap.org/forum/read.php?344,394338,407790#msg-407790 Re: Problems with the leveling https://reprap.org/forum/read.php?344,394338,407790#msg-407790 The only time I can think of when this would not work correctly is if the glass was somehow bent and like you said i think thats unlikely to happen.]]> mikefiatx19 Smart_Rap Mon, 15 Sep 2014 19:45:41 -0400 https://reprap.org/forum/read.php?344,394338,407761#msg-407761 Re: Problems with the leveling https://reprap.org/forum/read.php?344,394338,407761#msg-407761 just wanted to pass a comment on Mr Reg Pye's last post in this chain....because I too have had a sore head trying to understand how to calculate off-set, possibly due to zero experience at printing.

Many thanks to the detailed response by Reg this is clear for a single point setting on the bed – but what I am having a tough time trying to understand is how to take into consideration if the glass is at an angle or not perfectly flat (unlikely). .
So I was looking at the GCodes and I would have thought we need to use a G32 with M557 using a 4 point reference points to ensure against any twists.

Am I over thinking all of this?]]> zackary Smart_Rap Mon, 15 Sep 2014 17:34:25 -0400 https://reprap.org/forum/read.php?344,394338,407356#msg-407356 Re: Problems with the leveling https://reprap.org/forum/read.php?344,394338,407356#msg-407356
I'm testing aluminium heated bed for production , as people say that PLA can stick well on an alu bed at 60 and stop sticking at lower temp. I've never tried it before .

About the sensor mike, I use a 18mm ith 8mm detection, so it works with anything on the bed, tape, glue, whatever, it will work the same.]]> smartfriendz Smart_Rap Mon, 15 Sep 2014 02:52:35 -0400 https://reprap.org/forum/read.php?344,394338,406899#msg-406899 Re: Problems with the leveling https://reprap.org/forum/read.php?344,394338,406899#msg-406899
Metal beds seems to be a nice tought. If it would work, then why not to try use it as the heated bed in the same time. Only the mounting should be somehow heat resistant, and the bed shrinking from the changed temp. can be a bit problematic.

Annyway, Mikefiatx19 idea with measuring the gap in real time while printing sounds grate! :)]]> verteez Smart_Rap Sat, 13 Sep 2014 16:15:47 -0400 https://reprap.org/forum/read.php?344,394338,406887#msg-406887 Re: Problems with the leveling https://reprap.org/forum/read.php?344,394338,406887#msg-406887
maybe i will try that ? . Can be nice with not so plane metal beds :)]]> smartfriendz Smart_Rap Sat, 13 Sep 2014 15:32:24 -0400 https://reprap.org/forum/read.php?344,394338,406777#msg-406777 Re: Problems with the leveling https://reprap.org/forum/read.php?344,394338,406777#msg-406777 "I just finished testing with inductive sensor and small aluminium foil under the glass ..and it works perfectly."
If it sees the foil under the glass, will blue tape, PVA glue or kapton tape confuse the proximity sensor?
I mean if the probe probes the bed in 3 places, then those 3 points would have to be absolutely clear from tape, plastic or PVA right?

Another thought, maybe the machine could put down the first layer at a layer as measured by the sensor in real time. Without probing at all. So the machine constantly measures the gap and compensates for the height while working.
Regards
Mike]]> mikefiatx19 Smart_Rap Sat, 13 Sep 2014 09:14:10 -0400 https://reprap.org/forum/read.php?344,394338,404227#msg-404227 Re: Problems with the leveling https://reprap.org/forum/read.php?344,394338,404227#msg-404227 Just one variable to change in the firmware and then the rest is done automatically.
1. Home the Z.
2. Lower nozzle to bed position. Use paper to get the correct bed space.
3. Send M114 from Pronterface to read the position.
4. The reading shown on the screen will be the exact value to put in the firmware for the offset.
5. Program the board as usual.
Takes just a couple of minutes beginning to end and can be checked at anytime and changed if anything moves out of kilter So Easy.

// ENDSTOP SETTINGS:
// Sets direction of endstops when homing; 1=MAX, -1=MIN
#define X_HOME_DIR -1
#define Y_HOME_DIR -1
#define Z_HOME_DIR -1

#define min_software_endstops false // If true, axis won't move to coordinates less than HOME_POS.
#define max_software_endstops true // If true, axis won't move to coordinates greater than the defined lengths below.]]> regpye Smart_Rap Sat, 06 Sep 2014 22:51:17 -0400 https://reprap.org/forum/read.php?344,394338,403151#msg-403151 Re: Problems with the leveling https://reprap.org/forum/read.php?344,394338,403151#msg-403151
BUT... I just finished testing with inductive sensor and small aluminium foil under the glass ..and it works perfectly. I will integrate this solution right away ( even on the actual shipping kits). I found this really good and we don't need Z_PROBE_OFFSET_FROM_EXTRUDER_DELTA_X anymore because we never touch the bed anymore .

the sensor is : [www.aliexpress.com] ans it is used in place of the Z endstop.

However I'm interested by your solution with screws sweet peas ? I've never found a good one and i find good to have this option with the Smartrap.

thank you]]> smartfriendz Smart_Rap Thu, 04 Sep 2014 06:03:09 -0400 https://reprap.org/forum/read.php?344,394338,403120#msg-403120 Re: Problems with the leveling https://reprap.org/forum/read.php?344,394338,403120#msg-403120 I'll try to remember to take some snaps of it when I get home.

Much easier to do it with a set screw and it is now perfectly levelled.

/Pontus]]> SweetPeas Smart_Rap Thu, 04 Sep 2014 04:20:49 -0400 https://reprap.org/forum/read.php?344,394338,398645#msg-398645 Re: Problems with the leveling https://reprap.org/forum/read.php?344,394338,398645#msg-398645 duranza Smart_Rap Sun, 24 Aug 2014 17:18:01 -0400 https://reprap.org/forum/read.php?344,394338,398598#msg-398598 Re: Problems with the leveling https://reprap.org/forum/read.php?344,394338,398598#msg-398598 Regarding the thread above.
Should I replace the red X 0.5 with the X value from the G29 probes?
#define Z_PROBE_OFFSET_FROM_EXTRUDER_DELTA_X 0.5
Thanks
Mike]]> mikefiatx19 Smart_Rap Sun, 24 Aug 2014 15:10:15 -0400 https://reprap.org/forum/read.php?344,394338,396660#msg-396660 Re: Problems with the leveling https://reprap.org/forum/read.php?344,394338,396660#msg-396660 I managed to get it to print evenly on one end of the glass (Y) but then on the other end the same thing happened.
I am playing around with a Z_PROBE_OFFSET_FROM_EXTRUDER_DELTA_Y option to see if I can get everything to print evenly.]]> SweetPeas Smart_Rap Tue, 19 Aug 2014 07:11:00 -0400 https://reprap.org/forum/read.php?344,394338,394777#msg-394777 Re: Problems with the leveling https://reprap.org/forum/read.php?344,394338,394777#msg-394777
/Pontus]]> SweetPeas Smart_Rap Thu, 14 Aug 2014 06:50:44 -0400 https://reprap.org/forum/read.php?344,394338,394402#msg-394402 Re: Problems with the leveling https://reprap.org/forum/read.php?344,394338,394402#msg-394402 X 0.5 // smartrap: special quantic error mesurement from porte a faux design (see marlin.cpp)

This will add or subtract z height as the machine moves front to back to compensate for the glass flex.]]> duranza Smart_Rap Wed, 13 Aug 2014 07:43:04 -0400 https://reprap.org/forum/read.php?344,394338,394338#msg-394338 Problems with the leveling https://reprap.org/forum/read.php?344,394338,394338#msg-394338
I built my SmartRap a few months back and have been really pleased with it so far. Got some help from my friend Cliff to get everything up and running and it has been working fine until I started to try and print larger objects. The problem I have is that close to the frame the print gets smeared onto the glass and on the far end of the glass it barely sticks to the glass.

I noticed early that the glass was flexing when performing autoleveling and printed a support for the glass. I use a ballhead hex screw to be able to adjust the height easy as can be seen in the pictures.
[attachment 38305 IMG_20140813_093241-1024.jpg]
[attachment 38306 IMG_20140813_093257-1024.jpg]

I have executed the autoleveling according to Serge's instruction several time and although I think it works properly it does not make the printer print evenly.

Any tips anyone ?

/Pontus]]> SweetPeas Smart_Rap Wed, 13 Aug 2014 03:46:52 -0400