A Mystery failure

[edinnh]

My first attempt to print was a Nickel calibration model. It is a quarter circle with a round nickel size hole and x and y slots sized for a nickel on edge.

My first two attempts were ugly but showed the basic form I was trying to print.

My third attempt was a mess.

My fourth and subsequent tests have been a total failure.

Currently the printer will correctly home to the left rear corner. After reaching the home Y position the movement is messed up . X movement works but Y movement results in negative x movement (Y move commands in a positive direction results in negative X moves. Y negative moves result in positive x moves. )

This moves the extruder along the back edge of the printing plate and off the right side squirting a birds nest of melted filament below the build plate.

This happens with moves directed from G-code and moves using the control panel (RepRap style panel).

A subsequent command to home all axis from the panel moves the extruder to the home position.

At this point I have no idea what I broke and how I broke It, let alone how to fix it.

Suggestion will be appreciated.

Ed


_

[edinnh]

I am running on a Smoothie Board and my config file is attached.

Attachments:

config (23.86 KB)

[carlos]

By the look of those prints I would say that the bed is not leveled. Looks like the z-height is completely off, hence it's not squashing that first layer into the bed and printing properly off that.

[edinnh]

Carlos - the extruder movement is the big problem. With the extruder not moving away from Y max there is no way to print anything but a line. With y forward movement actually moving the extruder to the right the birds nest under the right side of the platform is unavoidable.

The first three prints stuck to the PEI bed surface well. Using the bubble level program on my cell phone the bed is level (as is the table).

[all3dprinting]

0,0 should be the front left corner of your printer. The end stops for x and Y are actually the x max and Y max. This may happen due to custom start code in your repetier or slicer software. If you have a g92 x0 y0 at the start of your custom start code this will mess stuff up for you. If this code gets called after you have homed the hotend.. then you have now set the back corner to 0,0 and your head will always try to move positive to 0 so it will be maxed out a that extent.

Let me know if that doesn't make sense...

[edinnh]

I seem to have a communications problem describing my problem.

I think the home position is the left rear corner  aka Y max and X min.  

My controller is a SmoothieBoard with a reprap discount LCD panel.

The home XYZ command from the panel results in a move to the home position 0, 195.  (and z 0 which is full up).

I described movements toward the front of the printer,  to lower Y positions,  as a movement in the negative direction.  Movement to increasing y positions,  to the rear of the printer,  is a move in a positive direction.

Movement in x is positive moving to the right.

When my printer is powered on,  the position shows as 0,0.
On my printer after homing all axis (moving to the left rear corner ) the panel shows the position as  0,195.

Since I can reproduce the problem from the panel without executing any G-code I don't think it could be my start G-code.   

Before using the panel "Home All Axis" command:  If the printer is powered on with the extruder in the middle of the print bed Y Jog commands move on the diagonal.  Negative Y jog commands move toward the front right corner.  X Jog commands work correctly.

After using the panel  "Home all axis" command: using the panel to jog the Y axis results in a move in the x axis only with the direction inverted.  Negative Y movement moves the extruder to the right.   X Jog commands work correctly.

I have not added any custom start code to slic3r.  I used the slic3r default without thinking about it:
    G28 ; home all axes

    G1 Z5 F5000 ; lift nozzle



Could you post a g-code file for a simple test object?  This would be useful for early testing and differentiate between a slicer program configuration problem and a firmware/hardware problem. 

[all3dprinting]

Mar 21, 2016 23:15:47 GMT edinnh said:

I seem to have a communications problem describing my problem.

I think the home position is the left rear corner  aka Y max and X min.  

My controller is a SmoothieBoard with a reprap discount LCD panel.

The home XYZ command from the panel results in a move to the home position 0, 195.  (and z 0 which is full up).

I described movements toward the front of the printer,  to lower Y positions,  as a movement in the negative direction.  Movement to increasing y positions,  to the rear of the printer,  is a move in a positive direction.

Movement in x is positive moving to the right.

When my printer is powered on,  the position shows as 0,0.
On my printer after homing all axis (moving to the left rear corner ) the panel shows the position as  0,195.

Since I can reproduce the problem from the panel without executing any G-code I don't think it could be my start G-code.   

Before using the panel "Home All Axis" command:  If the printer is powered on with the extruder in the middle of the print bed Y Jog commands move on the diagonal.  Negative Y jog commands move toward the front right corner.  X Jog commands work correctly.

After using the panel  "Home all axis" command: using the panel to jog the Y axis results in a move in the x axis only with the direction inverted.  Negative Y movement moves the extruder to the right.   X Jog commands work correctly.

I have not added any custom start code to slic3r.  I used the slic3r default without thinking about it:
    G28 ; home all axes

    G1 Z5 F5000 ; lift nozzle



Could you post a g-code file for a simple test object?  This would be useful for early testing and differentiate between a slicer program configuration problem and a firmware/hardware problem. 

If you move the head to the middle and jog and the head moves diagonally. Then one of the motors isn't working. Remove the belt aand check both motors. Find out which isn't moving and check the connection to the board.

And my apologies, end stop position is xmin Y max.

[edinnh]

I removed the belts and both motors turn for both x and y movement. I have no way to measure relative speed of the motors.

[3DprintedLife]

Check motor pulley set screws too, make sure they're tight

[all3dprinting]

One thing I just thought of to check, Make sure that you have the step size selector on your controller set correctly for each driver, your steps/mm in your config for X and Y are the same, but if you have either x or y set at 1/16 micro stepping and the other set at 1/32 then you will also see diagonal movement.

[edinnh]

The problem was the motor pulley on the right.  The pulley could spin independent of the shaft.  

I could not get the set screw tight enough to prevent the independent spinning so I took it off and looked for the cause.


This is the pulley with the set screws down. I had positioned it with about 1 mm of the shaft sticking out the top. Unfortunately in this position the set screws are down below the flat on the motor shaft and on the circular shaft.

I moved the pulley up so the setscrews could use the flat. The motor shaft is now 2.25 mm below the top of the pulley.

With the belts back on I am able to print.

Is the high pulley a good permanent fix or should I pull the motor out and grind an extension to the flat?

[3DprintedLife]

Mar 27, 2016 2:46:46 GMT edinnh said:

The problem was the motor pulley on the right.  The pulley could spin independent of the shaft.  

I could not get the set screw tight enough to prevent the independent spinning so I took it off and looked for the cause.


This is the pulley with the set screws down. I had positioned it with about 1 mm of the shaft sticking out the top. Unfortunately in this position the set screws are down below the flat on the motor shaft and on the circular shaft.

I moved the pulley up so the setscrews could use the flat. The motor shaft is now 2.25 mm below the top of the pulley.

With the belts back on I am able to print.

Is the high pulley a good permanent fix or should I pull the motor out and grind an extension to the flat?

Which belt is this, the high or low one? If it's the low one, you can simply flip the pulley upside down and then you should be fine. If it's the high one you probably can't do that, so your best bet would be to probably drill a small indentation at the height you want that the set screw can grab on to, then definitely use loctite on the grub screw to ensure it doesn't come loose!

[edinnh]

It is the high belt. My work around raises the belt 3mm higher than it would have been.

I don't think I will have good results attempting to drill close to the edge of the flat. I think I will have better results grinding longer flat. if I pull the motor out, tape over the bearing to prevent swarf from getting into the bearing, and grind it with my Dremel tool.

I wonder if the pulley being 3mm high is a problem.