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Topic: Print shifting on the Y axis

I printed a butterfly and now this 20mm hollow box and a few layers in the print shifts twards you on the Y axis heres a ppic you can kinda see it behind in the shadow

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2 (edited by MolecularConcept 2013-07-02 00:15:09)

Re: Print shifting on the Y axis

another cube this time the shift happened much later in the layers. is this a problem with slic3r? should i try another stand alone slicing program?

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Re: Print shifting on the Y axis

Do you have a fan on your controller??

4 (edited by MolecularConcept 2013-07-02 01:28:45)

Re: Print shifting on the Y axis

No I don't its not very  warm back there at all

I printed a few more hollow boxes trying to get the flow rate dialed in m still not getting close to .42  perimeters .78 is aas good as I get

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Re: Print shifting on the Y axis

+1 for the fan on the electronics.

You won't feel much heat from the general area, so ignore that.

The other day I had a random very poor print, and later discovered my electronics fan had come undone.

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Re: Print shifting on the Y axis

I've been fighting Y shifting for a REALLY long time.  I think I've finally figured it out.  Make sure your acceleration settings are correct.  Go into your firmware config in repetier host and check that your x-y accel is something reasonable (mine is 1000 to be safe) and more importantly your jerk settings are really low (mine is set to 5, but people are having success with 10 or higher).  This will keep the y axis from over accelerating and doing really strange things.

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Re: Print shifting on the Y axis

My acceleration is 1000as well I didn't see a jerk setting I'll recheck in the am. If it continues to be a problem I'll try a fan and finally diff software... any other suggestions?

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Re: Print shifting on the Y axis

My acceleration is 1000as well I didn't see a jerk setting I'll recheck in the am. If it continues to be a problem I'll try a fan and finally diff software... any other suggestions?

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Re: Print shifting on the Y axis

If your drive system isn't operating at it's peak then lowering the acceleration values could help but be careful if you go too slow it can also affect the print quality.

10 (edited by 2n2r5 2013-07-02 16:54:59)

Re: Print shifting on the Y axis

Switching software for layer shifts would be like replacing the engine to keep you from getting flat tires.  :-p

Usually layer shifts are due to something mechanical like belts need to be tensioned and aligned, filament is snagging, rods are warped or something over heating like you stepper drivers or the motors themselves. The motors and steppers are a bit under powered and over driven from the factory and overheating is almost inevitable. The stepper drivers can be brought up to range (from 1 amp to 2 amp)literally just but using active cooling. There are several posts in the forums about it but aside from doing a quick tension check on the belts (per solidoodle official how to) the fan is your best bet.

SD3 w/ mods:
Glass bed with QU-BD heat pad upgrade, threadless ballscrew w/ 8mm smooth rod, spectra line belt replacement, lawsy MK5 extruder, Lawsy replacement carriage, E3D hotend, Ramps 1.4 w/ reprap discount controller, DRV8825 drivers, 12v 30A PS, Acrylic case, Overkill Y-idlers, Filament alarm, Extruder fan + more.

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Re: Print shifting on the Y axis

so a fan for the motors or the controller or both?

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Re: Print shifting on the Y axis

I put a fan on my electronics board and it helped with layer shifting. Also check to make sure your filament is coming off the roll easily. Occasionally mine will snag and cause a Y layer shift. +1 for the belt adjustments as well.

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Re: Print shifting on the Y axis

So far I have eliminated the belts and filament snaging as the cause

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Re: Print shifting on the Y axis

MolecularConcept wrote:

so a fan for the motors or the controller or both?

The fan for the motherboard would be my first thing.

SD3 w/ mods:
Glass bed with QU-BD heat pad upgrade, threadless ballscrew w/ 8mm smooth rod, spectra line belt replacement, lawsy MK5 extruder, Lawsy replacement carriage, E3D hotend, Ramps 1.4 w/ reprap discount controller, DRV8825 drivers, 12v 30A PS, Acrylic case, Overkill Y-idlers, Filament alarm, Extruder fan + more.

15 (edited by MolecularConcept 2013-07-02 18:17:23)

Re: Print shifting on the Y axis

i dont have any little fans ATM but i got a big box fan pointed at the motherboard right  now.  its helping, but i still have y axis shifting.

its really weird  how it randomly just shifts like that. my X axis motor is really warm and my y axis is pretty cool. its counter-intuitive, youd think itd be the other way around.

i managed to get 3 functional thumbscrews printed, should make bed leveling way easier. but with this shifting im not gonna be able to print a cover to hold a fan over the electronics....

haha without access to the firmware source code i cant even enable a fan if i had one....  im gonna have to get a new motherboard if i expect to get any help on mods/upgrades.

16 (edited by 2n2r5 2013-07-02 18:30:23)

Re: Print shifting on the Y axis

This should only apply to the old boards. The new boards with the built in drivers use the board as a heat sink so they are rated to 2 amps.

These are the current settings for the stepper motor drivers. Keep in mind that pololu only rates the A4988 drivers for 1A max without cooling.

X axis: 1.11A
Y axis: 1.3A
Z axis: 1.25A
Extruder: 0.48A

The Y axis stepper driver is the most over driven of any of the drivers. The motor itself is rated for 1.33A so in theory all you need to do is put a small heat sink (or a 5/16" nut attached with thermal glue) and a fan and the Y-axis should be good to go.

SD3 w/ mods:
Glass bed with QU-BD heat pad upgrade, threadless ballscrew w/ 8mm smooth rod, spectra line belt replacement, lawsy MK5 extruder, Lawsy replacement carriage, E3D hotend, Ramps 1.4 w/ reprap discount controller, DRV8825 drivers, 12v 30A PS, Acrylic case, Overkill Y-idlers, Filament alarm, Extruder fan + more.

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Re: Print shifting on the Y axis

thanks! i can give that a try.

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Re: Print shifting on the Y axis

so i havent printed anything for a while machines been on but idle. printed a 20mm sqare that measured 19.80 x 20.24 x 9.56. . so obviously it is a heat related issue will have to print a cover and heatsink some bolts onto it untill i upgrade the motherboard. i will be measuring the potentiometers though just to be sure. just need to get a meter right quick.

an now the other issue im off on all my axis lol  particularly the x axis.  got the other two mixed up when i took it off the bed.

and i ripped kapton!

now that its idle again and the steppers are off i pulled the carriage twards me and Y feel kinda tight. the tention on the belts is not tight its just how it should be. what can i do to get Y to flow more smothly. im positive thats whats causing my issue. motor is working to hard heating up that chip.

19 (edited by MolecularConcept 2013-07-03 16:14:54)

Re: Print shifting on the Y axis

I think I was wrong, its not an over heated chip. Paying super close attention I hear that its skipping a step or something. I tried watching the belts to see what one it is but I can't tell. The belts are pretty firm. But that Y carriage is pretty stiff even after greasing it up. Now I'm pretty sure its the y carriage not moving freely enough. Its not binding but its not flowing....

This is getting frustrating I might just sell this damn thing

Here's another failed print

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20

Re: Print shifting on the Y axis

My printer does not have a fan on the electronics.  And I wasn't getting any y-axis shifts - until the ambient temperature in the house (no a/c) got up to over 80F and with high humidity.  I moved the printer down to the basement where it's about 60F or so and didn't have any y-axis shifts.  (I did get the filament tangled at one point which caused problems, but that was operator stupidity ...)

Since I have a wooden-bed model, I also took care to re-level the bed and re-set the z-stop after it spent in few days getting acclimated to the new space.

Before ditching the printer, get the electronics cooled down a bit.  And make sure the nozzle doesn't get caught up on any of those extruded bumps on the first layer.  That's happened to me as well when I've had the z-stop set to high (ie. too narrow a space between the nozzle and the bed) and the flowrate too high.

Hope that helps a bit,
Matt

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Re: Print shifting on the Y axis

If your Y axis isn't moving smoothly you should try doing the perfect circles calibration, it will help solve any slight misalignment between the two guide rails/pully mechanisms.

Davinci 1.0 - Filastruder - SD3 + Borosilicate  - Cupcake

22 (edited by MolecularConcept 2013-07-04 18:30:46)

Re: Print shifting on the Y axis

okie dokie so i went and followed the instructions in the video and when moving the y carriage back and forth  theres a spot that it stops on like its stuck. so far im not sure if its a pulley or the Y stepper motor.

AH HA! its the STEPPER! took it apart again and detached the drive pully and manually spunthe stepper by hand and it will bind in a certain spot

this is something that solidoodle should take care of right?



    **UPDATE**

Solidoodle Emailed me back already its the 4th of July! they are working on the holiday and so far are being really helpful.. Very cool.