How to invert the XY Axis for CoreXY system

Hi All

I have just built my first corexy 3d printer, but the X and Y axis are switched.

I.e moving in X direction , the hotend is moving in Y direction and vice versa

Can anyone assist in how to switch the X / Y axis please

Thanks

(warning just going on theory here.....)

from [www.corexy.com]

so if motors both turn same direction, X moves
it motors spin in oposite directions, Y moves.

To swap X and Y movement reverse direction of one motor (any one)
Just turn the stepper plug around if you can (while off!)

Edited 2 time(s). Last edit at 04/30/2014 06:21AM by Dust.

Thank you Dust, I've turned the X stepper motor plug and the XY not travelling in the correct axis.

There's one little problem left, is that I want to reverse the Y direction only,

I've tried to invert the direction in configuration.h of Marlin,

But the Axis have XY axis have now swapped back

Please can someone assist me with this problem.

Thanks so much.

to invert both X and Y direction, you invert both axis

but just Y or X?? himm...

I dont think thats possable with normal setting... so there must be some XY spesific stuff

You need to invert the directions when moving in oposite directions (ie a Y move)
But you need them non inverted when moing in same directions for X to stay the same...

Can you post some images of your machine? suspect you dont actuly have a core XY but a variant. (but im just guessing)

Edited 1 time(s). Last edit at 05/04/2014 06:55AM by Dust.

Hi Duckfriedrice

Did you resolve this? My new coreXY machine has exactly the same issue so all my prints end up as mirror images. Apart from that it's great!

Andy

Edited 1 time(s). Last edit at 05/09/2014 11:10AM by AndyCart.

Hi Guys

Im still working on theortical.. would you be willng to try a 'hack' on the code?
I have no way to test this, it might do bad thing elsewhere... have the power button handy!

in planner.cpp

// these equations follow the form of the dA and dB equations on [www.corexy.com]
block->steps_x = labs((target[X_AXIS]-position[X_AXIS]) + (target[Y_AXIS]-position[Y_AXIS]));
block->steps_y = labs((target[X_AXIS]-position[X_AXIS]) - (target[Y_AXIS]-position[Y_AXIS]));

to invert y change the block->steps_y to:
block->steps_y = labs(-(target[X_AXIS]-position[X_AXIS]) + (target[Y_AXIS]-position[Y_AXIS]));

Later tonight I will try and setup two steppers in corexy mode to play with, if I dont hear back from you.

Thanks Dust

Just tried your code alteration in the planner.cpp , but doesn't change in direction of Y axis

When I setup my HBOT, I had this kind of problem too. Its a bit too hard to explain exactly the way to get it right the first time but what you can do is this:

Plug in one motor backwards and see what changes (make sure motors are OFF before removing and plugging back in).

If that does not work, swap the motor plugs and see what happens.

Then flip the other motor plug backwards. Eventually you will either understand how the driver is trying to work, or you can methodically try each combination and get it right. Trust me, there is one combination that works without changing firmware. There are only 8 combinations:

X                        Y
M1 forward          M2 forward          
M1 forward          M2 backward
M1 backward       M2 forward          
M1 backward       M2 backward
M2 forward          M1 forward          
M2 forward          M1 backward
M2 backward       M1 forward          
M2 backward       M1 backward

Edited 1 time(s). Last edit at 05/10/2014 09:50PM by Hazer.

---

"Never argue with stupid people, they will drag you down to their level and then beat you with experience."

Ohh never thought of swapping them.. (unthinkable for a Cartesian!) thinking that threw...

swapping X and Y without rotating the plugs, should be a winner!

Edited 1 time(s). Last edit at 05/10/2014 10:40PM by Dust.

oh, didn't think of swapping M1 and M2, I'll give it a try later.

thanks

Hazier, you're a star. Issue resolved. Don't ask me about forgetting to swap the limit switches over when I swapped the motors over though. I'm much to embarrassed to talk about it

Thanks again.

Andy

I just found this post. I having the same problem with my CoreXY printer.

Confirmed, turn 180º the motor conector on one motor, i was able to achieve my printer work as expected.

Thank you all

Marcos

Quote
Hazer
When I setup my HBOT, I had this kind of problem too. Its a bit too hard to explain exactly the way to get it right the first time but what you can do is this:

Plug in one motor backwards and see what changes (make sure motors are OFF before removing and plugging back in).

If that does not work, swap the motor plugs and see what happens.

Then flip the other motor plug backwards. Eventually you will either understand how the driver is trying to work, or you can methodically try each combination and get it right. Trust me, there is one combination that works without changing firmware. There are only 8 combinations:

X                        Y
M1 forward          M2 forward          
M1 forward          M2 backward
M1 backward       M2 forward          
M1 backward       M2 backward
M2 forward          M1 forward          
M2 forward          M1 backward
M2 backward       M1 forward          
M2 backward       M1 backward

Thank you. This was brilliant and I found my correct setup at 6th step.

Quote
Hazer
When I setup my HBOT, I had this kind of problem too. Its a bit too hard to explain exactly the way to get it right the first time but what you can do is this:

Plug in one motor backwards and see what changes (make sure motors are OFF before removing and plugging back in).

If that does not work, swap the motor plugs and see what happens.

Then flip the other motor plug backwards. Eventually you will either understand how the driver is trying to work, or you can methodically try each combination and get it right. Trust me, there is one combination that works without changing firmware. There are only 8 combinations:

X                        Y
M1 forward          M2 forward          
M1 forward          M2 backward
M1 backward       M2 forward          
M1 backward       M2 backward
M2 forward          M1 forward          
M2 forward          M1 backward
M2 backward       M1 forward          
M2 backward       M1 backward

Thank you!

This solution work for me at my corexy printer.

Best,

I wrote a blog post on setting up coreXY motion.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Great blogpost, made setting the new printer (modified hypercube evolution) really easy. Thanks for your work!