stepper motors moving pen in the wrong direction?

[nsolcis]

Hey everyone! I just built a makelangelo custom with an arduino mega board and a ramps 1.4.. everything seem to be working great.. except for seemingly one thing.. when using the manual drive controls.. when I press -10 left.. it goes up, when I press 10 right, it moves down.. when I press -10 down it moves right.. and when I press 10 up it moves left…

I tried switching some of the stepper wires around but It just seemed to freeze the motors up..

I tried reversing the orientation of my stepper drivers, but I think that just fried them..

not sure what Im doing wrong..

HeWP!

[Dan]

I hope you reversed them with the power OFF. (dis)connecting motor or adjusting the voltage dial on an A4988 driver with power on WILL kill the driver.

https://mcr.dozuki.com/Guide/10.+Makelangelo+5+construction/3?lang=en#s375

Second thing to check is that you have setup your machine limits. New machines require a factory reset. In the latest firmware that’s an M502 command.

[Pete Moss]

Sorry, the belt was slipping on the left motor and now I can see that when I hit find home both motors move in the same direction (clockwise related to their mounting position, couterclockwise if you were looking at the motor from the side with the shaft).

[Pete Moss]

Hi Everyone! I’m having the same problem as nsolcis

I just built a makelangelo custom with an arduino mega board and a ramps 1.4.. everything seem to be working great.. except for seemingly one thing.. when using the manual drive controls.. when I press -10 left.. it goes up, when I press 10 right, it moves down.. when I press -10 down it moves right.. and when I press 10 up it moves left…

Also if I hit “find home” the gondola goes up instead of down and I need to manually hit the endstops to prevent damage. Do I need to update something in the firmware to flip the motors?

[Dan]

Pete – with power off unplug one motor and reverse it. when homing the left motor should move clockwise and the right motor should move counter clockwise to raise the weights and lower the pen holder.

[nsolcis]

yo DAn…

So i followed your advice, and now the motors are moving in the right direction after some tuning and reversing the motor wires…. thx!

of course now I have another problem… lol

I tried to then run a test print, but the motors just lowered the drawing rig continuously,
im guessing its because I dont have limit switches installed?

previously I built another makelangelo, but I used the older version of firmware.. from 2017 with a regular arduino board.. not sure which version that is.. but It had a “set home” button, and a calibration paper to set the home in the correct position.. there were no limit swiches then.. but it seems that this version (9.2.0) doesnt have a set home and works on the limit switches?

also as I looked through the tutorials, im a bit confused on how to hook the limit switches up and what exactly they do.. can you link me to the appropriate section that explains this? (i couldnt find it myself with my small brain)

thx dood.

ps.. another issue I had was if I moved the motors too fast, they would freeze for a moment.. im guessing this is because the output amps on my power supply is only 3a max.. I ordered a supply that outputs 5a..

[nsolcis]

oh also… perhpas this is the issue? im unsure how to perform this.

Second thing to check is that you have setup your machine limits. New machines require a factory reset. In the latest firmware that’s an M502 command.

[Dan]

If your machine thinks it is a v5 then yes, it is trying to go home forever. Make it a v3.3 in firmware and it will know it doesn’t have limit switches, so it won’t even try.

The older machine with an UNO is a v2. it also doesn’t have limit switches and wouldn’t run the latest firmware.

the attachment steps:
https://mcr.dozuki.com/Guide/10.+Makelangelo+5+construction/3?lang=en#s20
https://mcr.dozuki.com/Guide/10.+Makelangelo+5+construction/3?lang=en#s21

if the machine knows:
– the belt lengths
– the distance between motors
– it has limit switches

then it can drive until the weights hit the switches. At that point it will do the trigonometry and find the cartesian x,y position of the pen holder. This is way more reliable than holding up the test pattern and all that manual work.

Moving too fast is just moving too fast. Above a certain speed the motors just can’t move as fast as they’re told to move, and so they do nothing. Faster speeds can be reached with the right acceleration – eg, ramp up and ramp down.

[Author]

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