How could the hardware change?
There has been an unknown amount of thrashing around, so itâs worthwhile to start debugging from the basics.
For example, I wonder about the (computed) 6525 step/rev setting, because casual rummaging shows many drivers with 6400 step/rev, which would give a nice exact 6.25 ”m/step, rather than 6.130268 ”m/step. Iâd like to make sure the driver really does that and what its other choices might be.
Bonus: introducing somebody to how this stuff works is never a Bad Ideaâą.
Bear with me on this âŠ
I dont mind checking all the settings mainly because I bought it used and since I never did the initial setup, Lord knows what the settings are. This is also a learning curve for me and Iâm anxious to learn the steps to fix it.
Right now the carriage is placed in the middle of the work area and homing is disabled, and when main switch turned on just sits there without moving, good so far, Yesterday I had wrote and sent the maximum travel for âXâ and Y" of 690MM and I believe 480MM and now when using the controllers arrow keys the carriage travels the full length as it should.
I opened lightburn , tried to frame a small rectangle near the middle of the bed and it brought the carriage to top left limit and the âXâ motor kept trying to do as previous jumping around like crazy.
I will go out to my shop now and check the switch settings.
Most people want to use the laser, not understand how it works⊠If they are interested thatâs one thing⊠to assume that is another.
Some people walk away when it gets too confusingâŠ
Here is the dip switch settings for the âXâ and âYâ motor drivers. both are the same
1.off
2. on
3. on
4. off
5. off
6. on
7. off
8. on
Tom
I took a pic of the driver switch table settings, however my assistant is not here today to help me attach the pic to this thread
. . If you care to send me an email at ogatrains@gmail.com I can send you the pic back by email
failing that what settings shouldI be looking for on the table ?
Tom
And, based on personal experience, stepper motor configuration isnât in that particular wheelhouse ⊠
Excellent! That was the next thing to check and set, because 380Ă300 sounded small for a COâ laser.
Now one part of the configuration matches the actual hardware!
Because the machine no longer homes when it starts up, the controller assumes it starts up at the home switches. Putting the head in the middle of the platform, which seems like a reasonable place for you and me, means the controller thinks itâs in one corner and moves relative to that position.
Chaos ensues, but for a known reason.
Now you must look those setting up on the table printed on the side of the driver case, which is certainly screwed into a position where you canât actually read it.
Remember: your drivers may not match my drivers.
For example, assume those were my switches. The picture of my driver shows Switches 5-8 OFF ON OFF ON on the line with 6400 step/rev.
If thatâs what your driver says, weâve found another misconfiguration!
on the table showing 6400 pulse/rev it shows same as yours
5 -8 , off,on,off,on
sw4 is off for half current
the current table (top) shows peak to be 2.1,RMS to be 1.5, sw1 off, sw2 on, sw3 on
to repeat switch settings:
1-8 = off,on,on,off,off,on,off,on
Tom
Bingo!
Now you can compute the correct distance per step:
6.25 ”m = (40 mm/rev) / (6400 step/rev)
In the Vendor Settings for both the X and Y axes, on the Step Length line, change 6.13 to 6.25 and write it out.
Changing those values means the controller will now move the head the correct distance. Previously, it would move 2% too far, which you would eventually notice when you tried to cut something spanning the entire platform.
The settings for SW 1-3 set a reasonable current, although we may have reason to bump it up when we get to speeds & accelerations.
Because laser cutters donât need much force to maintain their position when the head isnât moving, leaving SW 4 set to Half Current reduces the power dissipation when nothing is going on.
Now that youâve set the platform size and step length, itâs time to get homing working.
Do the home switches light up when you threaten them with a cold steel knife blade?
the âXâ and âYâ homing switches can be easily depressed by hand and when depressed turns on two different ledâs at the controller so that tells me they are sending the signals to the controller board
Tom
.
I will make the change you mentioned
In your last reply to the thread you wrote 6.13um, whereas the machine settings are 6.310000um, to be changed to 6.25
Is that an error in your calculations or ?
Do you still want me to write it back as 6.25 ?
The 6.31 appears your original configuration screenshots and I mistyped it as 6.13. Keep a close eye on me, because I will, for sure, make mistakes!
You should change it to 6.25, because that value comes from the actual hardware: 40 mm per motor revolution and 6400 steps per revolution. Simply put: this will make the controllerâs configuration match reality!
Belay the knife!
Your laser has mechanical switches, rather than the proximity switches in mine, but watching those LEDs light up means the same thing to both of us: the switches work and the controller can see them.
You described the original homing problem as having the head move to the left and smash into the side.
On my laser, the X axis home switch is on the right.
Is the X axis home switch on the left side or the right side of your laser?
If your switch is on the right, then the controllerâs homing direction configuration is incorrect. However, fixing the homing direction involves two changes. Letâs make sure it needs fixing before proceeding.
ok I will change it to 6.25 and will write it . The homing limit switch is on the top right.
Normally when I turn power to On the carriage which is sitting at far top left will travel to top right and then back to top leftâŠ
OK, so the X axis homing seems to start in the proper direction.
The incorrect platform size and incorrect distance per step confused the controller: the hardware was moving more than the controller expected into a place where it shouldnât go. With those configuration values now set properly, homing should be much less exciting.
The X axis homing dance should go like this:
- The head move rightward at a stately pace
- It will tap the X axis home switch over on the right
- It will back off a few millimeters, then tap the switch again
- On mine, the head remains at the home position
In the Vendor Settings, set the X axis Enable Homing switch to True and write the configuration. Donât change the Y axis values yet; letâs not confuse things with too much motion.
Jog the head to the middle of the platform, turn the laserâs power off, turn it back on, and the head should do the X axis homing dance.
If the X axis moves after homing, then we have more misconfigurations to chase down.
bad news
I wrote to enable homing on the âXâ axis, then read it back which accepted the change, no movement until I opened the laser window in lightburn and clicked on the HOME icon
The gantry moved slowly from middle of work area in âYâ and in âXâ toward the top of bed, then to far left and all hell broke loose again shaking violently, had to power off the machine.
so basically the carriage never moved to the top right and never came close to the âXâ limit switch
which is located near top right position
Tom
I took the âXâ carriage belt off and turned on the machine, the motor turned counter clockwise which would have pulled the carriage to the left, I then finger tripped the âXâ carriage limit switch stopping the motr which would have stopped the movement, then is turned clockwise which would have released the limit switch, then it moved slowly counter clockwise, I then finger triggered the limit switch and motor stopped, describing whet you had mentioned earlier to give the exact adjust for homing. Like I said earlier, seems the carriage travels in the wrong direction.
Note:
funny that since the âYâ movement is still set at false, it brought the carriage in the âYâ direction to do a top homing
Tom
I want to keep LightBurn out of the loop until we get the controller properly configured, which is why I said to turn the laserâs power off and back on again.
LightBurn issues commands to the controller that itâs not configured to handle right now, so thereâs no telling what may happen.
OK, so the X axis homing direction is wrong: itâs moving away from the switch. Fixing that requires two changes.
The X Axis Direction Polarity switch controls the homing direction. Change it from False to True.
Because the X axis now moves in the other direction, change the Invert Keypad Direction switch from True to False. This will reverse the direction of the jog controls, so the arrows move the head in the direction youâd expect.
Write those to the controller, then turn the power off & on again.
The head should move to the right and, if the belt is still off, youâll have plenty of time to blip the switch as before.
If that works and nothing else happens, you can put the belt back on, snug it in place, blip the power, and watch the X axis home the way it should.
Also verify that the consoleâs left & right arrows (not the LightBurn buttons) jog the head in the proper directions. If not, change the Invert Keypad Direction switch back to True. Thatâs easy to get backwards when the head isnât actually moving, so donât get discouraged.
I have changed the invert keypad direction from true to false, there is no change in the direction of the âXâ motor, either way the motor still revolves counter clockwise whether true or false which still pulls the carriage away from the limit switch (to the left
It does however change the Ruida keypad direction arrows to opposite of what is shown
âinvert keypad directionâ set to true - gives correct direction according to arrows on Ruida keypad
âinvert keypad directionâ set to false - gives incorrect or different direction according to arrows on Ruida keypad.
I have only used Lightburn to read and write, Lightburn was not used otherwise
Tom
You must change the X Axis Direction Polarity switch to reverse the homing direction.
You also change the Invert Keypad Direction switch to make the arrow keys move the head as they used to.
Gotta flip 'em both!
Iâm confused. You wrote:
Thatâs what I wanted to avoid, by simply blipping the laserâs power.
LightBurn gives you access to the controllerâs fiddly configuration bits, but does a whole lot more under the covers. Best to keep things simple until we get everything else set up.
Donât worry about getting things wrong or backwards or whatever: none of this will cause any permanent hardware damage: even the horrible graunching sounds donât indicate anything breaking.
If the X axis goes the wrong way, now you know what to change!
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