X-AXis Run at Power On

[brightnight]

A few years ago I ran my mill once or twice on test parts and it worked well. I only ran it a couple times a few years ago due to time contraints but recently rewired it and getting it going again but don't have enough experience running it to know what's normal or remember the software setting I had. I have Gecko G320x motor drives running off a 60V supply and my mill is three axis and a daul Y motors. I have the power to everything in my mill going to a single power strip. There are two things I could use help with:

1) As soon as I turn the strip on my X-axis motor starting moving fairly quickly toward the side of the ball screw. At this point the computer hasn't booted up and the centroid software isn't even running because I just powered everything on. The X-axis running away has happened twice at power on (only on the X-axis) and I'm afraid to turn it on and have the X run into a hard stop. I'm in the process of setting up my limit switches but expected each axis to stay in one place until comandded by the acorn software. Why might my X-axis run as soon as it's powered on? For the axis to move I assume the brakes must be off and the driver must be sending a signal to the motor. Does the squaring process happen as soon as power is applied even if the sofwate hasn't booted up and does it normally start with the X-axis first? I can remove power from the X-axis and setup my limit switch but woud like to understand this issue more. If the software isn't running yet then I assume my limit switch won't do anything even once it's setup correctly unless the acorn CNC boards implements the squaring/limit switch process whenever power is applied.

2) I originally had my motor brakes wires to the NC relay so as soon as power way turned on the brakes would turn off. However, wiring it this way was too much for my supply at startup and it wouldn't start going into short circuit protection. I then wired the brakes to the normally open section of the relay. I I found the NO and NC pins of the relay by checking for continuiny when the relay was off. Is there a document showing a schematic for the relays? I looked by could only find documentation and videos for the old relay boards which had the NO and NC drawn in the silkscreen but my relay board is much newer and doesn't require an adpater board. If the brake is connected to the NO then I'm surpised the X-axis can move at all and I hear no clicks to indicate any of the brakes have been released when everything is powered on.

[cnckeith]

probably bad encoder connection, the drive is providing power to move the motor and doesn't see the encoder so it sends more power to get movement etc...

motor brakes are usually spring powered and do not require power to be in the "on" (brake applied) position, they require power to Remove the brake.

[brightnight]

Thank you, apprecaite it and will get back after I look at the wiring tonight.

Since my motor is all the way to the left (almost as far as it can run before it will hit the side) I want to move it back to the right side so it has more room to run if this issue happens again at startup. However, the way I have the motor mounted means unbolting it will be time consuming. Can I reverse the the PWR and GND on the motor side so it drives in the opposite way to get it back to the right?

[Gary Campbell]

It appears that you have some wiring errors in your build. The motor drives should not be getting power until the control software has booted up and does it's error check. Feed your drives thru a contractor that is activated by a relay designated as "NoFault"

[silver2row]

Hello,

AC/DC drives go to DB25. After that, make sure to use a specific mushroom head of sorts for halting and recounting back into the CNC12 source for altering your screen dialog.

Alter the x-axis, y-axis, and other formally known axes to move correctly until completion. There is a way to know but it will take the book.

By the way, to Centroid here, those two manuals for mills and lathes are full of detail and knowledge. Thank you...

Seth

P.S. Anyway, use the PWR and GND of the mushroom head e-stop at the correct pins also. Without that direct, correct connection, nothing will do as formally introduced.

...

I also use Gecko drives, smaller-insignificant compared to the G320 drives but nonetheless usable and very strong. Those puppies can handle some heat, driving force and even the magic smoke at times when I am too wiry to get it right. Did you post your set up yet? Use google photos... I can wait to see if you post later but some intricate wiring is sometimes made simple with a few tests and right about the continuity of L N G. Line is power, Neutral is well Neutral until fail for reverse current, and GND is well...yep. GND and it is for the backup of Neutral.

With that in mind, go slow and use the DB25 for the drives on specific pins or pick your own pins on the set up dialog for the DB25.

I have also noticed, and when I first started to learn more about the mechanical and electrical aspects to the Acorn CNC and CNC12 with a build, random occurrences but I was at fault. So, while powering your 24v or 5v supplies, find a common GND/COM.

from a website online

RelayOne.gif (8.48 KiB) Viewed 2379 times

Here is a starter photo of a random switch (mechanical) that needs electricity to become excited so that the coils attach or detach...

Do you have a e-stop?

[silver2row]

XYZ...

If endstops are located at various positions on the machine, tie them in (my opinion) to a single port/connector for input for each, separate one and output should be, well, for drives on the DB25.

If I am way off, okay. Just providing assistance. You can say negatory or whatever.

Seth

[brightnight]

Apprecaite all the input, all of you are extremely knowlegeable and I apprecaite it. I cleaned up a couple connetions on my x axis. It looked like my stepper driver 5V and Channel B wires might have had a short from the wire poking through when it got too hot during soldering. Doesn't explain why my x axis was moving at powerup but it's no longer moving at power up, I'm still trying to figure out why that might have been.

I can confirm my DB25 is wired correctly. I do have a E-stop and that had worked perfectly in the past and I didn't change of the the wiring for it, just the wiring from my motors to my motor drivers. My estop has two NO switches, both of which go to the relay. One NO switch on the E-stop goes to a NC relay which connects GND to the ERR/RES pin on my gecko driver. The other NO E-stop switch goes to the NO relay which connects 24V and GND to turn my motor brakes on/off.

I wired power directly to my steppers so when I turn everything on they get power at the same time. Since my motors are braked by default I thought that was ok, the Acorn should only enable the drivers to move the motors once it decides too with the relays but might have to revisit this after Gary's comment. Looking at the Acorn CNC standard connections axis brake release schematic I'm confused by what the Coil Power Supply is. Is the coil power supply the same as the Motor power supply?

I haven't posted photos because I figured the wiring will be too wild for anyone else to understand. Have all the signals running on ethernet cables to panelized connectors on the back of a metal touchscreen housing and then into the steppers. I ran seperate (red and black twisted) power cables into the back of the touchscreen housing as well (also panelized). The goal was to make cables easy to remove for the next time I have to mose. Despite these pictures, once it's up and running should be a pretty clean build.

[cnckeith]

brake is a separate power supply , and is not the same as motor supply, if you hooked it up to the motor supply you might have fried the brake coil.

getting old DC servos running well with step and direction is an advanced project.

i would seriously consider switching to well documented , easy , 'plug and play' axis motors and drives this is the way to success.

for this size machine it would be affordable and the time savings would easily pay for them.

[brightnight]

Appreciate the suggestions, I'll look into it. Do you have a suggestion for a plug and play motor? Looking at the Teknics clearpath integrated series, they start at $250 a motor so was hoping to avoid dropping another $1k on this project but will consider it.

[cnckeith]

can't go wrong with leadshine closed loop steppers when you are on a budget.