stepper motors don't move

MarlynSofia
Posts: 9
Joined: Tue Feb 25, 2014 12:04 am

stepper motors don't move

Post by MarlynSofia » Tue Feb 25, 2014 2:07 am

I got the full stock Shapeoko 2 a few days ago. We finished the assembly on Saturday night and I was ready to say Hello World on Sunday morning. Well.... it didn't go as planned. First, when I hit Send to write Shapeoko on the air I noticed the scale of the letters where bigger than the work area. Also the X and Y axis where not running in the correct direction.

I changed the Grbl settings to invert X and Y by changing $6 to 96. It didn't work.

The settings of my grbl were different to the ones recommended in the instructions so I went ahead and changed them to the recommended settings. At that point I also switched the green and black wires of both X and Y stepper motors. Now when I connect the arduino to the computer the motors make a particular sound they were not doing before but don't move at all.

These are the settings I used....


Grbl 0.8c

$0 = 40.20 (steps/mm x)
$1 = 40.20 (steps/mm y)
$2 = 320.00 (steps/mm z)
$3 = 30 (microseconds step pulse)
$4 = 500.00 (mm/min default feed rate)
$5 = 500.00 (mm/min default seek rate)
$6 = 28 (step port invert mask. binary = 00011100)
$7 = 255 (step idle delay, msec)
$8 = 25.00 (acceleration in mm/sec^2)
$9 = 0.050 (junction deviation, mm)
$10 = 0.100 (arc, mm/segment)
$11 = 25 (n-arc correction, int)
$12 = 3 (n-decimals, int)
$13 = 0 (report inches, bool)
$14 = 0 (auto start, bool)
$15 = 0 (invert step enable, bool)
$16 = 0 (hard limits, bool)
$17 = 0 (homing cycle, bool)
$18 = (homing dir invert mask, int:00000000)
$19 = 25.000 (homing feed, mm/min)
$20 = 250.000 (homing seek, mm/min)
$21 = 100 (homing debounce, msec)
$22 = 1.000 (homing pull-off, mm)

Any thoughts or ideas?

Thanks

dweibel
Posts: 1
Joined: Sun Feb 16, 2014 8:49 pm

Re: stepper motors don't move

Post by dweibel » Tue Feb 25, 2014 2:24 am

Sounds like I'm about the same point as you with a slightly different issue.

Purchased a full kit and finally got everything together this weekend. Yeah! Tried hello world and it didn't work. No!

I have my X and Z axis working but I'm having troubles with my Y axis. My Y axis motors are making a sound like they are grinding? or something. But there is no movement. At first I thought the gear was just spinning across the belt teeth. So I disconnected the belt and put a piece of tape on the motor gear. Its not turning so the grinding sound is within the stepper motors? Not sure how to debug that...I guess I will unmount the motor and try then stand alone again.

The most useful debug thing I have found is using the "Universal GCodeSenders" Machine Control and pressing the X/Y/Z +/- options to manually test things.

cvoinescu
Posts: 4442
Joined: Thu Jul 19, 2012 6:50 pm
Location: Camberley, UK
Contact:

Re: stepper motors don't move

Post by cvoinescu » Tue Feb 25, 2014 9:29 am

I know this is obvious, but check your connections. If the motors worked, you moved some wires, and they stopped working, maybe it's the wires. Each motor has two pairs of wires (red and blue are one pair, and green and black are the other pair), each pair connected to a winding (coil). Each driver has two so-called H-bridges, each of them designed to drive a winding. If you accidentally wire a motor with one wire of a pair into one H-bridge and the other wire into the other one, it won't work, but it may still make noise and vibrate. Also, if one wire isn't connected properly, so that only one coil is powered, the motor may vibrate and not move at all (or may move slightly in a random direction).

Dweibel: try increasing the motor current on the Y axis. Turn the Y axis trimpot up (clockwise) in small increments.
Proud owner of ShapeOko #709, eShapeOko #0, and of store.amberspyglass.co.uk

MarlynSofia
Posts: 9
Joined: Tue Feb 25, 2014 12:04 am

Re: stepper motors don't move

Post by MarlynSofia » Wed Feb 26, 2014 1:52 am

Thanks for the suggestions.

After checking the wires a few times I was sure I somehow messed up the grbl settings. I downloaded xloader and flashed grbl 8 again following the instruction in this page http://www.shapeoko.com/wiki/index.php/ ... uring_Grbl

I still need to fix and fine tune a few things but it worked, all motors are now moving. I tried Hello World once again and the scale of the letters seems to be correct now.

jbernardis
Posts: 42
Joined: Tue Mar 04, 2014 5:21 pm

Re: stepper motors don't move

Post by jbernardis » Tue Mar 04, 2014 8:32 pm

I too am having difficulty getting any motor movement. I am using an Arduino Uno and the Reactive GRBL shield. I am using the Universal G Code sender on a ubuntu platform. I am able to connect to the arduino and see/change the configuration, but when I try to move the motors, nothing happens.

I am familiar with adjusting the current on my pololu drivers as I've been operating a Reprap 3D printer for over a year, but nothing I've done has made any difference. I can increase the current to where the motors vibrate and make noise, and I can also hear the motors turn on and off if I reset the arduino. But when I go to the manual control tab of the program and try to move the axes, I get no motion whatsoever.

I've disconnected the motors and hooked them up one by one to a big easy driver I have that is being driven by an arduino with a test sketch. I am able to move the motors just fine in both directions. But when I reconnect to the GRBL shield, nothing happens.

I'm at work right now, so I can't try this, but it just occurred to me that something I saw on the sender's screen last night seemed odd. When I hit the movement buttons on the screen, I could see the commands that were being sent in the log. What I saw was this: "G91 G1 X100". Can I really merge the G91 set relative command with the G1 movement command on the same line? Or should there be a new line between. From what I know of Marlin over in the 3D printing world, I'm pretty sure it would ignore the G1 and after and only set the axis to relative movement. Could that be what's happening here?

cvoinescu
Posts: 4442
Joined: Thu Jul 19, 2012 6:50 pm
Location: Camberley, UK
Contact:

Re: stepper motors don't move

Post by cvoinescu » Tue Mar 04, 2014 8:43 pm

That is actually correct G-code, and it's the same as putting G91 on one line, and G1 X100 on another line.

Did you enable homing? If you did, GRBL will refuse to move until you've homed the machine ($H).

Did you build GRBL yourself, or did you use a pre-built binary (.hex file)?
Proud owner of ShapeOko #709, eShapeOko #0, and of store.amberspyglass.co.uk

jbernardis
Posts: 42
Joined: Tue Mar 04, 2014 5:21 pm

Re: stepper motors don't move

Post by jbernardis » Tue Mar 04, 2014 8:59 pm

I used a pre-built binary of GRBL.

Initially I thought I needed to home, so at some point I entered the $H command and nothing happened. I also played around with the config boolean, but I ended up leaving it in its original state: 0.

Incidentally after I tried the $H command, every time I reinitialized the board after that I got some warning. I forget the exact wording, but it led me to believe that it still have the home command queued, and it suggested that I could enter $x to get past this. I did that - and it cautioned me, but I proceeded anyway.

I'm beginning to think I made an assembly error on the board. I've examined it and it looks OK, but I'm thinking of going with an alternate product. One thing I didn't like about the Reactive Substances was that I had to use headers with extra long legs because there was absolutely no clearance between the board and the USB connector on the Arduino. If I hadn't used the longer legs, the USB connector would have shorted out the board.

cvoinescu
Posts: 4442
Joined: Thu Jul 19, 2012 6:50 pm
Location: Camberley, UK
Contact:

Re: stepper motors don't move

Post by cvoinescu » Tue Mar 04, 2014 9:47 pm

They used to supply the boards with regular male headers, and Arduino-style female headers with long pins, to use as extensions. I managed to find the really tall ones for my board (GAUPS), so it clears the USB by a few millimeters.
Proud owner of ShapeOko #709, eShapeOko #0, and of store.amberspyglass.co.uk

jbernardis
Posts: 42
Joined: Tue Mar 04, 2014 5:21 pm

Re: stepper motors don't move

Post by jbernardis » Wed Mar 05, 2014 12:25 am

Ok - here's an update. I get movement out of all three axes, but there is still an issue,

First off - in all the futzing around with the stepper drivers, I managed to destroy 1. So I had a spare so that is now in place.

Now the issue. I can enter all the G1 commands I want, but nothing will move until I enter the "~" command (start cycle). Is this normal? Is there a setting I am missing? Nothing seemed wrong in the GRBL config. I do have some axes that need to be inverted, but I can fix that.

cvoinescu
Posts: 4442
Joined: Thu Jul 19, 2012 6:50 pm
Location: Camberley, UK
Contact:

Re: stepper motors don't move

Post by cvoinescu » Wed Mar 05, 2014 3:20 am

Proud owner of ShapeOko #709, eShapeOko #0, and of store.amberspyglass.co.uk

Post Reply