Hi Guys,

I just attempted a surfacing job and it stopped 2/3rds of the way through. No alarm or limit switch. Just stopped all movement. I have an xPro with commands being sent using OpenBuildsMachineDriver software. I took a short video of the interface when it stopped. You'll see there are no errors. The interface says its idle. Though the video doesnt show this, pause and stop jobs were unresponsive. The gcode was generated from Fusion360 using the strooom post. I'm running all of this on Windows 10 laptop with no power saving settings enabled.

On the hardware side, its a Dewalt DWP611 plugged into a separate circuit than the controller. The usb cable has a big ol ferrule on it and is no where near the vacuum or router wires. The router power cord isnt bundled with the machine wires. All of my motor and limit switch wires are shielded cables with the drain wires attached to a ground bus.

With all of that info out of the way... I did notice the machine lagged on the last change of direction just before this happened. The best way I can explain it is that is seemed it had to think about what to do next. Like buffering or something. What does the "Queue" number mean in the bottom right hand part of the OBMD screen mean?

 

Queue = how many lines left to send (when it gets to zero the job is done).

If theres any errors they popup onscreen (from v1.0.110 onward) so you dont miss them. If you havent, please update to 1.0.110

Try again, see if you can pickup a pattern. Once off happening is probably just some EMI on the USB.

The driver doesnt pickup very quick disconnect/connects (as there is some expected latency) - so run USBLogView - Records the details of any USB device that is plugged or unplugged into your system and see if the device drops in/out (you can keep it running at the same time - very helpful tool)

 

Cool. I'll run it again today. I was on 1.0.110 when it happened. I'm the one that requested that the error messages stay on screen a bit longer

 

I had a similar issue. Turned out that the screw holding one of the Y axis belt tensioners vibrated loose. Re-tensioned the belt and the problem went away.

 

It looks to me as if the error is in the X-Axis, left to right.
However, it seems to be in exactly the same place, if it were me, I'd run the same program a couple of times and watch for any variation in error.
Maybe position your piece of material a couple on inches up or down, to see if the error is repeated in the equivalent position, or if the error moves with the position. If you can see what I'm getting at?

 

Are the steps/mm for the motors just a starting point? I just checked my Y axis and its not moving far enough for the given distance. (i.e. only 398mm instead of 400mm). I have it set to 26.667 as per the doc. I have checked the ruler I'm using with two other rulers to make sure thats not the problem.

 

That is just a starting point. You need to calibrate each axis like this:


There are other higher production value videos on the topic on youtube, as well. Also see this for more info on steps/mm calculation.
gnea/grbl

 

So for your situation (only going 398 istead of the 400 commanded), the math looks like this:

commanded 400mm/actual 398mm = 1.005025125628

1.005025125628*26.667 theoretical steps per mm = 26.801005025122 actual steps/mm

If you saw my math grades in both high school and college you would realize it would be best to double check this yourself.

 

Its more like 1515 x 1013 without motors. Add the length of your motors to the 1013 dimension. The drag chain runs under the motor so no need to account for that.

 

The easy solution is to build it with the rails under the bed laid flat like in the 1010. Just remember the farther you make the Z-axis reach, the greater the leverage that is applied to the system which can lead to torsional deflection of the X-axis resulting in lower quality cuts.

 

Yes and Yes. There's a guy selling 1" taller Y plates on ebay. You can also lower your wasteboard. You can even change you Z axis: Ideas to increase Z-axis cutting height in the Workbee cnc ?

 

I've gone through a few different setups. Currently, which I'm happy with, I have 3 20x80's laying on the 80 side with bracing in between (ignore the Y beam supports since you cant do that with a stock setup): Shawn's Workbee 1510

Edit: Found a better picture



Edit Edit: I guess I should explain that I dont attach my wasteboard like the stock build. I have a single sheet that I attached drop in t-nuts to that attach to the 20x80. Then on top of that I have replaceable sections. That way I never have to lift the frame up to change out any of the wasteboard.

 

The "Build" convers the writeup: See OpenBuilds Workbee 1510 (60" x 40")
Video: See (Embedded in the Build page linked above too)

 

Ahh good catch, I will alert the video team that the "chapter" links are broken!