All,
Should the gantry be able to hit the end plates? Mine runs all the way to the hard stop and the belt will skip. I see the Max Travel GRBL parameter, but it goes farther than that distance.
The GRBL parameters are not considered by the machine, how far the machine will go is regulated by Carbide Motion. When in doubt, please run Carbide Motion’s setup wizard again, taking care to select the correct size machine in the options. 99% of the time, that fixes it.
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You shouldn’t be able to jog and crash it.
But a g code will ignore any soft limits.
If you tell it to go 6 ft right then it will try to go there. Carbide motion has a warning message based off your machine for z height. I’ve never ran into it for x and y so I don’t know if it will warm you.
As @quicky06 and @wmoy point out jogging and running gcode are different. During jogging the limits are set in the shapeoko.json file and stops you from hitting the physical limits. However running gcode the limits are ignored and you can run the machine into the physical limits.
If during jogging your machine does go far enough left or to the front you can change that by opening CC and then the menu about and Open data directory. In the CM file system is the file shapeoko.json. You can modify the X Y and/or Z. This only affects the left and front on X and Y because the homing sets the right and rear limits. Not likely to want to change the Z settings. You can move your router/spindle in the mount to get lower or higher.
Here are my limits for my SO3 XXL so yours will be different. The numbers represent from the homing position.
“travelX”: -880.0,
“travelY”: -850.0,
“travelZ”: -140.0,
If you change any parameter in the shapeoko.json file you must close CM and restart the application for the changes to take effect. I think the shapeoko.json file is only read upon startup of the CM application. If running MAC OS it might be slightly different. If you modify the shapeoko.json file be sure to save it as a text file.
FYI: A JSON file stores data in a structured, human-readable text format called JavaScript Object Notation (JSON), which uses key-value pairs and arrays to represent data for data interchange between web servers and clients, configuration settings, and data in NoSQL database. It is lightweight, easy to parse, and compatible with many programming languages
Thank you gdon_2003.
Excellent answer, this is exactly what I was looking for and I was able to edit and prevent the machine from crashing into the end piece when jogging. I had to cange it from -859.0 to -855.0, which leaves me less than 1mm of clearance from the end plate. I am curious though, I bought this machine used and while everything seems to function properly, “why dont the stock values work?” I assume everyone else can jog -859.0 mm without any issues.
C3D decides the stock limits of each model they make. During the setup phase those stock limits are put into the shapeoko.json file. Did you get a computer that came with the Shapeoko because if you had your own computer and installed CM and ran setup you should have gotten the stock values. However if the previous owner had changed the shapeoko.json file that may be why you were able to hit the limits. The point is you got it fixed.
One thing that C3D has always done is make the X travel shorter than what is possible. The Suckit dust shoe used to be quite popular on Shapeoko machines. The Suckit had arms that extended beyond the edges of the Z assemblies. That made it possible to ram the arms into the rails. On my SO3 I purposely reduced my spoilboard size so when I flatten it I can hit the whole thing and not leave a line across the back or sides. So I adjusted my shapeoko.json file to I can jog off the edge of my spoilboard but not hit the rail.
Why your machine was able to hit the wall may never have an answer unless the previous owner can shed some light on the subject. The good news is you are fixed and can move on from here.
The last thing I would recommend you check out is the steps per MM. If the previous owner had modified the shapeoko.json file then they may have also changed the steps of stepper motors per MM. If the previous owner had more steps per MM that could cause your machine to hit the wall even with stock settings. This is not a likely scenario but you can check it out.
The steps per MM is not set in the shapeoko.json file but somewhere here on the forum is a post about how to set that or check it. Likely it is in the MDI menu in CM. That function is controlled by the Shapeoko controller. I have never had to set mine from the stock. An example of steps per MM being wrong is when someone selects the HDZ Z when they have a Z-Plus Z. The HDZ had more steps per MM than a Z-Plus. So if you pick the HDZ instead of the Z-Plus your system will cut deeper than intended. C3D has really improved the setup function over the years but the operator error cannot always be avoided.
gdon_2003
This is a fresh install on my own pc, the previous owner had passed and I purchased this machine at an estate sale.
I have verified the steps per mm and they are correct, my only guess is that the homing switch is somehow installed incorrectly, and actuating 3-4 mm early. But as you said, I have it fixed and can move on without any issues.
Thanks again for your help.
Gary
Problem Solved.
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FWIW, I also just went through this. My Standard was setup with -445 and -444 by default, which was too tight for X and not tight enough for Y front.
I ended up at -451.55 in X and -436.75 in Y.
And decided to install my 3rd spoilboard, with pre-flattening removal of thickness from areas not reachable, flattened with a 1.25" fly bit, and then engrave a shallow center line of the max travel in all directions (avoiding the BitSetter, of course). Note that this time I decided to extend the boards forward since that’s where some of my Standard’s precious space is. Should I do some vertical board milling, I’ll just remove the MDF panels and install some others.
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