I’m trying to help another team setup their omio cnc router and I have a few questions/looking for suggestions.
We’re trying to start by drilling a drivetrain hole pattern into wood first to get a feel for the machine in a lower risk/quicker setting than using metal. Whenever it tries to drill out one of the bearing holes, it has a lot of issues, driving to the left while making the hole to the point where it starts hitting the wall of the hole and making it very oblong. It doesn’t do this in the Fusion 360 sim. Is there a way to calibrate it somehow, or otherwise address the drift?
Any other suggestions for a team getting started with an omio would be great. I have some cnc experience from my own team and my high school manufacturing class, but it only goes so far.
This looks like a loose shaft coupler to me. Make sure all of the shaft couplings are tight. On each of the axis drives where they interface with the ballscrew shaft tighten everything down. You may even want to apply some locktite, but I would start with just tightening them.
Thank you. We’re making a sample part right now so we can measure the distance between two holes both with what the machine thinks it is and what it really is so we can get a scope of the error, and we can then take before and after measurements after tightening everything down to see if that’s what caused the issue
Have you by any chance changed your steps for any of the motors? I’ve heard some folks have issues if they change their mach3 units to inches and get some odd steps for the motors which caused oblong holes and such.
Honestly best to ask and search in the massive Omio thread.
Made two half inch holes, with the edges an inch apart. Measured .915 on the calipers. Tomorrow will probably be tightening things down and doing this same test again and measuring the results.
Also, on those holes you made, are you measuring the inside edges or outside edges?
Are the hole sizes under or oversized for what you expected?
Try putting a pencil or a marker in the machine. Set your Z above the wood and use MDI to make a square, or just some linear moves. Mark the starting and ending point and measure them. Starting at (0,0), type into MDI the following:
G0X0Y0
Enter (machine moves to (0,0)) G0X6
Enter (machine moves to (6,0)) G0Y6
Enter (machine moves to (6,6)) G0X0
Enter (machine moves to (0,6)) G0Y0
Enter (machine moves to (0,0))
You might need to change negatives or positives based on the location of your 0
Definitely looks like loose couplings to me. A downside feature of the Omio routers is that you gotta crank down HARD on those couplers otherwise they come loose and result in loss of positional motion.
I’ve found that some masking/whatever tape usually does the trick here. If you mic the couplers they’re usually a decent bit oversized for the screw (which means that the coupler is eccentric…the very problem it is supposed to fix)
Make sure to tighten the coupling on both the motor shaft and the ball screw shaft, and on all 3 axis. The masking tape trick @troy_dietz suggested is a good thing to try as well.
