I do not know if the issue is the machine or the software, but here is the condensed version:
I needed a part, could not find it, decided to make it myself. I am on my second Nomad3 and 12 months in, and have yet to have a complete run where I don’t get either the machine stopping randomly or I get some error, most often ‘limit switch hit’.
This started over a year ago. I want to make the part out of aluminum. I designed in SketchUp, did a couple prototypes on a 3d printer while I was developing that. Then I used renshape 450 to make it on the nomad3; that took over 10 tries to get one done. Not once did it go all the way through without having to start over - a process which is very time consuming because I have not been able to find a way to move forward in the toolpath and start where the error/stoppage was. That’s a separate issue; I am sure with the right knowledge you can do that but I have been too busy with the machine/software failures to spend time learning that one.
Anyway, long story shorter- yesterday I spent the entire day getting this set up. After many trials I was reasonably confident I have the right bit, feeds and speeds, and thought I was all set. I started the top run (this part will have to be flipped to complete) and literally watched it for hours, trying to notice anything that may not be right. Speed seemed to be fine, not stressing anything too much; speeding it up seemed to cause a vibration so settled in on something that seemed smooth. The depth per pass seemed to all be good. The contour offset pattern was actually kind of cool. I let it run for a few hours, watching it 50% of the time, and it was all good. I did a couple 2 hours passes to evaluate what kind of chips would be generated to see how long I could go without vacuuming them up.
I cleaned up chips and left my shop at midnight and let it run, knowing I would be back at 4:30am. When I got back this morning:
The ‘contour offset’ pattern had become something that looks like a 2 year old with a crayon would make.
Error message “limit switch hit”
The aluminum that I milled so I could bolt it in place is ruined for making this part.
I cannot do this anymore. I do not know if it is the software or the hardware; I do know that the combo does not work for me, has never worked for me. I have literally 100s of hours into trying to make this part. I expected it to be a long journey with bumps on the way, but I also expected it to be rewarding in the end. I did not go into this expecting to be here 12 months later and giving up. Several thousand dollars and hundreds of hours, and I find myself typing a forum post that says… F*** this, I give up. This s*** just does not work.
So now I start my search again on how to make this part.
Please do not leave the machine running unattended.
Please let us know the specifics of how your machine is plugged in (is it on a circuit w/ another heavy load such as a compressor? Can you try it on another circuit? Is it plugged into a GFCI outlet?) and photos showing your setup to support@carbide3d.com
(I don’t see an open ticket for you)
The best way forward in CNC (as in most things in life) is to learn from failures and problems — one won’t make any progress if one doesn’t determine what caused a failure and so learn to avoid it in the future.
What CAM tool are you using? What feeds and speeds and tooling? Cutting what alloy of aluminum?
the machine is plugged in on a dedicated, separate, 20a circuit. a dell inspiron laptop is also on that circuit, that’s all.
I had many ‘support tickets’ when I first started this, there was never any resolution as to what caused the issue. I agree that learning from failures is the key, and I was ready for that. But to date not one ‘cause’ for a failure has been made clear. Carbide did take one machine back due to repeated ‘limit switch hit’ errors, replacing a few switches, and giving up on that machine. I bought another from a 3rd party. The closest I ever got to a “cause” was the line from Carbide, direct quote, “sounds like a hiccup in the software”.
Aluminum is 6061- T6511. I have learned through trial and error what works with the aluminum. I originally started with the defaults in Meshcam when selecting the material “aluminum/metal” in the software but quickly found out that was not even close. I feel like I have that figured out enough to move forward, but then this result. Always some “hiccup” or error message, and never a clear, objective item or process to change to correct whatever happened.
I am using Sketchup to design and export to 3d file. then Meshcam, then Carbide Motion. I have not shut down my machine yet, or closed Carbide Motion, in case there was a way to diagnose something while it is still open and on. But like I keep saying, I have yet to have any direct reason for these failures so i don’t hold out much hope there.
screen shot attached of Meshcam setup, also will upload mcf file.
edit: this is the third circuit since project start.
edit: yes, I could have been here to watch it go off the rails. would that have told me what caused the issue this time? maybe, but I will bet against it. the point is that it goes haywire every time, not that I wasn’t here to witness it.
Here is the email from Carbide support- thank you for the response. Also below that is a question that maybe someone can answer before I proceed.
Carbide: First thing noted is that you are leveraging a 1/4 inch ball mill for your roughing. I think the only time I’ve used 1/4 tooling on aluminum in the nomad has been for facing stock with super light passes. I think it might be worth leveraging 1/8 tooling because the nomad doesn’t have the torque to run 1/4 tooling. Replacing the 1/4 with 1/8 endmill for roughing, you’ll need to change defaults for meshcam. I think they were probably populated with the nomad 883 pro. Pulling the default feeds/speeds for aluminum in carbide create (which I usually find to be a good starting point for feeds/speeds), I get (in inches) .062 stepover, .008 depth per pass, 10 for plunge rate, and 20 for feedrate, with an rpm of 24000.
My question: If this is the issue then I should be able to cut this using renshape, correct? Very little resistance but same size stock and same file.
I will try that first; please confirm that this should work, as it is eliminating the torque caused by aluminum.
I think softer/easier to machine material is a better place to be in to prove the toolpaths. I’d still move to a 1/8 inch endmill as well.
I’ve certainly been in a similar state where you are. The first project I wanted to do was a multisided operation of an stl, and I think from start of ‘hey this would be cool’ to actual project finish it was maybe a year and some change? Bunch of ruined stock, lot of learning what fusion360 is, gaps in wanting to do anything. It was frustrating path, but eventually I got there.
makes sense to switch to the 1/8" for the trial. but to me, this doesn’t look like a “torque” issue. I have pictures of before and after it went off the rails but this sight won’t let me post them
I’m pretty firmly in the “hobbyist” category of machinist so I won’t offer any technical advice.
But i will say this, I’ve played with cutting aluminum on my nomad3 for a year and change now. With all that time and practice, i am just now starting to develop a good intuition for what causes things to go just right (or horribly wrong)
There are a lot of knock on effects and strange things that can happen when something relatively small goes off the rails.
I guess what I’m trying to say is that you might save yourself some frustration by taking a step back and evaluating if you’ve got the intuition to make assumptions in terms of troubleshooting.
To me, your issues definitely sound like they could be related to torque (or rather, a lack of torque)
Skip a step or stall a spindle here or there and they can add up to a mess that looks like nothing you’ve seen before
Just to be clear, I’m not saying you don’t know what you’re doing. I’m just saying you might not and if that’s the case, you might be able to save yourself some frustration by letting out the reins a bit.
Anyway, good luck to you. If my experience is anything to go by, I’d say you’re in good hands
