Help - cannot finish a project without "drift"

[diyguy (james lowry)]

So this has been covered in different threads that were on different subjects, but I want to put it all here to see if I can get some resolution.

I have this Nomad 3 for over a year now. I have yet to finish a project without some kind of major malfunction that results in throwing away the stock and starting over. When I bought this machine, my understanding from what I read and was told on the phone by Carbide, was that I could load an stl file into Meshcam, create toolpaths, and cut aluminum. I know it is not that simple, but that has yet to happen. The machine seems to “drift”, almost every time I use it. From renshape to Aluminum, I have many examples of the same thing. And each time I see this happening, the first thing I do is check to see if the stock has moved and it has not. Even checking xy zero shows that the machine still has that set correctly. The last time I used it is drifted left into about 1/2" of aluminum and was taking shavings off the sidewall. I was in the other room and went in to see what the extra noise was about, I could see the spindle chattering, visibly moving around. I shut it down immediately and checked xy zero - it was right on. If anything it was a hair right of zero, which is the opposite direction of the ‘drift’.

I have many examples of this, some just gradual like this last one - where you can see how it was moving a bit (or a lot). Sometimes it is imperceptible until you go back and look at it closely afterward. Other examples are extreme and the thing was all over the place. But one thing is common to each attempt - I cannot finish a job without having to abort due to this issue.

Now the spindle does not feel tight; I can move it a bit if I hold the bit and wobble it. So I think the machine needs repair, and I cannot waste more time and money trying again until I get some resolution on what is going on.

I have spoken with Carbide many times when this first started happening, The closest to a solution I got was “may be a hiccup in the software”. Not sure what to do with that. I have a ticket in right now but they are ‘backed up’ so playing a waiting game there.

Does anyone have more “theories”? I really don’t know what to do to cure this. I am dead in the water after a full year of trying with no success.

[Robthatguy (Rob)]

Post your feed and speeds + photos of your machine and work holding + photos of your cam tool paths

[Faux_Ton_Ick (Michael)]

The one I operate here at work is used exclusively for Aluminum. Try running the same job with a different material, like MDF, or even a piece of pink foam insulation and see if you still have drift. If you don’t, then your parameters likely need dialed back. What I’ve learned is your feeds have to be extremely conservative. Spindle speed maxed out, but feeds tuned way way down.

[flynnjs (Jason)]

@diyguy

I shut it down immediately and checked xy zero - it was right on.

If you stop a job, it re-homes and therefore any missed steps are reset out of the system so when you go to check alignment it all seems fine. I started getting missed steps on my Z axis a few weeks ago and had to give the blocks a really good clean and oil and it was fine after that. This sounds like missed steps but that can be due to either mechanical or electrical issues.

What depth of cut are you using on Alu? Alu needs a very shallow pass on this machine.

@diyguy

Now the spindle does not feel tight; I can move it a bit if I hold the bit and wobble it.

That is definitiely not right. I’ve had this and support@carbide3d.com got me sorted out.