I have encountered unexpected problem with my Nomad 883 Pro. I spent last two days cutting some aluminum brackets for a project and today, after about 8 successful cuts I had tool dug into a material and ceased. After this accident I couldn’t make a single successful cut for two days. I have switched between 5 different pieces of stock material. I have replaced tool for new #102 bit and it still gets jammed diving nearly 2 mm into material in process on the first pass.
I use 6 mm thick 6061 aluminum stock.
Nomad #102 flat tip bit
Depth of cut per pass is 0.15 mm
Milling speed is 250 mm/min
Spindle 10000 rpm
I use sprayer to cool down the bit in process and there was always some water covering the cut.
Is there a possibility that something got lose in the machine itself? Z axis stepper for example? It still feels rigid and I can’t feel any play. Material is also securely fastened to the table with bolted clapms. My thinking is that something was yielding to allow the tool such a deep dive into the part. Trying to narrow down what it could be.
Is the tool slipping in the collet? Check the collet, tool shank, and collet seat for cleanliness, and that there are no chips in the slots of the collet.
Is the zero properly set? (check: increase z0 by, say, 10mm and run the job. It should start 10mm above the material)
Lots of other possibilities, but these would be first on my list.
Thanks for reply. Yes, the tool is super tight in the collet and after the jam is seems to return to correct zero if you jog it back.
Zeroing is a whole different story. I have posted a separate subject on that. It remembers the zero fine but after tool measurement cycle it often comes 2mm too high or too low to cut the part resulting in either tool hovering 2mm above the part and slowly lowering as it goes or jabbing the part ans ceasing on the spot. Its not happening 100% of the time. I’d say 50/50. When it comes to cut at correct Z position then it slowly digs into material and within an inch from starting point it buries itself to 2mm deep and stops.
Presuming that you are running the same g-code that was successful in the past, I am not sure where to go from here. There are a lot of possibles. The up-or-down 2mm is weird. If the spindle is moving in the mount, I don’t think it would move back on its own unless so free that you could move it easily.
The slow drop sounds like the tool walking in the collet, but if that isn’t it, the only thing that has a familiar feel is when I toasted a control board (note to self: don’t mill Grade-1 titanium with a Nomad), but doesn’t sound the same, as ALL axes punted negative at max feed once the machine started, not selectively, and your settings appear right in the zone to me.
On inconsistent height I tend to suspect the tool measure probe. It may react randomly which affects starting height on every cut. But for burying into material there must be some other mechanical reason. Softer stock is cut without problems. Its that aluminum stock that seems to be pulling bit in and machine can’t resist it.
I have identified the problem. Spindle core is lose and moves up and down limited by the pulley on top and larger diameter close o collet. I can even move it by hand now. Wonder if it is user serviceable or I shall get a replacement?
Suggest replacement. I know there was one user who has been inside the spindle to replace the bearings but i suspect it is probably not easy and may not result in proper operation.