I was just borrowing the phrasing from that video to keep from switching terms, but at first I was using pocket which follows the shape of the object like the first photo, and then based on your suggestion with that IDC video I used facing paths set to 90 deg to the X axis, and then 0 degrees to the X axis with a .5mm stepdown like in the next 2 photos.
My feed rate is set to 6000mm/min (230 ipm), speed is 24000 rpm. I have increased and decreased this feed rate using the interface where I could drop it 10% or raise it to 200% without a major change.
I’m in Montreal and drove down to pick it up but they wouldn’t let me tour production like that unfortunately. Do you know if they test all electronics? or do they just plug the rails into permanently mounted power supplies? I’m asking because they forgot to pack the power supply for my machine, which might not mean anything, but if they were supposed to test my power supply then it seems like they couldn’t have actually tested it since I had to ask for it after I got everything back here. I think I was one of the first to get these Gen 2’s, I had a schedule where I needed to pick this up by a certain day. They accommodated me but I wonder if that could have caused them to rush something? I’m not actually pointing fingers here, I like this company based on my experience with the X50 and even their response so far to figuring this out with me, just thinking out loud.
If I can find the Elite test cut file, I’ll run it myself and see if this pattern shows up in MDF.
My visits were pre Gen2, and perhaps their policies have changed (maybe insurance on new leases) regarding letting the public into the production space. I ask a lot of questions, and I remember asking about the testing like you. I was told that the machines and controllers are tested as a set, so your machine would have been fully assembled on a table, with your controller and HMI connected with your cables - I am assuming this based on the older X35 and Elite Gen1 machines around during my visits. As for cables, I can see how a power cable may be missed and left out of a box - no excuses - but from my experience as well there would be no hesitation in making it right once an issue was brought to support.
Yea could be that it changed, no hard feelings towards them if it’s a policy/insurance thing. I was really eager to see it because I’ve been a fan of this company for a while.
For the test: I meant the entire power supply unit - I didn’t get the HMI, so the big black box with the emergency stop that provides power to the entire machine wasn’t included in my boxes. I actually got the cable, just nothing to plug it into, haha.
They did indeed make it right fairly quickly, so no problem there. I only bring this up as far as being sure this test cut happened in the first place.
It took me a second to wrap my head around that, but I see what you’re saying now.
I don’t think so, the pattern I am seeing should not really be possible with more rigidity based on how this should work.
To over-explain this: The close up view of the tip of a 1/4” bit shows kind of a crown where the two flute tips touch first and the center of the bit is slightly recessed. When this is spinning it would cut a very slight domed shape if you were to only to touch the wood by moving the Z direction without moving in X or Y directions. If the bit is moving in X or Y, than that leading edge should act like a tiny flycutter creating a flat surface from the 2-tip plane.
What I am actually seeing is a periodic dome shape almost as if this bit faced the work by plunge drilling every 1/4” or less, leaving that domed shape.
This spindle was transferred from my X50. I intended to run the Makita on it until I could totally transfer the toolpaths over, but the slider doesn’t reach with just the trim router, so I’m stuck. But the variables here are the machine, post processor, heavy duty QCW table (instead of a pretty rough, shop-made table) and controller. Programs, spindle, bits feeds and speeds are the same.
I ran the Gen 2 test cut and see similar lines in the pocket cut. It’s harder to see in MDF, but once you know where to look in the hardwood test you can see it. Machine may have been tested but pocket quality is either not part of the evaluation or it wasn’t obvious to the operator. I can share photos if that’s helpful, but it’s similar to what I’ve been sharing so far.
I have a Gen 2 but have had no time to get the spoil board or dust collection set up yet. Stupid question but are you sure it’s a down spiral and not and up spiral maybe? Again more dumb questions but have you confirmed spindle direction?
couple other dumb questions…have you tried leaving your x, y feeds and speeds while lowering your z feed rate? Also, have you tried ramping your z movements? Speculating on what you said earlier about more vs less ridged machine…when doing a fast straight z plunge, material will get trapped and compressed under the bit and could potentially cause what you are seeing. Have you confirmed there is no vertical backlash on the Z? Potentially could be the coupler which you said you checked, but also could be the ball nut mounting screws? Your coupler might be tightly secured, but are the two faces of it completely seated together? If not it could cause a small amount of up and down play. Also, not sure how to adjust on 1f, but maybe talk to 1f about how to check pre-load on the ball nut/screw.
I’ve gone as low as 23 ipm using the interface at 10% speed. I’ve adjusted acceleration to very fast settings at first and then dialed them way back to slower than factory settings too
I have been using an up spiral as I always do for this, but I recently tested a down spiral from Bits and Bits with the same result. Definitely spinning the right direction.
There is only a couple Z moves where this might happen, but then the bit moves across the wood for extended periods of time back and forth leaving this swirling trail behind it.
to the best of my ability yes, I have tried moving it by hand, grabbing the z ball screw and trying to move it up and down. It seems tight.
I have to switch the motors back between the Z and X after a 1F test. I’ll make sure they’re tight, but they did seem fine in the first place.
Got me stumped. Maybe try playing around with z mounting height and spindle in the spindle mount location? Raise up you work piece and use the least amount of stub out to eliminate as much deflection as possible just to see if it helps?
If these machines had servomotors, I’d suspect some sort of limit-cycling of the Z-axis motor. With steppers I don’t see how that could be possible, but it could still be something upstream in the controller.
On my Gen 1 machine, I’ve found Z-axis motor coupler rotation to be to be a pretty sensitive visual indicatior of Z-axis motion. Have you tried watching that coupler as a program executes purely lateral move? It should be rock steady.
Another idea is to mount a dial indicator to the spindle, and indicate a known-flat surface atop the spoilboard as the machine moves laterally. That should flag any Z-axis motion, regardless of cause.
Pretty significant find, the X axis ball screw was very loose and the delrin bushing was almost completely out of its place and the set screw was loose. I have tightened things and running a test soon. I don’t really understand how this would be related since the stability should come from the gantry rather than the security of the ball screw, but I guess I can find a way to believe that the looseness in that X screw is being transmitted into the surface finish. The bad dome pattern is similar to the TPI of the screw, though I haven’t actually measured it.
It’s not great that you have the problem, but it’s great that you’ve located something that could be causing it. Just my curiosity, do you have the marks in one cutting direction more than the other. I’m guessing that in One direction the bit is pulling the Gantry along and then the other it’s pushing it so you’ll get marks more in One direction than in the other? I watched your video and it looks like you have a combination of climb and conventional cutting. As far as the ball screw is concerned, think about it. Like having a loose or broken u-joint in your drive shaft every time you start or stop there’s going to be a delay or a clunk unintended movements. Cncs are pretty simple machines but can be mysterious beasts it’s the at times
to eliminate as much deflection as possible just to see if it helps?