I have a 1F Elite Foreman. Anyone have any advice on how to help stabilize the Z axis assembly during carves? I have checked for loose bolts, etc. and everything is good, yet I continue to have issues with tool marks during carves. For example, if I do a profile cut and use tabs, the end mill will leave ‘dents’ in the edge of the piece at the beginning and end of each tab. Additionally, when I use my Jtech laser, the laser jiggles when the machine is changing directions, and it causes squiggly lines in the engraving. I have already reduced the acceleration settings to 1/2 of factory settings, and have set the PPR according to the most recent guidance from 1F. It did help some, but not enough.
I have read other posts which seem to indicate a difference between acceleration and ‘jerk’ settings on the Buildbotics controllers… but the MASSO only offers a setting for accelerations settings as far as I can tell.
Another example is the end mill will leave circular indentations at the bottom of a pocket. It’s as if when the Z axis moves up and down, the sudden start / stop of the motor causes the spindle to flex up and down if that makes any sense. I have the PWNcnc ATC spindle and I’m starting to wonder if it’s just too heavy for the machine.
I contacted jtech and they had a z20 compliant 80mm spindle mount. The mount that comes with it is pure trash since it’s got weight over leverage on an already shaky platform.
No issues since i started using that mount.
If this is what im thinking it is it’s nature of the beast as the movement is slowed down in that area. I’m assuming that it’s fine where its moving. Some 220 sandpaper, and/or a smaller bit on a finishing pass might minimize it. Could also look at adding ramps in your plunge, depending on the pocket something like an inch long spiral ramp might work but, play with it. That’s assuming it’s only on the plunges and not in the corners/changed in direction where the machine slows down.
You can also use a ball nose to create a scallop To make it a feature, and not a flaw
Id like to see pics of these dents. If it is what i think it is, again a final finishing pass. idk what software you’re using, but vectric has an option where it’ll cut X amount away for each pass, then on the last pass do a final pass at the line. .05" is a common setting for this. You might also notice some burnt marks at these dents too. Vectric has an option to do 3d tabs where it’ll ramp up then ramp down for the cut. I only use tabs on straights and when using this setting do it ¼" long, ⅛" tall. If it’s not practical or i don’t want to configure them I’ll go all but ⅛" then take it to the bandsaw and/or flush trim the rest.
I found this article which may help explain my suspicion:
While ATC is a heavy motor, i dont think it’s the culprit
Thank you for the reply… this is very helpful. I am using Vectric Aspire.
I have reached out to Jtech regarding the Z20 compliant spindle mount.
I am attaching some photos of the tool marks… note that the color core sign was done before I reduced my acceleration settings and increased my PPR, and that has improved some since I did that. However, I do continue to see similar… albeit less severe… markings on pocket bottoms in all materials. The tab ‘dents’ in the hard maple profile cut were done on a profile toolpath using a Jenny 1/4" compression bit, conventional, separate last pass in reverse (climb) direction with a .0197" allowance. However, I left the allowance offset under the machine vectors section at zero… which I believe may be the problem? Apparently those two settings work hand in hand, and I may not be using them correctly to get a clean last pass. I’ll have to read up on that more. Also, I posted on the 1F forum and someone suggested using 3D tabs as a way to reduce or eliminate the tab dents.
I have never had it read anything but zero. It oversizes/undersizes the cut according to the vector which I’ve never needed to do.
I would check feeds and speeds, and consider going faster on feed. Core board is soft (cutting wise) in comparison, maybe similar to pine.
3d tabs are likely to help, reason being deflexion. Instead of the machine stopping, raising moving, stopping, going down, proceeding, it goes up and down while minimally changing feedrate (depending on your bits plunge settings)
