MACH3 Shaking and jittery on 3D relief cut

neverhappen
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Model of CNC Machine: Legacy Maverick Gen 2

MACH3 Shaking and jittery on 3D relief cut

Post by neverhappen »

I've searched the forum, but still can't find an answer that works with my CNC, I have a new Legacy Maverick Gen 2. I replaced an Axiom CNC Router that used the RichAuto controller, which didn't have any tweaks. I now have MACH3. While cutting a 3D relief roughing pass at 80 IPM, the spindle about comes out if it mount it shakes and jumps so bad. It runs the G64 code at set up so CV is turned on. I've tried all the suggestions with turning up look ahead, changing the angle, turning off the check marks in the config lower right window. It's almost as if the cutter is stopping at every end line which as I watch the code go by is a lot of stops. I'm just looking to be able to get a smooth operation at a decent speed. The G-code was produced with Vectric Aspire 10.5, and the Legacy Post Pro. My biggest problem is with the Axiom, even though my best IPM was around 60 on a finished 3D cut, it never shook itself apart. Any comments are welcome, and thank you in advance.

rig gap
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Re: MACH3 Shaking and jittery on 3D relief cut

Post by rig gap »

You might try the Mach 2/3 post to see if that does better.

BillK
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Re: MACH3 Shaking and jittery on 3D relief cut

Post by BillK »

Check the vector in Aspire using the node tool. Excess number of nodes on the vector can influence this. You can use curve smoothing with Bezier curves to remove excess nodes.
BillK
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Greolt
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Re: MACH3 Shaking and jittery on 3D relief cut

Post by Greolt »

Reducing node count is often a good idea, however if CV is not working then that will only do so much.

In Mach3 go to "General Config"
Select Constant Velocity radio button under "Motion Mode"

Uncheck all four options under "CV Control"

Set "Look Ahead Lines" to default of 20. Yes it is the default for a reason.

On settings page Uncheck "CV Distance" and "CV Feedrate"

Try the above. You can set them back to whatever you want later

neverhappen
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Re: MACH3 Shaking and jittery on 3D relief cut

Post by neverhappen »

Update, haven't check back on the forum for a few days, got busy, and thank you for your input, Ran it with the MACH 2/3 Post Processor, same result, too the best of my knowledge "Node" is not an option on a 3d model, as it's all pixels. I did set the CV adjustments as per the last post, I don't have the option of a "settings" page so I'm not sure where to find it. I'll be running a new 3D cut over the weekend and see what the results are. BTW if I run this on the "Y" axis, smooth as silk at 120 IPM. Brand new Maverick so I can't imagine I have something loose on the gantry as I've check. Might be the last suggestion dos the trick, Time will tell.

Greolt
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Re: MACH3 Shaking and jittery on 3D relief cut

Post by Greolt »

neverhappen wrote:
Thu Dec 24, 2020 8:06 pm
I did set the CV adjustments as per the last post, I don't have the option of a "settings" page so I'm not sure where to find it..
I must assume you are using a third party sceenset if there is no settings page.

If so then go to "View" menu, select "Load Screens", select "1024.set"
Then you will have a settings page. Uncheck CV distance and CV feedrate.

You can easily go back to your chosen screenset by repeating the above steps.

Just try the above. You can revert to old settings if no improvement.

neverhappen
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Re: MACH3 Shaking and jittery on 3D relief cut

Post by neverhappen »

Again, Thank you,
Did all suggested, very little change in the end result, so I ask this question, If I run this across the "Y" axis, I get a perfect surface, a simple change in the G-code. The fact the the code really didn't change as all the X,Y,Z are all the same value, just the direction they ran in. But, I also have the 4th rotary axis, which runs on the "X". My turned projects have the same dimpled effect.
To clarify why this concerns me, I ran an Axiom Precision 2X3, one axis stepper motor on all three axis. Never a problem. The new Maverick runs with two (2) steppers motors on the "Y" axis. (Only one (1) on the "Y"). Is it possible the motors are out of sync, and the faster I ask it to go, the more they fight each other. I ran a simple dome shape at 120 IPM, and it actually jumped out of position it shuttered so hard. I've check for binding, reset the racks to eliminate any "Chatter". Any thoughts on this are appreciated. Just looking for a place to start diagnosing. and maybe there just isn't a fix.

rdean33422
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Re: MACH3 Shaking and jittery on 3D relief cut

Post by rdean33422 »

Are you running the speed faster than the speed you designed in ?
Like setting the speed at 50 IMP in the software and then telling Mach3 to run at 70 IMP.
If I over speed in Mach3 by more than 35% then I get exactly what you are experiencing.

Also which version of Mach3 are you running?

What is your motor tuning acc and velocity set to on the Xaxis and how does it compare to the Y axis?

Just some places to look.

neverhappen
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Re: MACH3 Shaking and jittery on 3D relief cut

Post by neverhappen »

Your speed question is interesting, What I hear you asking is:
If I set the feed on the tool at say 50 IPM, does MACH3 try to run it at 80 IPM?
I have a set buttons on my screen called "Increase/Decrease" Feed Rate with a area to input a new number called "Adjusted Feed".
It never matches the "Feed Rate" which on my screen is right above it.
I can Increase or Decrease the the IPM with these two buttons, OR, type a number in the "Feed Rate" box to increase the speed. I have search the web for an explanation of these two areas without an answer.
I will try and run a cut setting the Feed Rate in the G-code and match that know number in the "adjusted Feed Rate" box and see what happens. It's a start.
Second I have MACH3 version R3.043.062
Motor Tuning is exactly the same for both X and Y. Z is different by exactly 33% of the other two (2)

rdean33422
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Re: MACH3 Shaking and jittery on 3D relief cut

Post by rdean33422 »

Version 062 that you are using has proven to be the most stable for most things.
I forgot that you are using a 3rd party screen so many of the features will look different from the original Mach3 screen.
I am not familiar with the Adjusted Feed box. The original version has a + and a - button to increase or decrease the speed and separate sliders for Transport and Feed speeds.

Ray

neverhappen
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Re: MACH3 Shaking and jittery on 3D relief cut

Post by neverhappen »

Again Thank you
I don't have much hair left so pulling it out isn't the answer. I've tried every imaginable setting from your help and looking over videos on-line. If I could best describe this it would be like this:
In a 3d image a simple arc from Z-1 to Z-1.5 over a 3 inch span traveling along the X axis would have several (depending on the image) small increments as the Z traveled a little higher the farther it went through the arc and down the other side. There could be 20 or 40, the more he changes the smoother it should be. The Y axis only would change on the end of the line and and the same thing would repeat on the way back in reverse.
While my machine travels through that arc it seems to Start and Stop at each of those changes in code without a smooth transition from one to the next. I've change the "look ahead" number higher and lower to 20 (factory spec), changed the CV settings, turn them off, used different numbers, even tried using the plasma cutter setting I heard might work. Ran the code without the CV (removed G64 from the first line of code). The faster it goes the more violate the Start and Stop action. And this makes for a really bad surface on the piece.
So I ran a simple circle profile cut. Easy Right, 4 arcs, and every time it came to the change in the arc, the motion stopped, and then started again. the hesitation was only a split second, but enough when ran at a higher speed, it was very noticeable.
I have a support ticket started at Legacy, but with the holidays they aren't in a hurry to get back to me.
Most everyone on this forum has a lot more experience than I do with MACH3. My problem is, I had a less expensive Axiom CNC that never had this problem running a RichAuto handheld controller.
And again, running this along the "Y" axis seems as smooth as a babies butt.
Frustrating

bbiehl
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Re: MACH3 Shaking and jittery on 3D relief cut

Post by bbiehl »

neverhappen,
I also have a Maverick gen 2 (August 2020) and have noticed the (mild) shaking when doing a 3d carving. If I reduce the speed to 80 ipm or less the shaking goes away. The shaking seems to be mostly on the left hand side of the gantry. If I am doing a 2d carving then I can go much faster. I would be interested in Legacy's response.
-brian

neverhappen
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Re: MACH3 Shaking and jittery on 3D relief cut

Post by neverhappen »

bbiehl,

I will send you a PM when I get their attention. They promo how fast it will cut. I would say the gantry should be stiff enough to handle 150 IPM. I also see many folks on this forum cutting at 150 and producing quality 3D pieces. I ran a straight code, Z at 0, Y stepping over .0125, and had the x go from 1-10 inches. Back and forth, back and forth. I took a video at 150 IPM, and even without a 3D cut it can't go smoothly from 1-10 inches. They will get the video once I get their attention. Something is out of sync. My concern is I get the same dimple effect on the Rotary axis. I also don't have too much problem at 80. Although it still is not perfect. With what we spent for the Maverick, I'd expect better performance. And I'll say this again, If I run the code using the "Y" axis and just stepping the "X" the .0125, I can run at 130 without any problems at all. Problem is, I'm not sure if running the "Y" axis on the 4th rotary will work

neverhappen
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Re: MACH3 Shaking and jittery on 3D relief cut

Post by neverhappen »

bbiehi,

Can't private message you. My conversation with Legacy came to resetting the dip switches on the Stepper drivers. End result not much changed. One of the things I found is this, please change these setting at your own peril, I don't recommend it if you're not comfortable making changes. My Maverick was set up with some pretty aggressive settings under "motor tuning". When I first started with the new machine I was a little concerned at how fast it traveled during spindle warm up and so forth. My old numbers were 600 for the velocity and 18 for the acceleration for the x and y axis. Z was set to 1/3 of these settings. Do a little reading on your own to understand these numbers. The idea is to allow the motors to operate at their peak performance. I was cutting a 2d cut the other day, as it came to a corner to change direction I got the same jiggle and shake. You can actually hear the bit shaking in the cut. Before you do anything, back up your settings, or take a picture of the setting so you don't forget them. I changed my setting extremely down to 200 and 6. 1/3 of the settings for the x and y and the same for z. The cut was extremely better, no shaking or jittering. But a little too slow.
This does however change the speed that the gantry travels when jogging. I've made a few adjustments since and I'll allow you to play with it until you're happy. Also suggestions from others on this post also worked very well, remove the check marks on the CV settings. Makes the 3D lots better and lots smoother.

bbiehl
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Re: MACH3 Shaking and jittery on 3D relief cut

Post by bbiehl »

Thanks neverhappen got your message and will try out some of your suggestions.

-brian

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