The video link does not work for me either.
So I had a look at my machine.
The rails and bearings were dirty. I had to use an sos pad to get the buildup off of it… Doesn’t look like more than a black line down the contact area of the bearing but it sure smoothed out the X and Y movements.
Loosened a bunch of the bolts that tighten the bearings to the rails everywhere. Not much noticeable difference in moving with your hands (disconnect from RAMPS first).
It seems to only be movements that have a component of X and Y in their moves. Moving just in the X is smooth. Moving just in the Y is smooth. Anything else, a circle, diagonal, etc, all have a pulsing that you can feel and see…sounds like firmware. Not gcode, cause I’m using the manual controls to move things around at different speeds.
Ideas ?
I slowed the speed down to F50. You can hear it alternating between x and y steppers as it moves at a 45 degree angle. My 3D printer doesn’t do this. Hmm.
On my 3D printer, a diagonal line is very smooth. Circles may have some facets, but each facet is smooth.
This does seem like a firmware setting to me.
Following…I see the same thing:
This is with stuff purchased from me or no?
For me yes, all stock (no firmware updates). Estlcam 10 and Repetier.
Z
@Vicious1 yes this is the kit purchased from you. I am using Repetier and Fusion360 but all the tests I’ve made since discovering this is with manual control in Repetier. I did notice that the video from Estlcam on how to setup the xbox controller talks about feed rate, acceleration, and inertia (jerk basically) and how to set the upper limits. I’ve not done this on this machine. As noted though, my 3d printer uses the same hardware (RAMPS and Mega) and it does not do this.
@Vicious1, is there a documented procedure on how to tune these settings?
It really looks like this is the culprit. What do people have these set to?
Interesting, although my 3d printer prints well, I do get some jerk issues. I realized this when I recognized the same effect in my prints as shown in this post http://3dprinterwiki.info/wiki/wanhao-duplicator-i3/duplicator-i3-calibration/firmware-settings/. I will experiment with acceleration and jerk on both my 3d printer and mpcnc. I think this may be part of the problem. Although it doesn’t explain the alternating of x and y motors during diagonal moves…
The machine is pre-tuned, if you are using my hardware, That is why I ask if you are using my stuff or not. There a tons and tons of videos of people drawing with the mpcnc, This is not a common issue.
Me and you poking around in the dark is not getting us anywhere and I don’t have enough information to help. The questions in the sticky post really make helping easier but start with these.
1-Your machines are both double the recommended size in foot print but neither of you specificity the most important one of height. and what material are you using stainless or conduit.
2-Picture of your machine So I can spot an obvious errors. A picture is literally worth thousands of words in this case.
3-That jagged drawing I need to see how it was set up, what tool mount, what pen, what surface were you drawing on, how big is the actual drawing?
4-Screenshots of all the speeds you were using in whatever software.
Glad to hear it’s not a common problem. Will get you that info tonight. To answer some of the questions:
1-My height is reduced to the point where only 1.5" of tubing is showing on the feet.
2-Will post pics tonight.
3-I am using your mount with the router bolted to it. It’s solid. Will post a pic and the stl for it tonight.
4-Same, tonight.
I realize you are busy and really do appreciate the help @Vicious1.
So jerk is a setting that did not even work correctly in the firmware until RC7 (if I remember correctly). It could be a jerk issue but I doubt it. Who knows maybe the jerk setting is the problem as I have never tuned it other than the first time and set it for Milling, not printing. Low Jerk settings just mean more movements will use acceleration, High jerk means small movements will change speeds with no accel. (simplified) For cnc low settings means the bit will linger in a corner longer but not wobble, as a printer this means you could get bulging corners from lingering too long.
All you have to do is increase the number and try it.
This should be a fun project, get your hands dirty try some things if it doesn’t work flash it back. That should be part of the fun of having an inexpensive machine we are free to experiment.
My Guess to your problem is over tight hardware, but it could also 100% be software/firmware related. At this point in the MPCNC life I am fairly confident software and firmware issues and limitations a have been discovered. There are thousands of these machines out there, tons of videos of smooth drawings large and small.
1-Your machines are both double the recommended size in foot print but neither of you specificity the most important one of height. and what material are you using stainless or conduit.24"x36" is the workable area (34.4"x46.4 is the footprint). EMT 3/4" standard US Home Depot conduit.
2-Picture of your machine So I can spot an obvious errors. A picture is literally worth thousands of words in this case.
3-That jagged drawing I need to see how it was set up, what tool mount, what pen, what surface were you drawing on, how big is the actual drawing?Using your pen mount with a gel pen, barely touching an 8.5"x11" standard copy paper.
4-Screenshots of all the speeds you were using in whatever software.
My machine is ~120mm of Z travel… way more then I need that I know. Not sure if that matters at all when it just moving with nothing on the Z.
1" Stainless closet rails. 60" long.
I printed and configured and bought all my own components. Tuned as per the specs you have listed through out the site.
Most of the time I am using a 6 watt laser with a small chinese heatsink and 40mm fan. no appreciable weight compared to a router. Yes it hangs down several inches when engraving but like i said the problem occurs with 0 weight.
speeds i use are typically 600-1200 mm/min. My problem happens regardless of directional travel. Happens in X, Y and diagonal movement.
The only thing I cannot spin by hand is the long 5" tension bolt down thru the xyz axis. the hole is kinda tight. All bolts on the rollers, and x y center pieces I can spin by hand.
I do believe that it may have something to do with over all size. as it seems that when it starts the vibrating that the rails are bending slightly but the could be an optical illusion from the vibrating itself. But just straight rolling with no load should be smooth.
I have my self pretty well convinced it has to be a couple bad bearings.
Let me suggest the following experiment to separate physical origin from logical origin:
- create a sample job, e.g. a drawing
- remove any zeroing from the gcode, if any
- run the job
- shift the logical zero a few millimeters by manualy moving the gantry and issuing G92 (or just restarting arduino)
- rerun the same job and compare the artifact positions
If the artifacts stays with physical origin, the problem is attached to the frame - rails, bearings, etc. If the artifacts move to the new origin and stays in the same place relative to the job, the problem is attached to the firmware
I would believe it if was firmware the problem would be more wide spread as I am using the stock RC7 image from here just changed my sizes to fit my machine and steps per mm because I switched to 1/8 stepping.
1/8th stepping means curves will have a stair step. you should use at least 16th.
When I first built this I tested this, I made as large a circle as would fit in my machine and drew it. Then kept lowering the steps until I could see an issue, at 1.8th I saw stair stepping.
Hmmmm…does it seem better?
1-25.4mm SS Tubing. Leg height 40mm of tubing exposed. Scratch board to bottom of XYZ assembly 85mm.
2-Picture of your machine attached.
3-gcode file of what I was cutting (not drawing) is attached.
4-Screenshots attached.
Plus more videos and pics… MPCNC Jittering Diagonal Issue
Did I miss anything?
…Files are uploading at the moment. May take some time.