Uneven Circles

Ok, hopefully I can explain this well. I need some expertise on why my machine is making horrible looking small circles. I made a cribbage board and noticed that the holes were abnormally shaped and almost all of them look abnormal in the same way. I’m adding some pics to show what I mean.
The machine I have is an x-carve 1000mm with the dewalt router set at 4 speed, nema 26 stepper motors and the x-controller. I was using the upcut 1/16" bit from inventables. I have determined that my bed isn’t completely flat (a whole other issue) however I don’t think this would affect the roundness of the holes… maybe I’m wrong.
These were my settings for the carve:
55 in/min Feed rate
9 in/min Plunge rate
0.028 in Depth per pass
I don’t know how to import my project into here to have someone take a look and see if maybe I messed up on the circles somehow. Not sure if this link will work.

Or if you could tell me that maybe my machine is jacked up. Either way everyone on here is always so helpful so I’m hopeful I can get some advice and get this sorted out.

Where did you get this design? It doesn’t seem to have been created in Easel.

I think I got the original design from the forum here about cribbage boards on inventables. It was only the holes and I added the outer lines.

Odd. Something is wrong with the holes in that they cannot all be changed to ‘Fill’

Could be part of your problem.

If you have everything tight, have you calibrated your steps per millimeter? Those two not being done can cause what you are seeing.

That definitely could be part of the problem. What’s really weird is when I group all the circles together they get smaller and fill in. Could be the file is jacked and not an issue with my machine necessarily. I’ve had pretty solid results from other carves so I was really surprised to see such crappy circles. I thought maybe my feed rate was too high because I’ve never gone above about 45.

Shouldn’t be a speed issue. You can see that those are outline circles as opposed to fill circles. When I select the whole top section, I don’t get the option to change the cut type.

well maybe it’s a file problem then and not a machine problem. If you select any 2 of them and then combine them it turns them into smaller fill circles

Also Robert do you see in pictures 4 and 5 the straight north and south lines have a lot of what I would call chatter. What could that be from? I used easel to create those lines.

I had a similar problem. I did a lot all at once so I’m not sure what caused the problem but

  1. I calibrated my steps(they were off from stock settings.
  2. I readjusted all wheels and belts.
  3. I had to re set the wheel that raises and lowers the router it had like a 1mm up/down play in it when wiggling by hand.
  4. And i bought new collets for the size bit i was using instead of using the adapter.

One of these might solve your issue.

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Thanks Joe, are you talking about the hole issue or the straight line chattering? I will certainly try adjusting belts and pulleys. I do have a collet for the 1/8" bits so I’m good there. I am also going to re-design the file and see if that helps. Seems like part of the problem on the circles at least is the file I imported to easel.

The hole issue.
This is a video of the one problem.

An alternative to vcarve or Fusion 360 is to simulate peck drilling via a script. I’m a CamBam user and use variations of this script whenever I need to do peck drilling.

G90 G0 X$x Y$y Z$c
G90 G0 Z$s
G91 G1 Z-$q F$f (relative peck $q mm $f feedrate)
G91 G0 Z$r
G91 G1 Z-$q (2nd peck)
G91 G1 Z-$q (2nd peck)
G91 G0 Z$r
G91 G1 Z-$q (3rd peck)
G91 G1 Z-$q (3rd peck)
G90 G0 Z$r
G90 G1 Z$z
G90 G0 Z$c

CamBam fills in all the details: $x, $y is the location of the hole, $r is the retract height for the current peck, $c is the clearance height etc.

Alternatively, if you are a programmer it would be easy to write a program to take a list of hole locations, as well as peck depth etc. and generate the G-code. If all holes are the same you could probably do it with a bit of hacking with a text editor.

This would be my thought for the chatter as well.

If you click on edit points and then select each node and move it you will see that one node is not closed (connected to the others) this means it is not a joined path. if you correct this most of your issue will be solved.

as shown here the one I have highlighted is closed but the others were not.

CamBam is a CAM program, not free but fairly cheap, I got started with it before Fusion360 came out.

Grbl can’t do canned drilling cycles, so your CAM program has to simulate it somehow. On the other hand, the g-code for a simulated peck drill cycle is fairly simple, so hacking with a text editor or writing some code is definitely doable.

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Joe thanks, I will watch my z axis and see if that is happening… not sure.

I haven’t had much of a chance to mess with the machine yet but I will tonight and I’ll check the vwheels, which ones should I start with? z,x,y? Or just check them all?

Ok thanks Phil, I have intentions on downloading a free trial of Vcarve as I would like to do a lot more inlays. But Fusion360 sounds interesting too for stuff like this.