Sabre 408 Chatter

[StarSign]

This is 1/2" sintra routed with a 1/8" bit on 3 passes, I get this consistent chatter in a few spots. Could this be a mechanical problem, or is it the file (we can not see the chatter in the file). Thanks all, balmy 117 today!

 

[StarSign]

Sorry here is the pic

 

[GVP]

I wonder if the bit is too small - 1/8 doesn't allow much of a kerf width to clear the chips away, they could clogging the bit?

 

[nwsigns]

Looks like your material is moving on you, even slight movement up and down will cause that - especially with a an up cutting bit.

 

[J Hill Designs]

+1 for material hold-down issue

 

[fixtureman]

it looks like to many nodes in the arc. I cut 6m 12m 18m and 25m sintra all the time with a 1/8 bit and don't have that problem unless the file needs cleaning up

 

[signguy]

are you using a single or double flute bit?
I've had chatter like that using a double flute on 1/2 pvc before

 

[SebastienL]

The material is moving or somethin' is loose on the machine. Check if you have any play in the X and Y axis. If you can move any of the axis simply by pushing back and forth, it's the machine. Play can develop over time in the rack and pinion. A driver card can burn out. Try cutting small circle and check if they are round. If not, for sure it's the machine.

 

[StarSign]

We changed the acceleration from auto to slow.....now it's smooth as a baby's butt!!!

 

[Ragnarok1958]

+1 Starsign. I had the same trouble with 3/4'' MDF using a 1/4'' bit. I contacted Gerber about it a few years ago and was told it is caused by lead-screw wear (the problem didn't show up until after many years of machine use). I've found the "Auto" setting sometimes doesn't slow down everywhere it should imo. I also now use the "slow" setting exclusively for cuts where appearance matters.

BTW first post, still looking around.

R.

 

[johnnysigns]

X and Y axis lead screws is a costly repair. I know because we just went down that road w/ our gerber vendor. 3 passes on 1/2" sounds excessive w/out knowing the material in question.

 

[Dropout]

We changed the acceleration from auto to slow.....now it's smooth as a baby's butt!!!

Which doesn't mean the cause wasn't the material moving around during cutting. All your doing by slowing down the acceleration is slowing down the speed. I don't know about you, but I can't afford to run my machine with slow accel. It's also tough on the tool bits.

When my lead screws were going bad I didn't see any decrease in edge quality, just constant Y axis failures coming back to Y0.