[inicdam]

Hi all! I am having a problem while cutting MDF with my CNC.

The thing is that where the start node is, the router seems to go a little inwards and ruins the straight edge. I am not sure if I have explained myself correctly, so a picture will illustrate my problem better

Also, here is my cnc code, generated with ArtCam (the piece is a rectangle BTW)

%
G90
G49
M3 S15000
G0 X423.330 Y198.500 Z5.000
G1   Z-3.100 F3000
G1 X1.500   F4560
X1.500 Y1.500 
X438.500 Y1.500 
 Y198.500 
X423.330  
G1   Z-6.200 F3000
G1 X1.500   F4560
X1.500 Y1.500 
X438.500 Y1.500 
 Y198.500 
X423.330  
G0   Z5.000
G0 X0.000 Y0.000 
G0Z5.000
X0.000Y0.000
M05
M02
%

Any help will be highly appreciated.

Regards!

[KH0UJ]

Maybe because your code starts somewhere in between 3/4 of the face and ends at the same spot before it zeroes itself.



You can start diving your spindle at Zero itself, no need to reposition it to a different location, in that way you eliminate the jiggling while the spindle is on dive mode and end mode, you can also adjust the plunge feed rate to avoid jiggling while it`s diving, can you post the actual dimensions on your route path? I can make a sample code for you that`s not really aggressive while diving, start @ zero itself and ends @ zero, it can also be multi passed to avoid excessive vibrations while cutting the material.

[inicdam]

Hi! Thanks for the reply. I dont think that that would solve the problem, becuase if I have to cut 2 ( or more) pieces, only one would be placed at 0,0 and not the rest. Am I correct?

What I don't get is that if the spindle lowers at the Start Node, and then goes in the direction of cut, how can the start point be inwards and not the rest of the cut?
That means that the spindle is going down in the start node, spindle goes outwards a little bit and then makes the rest of the cut. Makes no sense to me at all.

Regards!

[KH0UJ]

Well it cuts perfectly straight on my code simulator, I think there`s an outside factor that causes it to mess with a straight route path, things like backlashes (X and Y axis), or noisy power supply that messes the stepper drivers and goes offset a little bit and back again, semi stuck ball screws. on my opinion the code is perfect even though it does`nt start @ zero.



With a route path



Without a route path.



Hint: even if you cut a hundred parts in one MDF board you can still dictate where to start in each and every route path you created, that`s what CAM programming does, You can take control of your spindle from start to finish.

[inicdam]

But is it possible that I have that problem exactly on each Start Node and nowhere else?

Regards!

[KH0UJ]

But is it possible that I have that problem exactly on each Start Node and nowhere else?

Regards!

Maybe only one way to find out, try another code that starts cutting at the edges and ends also @ edges of the rectangle, or post your rectangle dimensions here, let me code it for you starting @ 0,0,0 axis, specify also how thick is your MDF in mm, I dont use inches in my CAM coding.

[inicdam]

Alright. I can try with a 10 x 10 cm square.

Appreciate your help

[KH0UJ]

Ok here`s the code, I just assumed that your cutter diameter is 1/4, then the material is 3/4 I lowered the feed Rate to 2000 and the plunge rate to 1000 and the spindle speed @ 15K RPM just to try it out.

"Single Pass"

%
G90
G0 Z3.0
( T0 : 0.0 )
T0 M6
( Pass 1 )
G17
M3 S15000
G0 X0.0 Y0.0
G0 Z1.0
G1 F800.0 Z-19.0
G1 F2000.0 X103.2
G1 X117.4
G1 Y-106.4
G1 X0.0
G1 Y0.0
G0 Z0.0
M5
M02
%


Then Multi pass by 4 also just to try it out



%
G90
G0 Z3.0
( T0 : 0.0 )
T0 M6
( Pass 1 )
G17
M3 S15000
G0 X0.0 Y0.0
G0 Z1.0
G1 F1000.0 Z-4.75
G1 F2000.0 X103.2
G1 X117.4
G1 Y-106.4
G1 X0.0
G1 Y0.0
( Pass 2 )
S15000
G1 F1000.0 Z-9.5
G1 F2000.0 X103.2
G1 X117.4
G1 Y-106.4
G1 X0.0
G1 Y0.0
( Pass 3 )
S15000
G1 F1000.0 Z-14.25
G1 F2000.0 X103.2
G1 X117.4
G1 Y-106.4
G1 X0.0
G1 Y0.0
( Pass 4 )
S15000
G1 F1000.0 Z-19.0
G1 F2000.0 X103.2
G1 X117.4
G1 Y-106.4
G1 X0.0
G1 Y0.0
G0 Z0.0
M5
M02
%


Just copy and paste the code in notepad then save it as .nc or .txt

[inicdam]

Thanks for the help, but the issue seems to have been a problem with my code because I am not having this issue anymore

Kind regards