Need Help!- Cutting long parts on a small machine

[heli_bee]

Hello All.

I have finished my fixed gantry machine and with a 12" x 12" table. However, some of the parts that I wish to cut are longer than this. I have a good idea as to how I go about referencing a long part on a small table, but wish to hear from those of you that already do this type of cutting. How do you do it? I'm talking about settting up the CAM software and the tool paths.

I was given a good example here

http://www.rcgroups.com/forums/showp...08&postcount=2

and a pointer about the softwre set up here

http://www.vectric.com/forum/viewtopic.php?f=12&t=5801

Regards,
Martin.

[gadget47]

Hi Heli Bee,
I use the same method(s) of cutting large projects. for repetitive work the dowels are king. just lift the work to the next dowel position. for long work with different geometry, a reference point in the cad/cam machine layout has to be established- then create (or move) the design to the next section and soforth...I move the design in the y (in cad) and re-establish the cutpath of that section. you can cut and paste the g-code so you have one file when you are done. A bit tedious but i've managed to cut a 4 ft length out of my A-I design (12x12)

Gadget

[Curmudgeon]

I need to learn how to do this also. Is there any additional info on how to do this, example g code, a tutorial, I could use a jump start. I think I understand the cutting margins aspect, it's the reference point and dowels I'm not sure at all how to incorporate.

Thanks in advance for the help.

[universalfab]

Originally Posted by Curmudgeon I need to learn how to do this also. Is there any additional info on how to do this, example g code, a tutorial, I could use a jump start. I think I understand the cutting margins aspect, it's the reference point and dowels I'm not sure at all how to incorporate. Thanks in advance for the help.

Well all I have to say is if your working with liter material your tollerances aren't go to be that good. I use a larger machine for larger jobs, but in alot of peoples cases they don't have that option. If your workng with heavier material then you will probably be alright depending on your over hang, but you still will not get as tight of tollerances as you would when having the entire part clamped down to your table.

[Curmudgeon]

Originally Posted by universalfab Well all I have to say is if your working with liter material your tollerances aren't go to be that good. I use a larger machine for larger jobs, but in alot of peoples cases they don't have that option. If your workng with heavier material then you will probably be alright depending on your over hang, but you still will not get as tight of tollerances as you would when having the entire part clamped down to your table.

Cutting wooden signs. I think this approach will work for that. Going to give it a shot at least.

[nigjoe]

Before the 24ft bed Biesse came along I ran on a 442 Heian twin head, twin 63"x63" tables with a 2" seperation, I use a m40 to lock the tables in the program. Because the heads are fixed in the gantry and the tables move in y I have only 12.5" at the back of the machine where the stringer will not hit the beam uprights, if I ran the stringer in the front it would hit the saftey gates on either side of the table. I usually set the 0 of my program at my pinstops bottom lh side of the tables, so in this case I offset my part X-65" Y63 from my right hand table as I will machine every thing with head #1 (head seperation is 800mm) I make my tool paths in Mastercam, create the first program, save it take my second DXF and create the program. I cut and paste the programs together inserting an optional stop and releasing the vacumn so I can move the part, turn the vacumn back on, then restart the program to finish. If u r wondering, I have sub programs set up in the controller I made to put pins up/down, bring the machine back to home, turn vacumn on/off, they r the p#s. Here is an example of code, (I cut all the crap out) and a couple of DXF's
Hope this helps u out.
Cheers


%
O3499(7.375R X8.25RX13RISERS LH CLOSED PT1)
(MC9 FILE - U:\BOLTONPART\STAIR FOLDERS\STRINGERS\7.375 RISE X 8.25 RUN\7.375R X8.25RX13RISERS LH CLOSED PT1.MCX)
(POST - )
(PROGRAM - 7.375R X8.25RX13RISERS LH CLOSED PT1.NC)
(DATE - DEC-08-09)
(TIME - 10:10)
(T2 - 1/2" COMPRESSION - H2 - D18 - D0.5000")
G08 P1
M40
G91 G17 Y0.
P9000
M211
M232
M213
M234
M400 (CANCEL ALL HEADS SELECTION)
M76 (BRUSHES DOWN)
M401 (SELECT HEAD 1)
M06 T2 (1/2" COMPRESSION)
M03
M91 S18
(MAX - Z2.)
(MIN - Z-.375)
G00 G90 G54
X-6.4661 Y51.6833
G43 H2 Z2.
Z.25
G01 Z.1 F400.
G02 X-5.6739 Y52.2935 Z.0177 I.3961 J.3051
X
G00 Z2.
G91 G28 Z0.
G28 X0. Y0.
M92
M95
M214
M98 P9300
M231
M233
HAND MODIFIED CODE)
G91 G28 Y0
M0(MOVE PART BEFORE RESTARTING)
(END OF MODIFIED CODE)
7.375R X8.25RX13RISERS LH CLOSED PT2)
(MC9 FILE - U:\BOLTONPART\STAIR FOLDERS\STRINGERS\7.375 RISE X 8.25 RUN\7.375R X8.25RX13RISERS LH CLOSED PT2.MCX)
(POST - )
(PROGRAM - 7.375R X8.25RX13RISERS LH CLOSED PT2.NC)
(DATE - DEC-08-09)
(TIME - 10:12)
(T2 - 1/2" COMPRESSION - H2 - D18 - D0.5000")
G08 P1
M40
G91 G17 Y0.
P9000
M211
M232
M213
M234
M400 (CANCEL ALL HEADS SELECTION)
M76 (BRUSHES DOWN)
M401 (SELECT HEAD 1)
M06 T2 (1/2" COMPRESSION)
M03
M91 S1
(MAX - Z2.)
(MIN - Z-.375)
G00 G90 G54
X41.62 Y55.8634
G43 H2 Z2.
Z.25
G01 Z.1 F400.
G02 X42.6004 Y55.6664 Z.0177 I.4902 J-.0985

G40 X58.5661
Z-.125
G00 Z2.
G91 G28 Z0.
G28 X0. Y0.
M92
M95
M214
M98 P9300
M231
M233
M30
%