Learn CAD/CAM or Gcode

More
02 Feb 2013 10:14 #29462 by jaredts
Replied by jaredts on topic Learn CAD/CAM or Gcode
G17, G18, and G19 are all used on 3 axis mills if you are doing 3d machining. They are for xy, xz, and yz arcs. If you use a ballnose to cut half a cylinder into a mold that runs along the y axis you would be making xz arcs with G18. If you never, ever command a G18 or G19 then you don't ever need a G17 at the beginning of a program. It's just a safety thing--highly recommended though.

Please Log in or Create an account to join the conversation.

More
02 Feb 2013 17:39 #29476 by andypugh
Replied by andypugh on topic Learn CAD/CAM or Gcode

Don't feel bad I still don't know what the naive cam detector is... I only know what it does.

e

It's a "naive CAM detector". It detects that the G-code was created by a naive CAM system, one which uses lots of tiny straight lines rather than arcs.

So, it is a detector of naive CAM, not a naive detector of CAM :-)

Please Log in or Create an account to join the conversation.

More
02 Feb 2013 20:54 #29482 by BigJohnT
Replied by BigJohnT on topic Learn CAD/CAM or Gcode
It also works with arcs after me bugging jepler for a week or three back when I built my plasma torch. :)

John

Please Log in or Create an account to join the conversation.

More
08 Feb 2013 02:19 #29765 by Sterling
Replied by Sterling on topic Learn CAD/CAM or Gcode
Machine & my coding are starting to get along together. B) I ended up making 1/16" graph paper on my computer and just overlaied the peg-holes over it. then mapped out the coordinates. Granted, I made a couple typo's (had to redo it 5x's before the 1st attempt) but the first board is 90% perfect~!

The oly caveat I can see thus far is that it is still too slow IMHO. I set "F50"...and it still took about 30 minutes to drill a standard 2-player game (245 holes).
Hopefully I can happily declare "success" with my next post~!

>>> Sterl

Please Log in or Create an account to join the conversation.

More
08 Feb 2013 02:36 #29766 by BigJohnT
Replied by BigJohnT on topic Learn CAD/CAM or Gcode
It does sound like your making progress. Now you can look at ways to speed things up in your G code. If you want to pastebin the G code and post a link I'll take a look at it (upload is still broken afaik).

John
The following user(s) said Thank You: Sterling

Please Log in or Create an account to join the conversation.

More
08 Feb 2013 03:01 #29767 by Sterling
Replied by Sterling on topic Learn CAD/CAM or Gcode
Thanx big-guy~!

Message sent... B)

Please Log in or Create an account to join the conversation.

More
08 Feb 2013 04:52 #29770 by andypugh
Replied by andypugh on topic Learn CAD/CAM or Gcode
Completely untested (bored in a hotel room, no LinuxCNC machine to try it with)
;Cribbage Board Drilling

#<hole-to-hole> = 0.25
#<track-to-track> = 0.5
#<five-to-five> = 0.5
#<board-to-board> = 1

;Assumes bottom-left hole = (0,0)
#1 = 0 (x position)
#2 = 0 (y position)

G20 (inches)

G90 G98 G83 R0.1 Z -0.25 Q0.05 (peck drill, .05 steps, .25 deep, safe height 0.1)
O100 repeat[2]
O101 repeat[2]
O102 repeat[12]
O103 repeat[5]
X#1 Y#2  ; This line does the actual drilling
#1 = [#1 + #<hole-to-hole>]
O103 endrepeat
#1 = [#1 + #<five-to-five>]
O102 endrepeat
#1 = 0
#2 = [#2 + #<track-to-track>
O101 endrepeat
#1 = 0
#2 = [#2 + #<board-to-board> - #<track-to-track>]
O100 endrepeat
G80
M2

Please Log in or Create an account to join the conversation.

More
08 Feb 2013 05:06 #29771 by BigJohnT
Replied by BigJohnT on topic Learn CAD/CAM or Gcode
Just looking at the properties for your G code file and you have no rapids. The run time is 12.4 minutes in the Axis simulator. Replacing every instance of G1 X.5 with G0 X.5 and the run time is reduced to 10.2 minutes. Bear in mind the run time does not take into account acceleration and is based on 72IPM rapids for most sims. Opening up the modified file in a config that has a bit faster rapids of 180IPM reduced the time to 7.1 minutes. Actual run time will depend on the acceleration speed and direction changes. Running the modified file on this config resulted in a 9:25 cycle time. BTW, are you using the time component to have a cycle timer on your GUI?

But in any case you will get faster run time if you rapid out of the hole and rapid to the next hole location. Rapiding out will also help with reducing any burning from friction on the sides of the bit.

If you have slow acceleration I would make sure you specify G64 Pnn tolerance in your preamble or G61. If you accept the default G64 and have slow acceleration the path could cut corners when coming out of the hole (not good). Normally 0.1" is plenty of clearance from hole to hole and changing from G0 X0.5 to G0X.1 would cut the properties time to 4.6 minutes or about half again. Running in my config with 180IPM rapids gives me an actual run time of 6:25 so the shorter the moves the greater the difference between calculated and actual time. Optimizing your path to take the shortest distance between holes like doing all the holes in the first long row then working your way back will save some time too. I'll leave that up to you to try.

John

Please Log in or Create an account to join the conversation.

More
08 Feb 2013 05:09 - 08 Feb 2013 06:22 #29772 by BigJohnT
Replied by BigJohnT on topic Learn CAD/CAM or Gcode
After fixing the typo in Andy's code and adding a feed rate of 50 I get a properties time of 6.0 minutes for his code.

Edit: Andy's tool 19:43 to run...

John
Last edit: 08 Feb 2013 06:22 by BigJohnT.

Please Log in or Create an account to join the conversation.

More
08 Feb 2013 05:44 - 08 Feb 2013 05:53 #29773 by Sterling
Replied by Sterling on topic Learn CAD/CAM or Gcode

Just looking at the properties for your G code file and you have no rapids.

...I have no idea what a 'Rapid' is, sorry.

The run time is 12.4 minutes in the Axis simulator. Replacing every instance of G1 X.5 with G0 X.5 and the run time is reduced to 10.2 minutes.

Okay, that sounds simple enough, but to clarify: am I replacing all the G1 Z-.5 and G1 Z.5 with G0 Z-.5 / G0 Z.5?

Bear in mind the run time does not take into account acceleration and is based on 72IPM rapids for most sims. Opening up the modified file in a config that has a bit faster rapids of 180IPM reduced the time to 7.1 minutes. Actual run time will depend on the acceleration speed and direction changes. Running the modified file on this config resulted in a 9:25 cycle time. BTW, are you using the time component to have a cycle timer on your GUI?

I get some of that: Directional changes add up and can slow things down. So, if I re-write it so that it runs down the Y axis. The rest of that went over my head...

But in any case you will get faster run time if you rapid out of the hole and rapid to the next hole location. Rapiding out will also help with reducing any burning from friction on the sides of the bit. If you have slow acceleration I would make sure you specify G64 Pnn tolerance in your preamble or G61.

This will most likely take some re-reading for me to understand and enter the code, but I understand the gist of what you're saying, thanx~!

If you accept the default G64 and have slow acceleration the path could cut corners when coming out of the hole (not good).

I think I understand that one; it will nick the edge of the hole as it goes in/out. Yea - that's way bad.

Normally 0.1" is plenty of clearance from hole to hole and changing from G0 X0.5 to G0X.1 would cut the properties time to 4.6 minutes or about half again. Running in my config with 180IPM rapids gives me an actual run time of 6:25 so the shorter the moves the greater the difference between calculated and actual time. Optimizing your path to take the shortest distance between holes like doing all the holes in the first long row then working your way back will save some time too. I'll leave that up to you to try.

Saving time is good.
Groovy, thanx~!

>>> Sterl

PS - Sorry to hear you're stuck in a hotel...
Last edit: 08 Feb 2013 05:53 by Sterling.

Please Log in or Create an account to join the conversation.

Moderators: Skullworks
Time to create page: 0.171 seconds
Powered by Kunena Forum