Messages

831

G-Code, CAD, and CAM discussions / Re: [GCode] Newbie question, Thanks

« on: May 02, 2008, 01:36:44 AM »

If you were to draw it in LC or any other software, it would not let you draw a circle with a radius smaller than half the diameter. You can have a radius any size you like, as long as its not under half the diameter of the circle its taken from. It's just not possible, unless of course the universe collapses in on itself and all mathematical laws go out the window. I hate when that happens, i always hafta reset the radio stations in my car.

832

G-Code, CAD, and CAM discussions / Re: [GCode] Newbie question, Thanks

« on: May 02, 2008, 12:22:33 AM »

The reason why it gives you an error, is because after the arc command, you have not given a line move command, and Mach is still looking for arc information in the next line, which happens to be missing. Simply put a G01 in the next line after the arc. I believe what Ian meant in his reply was that you were specifying an arc with the same end points as the start points. This is not the case, though, as you have moved in Y position.

Below is a code i made with a circle curve, i figured it out fine but using the same method, dosnt seem to work, or im missing something

This is what I was talking about in my previous post about a missing error. Your circle is 3 in diameter. Any smaller that a 1.5 radius is impossible. Replace your R0.5 with R1.5 and you will see that nothing has changed.

833

G-Code, CAD, and CAM discussions / Re: [GCode] Newbie question, Thanks

« on: April 29, 2008, 08:46:51 PM »

mouse wheel zooms for me, and pan is hold down right mouse button, tilt is hold down left mouse. I'm sure there must be keyboard hotkeys, but I don't know them.

834

G-Code, CAD, and CAM discussions / Re: [GCode] Newbie question, Thanks

« on: April 29, 2008, 08:37:20 PM »

Code looks good. You shouldn't need to specify a feed rate except for the very first time, or when the feed rate changes. Going from a feed move,to a rapid, and back to a feed move will not change the rate. Also makes it allot easier to edit, if need be!  Only seen two potential errors. The last perimeter overlaps the previous perimeter on the first line move. Could be intended, I don't know. Also I see that in some lines you a use a space between the axis and the value, and no spaces between the two in other sections. (X 1.5 or X1.5) I see that Mach has no problem with this, but other machines may not run the code this way. Just a heads up.

835

G-Code, CAD, and CAM discussions / Re: [GCode] Newbie question, Thanks

« on: April 29, 2008, 08:22:40 PM »

Lazycam thats with Mach is one of many programs.
Sounds like your already more than your everyday average Joe Welder. I remember at one job, we made hydraulic cylinders for military aircraft. Needless to say you have to be certified. So when cert time rolled around, we just hooked up the gun to a mill table, turned on the table feed, set the wire feeder to automatic mode and let it lay the beads down for us. Your dog could get certified if need be. Hows that for a confidence booster to the guy shoving out tons of equipment out the back of a c130. There all welded robotic now I think, so it's not really an issue anymore.

836

General Mach Discussion / Re: Noobish Question On Motors & Drivers

« on: April 29, 2008, 07:58:50 PM »

comfortably run a 1" (25.4 mm) 4 flute endmill through carbon steel at a reasonable clip.

Yeah, that would definitely go beyond my description of a hobby machine, if theres any depth to that cut. The price for a good capable spindle alone would cost more than my entire setup.  Lets see those models you speak of! 

837

G-Code, CAD, and CAM discussions / Re: [GCode] Newbie question, Thanks

« on: April 29, 2008, 07:34:10 PM »

"G3 X0 Y25 R50" is only half the equation. The line before that tells the start of the arc, and what you gave us is the end of the arc position. What ever position Mach happens to be at when you load the file, is assumed to be the start point in this case. As far as the line disappearing, I have no idea. Here is another simple arc....

G90 G70 G01 F100
X0.0 Y0.0
G3 X-1 Y0.0 R0.5
M30

correct me if I'm wrong somebody, but shouldn't we get an error with a smaller radius than 0.5 in this particular code? Any smaller is impossible, and Mach just makes it 0.5 no matter what you specify smaller.

When arcs come into play, theres definitely more than one way to skin a cat. I+J, Incremental or absolute distance from/to  this/that point. Some machines methods can send your brain spinning in short order.
As Ian said, if your doing letters and stuff, its time to move on to learning a cam package. However, you still need to know the method behind the madness. Good luck.

How goes the welding? Got a bit burned myself this week. Grrrrrrrrrrr       

838

General Mach Discussion / Re: Noobish Question On Motors & Drivers

« on: April 29, 2008, 06:15:44 PM »

1700 oz would be Kong size to me . My steppers are only around 700-800 oz-in, and the first thing to wimp out is my weak porter cable router. I weigh in at 200 lbs, and I can't stop my gantry pushing against it with all my weight, and thats at a speed thats faster than my cutting speed. Steppers have more power the slower the speed, so If I were to really slow it down and run in reverse, I think the earth would start to slow down. As Stirling stated, a properly driven system is where all your power potential comes in to play. For instance, I can grab the ball screws or motor shaft and make the motor loose steps with little effort. It would be impossible for me to make the motor loose steps by hand from putting pressure against the ball nut on that same screw (or whatever the ball nut is attached to. Spindle, gantry, etc...) Same goes for my belt driven axis. By the time the power is transfered through the different pulleys, lost steps are of little concern. Most likely you won't need your machine to go 1000 inches/minute, so a properly built machine matched to do what you NEED it to do is fairly easy, even with small steppers. However, if somebody was to say, "hey, I'll set your machine up with this nice servo setup in trade for your steppers" I would gladly swap them. 1700 oz/inch?? Yeah, thats pretty big looking through my eyes. Wish mine were that powerful, just for the bragging rights. 

839

Forum suggestions and report forum problems. / Re: Forum feature request.

« on: April 25, 2008, 02:40:27 PM »

pffffft.  Tis not a spelling error if used with a capitol 'M'. Ahhh well, it's not the first time I lost the spelling bee, and it wont be the last for sure.

840

General Mach Discussion / Re: Stepper motor setup questions

« on: April 25, 2008, 02:33:44 PM »

As far as Mach having a problem with it, none. Mach works exactly as I have it set up to work. The most problems I have with small segments is that it takes longer to run the program, motors run hotter, harder on tooling (I use small bits for detailed stuff, and jerky movement will snap them in a heartbeat), and quality suffers. With good lines and arcs, everything works fluidly. Just less stress on the whole system and a better final product. It's allot easier to make edits, too. I have had programs that wanted to walk the machine across the floor because of the jerky motion. If I were doing a one-off part, I wouldn't really worry so much with it, but when you cut the same designs repeatedly I think it pays to invest some extra time for a better program.