Hello Guest it is August 06, 2020, 09:08:52 AM

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Messages - ryanosman

Pages: 1 2 »
1
heh heh... sorry, that's the numbers from my desk PC where I have the speed cranked.. crap, sorry to waste your time. Here's the real xml.

2
I've always had the F command implemented as a percentage of the maximum speed (guess that's what happens when you roll your own), and hadn't noticed the difference between 80 and 100 yet (I've had mach3 running for... oh... 3 days now). So actual velocity eh...so that's how the real world does it. OK.  :D

3
The F100 sets the feedrate to 100% of the maximum which is 80 inches per minute. Speed of G01 at F100 = speed of G0.

4
This should do a quick & easy demonstration of what I'm seeing.

F100
g00 x0y0z0
(accel decelled moves:)
g0 x1
x2
x3
x4
x5
(one fluid movement:)
g1 x4
x3
x2
x1
x0
(now with pauses:)
g0 x1
g1 x2
g0 x3
g1 x4
g0 x5

5
yep. printer port -> 3 custom programmed micros -> 12 high current transistors (... and a whole bunch more junk...) -> 3 stepper motors.

6
Okay I did some time tests. I have my machine set to 80 inches per minute, accell/decelling at 20 inches/sec/sec. When doing consecutive 1 inch G1 moves, my machine takes .73secs each 1inch move. That's the fastest condition. When I do consecutive G0 moves (with the stop between, but no pause). the machine takes .77 seconds each, so like I said, no cv on rapids is not a big deal. When I alternate G0 & G1, the machine takes 1.00 seconds per move. That means the delay is about 1/4 second.

But if it remains a mystery, I can just look for a smarter dxf->gcode converter. Lazycam doesn't seem too bad...?

7
Yes graham that's absolutely true. Maybe it's time I looked into that. Especially if this 'delay' thing doesn't get sorted out.

BTW hood, I really like your touch screen layout. Just discovering the whole customizable screen area of mach3... it's really, really satisfying!

-Ryan.

8
Try my example. cv or exact stop doesn't matter. Maybe it will be different on yours, but I've tried 2 PCs here, both about 1.7Ghz. This example is all the same axis so that the delay is more noticeable.

F100
(accel decelled moves:)
g0 x1
x2
x3
x4
x5
(one fluid movement:)
g1 x4
x3
x2
x1
x0
(now with pauses:)
g0 x1
g1 x2
g0 x3
g1 x4
g0 x5

When I use the term safe z, I may be using it in an inappropriate way. To be honest, I haven't looked into the safez options in mach3... I am using it to mean any movements on my mill that are made at a high level to clear the work area Here's an example to explain what I mean (typed in off the top of my head so I hope I get it right heh heh):

(engrave a square on lamacoid.)
f100
g0x0y0z0 ;initialize to known state
x1y1 ; go to first corner at rapid, 'safe z height'
z-1 ; drop engraving bit
g01 x2 ; draw bottom of square. There was a delay before this command.
g00 z0 ; this is the 'safe z' command that the cam program puts in. There was a slight delay before this command.
g00 z-1 ; it would take me a long time to remove these, plus sometimes they're needed, sometimes they're not. Mach should process these without delay anyway.
g01 y2 ; draw right side of square. There was a slight delay before this command.
g00 z0 ; go to safe z to move to beginning of next line. There was a slight delay before this command.
g00 z-1; (coincidentally, we are already here - no 'safe z' xy moves needed at this time)
g01 x1 ; draw top of square. There was a slight delay before this command.
g00 z0 ; go to safe z before moving to beginning of next line. There was a slight delay before this command.
g00 z-1
g01 y1 ; left side of square. There was a slight delay before this command.
g00 z0 ; There was a slight delay before this command.
x0y0 ; back home for something to do.

I suppose I should be clear about this too... I'll mention again I am talking about around 1/4 to 1/2 of a second of delay (haven't measured it). Doesn't sound like much, but in a gcode program with thousands of little segments, this can add up to a lot of extra time. Imagine a cnc machine emulating an artist with a sketch pencil & you'll get the idea.

*sigh* I was really hoping this would be a small, easy deal.

9
There is a noticeable delay going from g0 to g1 or g1 to g0. It isn't there going from g0 to g0 or g1 to g1. If you like, try it & you'll see what I'm talking about.

10
    Sounds like you're questioning my compotence? But why would someone of a thousand posts do that? I built my first CNC machine around 1990, and wrote the software to control it on a first generation commodore amiga. Since then, I've had many different machines and operating scenarios which we have used every day in our business which is designing and manufacturing custom electronic based equipment.

Back to the subject...

I find Mach3 to be a brilliant piece of work, well worth the money. I've noticed that it adds delays where it seems to me that there shouldn't be any. I thought it would be helpful to point it out in case anyone on the development team wants to look into it.

Thanks!

Pages: 1 2 »