Author Topic: Tempest Planning - Preliminary information and testing  (Read 274526 times)

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Offline Mike_F

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Re: Tempest Planning - Preliminary information and testing
« Reply #40 on: September 28, 2009, 04:58:36 AM »
Hi Art,

XML is attached but maybe not needed. I did some more testing and the file does in fact run but will not simulate. The error only appears when I use the 'Simulate Program Run' button on the 'Toolpath' screen. I have not actually tried it on my machine yet but will report back as soon as I can get some time.

Thanks,

Mike

Offline ART

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Re: Tempest Planning - Preliminary information and testing
« Reply #41 on: September 28, 2009, 09:16:44 AM »
Mike:

 Thx, that probably explains it. I havent done anything to support simulation. Tempest is tied into Mach3 because M3 is a great
test platform, but since its written a sa standalone planner, its really just tacked in there where I could. Some functions like
estimate and simulate may or may not work.

thx
Art

Offline Mike_F

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Re: Tempest Planning - Preliminary information and testing
« Reply #42 on: September 28, 2009, 09:29:09 AM »
Hi Art,

Thanks for the response - I can now get on with some machine testing :)

Mike

Offline Mike_F

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Re: Tempest Planning - Preliminary information and testing
« Reply #43 on: September 28, 2009, 12:14:03 PM »
Hi Art,

I have been trying to run the 'Nose Cone' program on my machine but the Z axis keeps faulting at line 6 - G17G3X69.991Z3.332Y35.925I-0.075J2.994F600.0 - I am only doing air cuts and zeroed all the axes before hitting 'Cycle Start'. The tool moves to position then faults when trying to move the Z axis. I have tried reducing the acceleration on Z but this has no effect, the axis still faults at the same line.

Let me know if there is any more information you need.

Mike

Offline ART

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Re: Tempest Planning - Preliminary information and testing
« Reply #44 on: September 28, 2009, 01:26:39 PM »
Hi Mike:

 And this is on the 27 version? Ill start tracing for less jerk allowance. That line 6 is the maximum theoretical jerk point as it has to cv a hermitic curve between two full circles.
It does cause a slight aberation, but in my version 27 I got that aberation low enough that it wont trigger any jerk alarm on my system. Ill trace deeper.

Thx
Art

Offline Mike_F

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Re: Tempest Planning - Preliminary information and testing
« Reply #45 on: September 28, 2009, 02:08:29 PM »
Hi Art,

Big apologies - I was still using v25. Just loaded v27 and it works just fine. A few questions if I may.

What effect does the blend radius value have on small segment code?
With a very small value in blend radius does it negate the use of Tempest?
Will blend radius have a detrimental effect on 90 degree corners cut in the YZ plane?

I notice you have a default value of 10 units for blend radius - is this determined through testing or is it just an arbitrary value?

Thanks,

Mike

Offline ART

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Re: Tempest Planning - Preliminary information and testing
« Reply #46 on: September 28, 2009, 05:41:27 PM »
Hi Mike:

  Actually, I just cut the nose cone in a block of spruce, it cut very well, and turned out perfect.

As to the blend radius. Think of it as the worst-case deviation from the path you have set. In reality, it follows a
"Ruile of 1/8th" . That is to say if two lines are joined to gether, the blend will be at most the setting in the dialog,
say..10mm as default, but will always be a maximum of either 1/8th the length of the shortest of the two lines, or the
set amount. SO two 100mm motions will have 10mm raidus by default, a 100mm line entering a 60mm line woudl have
60 * .125 = 7.5mm as its blend. In micro segment code, this means the blends will be very small to make it all very accurate,
if two lines are .1mm each, then the blend between them will be .0125mm radius.

  In this way the accuracy increses as the line segment sizes shrinks. As blends shrink the max speed though them shrinks as well,
but the physical  limits are generally high, so it isnt generally noticable. SO basically, a 10mm or in inch mode perhaps .5" would be good for all
program types as loong as a .5" radius is not too much for you. Set it as low as you like, its only a maximum.

  I was very pleased at the running of the nose-cone, seemed to work well. Vary your jerk setting till you like the smoothness offered, and you should
be able to leave it there, though it can be handy to raise Jerk limits for very tight code to allow for faster motion overall.

Art
« Last Edit: September 28, 2009, 07:36:55 PM by ART »

Offline Mike_F

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Re: Tempest Planning - Preliminary information and testing
« Reply #47 on: September 28, 2009, 06:22:57 PM »
Hi Art,

Thanks for the very informative reply - I think I am beginning to understand :)

I'm glad the nose cone cut OK. I have already cut some aluminium ones using the standard Mach and I am very tempted to cut another using Tempest. I think I will play a little longer with some settings first, before committing to the aluminium.

Do I understand correctly that the trajectory planner appears to be a module within Mach that can be changed easily as and when developments take place? Being able to switch from one to another would imply it is.

Mike

Offline ART

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Re: Tempest Planning - Preliminary information and testing
« Reply #48 on: September 28, 2009, 07:35:19 PM »
Mike:

 Yes, the planner IS a module, BUT the current planner in Mach3 is a very speciallly modified planner module that is hooked in many spots in special ways to allow for things such as partial motions due to feedhold, and reverse run and such. It is not planned to make those same connections but to make the new planner mathmatically pure, that is to say it will follow a real-world physics engine of calculations based on accelerations, velocities and tangental acceleration calculations. This means it will likely never appear as Mach3's standard planner, though if it does work as well as I hope, it may be offered as an upgrade module for those that need or want it. Its in early days, but my vision is one that woudl allow for graphically identfying the configuration of a system and allow the kinematics to
control the 9 axis to produce in the end a 3D coordinate from all 9 axis. It woudl allow for proper robotic control, or perhaps hexapod type running from normal 3d GCode.

  Its a very long way from here to there, but the first most important step is to get the accuracy and jerk reduction under control. After running the nose cone Id say Im happy with both at this point.
Ill watch further testing and move on to proper math pure and jerk free feedhold code, then it will be on to kinematics matrix configurations. Youll likely have test versions available for awhile till it is at least a match for all spec'ed capability. We'll see where testing takes us. :) . Each error last week fixed up important sections to the point that other than feedhold im pretty happy ( very happy actually)
with the run time performance, while it is slower then Mach3 dependant on jerk limitation set ( as one woudl expect) , it offers higher accuracy at high speeds through most types of code.

Art

Offline Mike_F

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Re: Tempest Planning - Preliminary information and testing
« Reply #49 on: September 29, 2009, 06:16:21 AM »
Hi Art,

This is all very interesting stuff and I envy your ability to get your head around the maths and physics. It's this kind of 'pushing the boundaries' that keeps us alive.

Another question - does the lookahead setting have an effect on Tempest?

Mike