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Author Topic: Erratic Feedrate When Cutting Spline Lines  (Read 4342 times)

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Offline Chaoticone

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Re: Erratic Feedrate When Cutting Spline Lines
« Reply #20 on: September 27, 2017, 09:37:43 AM »
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I too use Metric mm and it is a bit time consuming to set up and test in metric, so I look forward to seeing it in Metric version.

Don't hold your breath then. Without some putting in their time (I guarantee you setting up an inch profile for a machine is way faster than writing this wizard) to do some real world test and give results in inch I highly doubt I will spend any more of my time adding metric.

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So in your Wizard can you add a Maximum Velocity speed so when it writes the data to machine.ini it will replace all the higher numbers with this G-Code maximum?

Absolutely not. Setting the max speed any angle will go at to hold a tolerance has nothing at all to do with the feed rate you program. If your programed feed rate is lower than it can take the angle at....... it simply doesn't slow down because it doesn't have too to hold the tolerance. The speed capable does not in any way speed the feed rate up over the programmed feed rate. It will simply lower the speed in angles it needs too, it will never speed it up over programmed feed rate.

The angle is measured from current trajectory to next trajectory. Simply the difference of what it is doing now to what it will do next.

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Previously I had selected Constant Velocity and then later found out about the Wizard, when I went into the Wizard for the first time all angles were 0 and the CV Feedrate On/Off button was set to Off, even though I had selected Constant Velocity in the Configuration Menu. So the way I see it is selecting Constant Velocity in the Configuration menu actually does nothing unless you change the settings in the Wizard, is that right?

Not exactly but enabling CV in general config. does not populate the CV_Feed rate table in any way, therefore you are not taking advantage of that added feature until you populate the table.

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My plan was to set 0 degrees  to the full feed rate I generally use and then gradually decrease the feedrates and probably have 0 in a lot of the tighter angles

You can populate the table any way you want, what ever works for you. That is kind of the way the last version works. I can't imagine a scenario that this version is not far superior though. This version is much smarter.
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Offline Mauri

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Re: Erratic Feedrate When Cutting Spline Lines
« Reply #21 on: September 27, 2017, 10:19:32 PM »
Chaoticone,
Thanks for your reply.
Are the CV values generated by your program changed to Integers?
If we convert the Imperial version to Metric do we need to change them to Integers or leave them in decimal form?
Is this curve generated by your CV program a form of a Polynomial?
Regards,
Mauri.

Offline Chaoticone

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Re: Erratic Feedrate When Cutting Spline Lines
« Reply #22 on: September 27, 2017, 10:43:22 PM »
No problem

No, no conversion to integers. They begin as integers and end as integers. I suspect if I wanted to add resolution they could very well end as floating point but i don't see the need for that. Never heard of anyone programming a feedrate as a floating point but that doesn't mean it would necessarily be illegal to do so but it might be. I haven't ever given it enough though to know for sure one way or the other TBH.

I think I would convert to integers just to play it safe.

Well, I use polynomials to get there. But I also use tables and conditionals but most of it is polynomials I guess.

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Re: Erratic Feedrate When Cutting Spline Lines
« Reply #23 on: September 28, 2017, 06:25:12 PM »
I too work in mm, so have been reading this post with interest and have had a look at the document that Mauri uploaded.

I haven'd installed the wizard onto my machine yet, but have a question about the output into the table. For instance take the following output generated in inches.

Angle_100=6.000000
Angle_101=6.000000
Angle_102=6.000000
Angle_103=5.000000
Angle_104=5.000000
Angle_105=5.000000

Would I input values into my table as such for metric?

Angle_100=152.4
Angle_101=152.4
Angle_102=152.4
Angle_103=127
Angle_104=127
Angle_105=127

Offline Mauri

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Re: Erratic Feedrate When Cutting Spline Lines
« Reply #24 on: September 28, 2017, 07:04:42 PM »
 Allen,
Yes all you have to do is multiple the CV Imperial values by 25.4.
Then Copy them into the machine.ini.
To make it easier for you to do this:
Copy Angle_0=x.****************** to Angle_179=x.****************** into Excel.
Then use Replace to change Angle_???= to blank you will have to do this 3 times Angle_?= then Angle_?? and Angle_???=
Then multiple all 180 value by 25.4.
On another column enter Angle_1 and then on the next 2 lines Angle_2 and Angle_3.
Then highlight the 3 and double click the dot on the bottom right hand corner of the highlight this will make a column from 0 to 179.
Next on another column make a column of =
Finally copy the column of you metric values to the right of the = column.
Then copy all the 3 columns and replace the one in machine.ini be selecting Paste Special Text .
Then fire up Mach4, followed by exit.
Save this file line machine2A00254.ini meaning 2 axis .00254mm error or any equivalent tolerance conversion for .1 to .0001 to metric.
By doing this the tabs will disappear in the machine.ini copy that you made and all the Angles, =, numbers will come together.
You can make multiple sets with other combinations of Axis and Tolerance.
So every time you want another type click open in notepad and save it as machine.ini.
Hope this helps to make it easier.
Regards,
Mauri.

Offline Mauri

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Re: Erratic Feedrate When Cutting Spline Lines
« Reply #25 on: September 28, 2017, 07:06:29 PM »
Allen,
I forgot to mention make the numbers column in excel numbers with 0 decimal that way they will roundup to the nearest Integer value.
Regards,
Mauri.

Offline Chaoticone

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Re: Erratic Feedrate When Cutting Spline Lines
« Reply #26 on: September 28, 2017, 08:06:36 PM »
Guys, I hope to have a version that will work in machine setup units (inch or metric) later tonight or tomorrow.

I hope this wizard will eliminate the need for multiple setups. If job tolerance changes or job type that changes axis involved, just run the wizard.
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Offline dq828

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Re: Erratic Feedrate When Cutting Spline Lines
« Reply #27 on: September 28, 2017, 10:32:51 PM »
Excellent thanks

Offline Chaoticone

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Re: Erratic Feedrate When Cutting Spline Lines
« Reply #28 on: September 28, 2017, 10:38:56 PM »
Here you go...... this update populates the CV_Feedrate table in inch or mm and the tolerance you enter is inch or mm........ all dependent on machine setup units.

Let me know how it goes.
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Offline Mauri

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Re: Erratic Feedrate When Cutting Spline Lines
« Reply #29 on: September 29, 2017, 02:58:11 AM »
Chaoticone,
That is much easier, thanks.
It seems to follow the profiles very well on small .01mm cut profiles, tested many different types in simulation.
I will run some controller tests soon and compare process times on some profiles your system vs our all angles the same version.
Regards,
Mauri.