Disable "Stop at angles degrees"

[Greolt]

To disable "Stop at angles degrees" do you set 180 or 0? Or some other number?

[Robertspark]

why do you want to "disable" it?

From the manual it only affects the lookahead and how the tradjectory planner operates, it does not actually stop the motion when an angle over so many degrees is found.

{I think it did something different in Mach3 in that it actually stopped the CV motion at angles over the set number of degrees}

[Greolt]

OK perhaps I misunderstand it.

Never wanted or used it in Mach3. So I had thought to disable it in UCCNC

The name "Stop at angles degrees" certainly suggests it stops.

[Robertspark]

Yes, I thought the same thing that it changed from CV to exact stop if an angle over xx degrees was found between motion moves G1, G2 & G3.

Mach3 explanation here (similar name, totally different in application, it is a physical "stop" in motion at angles greater than the setting):
http://www.machsupport.com/wp-content/u ... ngs_v2.pdf

In UCCNC, suspect what it does is tries to give you a sharper corner, so it forces the tradjectory planner to calculate the end points exactly, then take into account the corner error max which relates to the feedrate adjustment because you are attempting Constant Velocity, having Corner Error Max small relative to your feedrate forces the feedrate to drop to achieve the fixed Corner Error Max between motion moves G1, G2 and G3.

You need to consider the other parameters of:
- Linear error max
- Linear addition length max
- Linear unify length max
and their explanations in the manual.

given without the "Stop at angles degrees" setting their could be some amount of the 3 trajectory "tolerance" parameters still present {or at least that is the way I look at it.

I would leave it at the default setting (89 degrees)

Corner error max discussion here: viewtopic.php?f=4&t=456
check out my posts:
Mon Oct 30, 2017 9:20 am
Sun Oct 29, 2017 6:51 pm
Sun Oct 29, 2017 6:47 pm

[ger21]

I think you would set it to 180, which is reversing back on itself.

[Greolt]

Thanks Gents for the response.

Rob's explanation makes some sense.

I was hoping support might chime in with some clarification or confirmation.

[Robertspark]

Sorry, should have said in my earlier post, check the user manual, because that is where I got or expanded on the manual in my post

[Greolt]

Yes I have read the manual several times on this .

.......then stop the looking ahead at that point and only interpolate the previous segments. The looking ahead will start again after the point......

Still sound like a stop to me. That is why I am hoping for some clarification or confirmation from support on this.

[cncdrive]

The looking ahead stops and decceleration happens to the programmed point on connection angles on the path which are greater than the value you set in the CV settings.

So, to fully enable the setting, so the look ahead will not stop because of the too high conn.angle you set 360, because connection angle on the path can't be greater than 360°, so no stop will happen.
A 360°angle is a full circle, it is for example when one axis completely changing direction while the other axes don't move.

And to fully disable it, so the motion will always deccelerate on all points you set 0°, because every connection angle is greater than 0° on any paths.

You can easily verify this visually with for example this code:

Code: Select all

G64 G90
G00 X0 Y0 Z0
G1 X0 Y0 F1000
G1 X10 Y0
G1 X10 Y10
G1 X0 Y10
G1 X0 Y0
M30

Then set your X and Y axis accelerations low, e.g. value 50.
And then set the Stop on angle parameter to 0 first and run the g-code and watch the toolpath.
And next set the Stop on angle parameter to 360 and run the g-code and watch the toolpath again.
And set the linear error, the lin.unify lenght, lin. addition lenght and corner max. all to e.g. value 1, so they are great enough for you to see the rounding.

You will see that with Stop at angle 0 value the TCP marker on the toolpath will go out to all endpoints of the square,
and you will see that rounding happens on all endpoints, corners when the Stop at angle value is set to 360.

[Greolt]

Thanks very much for that explanation. I will need to read it a few times for it to sink into my old brain.

On first read it sounds like, even though UCCNC and Mach3 have very different trajectory planers, that on this particular point they act the same.

As in the motion comes to a halt at the specified corners. Or as if CV was turned off for that point.

I am about to go out the door for a few days away, so I will not be able to work through you demo code right now.

However when I return I certainly will, for my own education.

Thanks again.