Re: [Emc-users] Thread timings: (Was: Rock64 pre-orders on Banggood.)

[Gene Heskett]

On Tuesday 26 March 2019 09:01:29 andy pugh wrote:

> On Tue, 26 Mar 2019 at 12:37, Gene Heskett  
wrote:
> > > This is why I was suggesting a 180 degree home switch target
> > > wheel.
> >
> > I must have got stoned and missed that. ;-) 'splain plz..
>
> You didn't miss it, you even discussed it:
>
> "Ahh, white turn one way, black the other. But once the boundary is
> encountered, do a fixed edge sequence so it always hits the stop from
> the same direction"

Duh...  So I did.  Need a hot wet washrag for the egg on my face...

And I didn't follow thru, using a normal roller tipped switch instead 
because I had it, and the cam was the corner of a plastic box laying on 
the table saw.  Didn't have the opto stuff on hand. 

Observing it now, the initial stop when its doing 120 degrees a sec, is 
right on the peak of the cam, probably a good 2 degrees past the switch 
click, then it creeps backwards till it opens, then a quick growp and 
its at the ini files stated offset showing 0. in the dro. Seems 
repeatable, so I quit screwing with it.  I do need to fiddle with that 
offset though, so that a lathe tool caught in the 3 jaw is pointing 
straight up. Then a precise grind is a piece of cake. :)

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page 



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Re: [Emc-users] Thread timings: (Was: Rock64 pre-orders on Banggood.)

[andy pugh]

On Tue, 26 Mar 2019 at 12:37, Gene Heskett  wrote:

> > This is why I was suggesting a 180 degree home switch target wheel.
>
> I must have got stoned and missed that. ;-) 'splain plz..

You didn't miss it, you even discussed it:

"Ahh, white turn one way, black the other. But once the boundary is
encountered, do a fixed edge sequence so it always hits the stop from
the same direction"


-- 
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1916


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Re: [Emc-users] Thread timings: (Was: Rock64 pre-orders on Banggood.)

[Gene Heskett]

On Tuesday 26 March 2019 08:08:02 andy pugh wrote:

> On Tue, 26 Mar 2019 at 12:05, Gene Heskett  
wrote:
> > I've not more than thought of it, but have wondered if it would be
> > possible to set up a 10 kilohertz base thread that accessed the
> > parport, while leaving the 1 kilohertz stuff on the 7i76?
>
> Yes, but it wouldn't necessarily help. LinuxCNC only checks the home
> switch state in the servo thread.
>
Oh, no help there then. That leaves a triangular accel pattern to the 
search_vel. Unforch I could see things being demolished if it guessed 
where it is wrong as it starts the home switch search move.

> This is why I was suggesting a 180 degree home switch target wheel.

I must have got stoned and missed that. ;-) 'splain plz..

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page 



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[Emc-users] Thread timings: (Was: Rock64 pre-orders on Banggood.)

[andy pugh]

On Tue, 26 Mar 2019 at 12:05, Gene Heskett  wrote:

> I've not more than though of it, but have wondered if it would be
> possible to set up a 10 kilohertz base thread that accessed the parport,
> while leaving the 1 kilohertz stuff on the 7i76?

Yes, but it wouldn't necessarily help. LinuxCNC only checks the home
switch state in the servo thread.

This is why I was suggesting a 180 degree home switch target wheel.

-- 
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1916


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