Re: [Emc-users] NURBS G5.2 G5.3 works well

[Mark Johnsen]

Looks great!  :-)


>
> attached again, after a lot of cropping in gimp
>
>
>

___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] NURBS G5.2 G5.3 works well

[Gene Heskett]

On Wednesday 20 January 2021 17:50:17 Frank Tkalcevic wrote:

> > Since I can't buy a 30mm wrench that doesn't weigh 10+ lbs, and is
> > 15-20" long, I am carving out a 30mm ER20 nut wrench from 1/2" alu
> > plate, using G5.2/G5.3 to carve out a profiled handle, and its
> > working rather well.
>
> Do we get a photo?

Attached. Or was, by the time it was base64'd, a 273k jpg was 380k and 
too big. So I removed it for a resend.

I had it clamped to a planed flat cherry spoilboard, but had to 
heavily modify the code because even with a nice flat 3/4" cherry under 
it, it was still a mm+ out of flat with the 6040 bed. So I had to do 
some commenting and adjusting of the code to get it cut completely free.

> And how did you write the gcode?

By hand, with some help from argenm18.py for the circular stuff. I have 
the beta freecad, but not the knowledge to run it. So I write one good 
line of code, or a short paragraph, and wrap it in a loop. At the moment 
its still only about 100 LOC.

> Did you use the axis backplot to check the curves?

Yes, but the backplot wasn't as accurate as the mill, so there is a 
detectable glitch at the root of the handle on both sides.  So I had to 
re-write all the whiles to make 2 final passes deep enough to actually 
cut it loose.

I need to make the other wrench yet, so I'll be hacking on it to do that, 
and then I will post the code. I also intend to further lighten them by 
removing quite a bit of the handle thickness which I'll do in a 
separate .ngc file.  And some of tomorrow is wasted, getting fresh 
rubber on the truck.  And my 8 oz coke bottle for mister supply needs 
swapped for a bigger one if all the code is enabled at one time. I had 
to refill it twice.

Now I hope it will get past the size limits. The smunched pix is 273k, 
any more smunch and the color goes to pot.

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)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] NURBS G5.2 G5.3 works well

[Frank Tkalcevic]

> Since I can't buy a 30mm wrench that doesn't weigh 10+ lbs, and is 15-20" 
> long, I am carving out a 30mm ER20 nut wrench from 1/2" alu plate, using 
> G5.2/G5.3 to carve out a profiled handle, and its working rather well.

Do we get a photo?  And how did you write the gcode?  Did you use the axis
backplot to check the curves?



___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Another Mesa vhdl question

[Peter C. Wallace]

On Wed, 20 Jan 2021, Ralph Stirling wrote:


Date: Wed, 20 Jan 2021 22:27:34 +
From: Ralph Stirling 
Reply-To: "Enhanced Machine Controller (EMC)"

To: "Enhanced Machine Controller (EMC)" 
Subject: Re: [Emc-users] Another Mesa vhdl question

I've tried it both ways, and while the pulse train
moves to the other trace, I get no more response.

-- Ralph


Well its  neccesary  for FPGA TX --> uC RX  and  uC TX --> FPGA RX
but clearly not sufficient. Are you sure the uC baud rate is correct?





From: Peter C. Wallace [p...@mesanet.com]
Sent: Wednesday, January 20, 2021 2:15 PM
To: Enhanced Machine Controller (EMC)
Subject: Re: [Emc-users] Another Mesa vhdl question

Looks like you have RX connected to RX and TX to TX
you need RX to TX and TX to RX


Peter Wallace
Mesa Electronics


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.sourceforge.net%2Flists%2Flistinfo%2Femc-usersdata=04%7C01%7Cralph.stirling%40wallawalla.edu%7C0e7d00f65ecf41153a6008d8bd90fffa%7Cd958f048e43142779c8debfb75e7aa64%7C0%7C0%7C63746766597506%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000sdata=D%2FZGjx23N2UME8DmtbJiSfE1D%2F%2FL7ejXyuici0XXkPs%3Dreserved=0


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users



Peter Wallace
Mesa Electronics

(\__/)
(='.'=) This is Bunny. Copy and paste bunny into your
(")_(") signature to help him gain world domination.



___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Another Mesa vhdl question

[Ralph Stirling]

I've tried it both ways, and while the pulse train
moves to the other trace, I get no more response.

-- Ralph

From: Peter C. Wallace [p...@mesanet.com]
Sent: Wednesday, January 20, 2021 2:15 PM
To: Enhanced Machine Controller (EMC)
Subject: Re: [Emc-users] Another Mesa vhdl question

Looks like you have RX connected to RX and TX to TX
you need RX to TX and TX to RX


Peter Wallace
Mesa Electronics


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.sourceforge.net%2Flists%2Flistinfo%2Femc-usersdata=04%7C01%7Cralph.stirling%40wallawalla.edu%7C0e7d00f65ecf41153a6008d8bd90fffa%7Cd958f048e43142779c8debfb75e7aa64%7C0%7C0%7C63746766597506%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000sdata=D%2FZGjx23N2UME8DmtbJiSfE1D%2F%2FL7ejXyuici0XXkPs%3Dreserved=0


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Another Mesa vhdl question

[Peter C. Wallace]

On Wed, 20 Jan 2021, Ralph Stirling wrote:


Date: Wed, 20 Jan 2021 22:06:45 +
From: Ralph Stirling 
Reply-To: "Enhanced Machine Controller (EMC)"

To: "Enhanced Machine Controller (EMC)" 
Subject: Re: [Emc-users] Another Mesa vhdl question

I've got the STMBL code flashed on an STM32F407G Discovery
eval board, and running with the Servoterm control software
(which I am very delighted to have achieved).

I seem to be missing something in setting up sserial in Linuxcnc
though.  Axis loads without error, but shows only gpio for the
pins that are supposed to be sserial.  Here is what I've done:

1. Vhdl file has sserial module tag defined.

   (SSerialTag,x"00",  ClockLowTag,x"01",  
SSerialCommandAddr,SSerialNumRegs, x"10",  SSerialMPBitMask),

2. Vhdl file has sserial pins defined.

   IOPortTag & x"00" & SSerialTag & SSerialRX0Pin,  -- I/O 48
   IOPortTag & x"00" & SSerialTag & SSerialTX0Pin,  -- I/O 49
   IOPortTag & x"00" & SSerialTag & SSerialTXEn0Pin,-- I/O 50

3. HAL file has config including sserial_port_0 defined.  Linuxcnc version is 
2.8.1
  running on Raspberry Pi 3b+ buster.

  loadrt hostmot2 debug_idrom=1
  loadrt hm2_rpspi config="num_encoders=2 num_pwmgens=2 num_stepgens=4 
sserial_port_0=0XXX" spiclk_rate=12500

4. The STMBL sserial rx pin (PA10) is connected to the 7i90 pin P3-01 and 
sserial tx pin (PA8) is connected to 7i90 P3-03.

5. When I run linuxcnc, those pins show up as gpio.

  hm2/hm2_7i90.0: Smart Serial Firmware Version 43
  
  hm2/hm2_7i90.0: IO Pin 048 (P3-01): IOPort
  hm2/hm2_7i90.0: IO Pin 049 (P3-03): IOPort

6. A scope watching PA8/P3-03 and PA10/P3-01 shows
   a series of 10us active low pulses on PA8/P3-03.
   PA10/P3-01 has short glitches.  To minimize signal
   integrity issues, I stacked some connectors to join
   the STMBL board and the 7I90.  Signals were the
   same using 6" jumper wires though.

(see photos at 
https://gab.wallawalla.edu/~ralph.stirling/projects/linuxcnc/stmbl)

7. On the STMBL board, I have a config of:

load sserial
load adc

sserial0.pos_fb = adc0.cos0

I'm hoping there is just some simple step I'm missing.  I
don't know if the problem lies at the STMBL or 7I90 end.


Looks like you have RX connected to RX and TX to TX
you need RX to TX and TX to RX


Peter Wallace
Mesa Electronics


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Spindle speed changes with threading.

[Robert Ellenberg]

Hi John,

Good catch! Andy also pointed out that multi-start threading is of course
possible if you do a Z offset like you describe. I was thinking of "native"
support for multi-start in G33 / G33.1, like with a word specifying the
start location in degrees.

-Rob

___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] NURBS G5.2 G5.3 works well

[Todd Zuercher]

Over here I think we call them a "striking open end wrench"
The only thing we call spanners are the ones with the little hook pin, 
everything else is a wrench.

Todd Zuercher
P. Graham Dunn Inc.
630 Henry Street 
Dalton, Ohio 44618
Phone:  (330)828-2105ext. 2031

-Original Message-
From: Andy Pugh  
Sent: Wednesday, January 20, 2021 3:12 PM
To: Enhanced Machine Controller (EMC) 
Subject: Re: [Emc-users] NURBS G5.2 G5.3 works well

[EXTERNAL EMAIL] Be sure links are safe.

> On 20 Jan 2021, at 19:10, Gene Heskett  wrote:
>
> Since I can't buy a 30mm wrench that doesn't weigh 10+ lbs, and is 15-20"

What term do you use for slogging spanners in the US?
https://www.ebay.com/itm/Striking-Slugging-Slogging-Flogging-Open-End-Spanner-Metric-20-58mm-Individual/191875402318
I got one of those for my spindle.
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Another Mesa vhdl question

[Ralph Stirling]

I've got the STMBL code flashed on an STM32F407G Discovery
eval board, and running with the Servoterm control software
(which I am very delighted to have achieved).

I seem to be missing something in setting up sserial in Linuxcnc
though.  Axis loads without error, but shows only gpio for the
pins that are supposed to be sserial.  Here is what I've done:

1. Vhdl file has sserial module tag defined.

(SSerialTag,x"00",  ClockLowTag,x"01",  
SSerialCommandAddr,SSerialNumRegs, x"10",  SSerialMPBitMask),

2. Vhdl file has sserial pins defined.

IOPortTag & x"00" & SSerialTag & SSerialRX0Pin,  -- I/O 48
IOPortTag & x"00" & SSerialTag & SSerialTX0Pin,  -- I/O 49
IOPortTag & x"00" & SSerialTag & SSerialTXEn0Pin,-- I/O 50

3. HAL file has config including sserial_port_0 defined.  Linuxcnc version is 
2.8.1
   running on Raspberry Pi 3b+ buster.

   loadrt hostmot2 debug_idrom=1
   loadrt hm2_rpspi config="num_encoders=2 num_pwmgens=2 num_stepgens=4 
sserial_port_0=0XXX" spiclk_rate=12500

4. The STMBL sserial rx pin (PA10) is connected to the 7i90 pin P3-01 and 
sserial tx pin (PA8) is connected to 7i90 P3-03.

5. When I run linuxcnc, those pins show up as gpio.

   hm2/hm2_7i90.0: Smart Serial Firmware Version 43
   
   hm2/hm2_7i90.0: IO Pin 048 (P3-01): IOPort
   hm2/hm2_7i90.0: IO Pin 049 (P3-03): IOPort

6. A scope watching PA8/P3-03 and PA10/P3-01 shows
a series of 10us active low pulses on PA8/P3-03.
PA10/P3-01 has short glitches.  To minimize signal
integrity issues, I stacked some connectors to join
the STMBL board and the 7I90.  Signals were the
same using 6" jumper wires though.

 (see photos at 
https://gab.wallawalla.edu/~ralph.stirling/projects/linuxcnc/stmbl)

7. On the STMBL board, I have a config of:

 load sserial
 load adc

 sserial0.pos_fb = adc0.cos0

I'm hoping there is just some simple step I'm missing.  I
don't know if the problem lies at the STMBL or 7I90 end.

Thanks again.
-- Ralph

From: andy pugh [bodge...@gmail.com]
Sent: Monday, January 18, 2021 10:24 AM
To: Enhanced Machine Controller (EMC)
Subject: Re: [Emc-users] Another Mesa vhdl question

CAUTION: This email originated from outside the Walla Walla University email 
system.


On Mon, 18 Jan 2021 at 16:42, Ralph Stirling
 wrote:
>
> The AD7740 v-to-f converters don't work as well
> as I'd like, and I'm thinking about just using a
> little microcontroller, like the STM32G031 to do
> my A/D conversion.

One option there might be to use the STMBL source, that converts the
STM32 into a smart-serial device, that could pass the voltage as an
all-digital number straight to HAL.
(STMBL does far more than that too, but you wouldn't need all of it)

--
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, 1912

___


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] NURBS G5.2 G5.3 works well

[Ralph Stirling]

Ebay has my favorite search functions.  The "must include"
and "must exclude" logic is very powerful.

shaker +(paint,can) -(salt,pepper)

although in my case, just searching on "paint shaker"
gives me pages of the real thing and no salt or pepper shakers.

-- Ralph

From: Gene Heskett [ghesk...@shentel.net]
Sent: Wednesday, January 20, 2021 1:54 PM
To: emc-users@lists.sourceforge.net
Subject: Re: [Emc-users] NURBS G5.2 G5.3 works well

CAUTION: This email originated from outside the Walla Walla University email 
system.


On Wednesday 20 January 2021 15:53:55 Ralph Stirling wrote:

> Try "er20 wrench" on ebay:
>
> https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.ebay.com%2Fitm%2F122474104173data=04%7C01%7Cralph.stirling%40wallawalla.edu%7C94139b487d1f4b0ba30b08d8bd8e095c%7Cd958f048e43142779c8debfb75e7aa64%7C0%7C0%7C637467765023530628%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000sdata=yMZdiEak55SSrgjDyq5%2FLzBt8%2FTULSqUERIGojNoz64%3Dreserved=0

I must be getting slow in my dotage, Ralph. Fleabays search engine is so
poor I never thought of it. It usually finds just the stuff you don't
need. Why else, when I was looking for a paint shaker, would it show me
100 salt * pepper shakers for every paint shaker? Boggles what little
mind I have left. :)

[...]

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)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 



___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.sourceforge.net%2Flists%2Flistinfo%2Femc-usersdata=04%7C01%7Cralph.stirling%40wallawalla.edu%7C94139b487d1f4b0ba30b08d8bd8e095c%7Cd958f048e43142779c8debfb75e7aa64%7C0%7C0%7C637467765023540624%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000sdata=mDVkRVv6XaJViphsnnOkn5fDSKAyXHNQzGhWnq2AkQM%3Dreserved=0


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] NURBS G5.2 G5.3 works well

[ken.strauss]

Really? See
https://www.amazon.com/Slogging-Spanne-Striking-Wrench-Spanner/dp/B08291ZK8P
/


-Original Message-
From: Gene Heskett  
Sent: January 20, 2021 4:16 PM
To: emc-users@lists.sourceforge.net
Subject: Re: [Emc-users] NURBS G5.2 G5.3 works well

On Wednesday 20 January 2021 15:12:25 Andy Pugh wrote:

> > On 20 Jan 2021, at 19:10, Gene Heskett  wrote:
> >
> > Since I can't buy a 30mm wrench that doesn't weigh 10+ lbs, and is 
> > 15-20"
>
> What term do you use for slogging spanners in the US?
> https://www.ebay.com/itm/Striking-Slugging-Slogging-Flogging-Open-End-
>Spanner-Metric-20-58mm-Individual/191875402318 I got one of those for  
>my spindle.

I've seen them , but no one in this row of apple trees knows what to call
them, including me, let alone have any for sale.

Thanks Andy.

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)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users



___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] NURBS G5.2 G5.3 works well

[Gene Heskett]

On Wednesday 20 January 2021 15:53:55 Ralph Stirling wrote:

> Try "er20 wrench" on ebay:
>
> https://www.ebay.com/itm/122474104173

I must be getting slow in my dotage, Ralph. Fleabays search engine is so 
poor I never thought of it. It usually finds just the stuff you don't 
need. Why else, when I was looking for a paint shaker, would it show me 
100 salt * pepper shakers for every paint shaker? Boggles what little 
mind I have left. :)

[...]

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)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] NURBS G5.2 G5.3 works well

[Ralph Stirling]

Try "er20 wrench" on ebay:

https://www.ebay.com/itm/122474104173

-- Ralph

From: Gene Heskett [ghesk...@shentel.net]
Sent: Wednesday, January 20, 2021 11:08 AM
To: Enhanced Machine Controller (EMC)
Subject: [Emc-users] NURBS G5.2 G5.3 works well

CAUTION: This email originated from outside the Walla Walla University email 
system.


Greetings all;

Since I can't buy a 30mm wrench that doesn't weigh 10+ lbs, and is 15-20"
long, I am carving out a 30mm ER20 nut wrench from 1/2" alu plate, using
G5.2/G5.3 to carve out a profiled handle, and its working rather well.

The total amount of spindle time however, is gonna make me sell the pair
for about $200 though.  Those puny X rails on a 6040 are wanting to let
it chatter, a lot.

I'll use the same basic code to make the 21mm version to fit the double D
flats on the chuck. Conditionalized of course,  so it makes one or the
other.

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)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 



___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.sourceforge.net%2Flists%2Flistinfo%2Femc-usersdata=04%7C01%7Cralph.stirling%40wallawalla.edu%7C054d64705ac7400d0afb08d8bd76c461%7Cd958f048e43142779c8debfb75e7aa64%7C0%7C0%7C637467665096607652%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000sdata=1NWI1qMO9uea3OgyIRQ224KQUw8iLhCd5gNCaydo1Bg%3Dreserved=0


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] NURBS G5.2 G5.3 works well

[Gene Heskett]

On Wednesday 20 January 2021 15:16:25 Gregg Eshelman via Emc-users wrote:

> What about making a double ended wrench instead of two wrenches?
>
'cuz you need one to hold the spindle and the other to run the nut? :)
>
> On Wednesday, January 20, 2021, 12:10:39 PM MST, Gene Heskett
>  wrote:
>
>  Greetings all;
>
> Since I can't buy a 30mm wrench that doesn't weigh 10+ lbs, and is
> 15-20" long, I am carving out a 30mm ER20 nut wrench from 1/2" alu
> plate, using G5.2/G5.3 to carve out a profiled handle, and its working
> rather well.
>
> The total amount of spindle time however, is gonna make me sell the
> pair for about $200 though.  Those puny X rails on a 6040 are wanting
> to let it chatter, a lot.
>
> I'll use the same basic code to make the 21mm version to fit the
> double D flats on the chuck. Conditionalized of course,  so it makes
> one or the other.
>
> Cheers, Gene Heskett
>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users


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)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] NURBS G5.2 G5.3 works well

[Gene Heskett]

On Wednesday 20 January 2021 15:12:25 Andy Pugh wrote:

> > On 20 Jan 2021, at 19:10, Gene Heskett  wrote:
> >
> > Since I can't buy a 30mm wrench that doesn't weigh 10+ lbs, and is
> > 15-20"
>
> What term do you use for slogging spanners in the US?
> https://www.ebay.com/itm/Striking-Slugging-Slogging-Flogging-Open-End-
>Spanner-Metric-20-58mm-Individual/191875402318 I got one of those for
> my spindle.

I've seen them , but no one in this row of apple trees knows what to call 
them, including me, let alone have any for sale.

Thanks Andy.

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)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Spindle speed changes with threading.

[John Dammeyer]

Thanks Rob,  
Comments below.

> -Original Message-
> From: Robert Ellenberg [mailto:rwe...@gmail.com]
> Sent: January-20-21 10:12 AM
> To: Enhanced Machine Controller (EMC)
> Subject: Re: [Emc-users] Spindle speed changes with threading.
> 
> Hi All,
> 
> As others have said, during position-synched moves, the axes follow the
> spindle position, so you don't need fine control of spindle speed. However,
> you should have both a stable spindle RPM and a high-ish resolution encoder
> to get the best results. John, for your example, as each encoder pulse
> arrives, the TP will be constantly accelerating / decelerating to try to
> track that position signal. Luckily, it can't get too far off because of
> the axis acceleration limits, but the amplitude of the jitter will
> definitely be higher with a low resolution encoder.
> 
> Here's how spindle synchronization broadly works from within the TP (i.e.
> what occurs in motion after START_FEED_SPEED_SYNCH)
> 
>1. The TP waits (with axes stopped) for a spindle index mark.
>2. Once the spindle has just passed the mark, the machine axes
>accelerate until they reach (spindle speed * requested units/rev).
>3. Once the axes reach the expected velocity, then synchronization is
>declared, and the TP maintains position synchronization from that point
>onwards. At higher spindle RPM, synchronization takes longer, so the
>spindle rotates farther before the axes are synchronized. Multiple
>threading passes at different spindle RPM will not quite follow the same
>path.
>4. After synchronization, the TP computes a position error based on the
>measured spindle position. The axis velocity is nominally spindle speed *
>uu / rev, but that velocity is corrected up or down as needed to drive the
>position error toward zero.
> 
> Note that multi-start threading is not currently possible (because the TP
> always synchs at 0 deg, i.e. at the index mark), but we could modify the TP
> to start synchronization at some angle after the index mark.

I'm surprised that multi-start threads are not possible.   I would think, 
assuming the spindle speed is _not_ allowed to be different, that changing the 
start_z position by say 50% of thread pitch that synchronizing on the index 
would then reliably create a two start thread.  It's how I do it on my ELS.

> 
> Finally, the obvious fix for the inconsistency in the acceleration phase is
> to just declare synchronization at the index mark right away. With the axes
> starting from rest, there would be a huge initial velocity error for the TP
> to correct. It will do so eventually, but there are large position over- /
> under-shoots until it stabilizes. Luckily, we know what the axis
> acceleration looks like (based on axis max acceleration and nominal spindle
> speed), so you can anticipate this and start the axes moving before the
> spindle reaches the index mark. That way, the axes are moving at the
> nominal speed just as the spindle reaches zero. This removes most of the
> position error at the start, and the TP corrects for any residual error
> very quickly. This is roughly the approach we used in PathPilot, and I
> think LinuxCNC 2.8 or 2.9 would benefit from it as well.
> 
> Best,
> Rob

I like the idea. Since the Z is stopped until synchronized and we know using 
standard physics where the Z will be after acceleration up to speed,  that 
regardless of the number of index pulses the time from index to that same 
angular position should be relatively simple using time instead of index 
pulses.  Much better granularity and doesn't force a specific encoder size.  
And the speed is calculated every N encoder pulses so even variations in one 
turn (when the spindle is turning slowly) will not impact entry into the 
existing thread path.

John


> 
> On Wed, Jan 20, 2021 at 12:47 PM John Dammeyer 
> wrote:
> 
> >
> >
> > > From: andy pugh [mailto:bodge...@gmail.com]
> > >
> > > On Wed, 20 Jan 2021 at 16:09, Kirk Wallace 
> > wrote:
> > >
> > > > I left the trail here:
> > > > >
> > https://github.com/LinuxCNC/linuxcnc/blob/master/src/emc/rs274ngc/interp_convert.cc#L4881-L5028
> > >
> > > There seems to have been a lot of time spent investigating theory that
> > > could have been settled in 5 minutes with an experiment.
> > >
> > > --
> > > atp
> >
> > Dropping an apple from a tree and observing that it falls and smashes on
> > the ground doesn't splatter into the words that spell out laws of motion
> > made up of bits of peel and apple.
> >
> > I'm assuming that the authors of this code were clever enough to take into
> > account the motor acceleration relative to spindle speed on each pass.  But
> > that doesn't explain how they do that.
> >
> > And if there are 60 teeth on the spindle encoder with a single sensor then
> > 120 edges are the most you get.  That's 3 degrees per edge assuming the
> > slots are symmetrical and I don't think there's a rule that they must be.
> > Might be 1 

Re: [Emc-users] NURBS G5.2 G5.3 works well

[Gene Heskett]

On Wednesday 20 January 2021 14:52:53 Todd Zuercher wrote:

> It isn't specifically a 30mm wrench but it will suffice.
> https://www.mscdirect.com/product/details/07829864
>
> Todd Zuercher
> P. Graham Dunn Inc.
> 630 Henry Street 
> Dalton, Ohio 44618
> Phone:  (330)828-2105ext. 2031

Probably weighs more although they don't list that. Besides, I had the 
alu, and the curiosity to see if I could do it. And it looks like I can.

Do I need more excuse than that? ;-)

> -Original Message-
> From: Gene Heskett 
> Sent: Wednesday, January 20, 2021 2:08 PM
> To: Enhanced Machine Controller (EMC)
>  Subject: [Emc-users] NURBS G5.2 G5.3
> works well
>
> [EXTERNAL EMAIL] Be sure links are safe.
>
> Greetings all;
>
> Since I can't buy a 30mm wrench that doesn't weigh 10+ lbs, and is
> 15-20" long, I am carving out a 30mm ER20 nut wrench from 1/2" alu
> plate, using G5.2/G5.3 to carve out a profiled handle, and its working
> rather well.
>
> The total amount of spindle time however, is gonna make me sell the
> pair for about $200 though.  Those puny X rails on a 6040 are wanting
> to let it chatter, a lot.
>
> I'll use the same basic code to make the 21mm version to fit the
> double D flats on the chuck. Conditionalized of course,  so it makes
> one or the other.
>
> 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)
> If we desire respect for the law, we must first make the law
> respectable. - Louis D. Brandeis
> Genes Web page 
>
>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>
>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users


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)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] NURBS G5.2 G5.3 works well

[Gregg Eshelman via Emc-users]

What about making a double ended wrench instead of two wrenches?
 

On Wednesday, January 20, 2021, 12:10:39 PM MST, Gene Heskett 
 wrote:  
 
 Greetings all;

Since I can't buy a 30mm wrench that doesn't weigh 10+ lbs, and is 15-20" 
long, I am carving out a 30mm ER20 nut wrench from 1/2" alu plate, using 
G5.2/G5.3 to carve out a profiled handle, and its working rather well.

The total amount of spindle time however, is gonna make me sell the pair 
for about $200 though.  Those puny X rails on a 6040 are wanting to let 
it chatter, a lot.

I'll use the same basic code to make the 21mm version to fit the double D 
flats on the chuck. Conditionalized of course,  so it makes one or the 
other.

Cheers, Gene Heskett
  
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] NURBS G5.2 G5.3 works well

[Andy Pugh]

> On 20 Jan 2021, at 19:10, Gene Heskett  wrote:
> 
> Since I can't buy a 30mm wrench that doesn't weigh 10+ lbs, and is 15-20"

What term do you use for slogging spanners in the US?
https://www.ebay.com/itm/Striking-Slugging-Slogging-Flogging-Open-End-Spanner-Metric-20-58mm-Individual/191875402318
I got one of those for my spindle. 
___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] NURBS G5.2 G5.3 works well

[Todd Zuercher]

It isn't specifically a 30mm wrench but it will suffice.
https://www.mscdirect.com/product/details/07829864

Todd Zuercher
P. Graham Dunn Inc.
630 Henry Street 
Dalton, Ohio 44618
Phone:  (330)828-2105ext. 2031

-Original Message-
From: Gene Heskett  
Sent: Wednesday, January 20, 2021 2:08 PM
To: Enhanced Machine Controller (EMC) 
Subject: [Emc-users] NURBS G5.2 G5.3 works well

[EXTERNAL EMAIL] Be sure links are safe.

Greetings all;

Since I can't buy a 30mm wrench that doesn't weigh 10+ lbs, and is 15-20"
long, I am carving out a 30mm ER20 nut wrench from 1/2" alu plate, using
G5.2/G5.3 to carve out a profiled handle, and its working rather well.

The total amount of spindle time however, is gonna make me sell the pair for 
about $200 though.  Those puny X rails on a 6040 are wanting to let it chatter, 
a lot.

I'll use the same basic code to make the 21mm version to fit the double D flats 
on the chuck. Conditionalized of course,  so it makes one or the other.

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)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Spindle speed changes with threading.

[Leonardo Marsaglia]

>
> Ahh, good point! It would be nice to be able to explicitly specify a
> spindle angle too, but that's a good workaround.


I always thought about having a way to offet the index pulse. But since
most people use hardware for encoder counting, I suspect the solution
should be right there in the hardware.

El mié, 20 ene 2021 a las 15:58, Robert Ellenberg ()
escribió:

> Ahh, good point! It would be nice to be able to explicitly specify a
> spindle angle too, but that's a good workaround.
>
> On Wed, Jan 20, 2021, 1:50 PM Andy Pugh  wrote:
>
> >
> >
> > > On 20 Jan 2021, at 18:14, Robert Ellenberg  wrote:
> > >
> > >
> > > Note that multi-start threading is not currently possible
> >
> >
> > You can do it by offsetting the start point.
> > (If there is room)
> >
> >
> >
> > ___
> > Emc-users mailing list
> > Emc-users@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/emc-users
> >
>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>

___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

[Emc-users] NURBS G5.2 G5.3 works well

[Gene Heskett]

Greetings all;

Since I can't buy a 30mm wrench that doesn't weigh 10+ lbs, and is 15-20" 
long, I am carving out a 30mm ER20 nut wrench from 1/2" alu plate, using 
G5.2/G5.3 to carve out a profiled handle, and its working rather well.

The total amount of spindle time however, is gonna make me sell the pair 
for about $200 though.  Those puny X rails on a 6040 are wanting to let 
it chatter, a lot.

I'll use the same basic code to make the 21mm version to fit the double D 
flats on the chuck. Conditionalized of course,  so it makes one or the 
other.

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)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page 


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Spindle speed changes with threading.

[Robert Ellenberg]

Ahh, good point! It would be nice to be able to explicitly specify a
spindle angle too, but that's a good workaround.

On Wed, Jan 20, 2021, 1:50 PM Andy Pugh  wrote:

>
>
> > On 20 Jan 2021, at 18:14, Robert Ellenberg  wrote:
> >
> >
> > Note that multi-start threading is not currently possible
>
>
> You can do it by offsetting the start point.
> (If there is room)
>
>
>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>

___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Spindle speed changes with threading.

[Andy Pugh]

> On 20 Jan 2021, at 18:14, Robert Ellenberg  wrote:
> 
> 
> Note that multi-start threading is not currently possible


You can do it by offsetting the start point. 
(If there is room)



___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Spindle speed changes with threading.

[Robert Ellenberg]

Hi All,

As others have said, during position-synched moves, the axes follow the
spindle position, so you don't need fine control of spindle speed. However,
you should have both a stable spindle RPM and a high-ish resolution encoder
to get the best results. John, for your example, as each encoder pulse
arrives, the TP will be constantly accelerating / decelerating to try to
track that position signal. Luckily, it can't get too far off because of
the axis acceleration limits, but the amplitude of the jitter will
definitely be higher with a low resolution encoder.

Here's how spindle synchronization broadly works from within the TP (i.e.
what occurs in motion after START_FEED_SPEED_SYNCH)

   1. The TP waits (with axes stopped) for a spindle index mark.
   2. Once the spindle has just passed the mark, the machine axes
   accelerate until they reach (spindle speed * requested units/rev).
   3. Once the axes reach the expected velocity, then synchronization is
   declared, and the TP maintains position synchronization from that point
   onwards. At higher spindle RPM, synchronization takes longer, so the
   spindle rotates farther before the axes are synchronized. Multiple
   threading passes at different spindle RPM will not quite follow the same
   path.
   4. After synchronization, the TP computes a position error based on the
   measured spindle position. The axis velocity is nominally spindle speed *
   uu / rev, but that velocity is corrected up or down as needed to drive the
   position error toward zero.

Note that multi-start threading is not currently possible (because the TP
always synchs at 0 deg, i.e. at the index mark), but we could modify the TP
to start synchronization at some angle after the index mark.

Finally, the obvious fix for the inconsistency in the acceleration phase is
to just declare synchronization at the index mark right away. With the axes
starting from rest, there would be a huge initial velocity error for the TP
to correct. It will do so eventually, but there are large position over- /
under-shoots until it stabilizes. Luckily, we know what the axis
acceleration looks like (based on axis max acceleration and nominal spindle
speed), so you can anticipate this and start the axes moving before the
spindle reaches the index mark. That way, the axes are moving at the
nominal speed just as the spindle reaches zero. This removes most of the
position error at the start, and the TP corrects for any residual error
very quickly. This is roughly the approach we used in PathPilot, and I
think LinuxCNC 2.8 or 2.9 would benefit from it as well.

Best,
Rob

On Wed, Jan 20, 2021 at 12:47 PM John Dammeyer 
wrote:

>
>
> > From: andy pugh [mailto:bodge...@gmail.com]
> >
> > On Wed, 20 Jan 2021 at 16:09, Kirk Wallace 
> wrote:
> >
> > > I left the trail here:
> > > >
> https://github.com/LinuxCNC/linuxcnc/blob/master/src/emc/rs274ngc/interp_convert.cc#L4881-L5028
> >
> > There seems to have been a lot of time spent investigating theory that
> > could have been settled in 5 minutes with an experiment.
> >
> > --
> > atp
>
> Dropping an apple from a tree and observing that it falls and smashes on
> the ground doesn't splatter into the words that spell out laws of motion
> made up of bits of peel and apple.
>
> I'm assuming that the authors of this code were clever enough to take into
> account the motor acceleration relative to spindle speed on each pass.  But
> that doesn't explain how they do that.
>
> And if there are 60 teeth on the spindle encoder with a single sensor then
> 120 edges are the most you get.  That's 3 degrees per edge assuming the
> slots are symmetrical and I don't think there's a rule that they must be.
> Might be 1 and 5 degrees.  So assume then an index single rising edge is
> used every 6 degrees.
>
> A half inch shaft has a circumference of 0.3925" and each 6 degree index
> is 0.00654".  The implication is depending on spindle speed and motor
> acceleration you might be off by almost 0.006".  That's a lot isn't it?
>
> John
>
>
>
>
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users
>

___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Spindle speed changes with threading.

[John Dammeyer]

> From: andy pugh [mailto:bodge...@gmail.com]
> 
> On Wed, 20 Jan 2021 at 16:09, Kirk Wallace  
> wrote:
> 
> > I left the trail here:
> > > https://github.com/LinuxCNC/linuxcnc/blob/master/src/emc/rs274ngc/interp_convert.cc#L4881-L5028
> 
> There seems to have been a lot of time spent investigating theory that
> could have been settled in 5 minutes with an experiment.
> 
> --
> atp

Dropping an apple from a tree and observing that it falls and smashes on the 
ground doesn't splatter into the words that spell out laws of motion made up of 
bits of peel and apple.

I'm assuming that the authors of this code were clever enough to take into 
account the motor acceleration relative to spindle speed on each pass.  But 
that doesn't explain how they do that.  

And if there are 60 teeth on the spindle encoder with a single sensor then 120 
edges are the most you get.  That's 3 degrees per edge assuming the slots are 
symmetrical and I don't think there's a rule that they must be.  Might be 1 and 
5 degrees.  So assume then an index single rising edge is used every 6 degrees. 
 

A half inch shaft has a circumference of 0.3925" and each 6 degree index is 
0.00654".  The implication is depending on spindle speed and motor acceleration 
you might be off by almost 0.006".  That's a lot isn't it?

John




___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Spindle speed changes with threading.

[John Dammeyer]

Hi Kirk,
Every big windstorm we have has me wondering which tree will fall across our 
powerline or house.  But I like the trees too much to remove them.

The problem I find when looking for  " START_SPEED_FEED_SYNCH " is they are all 
either printf functions or null as in they don't appear to do anything: 

void START_SPEED_FEED_SYNCH(int spindle, double feed_per_revolution, bool 
velocity_mode) {}

After that function (wherever it is and whatever it does) returns the actual 
threading pass to the target_z position is done:
STRAIGHT_FEED(block->line_number, boring? safe_x + depth: safe_x - 
depth, 
  start_y, target_z - zoff, AABBCC); //over

The carriage is brought to the correct Z + offset location where the offset is 
the tan of the X distance and angle to follow the slope of the thread angle.  
Like setting the compound to 29.5 degrees.

Then we wait for some sort of sync.  It appears the Z may well be stopped at 
this point and the tool is at the depth for cutting the next pass.  I guess it 
depends on how slow the spindle is moving.

But that parameter "feed_per_revolution" probably is probably used along with 
the Z axis "MAX_ACCELERATION" in the INI and HAL files to count out a specific 
index position so the START_SPEED_FEED_SYNCH function returns not at the index 
position but where it would be given Z axis acceleration at the current angular 
velocity of the spindle.

Have I got that right?  And if so where is the real code for 
START_SPEED_FEED_SYNCH?
John Dammeyer
 

> -Original Message-
> From: Kirk Wallace [mailto:kwall...@wallacecompany.com]
> Sent: January-20-21 8:07 AM
> To: emc-users@lists.sourceforge.net
> Subject: Re: [Emc-users] Spindle speed changes with threading.
> 
> (bottom posted this one)
> 
> On 1/19/21 9:42 PM, John Dammeyer wrote:
> >> I dont think, the z position is "geared" to the counts beyond
> >> index so locked unambiguously to spindle angle beyond index,
> >> after initial sync is acheived.
> >>
> >>
> >> Peter Wallace
> >> Mesa Electronics
> > So far that makes sense.  From "LinuxCNC User manual"
> >
> > "The tool will pause briefly for synchronization before each threading 
> > pass, so a relief groove will be required at the entry unless the
> beginning of the thread is past the end of the material or an entry taper is 
> used."
> >
> > Following that is:
> > "Unless using an exit taper, the exit move is not synchronized to the 
> > spindle speed and will be a rapid move. With a slow spindle,the
> exit move might take only a small fraction of a revolution. If the spindle 
> speed is increased after several passes are complete,
> subsequent exit moves will require a larger portion of a revolution, 
> resulting in a very heavy cut during the exit move. This can be
> avoided by providing a relief groove at the exit, or by not changing the 
> spindle speed while threading."
> >
> > So there are side effects to changing the spindle speed but nothing that 
> > infers it can't or shouldn't be done.
> >
> > The implication is that at the start of the G76 based on spindle speed and 
> > Z axis acceleration along with target Z axis speed a specific
> spindle encoder value is used after that to determine when the axis is 
> synchronized.
> >
> > Or N encoder counts before the index is used as the starting point for the 
> > Z to begin so it's up to speed, ready to engage, at the
> spindle index mark.
> >
> > Synchronizing it to the index mark for up to speed condition if you want to 
> > create multi-start threads makes sense.   Move the start
> point by half the pitch to the right.  Since the position of tool entry at 
> speed is the index pulse regardless of spindle speed the thread
> should start 180 degrees from the first.
> >
> > So where is this calculated?  In the Trajectory Planner?  I'd like to look 
> > at the code but no idea where to even start looking.
> >
> > John Dammeyer
> >
> 
> snip ...
> 
> I left the trail here:
> 
> > https://github.com/LinuxCNC/linuxcnc/blob/master/src/emc/rs274ngc/interp_convert.cc#L4881-L5028
> 
> I think this is my next stop:
> 
> > https://github.com/LinuxCNC/linuxcnc/tree/master/src/emc/motion
> 
> (but after a day of 50 mph winds, there are a few chores to attend to)
> 
> Kirk Wallace
> 
> 
> ___
> Emc-users mailing list
> Emc-users@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/emc-users



___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Spindle speed changes with threading.

[andy pugh]

On Wed, 20 Jan 2021 at 16:09, Kirk Wallace  wrote:

> I left the trail here:
> > https://github.com/LinuxCNC/linuxcnc/blob/master/src/emc/rs274ngc/interp_convert.cc#L4881-L5028

There seems to have been a lot of time spent investigating theory that
could have been settled in 5 minutes with an experiment.

-- 
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, 1912


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Re: [Emc-users] Spindle speed changes with threading.

[Kirk Wallace]

(bottom posted this one)

On 1/19/21 9:42 PM, John Dammeyer wrote:

I dont think, the z position is "geared" to the counts beyond
index so locked unambiguously to spindle angle beyond index,
after initial sync is acheived.


Peter Wallace
Mesa Electronics

So far that makes sense.  From "LinuxCNC User manual"

"The tool will pause briefly for synchronization before each threading pass, so a 
relief groove will be required at the entry unless the beginning of the thread is past 
the end of the material or an entry taper is used."

Following that is:
"Unless using an exit taper, the exit move is not synchronized to the spindle speed 
and will be a rapid move. With a slow spindle,the exit move might take only a small 
fraction of a revolution. If the spindle speed is increased after several passes are 
complete, subsequent exit moves will require a larger portion of a revolution, resulting 
in a very heavy cut during the exit move. This can be avoided by providing a relief 
groove at the exit, or by not changing the spindle speed while threading."

So there are side effects to changing the spindle speed but nothing that infers 
it can't or shouldn't be done.

The implication is that at the start of the G76 based on spindle speed and Z 
axis acceleration along with target Z axis speed a specific spindle encoder 
value is used after that to determine when the axis is synchronized.

Or N encoder counts before the index is used as the starting point for the Z to 
begin so it's up to speed, ready to engage, at the spindle index mark.

Synchronizing it to the index mark for up to speed condition if you want to 
create multi-start threads makes sense.   Move the start point by half the 
pitch to the right.  Since the position of tool entry at speed is the index 
pulse regardless of spindle speed the thread should start 180 degrees from the 
first.

So where is this calculated?  In the Trajectory Planner?  I'd like to look at 
the code but no idea where to even start looking.

John Dammeyer



snip ...

I left the trail here:


https://github.com/LinuxCNC/linuxcnc/blob/master/src/emc/rs274ngc/interp_convert.cc#L4881-L5028


I think this is my next stop:


https://github.com/LinuxCNC/linuxcnc/tree/master/src/emc/motion


(but after a day of 50 mph winds, there are a few chores to attend to)

Kirk Wallace


___
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users