Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: chessie on September 08, 2019, 02:22:07 PM
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hi everyone
i have just started to turn a thread with my mach3 turn lathe . i have an issue . the rev counter works so i guess mach is receiving the signal ok.
when i started the program using either g32 or g76 . it moves in to position to cut the thread but just sits and waits doing nothing.
i would guess its waiting for the rpm signal . i presume i dont have some of the settings configured properly
can anyone help
cheers
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if you turn the spindle slowly by hand and watch the index LED on the diagnostic screen do you see a pulse?
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yes
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chessie,
Mach is monitoring the spindle rpm, and will allow the Z axis to start the thread path, once Mach is satisfied that an amount of index signals received are appropriate.
Adjust the Index Debounce in General Logic Configuration. See Figure 7.1.4 in Threading On the Lathe write up.
RICH
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hi rich
the index debounce is already set to 10 , i tried 1 and no difference.
the feed per rev (1.5) was flashing 1.5 /off
when looking at diagnostics the index flashes if i turn it by hand ,its intermittent at high revs
the true spindle speed registers ok
i have a npn proximity switch picking up a bolt head on a disc on the spindle
will this provide a good consistent signal
cheers
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Try a higher number for the debounce. I use 10, some can use a lower number, yet others have needed to increase it.
Just depends on the signal. If the rpm is fluctuating too much Mach will sit there a long time waiting to get a consistent rpm.
At higher rpm's the DRO can't update fast enough to shows the rpm for each time an index is sensed.
You rpm should be within say 1 rpm under no load at spindle. I use a Halls affect sensor along with small magnet and works a treat.
Try this......... dry run with a few different rpms settings for threading and leave the index setting at 10. Say 50/100/200 etc and see if the thread path will start. Some sensors are not good at higher spindle rpm,s .
As to quality of signal one can view with an O'scope but most don't have one.
RICH
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chessie,
Found my notes on index debounce and will post some info for your use ( I just don't keep all this stuff in the cloud
above my head anymore ). ;)
RICH
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chessie,
Info on debounce see attached file
RICH
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hi i still have the same issue .i changed the sensor to a hall effect and the index light flashes on diagnostics page. rev counter works ok and i can calibrate spindle rpm.
(THREAD1)
N28 M6T0707
N29 G54
N30 G95
N31 G97 S500 M3
N32 G0 X45.4 Z5.
N33 G0 Z7.5
N34 X23.6
N35 G32 Z-24.8 F1.5
N36 X24. Z-25. F1.5
N37 G0 X45.4
N38 Z7.5
it just sits waiting on the g32 line.
is there some tick in the box im missing .i only have input for index , left timing unabled or is itsomething wrong with the code
forgot to add i use a UC400ETH Motion Controller
thanks
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The UC400eth uses an encoder for threading ABI signals required.
Just a thought , (;-) TP
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Do you have a licence for Mach?
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all good now
took the tick out of use spindle feedback in sync modes box
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not all good now the thread looks bad .
the mach3 threading pdf said it needs the spindle feedback in sync modes boxed checked.
is this correct?
are there any other configuration settings that need to be input
thanks
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chessie,
You are using an external motion device and should have said so right from the get go.
Have no experience with the UC400 ETH controller. There should be a installation
and user guide available for use with Mach from the seller / manufacturer. There are product downloads available
for the 400. Did you have a read of that info?
If someone has experience with UC400 ETH they can help you and may reply
here. If not, I would suggest that you go back to the manufacturer for specifics.
The mach3 threading pdf does not address the UC400 ETH.
RICH
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As Rich has said you need to ask any questions you have regarding threading on the CNC Drive forum http://forum.cncdrive.com/viewforum.php?f=22
Tweakie.
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Gee guys I tried to answer the question. (;-)
(;-) TP
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OK thanks what do u have to do or buy to fix this please
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Gee guys I tried to answer the question. (;-)
(;-) TP
Sorry TP (I missed your posting).
Tweakie.
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I see the user has made an inquiry over at the UCCNC forum. Lets see where that leads to as far as an answer.
(;-) TP
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are you saying this wont work with a disc and proximity sensor connected to index ?
If not do you have a solution
cheers
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The UCCNC boards require a 3 channel encoder( ABI ) for threading. The encoder HAS to be running at 1:1 with the spindle. With this setup you can do guage perfect threads every time.
(;-) TP
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thanks for your help
i dont have a uccnc board i have a cnc4you Breakout board CP0-10V CNC 4 Axis with Charge Pump and Relay
so does it look like i will need to change it ?
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You do have a UC400eth correct ? That is a UCCNC control board. The breakout board is not a concern unless teh Opto couplers are too slow to see the encoder signals properly.
Yes I know it gets complicated some times.
(;-) TP
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h
i have used the cnc4you break out board you are using on a few lathe projects & never had any problems ,they worked 1st time & every , some times doing 300 parts with threads in a day
i used the proximity switch that you can buy from cnc4you , you have to mount these within about 20 thou's of your disc on the back end of your spindle but you have to use a disc with an extension leg because a proximity switch will not work with a slot , you also need to get a decent length of signal to get a very speed range , on my machines the measuring leg is 1" + in width this gives a very stable speed from 50 to 2000 rpm which only alters by 1 rpm over such a wide range & can thread at 600rpm for a 5/8" x 26 tpi thread
hope this helps
robert
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thanks Robert
i changed from a proximity switch to a hall effect and magnet .
i have a 12mm magnet on about an 100mm radius on a disc
before i had an m8 bolt head .
im just trying to find out if the problem is using uc400etc or the index detection isnt good enough my max rpm is 2500
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im just trying to find out if the problem is using uc400etc or the index detection isnt good enough my max rpm is 2500
Your problem is that you don't understand what the UC 400ETH requires in order to do threading and the required configuration of the external controller board. One would think that UNCNC would provide specific instructions on how to use that board with MACH. Usualy there is a specific plug in provided for use of the board along with MACH.
There is a manual for the UC400ETH but the site didn't list a UC400 users guide like it has for the 100 and 300. There are utility files for the UC400ETH.
Using a Hall sensor is just providing an index and is not the same as using an encoder as BR549 remarked.
RICH
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The UCCNC boards require a 3 channel encoder( ABI ) for threading. The encoder HAS to be running at 1:1 with the spindle. With this setup you can do guage perfect threads every time.
(;-) TP
"For G33 and G76 thread cutting you need to have a quadrature encoder A and B and Index channels. And there must be one index signal per turn.
Yes, the signals have to be quadrature otherwise the controller could not detect the direction of rotation which could lead to issues.
Index only threading is not supported, because it is too unprecise solution in our opinion."
http://www.forum.cncdrive.com/viewtopic.php?f=4&t=1377&p=10290&hilit=lathe+threading#p10290
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Russ,
So the board uses G33, not G32, and the G76 of UCCNC board uses a G76 command, but must add, that the G76 command is different as compared to the MACH3 command.
?
RICH
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Hi Rich, NO in mach3 threading is G32. Only when using UCCNC does it use G33. Yes teh G76 is different BUT I do have a copy of a G76 macro I wrote that will work in Mach3 using teh UC400eth.
As to teh encoder it can be done many ways as long as teh results is quadrature AB with a single index per turn of teh spindle.
The parameters and Gcode call is exactly the same as LinuxCNC uses. I have a doc for that as well if needed
There is also a Macro to do rigid tapping in Mach3.
CNCDrive does not tlak about the plugin for Mach3 as they officially do not support TURN with UCCNC products. EVEN though they did create teh thread function for it.
(;-) TP
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sorry if i ask stupid questions but this is new to me and i thought i would come here for help .
i am more than happy to modify my lathe for an encoder .
ive seen some omron 2000 p a b and z . i think the z is one pulse per rev so is that suitable?
if i build this ,i presume from what you have said that i will need to have a new g76 macro. will i be able to get/buy a copy of this and/or any other code?
correct me if im wrong but am i right in thinking
mount abi(z) encoder 1:1 with spindle
wire the encoder to my breakout board
configure ports and pins (any ideas where they are needed to connected to)
have a new macro for g76
anything else?
thanks again
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Read all the info describing the encoder resolution in relation to the speed of the signals.
And, the notes about QUALITY high speed onto-couplers that some BoB's utilize and so many other lower quality ones do not.
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I would keep teh Pulse count low as in 100-400 PPR and yes teh ABZ is what you want. as to wiring it up I have no idea how your machine is wired. Only you will know that.
(;-) TP
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When you get the encoder set up TRY teh Mach3 G32/G76 routines to see if they work. The testing I did with this was 3 years ago.
(;-) TP
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thanks for the help
i just updated the firmware for the uc400eth . ;D
its working and threading lovely now using the hall effect proximity switch for some reason . i can now have the spindle sync ticked in mach3 and it works