Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: GRAYHIL on June 19, 2018, 03:56:35 PM
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Hi ALL
Spec
MACH 3 version .062
TB6560
WIN XP
PARALLEL PORT
Use spindle feed back in sinc mode ticked
Closed loop spindle control ticked
Spindle speed av ticked
Persistent jog mode ticked
Feed override persist ticked
Cannot get feed rate to display during a program run or be able to adjust it with the arrows yet the same settings on the mill work OK.
I have tried different settings but have had no luck.
Other than that everything is working even screw cutting!
Any thoughts
Graham
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Silly question, but have you clicked the S button so M3 knows the spindle is running?
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Hi John
All programs start
G95 S600 F.01 M3 G90
and go on from there
MDI input is the same
Is there another way?
Graham
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Spindle button 3rd to the right of Estop. You may not need it if using Mach3 to control speed, but when I started doing threading I didn't realise that until you "press" this button Mach3 doesn't think the spindle has started. Worth a try?
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Hi John
Will try that when I go into workshop after breakfast.
Graham
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OK
Start m/c manually by button on vfd
Start prog in auto, speed reads in and displays, feed reads in but does not display
At end of prog speed display 0 feed displays program feed
As above but during prog adjust feed rate
During prog nothing displays on feed rate and no difference in actual cut
At end of prog speed display shows zero and feed displays adjusted feed rate
Next run of prog runs at adjusted feed rate
Is it possible to adjust feed rate during cutting at all?
Graham
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ps pressing the third button just switches the top speed display on/off
Graham
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What do you mean by the top speed display? Isn't that the actual measured speed? If you toggle the button I think it should show the actual speed or zero (thinking machine is stopped).
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Hi John
Yes it is the actual measured measure speed that changes from zero to whatever the spindle is rotating at. The programmed speed does not change (the lower dro)
Graham
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I ask again
Is it possible to adjust feed rate during cutting at all?
Graham
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Aha! I think I see what you are asking now, and the answer I think is in Turn you can't - I have seen the same thing.
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Hi,
Is it possible to adjust feed rate during cutting at all?
The short answer is 'I don't know' however I think not.
My reasoning goes: Machs trajectory planner plans a move and passes that P(osition) V(elocity) over T(ime) data to the motion controller. The motion controller
calculates the required pulse stream to the motor drives for the axes involved in the move. Once that move is under way THEN you want to change the feedrate.
I don't think your motion controller can recalculate the pulse streams that are already under way. It could and would recalculate the next and subsequent moves
just not the current one.
Craig
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It certainly does work in Mill. Quite often I find that I've underestimated the usable feed rate and use the adjust buttons to up it, by up to 300%, during program execution. But it doesn't work in Turn for some reason.
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I use a modified screen for the lathe.
It has the same + and - increase / decrease increment arrow buttons which reflect the initial incement
FRO value as the generic screen. Note that you input the increment value in the dro, say 5 ipm, then
when you press the + arrow button it will show 10 ipm and so on in increments of 5.
I added a slider from the mill screen STD code 21 and also a 100% FRO button.
So if I click the 100% the FRO value will change to MAX Velocity set in in motor tuning for the axes.
I can also use the slider and even though it may allow 250% you can only increase feedrate to 100%
or your max velocity. The feed rate value will change in the DRO showing the set / current federate.
Now note that in my configuration "Lock rapid fro to feed fro" is checked.
G48 and G49 act as toggle for turning FRO on and off and is modal.
So the feedrate can be changed during a G0 or G01 when in G94 mode.
Don't have time to see what happen when in G95 mode, and would not use in that mode anyway,
since G95 is for turn only and it has to do with threading where feedrate is based on real time rpm along
with a feedrate relative to the thread being cut.
If I get a chance I'll check out the G95 mode but will guess fro won't work in that mode.
Till Whenever,
RICH
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Hi All
Between you all you have answered my question.
It works in mill (and mine does)
It does not work properly on the lathe (G95)
Thank you all
Graham