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Author Topic: FEED ADJUST MACH 3 LATHE  (Read 939 times)

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Re: FEED ADJUST MACH 3 LATHE
« Reply #10 on: June 24, 2018, 05:32:40 AM »
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.
Re: FEED ADJUST MACH 3 LATHE
« Reply #11 on: June 24, 2018, 05:34:15 AM »
Hi,

Quote
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
My wife left with my best friend...
     and I miss him!
Re: FEED ADJUST MACH 3 LATHE
« Reply #12 on: June 24, 2018, 06:22:12 AM »
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.

Offline RICH

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Re: FEED ADJUST MACH 3 LATHE
« Reply #13 on: June 24, 2018, 08:45:48 AM »
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
« Last Edit: June 24, 2018, 08:51:09 AM by RICH »
Re: FEED ADJUST MACH 3 LATHE
« Reply #14 on: June 24, 2018, 03:13:53 PM »
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