Thanks very much.
V
CNC machines questions (help)
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CNC machines questions (help)
Last edited by Vlady on Mon 29 Oct , 2007 22:16 pm, edited 2 times in total.
- Triac whizz
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think I've seem all this over on cnczone perhaps last year.
the binary notation is unknown to me & I think completely irrelevant to using a cnc machine
transducer? encoder yes I've heard of linear is attached to table so table position known, rotary attached motor so position infered
mach datum, = home wher it knows where it is
prog datum known point of job
H/W vfd servos cpu
s/w cad cam.....
Now if you'd bothered to get up last thursday morning you'd probably have known all this
Why not ask the prof?
and write a thousand times google is your best friend
the binary notation is unknown to me & I think completely irrelevant to using a cnc machine

transducer? encoder yes I've heard of linear is attached to table so table position known, rotary attached motor so position infered
mach datum, = home wher it knows where it is
prog datum known point of job
H/W vfd servos cpu
s/w cad cam.....
Now if you'd bothered to get up last thursday morning you'd probably have known all this

Why not ask the prof?
and write a thousand times google is your best friend
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I wish I could have got the internet to do my homework for me
A linear device will suffer from alignment errors, heat expansion and be expensive to make... but will be the most accurate over a distance.
Program datum is the position that tells the CNC where the job is (which will vary).
Machine datum tells the CNC where a fixed postion is (eg home which should never vary).

This question seems to crop up every year - it must be a throw back to the olden days of punched tape or peg boards using a binary format to store CNC programs/commandsQ1. Explain the binary notation used in the application of a CNC Program.
A rotary position measuring devices (transducer or encoder) will suffer from mechanical and backlash measurement errors, but is cheaper.Q2. State the purpose of a rotary or linear transducer and list advantages and limitations of each.
A linear device will suffer from alignment errors, heat expansion and be expensive to make... but will be the most accurate over a distance.
Q3. Explain the purpose of the “program datum” and the relevance of the “machine datum” when setting up a CNC machine.
Program datum is the position that tells the CNC where the job is (which will vary).
Machine datum tells the CNC where a fixed postion is (eg home which should never vary).
Yes - how about covering CAD/CAM sw as well - show the whole process from design (CAD) to programming (CAM) to simulation (CAM or CNC) then manufacture (CNC).Q4. Describe the hardware and software used in CNC system.
(Should I talk about machine spindles, transducers, slide drives, machine drives, spindle drives, leadscrews, machine spindles and tools for hardware and G-code? for software?)