Hi everyone,
I want to be able to machine and work on 2x4, 2x6 and similar boards with a relatively small CNC machine. Something around 15 cm Z-axis travel, 20 cm Y-axis travel and "endless" X-axis travel. I want to merge a typical CNC with a "Robot" to achieve this.
My background is mainly in programming and electronics (B.Sc EE, nearly complete M.Sc EE). I have about 300 hours of experience with additive manufacturing, and some in subtractive manufacturing.
Some goals:
Extending X-axis infinitely by combining robot with CNC
Able to do aggressive cuts in wood (and in time metal). "Driving" the material directly is out of the question.
Able to work with common G-Code.
Basically the needed action is this:
The machine needs to move "work X-axis position" to increase X-axis travel.
Planned first steps.
Software:
1. Learn more about G-code
2. Learn more about motion generation.
3. Figure out motion path generation that steadily increases x-travel, instead of using the "full" allowed travel often.
4. Write software routines for that will be run on the CNC in "robot mode" - activatable by M-codes.
5. Write a G-code interpreter/reader that manipulates normal G-code so that the new hardware can use it.
Hardware:
1. Build an actual 3 axis small CNC machine and make it work
2. Figure out a suitable active work-holding solution
3. Figure out a suitable "move work" - actuator/routine
Own comments to first steps.
Software 1, 2, 3: Basically fresh up on everything.
Software 4: Probably the whole subroutine will be programmed in C or similar, and simply activated by a single M-code.
Software 5: The modification of the G-Code can be tricky. Basically, once X-travel is nearly spent in one direction - insert M-code for robot move, change G92 temporary offset and maybe edit machine registers too. Long X-axis moves must also be split up into smaller parts, to make it easier for a script to modify the code.
Hardware 1. Maybe I will just by a cheap china router to spare some time.
Hardware 2. Very open for suggestion. Guessing pneumatics is a good start?
Hardware 3. Also open for suggestion. Repeatabillity is super important. I think a pneumatic actuator, locking the work to the Z or Y axis (ZY plane) (of course releasing the normal clamp), - and then using the X axis for the move is the best option. I might try to use a repurposed computer mouse to somewhat verify the distance moved, but that is low on the priority list. (I have tested this before, and a normal computer mouse does not give a accurate and repeatable distance measurement - but it is more than good enough to verify that the work is moving and not slipping)
This is a hobby project and the time needed to complete it is not easy to tell, wish me luck - I'm going to need it.