i just got a dyna myte DM2900 mini mill. its travel is something like 10" x 7" x 10" (specs are hard to come by and i cant measure the travel yet)
i would like a 4th axis, but im not sure exactly how MUCH 4th axis I need. I think i would get the biggest bang for the buck, for the kinds of parts I make, using it as an indexer to allow multiple planes of machining without requiring multiple fixtures and/or manual refixturing. I doubt I would ever actually have true 4 axis parts being made. so it can be slow.
I'd like to look into making my own 4th axis. I have access to an accurate manual-lathe with DRO to make parts for it.
Some "big picture" things I am not sure about though, and would really appreciate the advice of more experienced folks who have used 4th axis, are:
-how big does the 4th axis have to be to not significantly detract from rigidity? i know this is a complex question, but at the moment I have no idea how much rigidity im going to lose. (thats what he said)
-my mill bed is pretty small, maybe 9" x 18". im not sure how much room that gives me for a 4th axis. maybe this is all moot.
-what basic parts am I going to need? i'm assuming ill be buying a precision bearing, but i probably dont need a chuck as most likely ill be bolting fixtures directly to the 4th axis. i.e. assuming a textbook design, how many bearings and how are they supported at both ends? what kind of shaft diameter are we talking about? i.e. whats the bare bones "body plan" of a simple 4th axis?
-does the motor holding torque become a significant requirement or does the transmission somehow lock things in place?
-since i dont need it to be fast, and i can make some of its parts myself on my mill or lathe, im assuming i can save a significant amount of money here (yes i want to do it CHEAP. there I admit it.) heres a design i think would work, or at least a starting point
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i would like a 4th axis, but im not sure exactly how MUCH 4th axis I need. I think i would get the biggest bang for the buck, for the kinds of parts I make, using it as an indexer to allow multiple planes of machining without requiring multiple fixtures and/or manual refixturing. I doubt I would ever actually have true 4 axis parts being made. so it can be slow.
I'd like to look into making my own 4th axis. I have access to an accurate manual-lathe with DRO to make parts for it.
Some "big picture" things I am not sure about though, and would really appreciate the advice of more experienced folks who have used 4th axis, are:
-how big does the 4th axis have to be to not significantly detract from rigidity? i know this is a complex question, but at the moment I have no idea how much rigidity im going to lose. (thats what he said)
-my mill bed is pretty small, maybe 9" x 18". im not sure how much room that gives me for a 4th axis. maybe this is all moot.
-what basic parts am I going to need? i'm assuming ill be buying a precision bearing, but i probably dont need a chuck as most likely ill be bolting fixtures directly to the 4th axis. i.e. assuming a textbook design, how many bearings and how are they supported at both ends? what kind of shaft diameter are we talking about? i.e. whats the bare bones "body plan" of a simple 4th axis?
-does the motor holding torque become a significant requirement or does the transmission somehow lock things in place?
-since i dont need it to be fast, and i can make some of its parts myself on my mill or lathe, im assuming i can save a significant amount of money here (yes i want to do it CHEAP. there I admit it.) heres a design i think would work, or at least a starting point