DIY Hobby Size 5-axis mill
Hey guys. I'm in the process of getting parts together for a diy 5 axis cnc.
Lets not talk about the g-code or cam software. I'm only interested in talking about the electronics. (which im not an expert with) and the trunnion table rotary bed build.
I'm not concerned about head clearances either. This can be changed. The rotary bed on the trunion table will be 6" and will hold a 5" chuck.
I'm going to build it around a 'little machine shop hi-torque mini-mill model 3900'.
I spent some time looking at stepper motor sizes. I got some calculators. It was a decision for me to go with overkill using g203v drivers to allow for upgrading the machine later. (stiffer and better spindle.)
I decided to go with 381oz/in steppers all around. With g504 4 axis and g251 driver. Smooth stepper. And a C11G breakoutboard for the 5th axis breakout and pump/spindle control. 48VDC 20A power supply
Heres the current order list for the electronics from AutomationTechnologies.
Gecko Diver G540 4 Axis Driver, Current Version
NEMA23 381oz/in 3.5A Single Shaft Stepper Motor KL23H2100-35-4A
Ethernet SmoothStepper Motion Control Board for Mach3
Geckodrive G251 50V/3.5A Stepper Motor Driver
E-stop Switch
Coupling 1/4" and 1/4 "
Micro Limit switch
Ethernet SmoothStepper Cable Combo
4 conductor 22 GA Shielded Motor wires
Motor cable connector
C11G - Multifunction CNC Breakout Board
Unregulated Linear 960W/ 48 VDC/20A Toroidal PSU (KL-4820)
I also plan to build an enclosure for it.
I could use some suggestions on the electronics. I wasn't sure about the C11G breakout board. But it seems like it has a lot of room for expansion.
Lets hear your thoughts.
Cheers
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Re: DIY Hobby Size 5-axis mill
Alright dissected everything again and now its coming together. Ready to fit and extend the y axis. I'll have to order a new ballscrew. Got aluminum for machining some 4th axis stuff. Couple things left to do and I can start fiddling with 5th axis.
Here's some more pics
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Re: DIY Hobby Size 5-axis mill
Little update
After shimming the extended base down I welded it to the steel it rests on. I have 1/2" bolts holding the rest of it down where the mounts allow. I was thinking about braze welding the cast iron together as a more permanent solution. I'm still waiting for the longer c1 ballscrew in the mail to arrive so I can put everything back together and start drilling holes into the rest of the components.
I was about to make a stepper motor mount from a solid piece of aluminum for my rotary table. And quickly decided it would be easier to test it out by welding some flanges to a piece of pipe. I decided to machine the whole thing down because it looks nicer.
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Re: DIY Hobby Size 5-axis mill
I got a used harmonic drive off ebay for a decent price. Seems to work just fine. I'm making an aluminum housing for it and the stepper motor. It will bolt to the steel mounting body. Allowing me to upgrade to a better drive in the future, if I need.
These tapered roller bearings are actually wheel bearings that I snagged from work that are in excellent condition. The harmonic drive will directly turn a shaft. The shaft is a machined 1" bolt that is applying preload between the wheel bearing and another bearing housed inside a machined 2" piece of pipe.
I know it may not be incredibly accurate with the worm driven 5th axis backlash issues. But this is the absolute best way to learn, without forking out a ton of money into something you're unsure of. I use what I can get my hands on for little to no cost. I've already learnt so much just by thinking about how it all gets put together.
Here's the two rough cad drawings of the main dimensions.
I'll post some more pictures as I go.